HUBER ReportInternational 1 / 2005

The QualityCompany –Worldwide

Mechanical WastewaterTreatment 2

➤ Large Size Waste WaterTreatment Plants – HUBERTechnology in Chongqing City 2

➤ New screens for the Lisbonwastewater treatment plant 3

➤ ROTAMAT® Membrane Screen RoMem 3

Screenings Treatment 4

Grit Separation 4

Grit Treatment 4

➤ 1000 COANDA Grit Washing Plant installations – The original sets the standards! 5

➤ A global success: The COANDA Grit Washer isworldwide installed on largewastewater treatment plants 5

Sewer System Management and Stormwater Treatment 6

➤ Cooperation pays off! 6

➤ Combined sewage screening at overflow structures with the ROTAMAT®

Storm Screen RoK 2 7

Sludge Treatment 8

➤ Successful Introduction of the first HUBER Centrifuge in Switzerland! 8

➤ First sewage sludge drying plant in Switzerland utilisingWWTP effluent to supply thermal energy – made possible by the KULT® LowTemperature Dryer 9

➤ Ecologically aware and energy-conscious – HUBERinstalls its first combined solar and regenerative sewage sludge drying project 9

Sedimentation 10

Filtration 10

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➤➤➤ Where to find your topic!

Dear Reader,

IFAT 2005 is most certainly animportant event to all those who areactive in environmental protectionand in particular the field ofwastewater and sludge treatment.HUBER will, of course, present at IFAT2005, showing both its potential andglobal presence within these fieldsand it would be a pleasure towelcome you at our stand. Weappreciate the importance ofcustomer contact in order to not onlylearn from our customers technicalsolutions. Huber would appreciatethis opportunity to inform you aboutits wide range of excellent productsand services.

It is our goal as a company to offer ascomplete a program as possible forthe field of water, wastewater andsludge treatment. Even though wehave already progressed a long waytowards this, it does not mean that weshould be complacent but regard thisas an incentive for the company to

consider how it can further improveour products and program.

As a company Huber is also trying toidentify new challenges the market isfacing and then develop appropriatesuitable products and solutions. Forexample, adapted technologies forcountries outside Europe, or systems,where required and reasonable, forreuse of treated wastewater and ofcourse where justifiable under econo-mic and hygienic restrictions. As anexample of this within the HUBERReport issue we have detailed a was-tewater disposal concept within a dis-trict of the city of Jerusalem where thetreated wastewater is utilised for irri-gation purposes.

Huber as a company are prepared torise to the challenge of new goals andrequirements brought about by perso-nal discussions with the customers,whether in Germany or abroad. Allthese experiences are regarded asbeing the basis for development ofnew products and further improve-ment to the existing products. Ourmotivation is the conviction that wewill continue to contribute to thetechnological progress and thus safe-guard the future.

We look forward to seeing you at theIFAT!

Hans G. Huber

Page 1

➤➤➤ HUBER Technologypresentation at the IFAT 2005

At the IFAT 2005 that takes place inMunich from 25th to 29th April theHans Huber AG will present its com-plete range of products and fields ofapplication.

As one of the market leaders in deve-lopment, production and sales of awide range of machines and plants forthe whole field of drinking water, was-tewater and sludge treatment HUBERTechnology offers well-proven andinnovative solutions both for munici-palities and industries.

On an exhibition space of 1000 m2

HUBER will present different topics,the products and their fields of appli-cation.

For the field of mechanical preliminarytreatment the customer can of courseexpect to see the ROTAMAT® andSTEP SCREEN® units, but also the newMAX screens. Also presented will beinnovative further developed fine andmicro screens that are suitable forapplication as preliminary screensprior to membrane plants or for COD

To be continued on page 20

➤ Clarified water discharge for the SBR tank on WWTPRiezlern, Austria 10

Decentralised WastewaterTreatment 11

Advanced Wastewater Treatment 11

Drinking Water Treatment 11

➤ Water reuse – a burning issueJerusalem’s wastewater treatment system 12

Solutions for IndustrialWastewater 13

➤ 64 HUBER SSV Step Screens for River Water Screening inSouth Africa 13

➤ The ISKA® Concept 14

Stainless Steel Equipment 15

➤ Case History - Drinking WaterRecovery Project Dongola City 18

Membrane Technology 16

➤ First orders for VRM®

Membrane plants 16

➤ The HUBER VRM® membranefiltration system – Moderntechnology for wastewater reuse on the Canary Islands 17

➤ Wastewater becomes service water - HUBER membrane systems providevarious possibilities for treatment and reuse of wastewater 18

HUBER Technology Worldwide Contacts 18-19

Global Service 18

➤ Huber Technology Prize 20

➤ HUBER Technology presentation at the IFAT 2005 20

IFAT 2002: exhibition stand

Page 2

Chongqing, a city with about 7.5 mil peo-ple living in the urban area and a total ofmore than 32 mil inhabitants in the entiremunicipality. Thus, it is one of Chinas big-gest cities. It is located at the upper streamof the Yangtze River directly above theThree Gorges Damn. Its water dischargesare filling the newly erected reservoir.Chongqing government has realised thatthe water needs treatment in order to pro-tect the Three Gorges Area. Therefore anexhaustive programme was established toclean the 2 mill m3/day. Three waste watertreatment plants shall make the job:Jiguanshi and Taipingmen Pre-TreatmentStations and Tangjiatuo Waste Water Treat-ment Plant.

Over a number of years our sales and tech-nology team of our JV Huadu-Huber Co.Ltd. has discussed with the customers,design institutes and contractors how todevelop an adapted technological solutionmeeting the environmental requirements

as well as handling the enormous quantityof the city`s waste water. Due to the out-standing performance of our ROTAMAT®

Fine Screens in China as well as there easyhandling and reliable operation, we havebeen able to supply the complete finescreening of all three Plants, including 6units of the Ro 1 with an exceptional 3000mm diameter at the Jiguanshi WWTP andnot less impressive 12 units Ro 1 with a bas-ket diameter of 2400 for the other twoplants. Now China is operating the largestnumber of our Huber Technology Super-Size Screens totalling to 40 units of screenswith screening baskets 2 m and bigger.Beside the screens, we supplied our highefficient Grit Classifiers RoSF 3, the Wash-press WAP for the core screens.

Installation and start up have been handledby the service team of our Joint Venture.Whereas it was first considered to inviteGerman technicians to install especially thelarge Ro1-3000 screens, it turned out notto be necessary. The continuous training aswell as the experience out of more than

120 installations of ROTAMAT® screens inChina during the past 7 years show theirfruits. Nevertheless, close contact betweenthe service teams, technical experts, desi-gners, and sales staff of our company inChina and our headquarters are maintai-ned for continuous experience exchange inboth directions.

The concept of combining German Engi-neering with localised support has helpedus to develop the Chinese market and ena-ble us to support in a qualified manner ourChinese customers. Thus, we where able tosupply over 250 WWTP with more than 600machines only in the municipal sector - notconsidering the numerous industrial appli-cations. This has lead us in 2004 to increaseour investment in China and thus our com-mitment to the Chinese market. We areproud of our team at Huadu-Huber Co. Ltd.in China!

Martin WildererExecutive Director, HUADU-HUBER Ltd.,China

➤➤➤ Large Size Waste Water Treatment Plants – HUBER Technology in Chongqing City

Tangjiatuo Waste Water Screening Station, Ro 1-2400

Our Team in China – Opening Ceremony of our New Workshop

Mechanical wastewater treatment

Mechanical treatment is indispensable asthe first process step of preliminary treat-ment for both municipal and industrialwastewater applications. Initially coarsematerial has to be removed in order toprotect subsequent treatment stagesagainst damage/pollution or to relievethem. The goal is usually to completelyseparate floating, settling and suspendedmaterial, dependent upon the bar spa-cing or perforation, and remove thematerial from the flow into a container.

Based on the ROTAMAT® principle ofscreening – washing – transport – dewa-tering within one unit a complete ROTA-MAT® family was developed and thensuccessfully launched within the worldwi-de wastewater treatment market. Inrecent years the STEP SCREEN® familyand now the MAX® family have beenadded to complement the range. TheHUBER screening range therefore compri-ses of a range of screen systems and ena-bles us to offer the perfect solution for

➤ any site specific installationconditions

➤ any flow rate

➤ any bar spacing

The development of finer screensopens up new fields of application

The development of very fine screens forseparation of finer particles opens up

new fields of application in wastewatertreatment. For the recently introducednew type of membrane bioreactors wit-hin the market an improved performance

is required to ensure reliable separation ofhairs and fibrous material to allow themembrane process to function effectively.

A further application for these units isriver and sea outfalls which frequentlyonly have coarse mechanical screeninginstalled but feel it will increasingly beco-me more common and important toreduce the COD/BOD concentration ofthe wastewater discharged into the recei-ving water course. These new fine screenswithin a single process step can removeundegradable toilet and plastic particlesalong with organic material containedwithin the wastewater. By application ofthis new technology a high degree ofenvironmental protection can thereforebe achieved at a reasonable cost. For furt-her improvement of the screens' efficien-cy precipitants and coagulants can beadded which have the effect that dissol-ved and very fine particles contained inthe wastewater are converted into sepa-rable particles to enable the filterablesolids to be reduced by up to 95%,COD/BOD by 65% and phosphorus by60%. With many regions within theworld with no wastewater treatmentplants, or insufficient wastewater treat-ment plants, fine screening can be a firstand quick step in the right direction.

Fine screen

Coarse screen

Perforated plate screen

Mesh screen

➤➤➤ Mechanical wastewater treatment

Portugal's largest wastewater treatmentplant for 630,000 PT has been upgraded.Three HUBER ROTAMAT Wedge SectionsScreens Ro 2 3000 x 6 mm were installed.

The WWTP Alcantara treats 42% of thecatchment area around Lisbon, Oeiras andAmadora. After mechanical preliminary tre-atment and pre-clarification the wholewastewater is discharged into the Taguswithout prior biological treatment. Toimprove this situation the wastewaterauthority SIMTEJO, the plant operator,

commissioned main contractors with thefirst step of modernisation, the replace-ment of the 15 mm screen by three HUBERROTAMAT Wedge Section Screens Ro 2

with 3000 mm diameter and 6.0 mm barspacing. The wastewater treatment plant isdesigned for the maximum storm weatherflow of 4500 l/s. This flow can be handledby two HUBER ROTAMAT Wedge SectionScreens Ro 2 3000 x 6 mm. One screen isinstalled as a standby unit.

A main advantage of the HUBER machinescompared with the customer's previoussystem is, in addition to the smaller bar spa-cing, the fact that the machines combinefour functions in one unit: solids/liquidseparation, integrated screenings washing(IRGA), screenings transport and screeningscompaction to approx. 50% so that adewatering efficiency of approx. 35% DS isachieved.

The heavy screens were a challenge thatexceeded even the crane capacities of themodern HUBER factory with a size ofmeanwhile 21,500 m2. The excess width

caused also transport problems but thesecould be solved by delivering the accessoryparts on trucks and ship the machinesthemselves by sea freight.

According to Weber Engineers Pforzheimwho are responsible for the complete pro-ject planning in cooperation with WeberEngineers Portugal, the next challenge willbe placing the biological treatment stageon the scarce available space.

Daniela NutzExport Sales, Hans Huber AG, Berching,Germany

➤➤➤ New screens for the Lisbon wastewater treatment plant

Grit washed by the original

Grit washed by the original

Page 3

This machine was exhibited for the firsttime at IFAT 2002. The possibility of scree-ning large amounts of wastewater with0.75 and 1.0 mm mesh was received withgreat interest by visitors to the exhibition.The main field of application for this screenis considered to be preliminary screeningprior to membrane-activated sludge plants.

Membrane-activated sludge plants thathave recently become available require veryfine preliminary screening in order to ope-rate without problems and with minimummaintenance. For traditional biological tre-atment systems (trickling filter and activa-ted sludge plants) 3 and 6 mm bar spacingis sufficient.

For membrane-activated sludge plants,

however, the efficiency of screens with thelarger bar spacings is insufficient in thisapplication. The newly developed HUBERMembrane Screen uses a square mesh thatprovides, contrary to conventional slotscreens, a defined separation size andensures reliable separation of fibres andhairs. Slot screens are not able to achieve

the same efficiency due to their undefinedseparation size. Mesh screens not only pro-vide the advantage of a higher separationefficiency, but their hydraulic capacity isalso superior. The large free surface of amesh allows for an economical and affor-dable design.

The selection of the mesh size depends onthe applied membrane system. Membrane

modules are divided into hollow fibre andplate modules. In particular hairs and fibresentwine themselves around the free tomove hollow fibre modules and thereforeimpair the permeability and hydraulic capa-city. Cleaning of the modules involves highoperating and operational costs. As aresult, the finest possible screening is requi-red and as such mesh sizes between 0.75and 1.0 mm are used. Plate modules areless sensitive to the cross flow generated bythe pressure air applied for module clea-ning and due to its open top design. Toincrease the functional reliability of thistechnology, a bigger mesh size, finer bar

spacing or even smaller perforated plate ofup to 3 mm perforation can be used.

When using such fine bar spacings itunavoidably also removes the organics. Towash out these organics from the scree-nings the IRGA unit (integrated screeningswashing system) can be used and the orga-nic carbon is then returned for denitrifica-tion. At the same time, the screenings aredewatered and compacted in the integra-ted screenings press.

Christian FrommannHead of Business Unit Mechanical Waste-water Treatment, Hans Huber AG, Ber-ching, Germany

➤➤➤ ROTAMAT® Membrane Screen RoMem

ROTAMAT® Membrane Screen RoMem

Installation example of the RoMem

Page 4

For the reason of operating reliability ofwastewater treatment plants it is necessa-ry to separate the grit transported withthe wastewater and other mineral materi-als (approx. 60 l / 1000 m3 of wastewater)from the digestible organic material.

Grit separation from wastewater can pre-vent operational problems, such as gritsedimentation (in aeration tanks anddigestors), increased wear of equipment(pumps or stirrers), blockages (hoppers orpipelines) along with wear reduction ofmechanical equipment (e.g. a centrifuge,etc.).

The aim for the system is to separate asmuch as possible of the grit and inorganicmaterial up to 0.20 mm grain diameterwhilst at the same time separate themineral and organic particles within thegrit trap.

The grit separating systems utilised todayare divided into longitudinal grit traps, cir-cular grit traps and vortex grit traps,dependent upon their design and process

layout, and each will separate the grit eit-her by gravity (longitudinal grit traps) orcentrifugal force (circular and vortex grittraps). For longitudinal grit removal scra-pers or screw conveyors are frequentlyutilised with solids removal in the subse-quent course of the process by a pump,grit classifier or integrated grit classifyingscrew.

Due to the significant organics contentwithin the classified grit longitudinal grittraps they are today additionally aeratedto at least partly avoid the settling oforganic material within the grit trap andwill cause floating material (grease) to riseto the surface. According to Kalbskopf,aerated grit traps are generally laid out onthe basis of the residence time of waste-water within the grit trap. However, evenaerated grit traps are unable to ensurereliable separation of grit from organicsand this can only be achieved and guar-anteed by well performing grit washingplants.

➤➤➤ Grit Separation

ROTAMAT® Complete Plant Ro 5HD

Grit channel

➤➤➤ Grit TreatmentGrit and mineral material from wastewa-ter treatment plants or sewer and roadcleaning is very variable and can either bemore or less contaminated with organicparticles or other foreign matter similar todomestic waste. Such contamination wit-hin the heterogeneous mixture results in arelatively low dry substance content [DR],ranging between 40 % and 70 %, and ina relatively high loss on ignition [GV] inthe range of 10 - 80 %. The purpose of awell performing grit treatment system isremoval of grit up to 0.20 mm grain sizeand subsequent separation of the valua-ble recyclable grit and mineral fractionfrom the contamination material. The endproduct of grit treatment should be regar-ded as a valuable product with a low losson ignition (< 3 %) and a high DR(> 90 %). Grit treatment thus reducesboth the disposal costs whilst providing asecondary raw material as a by productwhich can be reused and recycled.

As the composition of the polluted grit tobe treated can be vary greatly, dependingon its source of production, the decisionon which is the best suited treatment sys-tem is the deciding factor at the conceptplanning of a treatment plant.

Treatment of grit from wastewatertreatment plants

If the grit to be treated is material fromthe grit trap of a wastewater treatmentplant, the best worldwide proven solutionis the HUBER Grit Washing Plant. TheHUBER Grit Washing Plant ensures thatthe organics within the grit are washed

out to such a degree that the treated grithas a loss on ignition of below 3 %, whichallows low-cost grit disposal or direct reu-se of the resultant grit.

Many countries meanwhile also havelegislation in place that defines the requi-rements for washed grit. In practicehowever, not only the effective separationof organic and mineral material is decisi-ve, but also the retention of fine grit. TheHUBER Grit Washing Plant takes this factinto account.

Treatment of grit from sewers androad refuse

Grit from sewers or road pits or road refu-se requires individually designed grit treat-ment systems. Depending on the systemcapacity, input material composition,requested material output, etc., the treat-ment technology has to be tailored tomeet these specific requirements such asthe following main process steps: accep-tance tank, foreign matter separation,wash drum for pre-classification, grit was-hing plant for separation of organic mate-rial.

If the external supply and treatment of thewash water required for grit treatmentcannot be provided, an additional washwater treatment unit can be offered as anoption for recycling of the water necessa-ry.

On the basis of its wealth of worldwideexperience in developing complete grittreatment systems, HUBER is able to pro-vide a tailored concept for each individualgrit treatment project.

Screenings are normally produced byscreens in waste treatment plants (waste-water treatment plants, pumping sta-tions, etc.) and predominantly consist ofmaterial similar to domestic waste, fae-ces, paper and mineral materials.

The screenings volume produced isdependent upon the separation size ofthe screen, the sewer system and the pre-

ceding pumping stations. The water con-tent of municipal screenings varies bet-ween 10 % and 25 %, depending uponthe type of screen used whilst the orga-nics contained within the screeningsamount on average to approx. 90 % ofthe dry residue [DR]. Due to the very highwater content, the very heterogenouscomposition and unanesthetic appearan-

ce screenings must be pretreated prior todisposal. The best pretreatment systemsare screenings wash presses that washout faeces and suspended organic mate-rial through addition of wash water andmechanical energy.

As a result, a BOD5 load increase of up to6 % at the inlet to the biological treat-ment stage can be expected. After was-hing, the screenings are compacted toachieve a significant reduction of the

water content within the washed scree-nings and due to the washout of faecesscreenings dewatering is often signifi-cantly improved. Dependent upon theselected washing process and press type aweight and volume reduction of up to 80% can be achieved.

The weight reduction reduces the scree-nings disposal volume and has thus adirect impact on screenings disposalcosts.

➤➤➤ Screenings Treatment

Unwashed screenings

Washed screenings

Page 5

At the forthcoming IFAT in Munich the unri-valled market leader in the field of grit was-hing plants will present itself as a real cham-pion: The 1000 COANDA Grit Washingunits sold impressively demonstrate thatthis plant is being accepted as the standardsolution in mechanical wastewater treat-ment.

When the first pilot plants were built in1994, many considered it unnecessary toadditionally wash the grit produced by asewage treatment plant. The industry tooka stance against this technology regardingit as technically infeasible. When attendingsite a sense of amusement by the plantoperators was apparent as we arrived onsite in our blue overalls, carrying tools andhoses to work on the COANDA Grit Was-hing Plant.

But it worked! It worked so well that Huber

decided to patent the COANDA Grit Was-hing Plant and introduced it market wideimmediately. The launch was a complete ifunexpected success. It should be noted thatnone of the competitors – with the excep-tion of a small mechanical engineeringcompany, realised that contaminated sewa-ge treatment plant grit could be washed atall.

Today, 10 years later, sewage treatment gritwashing plants are state-of-the-art techno-logy. Following our lead virtually all of ourcompetitors now offer their grit washingplant. The fact that about 95% of our com-petitors imitate or follow the HUBER princi-ple underlines the excellent function of ourCOANDA Grit Washing Plant. With theexception of a few competitors who simplycopy the original and consequently facelegal action for patent infringement, the

others try omitting one patented featurewhich results in the loss of equipment func-tion and performance. As a result, thesecopies have significant weak points compa-red to the original, including the following:

➤ The plant requires < 4 mm preliminaryscreening resulting in a large amountof unwashed grit/gravel bypassing thescreening process.

➤ Higher wear due to the high speedstirrer

➤ Excessive wear caused by large piecesof stone and gravel being in contactwith the stirrer.

➤ The plant settings have to be changedfor coarse grit/gravel or fine grit.

➤ The plant has a very high surfacecharacteristic and is therefore unableto achieve the requested separationefficiency.

➤ The plant has no separate dischargefor washed out organics.

➤ The plant works with a constantfluidised bed and therefore achievesonly sporadic satisfactory results.

At the present time investments required bylegislation are frequently postponed due toa lack of funds. The few grit washing pro-jects that are undertaken are subject toincreasingly intense competition resulting,in most cases, price being the deciding fac-tor at the cost of functionality and technicalfeatures. It is only after the project has beencompleted and a short time has elapsedthat it is found that the separation and was-hing requirements are not met, the plantproduces excessive wear or the mineralsyield is unsatisfactory. This then means thatan investment is required in order to meetthe plant requirements.

Continuity and quality has been proven

with the Huber unit with over 1000 units inoperation. The original Huber unit offersmaximum separation and washing efficien-cy supported by many years of experienceand state-of-the-art technology for sewageplant grit treatment. Furthermore, theCOANDA Grit Washing Plant can easily be

integrated into systems that additionallytreat sewer grit, sink pit contents or roadrefuse. Please do not hesitate to contact usand we will be delighted to show you oneof our 1000 reference installations world-wide. Our challenge is customer satisfac-tion!

Wolfgang BrannerProduct Manager Grit Treatment, HansHuber AG, Berching, Germany

➤➤➤ 1000 COANDA Grit Washing Plant installations - The original sets the standards!

Grit washed by the original

Only HUBER is the original!

At the IFAT 2005 we will present the1000th COANDA Grit Washer RoSF 4 tothe exhibition visitors and our competitors.Our 1000 references stand for the innova-tion, continuity, quality and best know-howwe provide for the benefit of our custo-mers. The HUBER original offers optimalseparation and washing efficiency, combi-ned with our many years of experience andstate-of-the-art process technology for thetreatment of grit from wastewater treat-ment plants.

But these 1000 originals sold impressivelydemonstrate that our COANDA Grit Was-her is at home on both large and smallWWTPs. Some of the references are listedin the following table to show that theHUBER COANDA Grit Washer is widelyaccepted even on very large WWTPs. Butthis is no surprise in view of the benefits theCOANDA Grit Washer offers:

➤ No additional preceding screeningrequired (e.g. < 4 mm)

➤ High grit and gravel yield

➤ Suitable for treatment of grit fromsewers, gully waste, road sweepings

➤ No crushing of stones and gravel

➤ The screw is supported on both endsfor minimised wear.

➤ On-line grit level measurement duringgrit feeding

➤ Grit level measurement independent ofgrit particle size

➤ Low surface overflow rate plus vortexchamber plus COANDA Tulip

➤ Separate organics discharge

➤ Large diameter screws for a high solidsthroughput

➤ Stainless steel stirrer and screw

➤ More than 1000 installationsworldwide

Be careful with your decision! The purchaseprice alone can be misleading as it must beconsidered in relation to the equipmentfunctionality and applied process technolo-gy. The bad end may come later when therequired separation and washing resultscannot be achieved, the plant produces

excessive wear, or the mineral material yieldis much too low. A lot of trouble will beinevitable and additional investment costsincurring.

Please do not hesitate to contact us and wewill be delighted to show you one of our1000 reference installations worldwide.Make use of our know-how!

Wolfgang BrannerProduct Manager Grit Treatment, Hans Huber AG, Berching, Germany

➤➤➤ A global success: The COANDA Grit Washer is worldwideinstalled on large wastewater treatment plants

COANDA Grit Washer in Paris (Valenton)Worldwide references

Page 6

Equipment and system solutions forapplication in combined and separa-ted sewer systems

Advanced combined and stormwater tre-atment in municipal combined sewers is amain issue with regard to sustainableenvironmental and water protection. Thebuilding of new wastewater treatmentplants and the upgrading or refurbishing

continuous wastewater discharges hassignificantly increased the quality ofmany watercourses. Despite all of these

efforts however, there are still ecologicalproblems caused by floating and coarsematerial discharged from the sewer sys-tem into the waters in a stormwater over-flow discharge event in both a combinedand separated sewer system. For the pur-pose of specific environmental protectionappropriate measures will have to betaken in future to minimise these pro-blems.

Combined water screening

HUBER screening plants prevent the floa-

ting and/or coarse material passing fromthe sewer system into watercourses. TheHUBER systems available differ in theirtype of screening elements (bar screen orperforated plate) and their installationposition that can be on or behind theoverflow sill. In order to achieve the maxi-mum possible solids retention, each plantis individually tailored to optimally suitsite specific hydraulic and constructionalconditions. With its vast reference listHUBER has a attained the experience andknowledge to handle any application andsituation that may arise throughout theworld

Cleaning of stormwater retentiontanks

To maintain the performance of storm-water storage basins, sewers or sewerswith storage capacity and overflow, it isnecessary to provide suitable cleaningsystems in order for these facilities to, eli-minate odours caused by biogas produc-tion and prevent biological activity of themainly organic substances in the sedi-ment of the sewer or tank bottom whichcould become an increasing health risk.

The most efficient, reliable and cost-effective cleaning method available issewer flushing. The HUBER TippingBuckets SK with their mature design haveover the years been well proven for theirefficiency in the cleaning of storagetanks.

Sewer flushing system

An innovative sewer flushing system withpatented gates has been developed forsewers, and sewers with storage capacityand overflow. This system includes for theoption for sewer network control andsewer storage capacity activation.

Constant design retention level

Another main product line available is theeconomical and intelligent HUBER systemsolutions for combined and stormwatertreatment. Against the background thatinvestment and operating costs need tobe reduced, it is imperative to utiliseunused storage potentials through main-tenance of a constant design retentionlevel in combination with a screen. Inaddition to the high economic benefitachieved by reduced investment costs forstorage structures the environmental bur-den can significantly be minimised byusing a screening plant whilst the opera-tional behaviour of storage structures isalso gaining in importance. Measuringdevices are therefore required at overflowsills for accurate measurement of thescreened combined water overflow. Thecombination of measuring equipmentwith a screening plant had been previous-ly impossible but is now no longer a pro-blem with the Huber system availablewhich is a favourably priced and efficientsolution for any application.

➤➤➤ Sewer System Management and Stormwater Treatment

Sedimentation in a sewer

A close co-operation between plan-ners, customers and suppliers is para-mount for a successful project. The fol-lowing case history is one examplefrom a number of successful projects. Astormwater overflow tank near Bre-genz (South West Germany) is equip-ped with six HUBER High PerformanceFlow Screens.

A variety of machines and equipment isavailable from several suppliers in the fieldof wastewater treatment. These are fre-quently available only in defined sizes andcannot be tailored to specific site require-ments. HUBER offers a wide range of diffe-rent products in many defined sizes. Howe-ver, project-related layout and technicaladvice are readily available for each indivi-dual project. This has also been the casewith the project near Bregenz on Lake Con-stance planned by engineers Rudhardt &Gassner, Bregenz for the water authorityclient Hofsteig. The project requirementwas to pass 9000 l/s through a horizontalflow screen taking into account specific siteoperating conditions.

Following a site visit by HUBER representati-ves it became clear that it would not bepossible to place the screens into the custo-mer's existing structure because of specificconstruction difficulties. These difficultieswere overcome by careful preliminary plan-ning and consultation with the local engi-neers and particularly the inventiveness ofHuber's fitters who managed to overcomethe specific site obstacles.

A special requirement was a low noiseemission stipulation due to local housingestates situated within 10 m of the siteitself. The HUBER High Performance FlowScreen HSW has a wastewater-protectedlinear electric chain drive (not a hydraulicdrive) and was able to exactly meet thisrequirement.

A further challenge was to meet therequested hydraulic requirements whilstconsidering the configuration of the custo-

mer's building. A further considerationwhen choosing the correct screen was con-sultation with the planning engineers withrespect to the problem free operation ofthe sewer network as a whole. Once againthe close cooperation with Rudhardt &Gassner and the water authority Hofsteigresulted in the creation of the best hydrau-lic solution for the whole project.

The six HUBER High Performance FlowScreens have now been operating withoutproblems for two years. The close co-ope-ration and mutual trust between all associ-ated parties has proven to be advantageousin providing the best technical, cost effecti-ve and reliable solution and should beregarded as a model for all future projects.

Albin Dengler, Robert Freygang,Christian GelhausHans Huber AG, Berching, Germany

➤➤➤ Co-operation pays off!

Facing adverse working conditions in the narrow building

Upstream view of the screen after successful installation

Page 7

HUBER expand their range of productsfor combined sewage treatment

Environmental protection, and thereforethe necessity of advanced combined sewa-ge treatment, concerns everyone. This hasled to increasing efforts to substantiallyimprove the protection of waters. In thecourse of such further development HUBERhas expanded its product range for thisfield in order to better meet the challenge.

In the field of advanced combined sewagetreatment HUBER has developed the ROTA-MAT® Storm Screen RoK 1 for reliableremoval of floating and suspended materi-al from combined sewage flows. Withmore than 700 installations worldwide thiswell-proven machine is firmly established inthe wastewater technology markets.

In the course of further research and deve-lopment a new type of screen has beendeveloped for combined sewage treatment– the ROTAMAT® Storm Screen RoK 2.

The ROTAMAT® Storm Screen RoK 2, likethe ROTAMAT® Storm Screen RoK 1,belongs to the group of fine screens and isdesigned for high flow rates. The screen ishorizontally situated immediately in frontof the overflow sill.

A helically wound screw is installed ontothe semi circular screening face. The scree-nings are transported to the screw endwhere the discharge opening is situated.Simultaneously, the screening face is clean-ed by the action of a wear-resistant brushfitted to the periphery the screw flights. Thescrew is supported by a series of bearingsand ensures a constant optimal removalefficiency. The major difference from theROTAMAT® Storm Screen RoK 1 is however,that wastewater screening takes place in

front of the overflow weir and not behind,so that the screenings remain in the tank orWWTP inlet. Another innovation is theremovable screening basket that providesaccess to the screw from the top for brushreplacement. The individual screen basketlengths have been limited according to thescreen size and weight to enable them tobe removed without the need for any auxi-liary means, such as a crane or davit. This

allows for a reduction in maintenancecosts.

Figure 2 shows the removable screen bas-kets that are equipped with handles to faci-

litate disassembly and maintenance. A furt-her difference with the ROTAMAT® StormScreen RoK 2 is that it is available as a pushscreen only and not as a pull screen as theRoK 1. The screenings are discharged at theend of the screen basket through a kidney-shaped opening in the outlet end plate andback into the tank. It is, therefore, unneces-sary to pump the screenings over the weirand back into the tank or WWTP inlet. Dueto its design the ROTAMAT® Storm ScreenRoK 2 is mounted on the wet side of theoverflow weir in such a way that the flowapproaches the full screening face within arelatively short time frame whilst still able toachieve the maximum screening efficiency.

Huber ROTAMAT® Storm Screens RoK 2can be used for the following discharges inthe combined sewage sector:

➤ storm-water tanks with overflow

➤ sewer with storage capacity andoverflow

➤ storm-water tank retaining the firstflush of storm-water

➤ retention tanks

➤ storm-water tank with overflow forsettled combined sewage

This design results in the following benefits:

➤ Screenings remain on the pollutedwater side

➤ Suitable for retrofitting into existingstructures

➤ Possibility of completely submergingthe screen (emergency runningproperties)

➤ Optimal solids retention by means oftwo-dimensional screening

➤ The perfect solution for dischargeswith limited upstream head restraints

Figure 3 shows a ROTAMAT® Storm ScreenRoK 2 under final assembly The specifichydraulic conditions make it necessary toleave a part of the screen basket unperfora-ted. The kidney-shaped opening in the endplate is visible on the right. This openingensures screenings discharge into the tankor WWTP inlet.

The following table specifies the availableunit sizes:

The maximum design length of size 300,500 and 700 is 7500 mm, whereas the size1000 unit has the longest design lengthwith 5000 mm.

With the ROTAMAT® Storm Screen RoK 2HUBER offers an additional machine forcombined sewage screening in order to beable to better meet customer requirementsand specific constructional and hydraulicsite conditions.

Christian GelhausProduct Manager Sewer and StormwaterTreatment, Hans Huber AG, Berching, Ger-many

➤➤➤ Combined sewage screening at overflow structures withthe ROTAMAT® Storm Screen RoK 2

Fig. 1: ROTAMAT® Storm Screen RoK 2 installed behind the customer's scumboard

Fig. 2: ROTAMAT® Strom Screen RoK

Fig. 3: ROTAMAT® Storm Screen RoK 2 under final assembly

Page 8

The main waste within a municipal was-tewater treatment plant is the sewagesludge that is produced by mechanical,biological and chemical wastewater treat-ment. The sewage sludge volume produ-ced is dependent upon the treatment sys-tems utilised and on how many house-holds are connected to the treatmentplant. This figure will differ dependentupon the country and even the differencebetween urban and rural areas.

The amount of sludge produced furtherdepends upon the composition of thewastewater to be treated and the applica-ble treatment systems and of course theirperformance.

It can be assessed at approx. 20 – 45 kgDS per year, according to the individualcountry.

There are several sludge properties thatare significant for the sludge treatmentcosts. The water content plays an impor-tant role as it determines the sludge qua-lity and thus the applicable transport faci-lities required and associated disposalcosts along with the dry residue whichvaries depending upon the type of sludgeand the sludge treatment method appli-cable.

The chemical composition of the sludge isalso dependent upon the wastewater

quality and treatment method. Of parti-cular importance is the heavy metal con-tent as this will be a limiting factor forland application of sludge or recultiva-tion.

Recently it has been noted that this parti-cular disposal route is not as safe as hasbeen assumed for a long time as evenwhen disposal to agricultural land takesplace within the limits of legislation, accu-mulation of heavy metals in the soil canbe observed.

Additionally, sewage sludge containsvarious endocrine substances, the con-tent of which differs and the spreading of

sewage sludge onto agricultural land willlead to serious loading of the soil withendocrine substances.

As the new legislation requires a maxi-mum loss on ignition of 5% for residues,landfilling of untreated sewage sludgewill no longer be possible. If the driedsewage sludge is incinerated, then theproduced energy can be utilised for dry-ing, as the thermal value of the driedsludge is similar to that of brown coal.

HUBER offers the complete program ofsludge treatment equipment.

Screening – Thickening – Dewatering– Drying – From One Source.

➤➤➤ Sludge Treatment

Sludge screening

Sludge dryingSludge thickening

Sludge dewatering

Tests on WWTP Würenlingen convin-ced the WWTP operators. They finallyordered a HUBER Centrifuge RoD, size1500.

This machine was delivered as scheduledand successfully commissioned.

The installation was completed and theplant made fully operational at the end ofAugust 2004.

The new sludge dewatering plant was gra-dually brought into full operation with theco-operation of the site operating staff.

The setting of all operational parameters ofthe centrifuge were checked and optimisedto suit the customer's specific sewage slud-ge.

The machine was started via the customer'sprocess control system and within a fewminutes achieved the required dischargeparameters.

The final DS content has constantly remai-ned at 32% since plant start-up in August,with a throughput of 7 – 10 m3/h and virtu-ally solids-free centrate.

The coagulant agent consumption has sta-bilised at between 7 and 8 kg effective sub-stance / t DS with the FLONEX coagulant

agent used during the test phase still beingused and proving its effectiveness.

Rolf Hirt, the works manager on WWTPWürenlingen, quickly familiarised himselfwith the new technique and is more thansatisfied with the HUBER ROTAMAT® Cen-trifuge RoD which achieves 6 – 8% DSmore than the previously installed dewate-ring system. This gives a reduction in overallcosts for transportation of the sludge to theincineration plant. A further benefit is thereduction in the solids load within the cen-trate is significantly reduced which in turnenhances the fine material circulation wit-hin the wastewater treatment plant andleads to improved effluent values.

A reduction in operator attendance hasalso been achieved.

The successful installation and operationcoupled with customer satisfaction withthe project gives a perfect start for our sub-sidiary Picatech-HUBER AG with our newcentrifuges in Switzerland!

Rainer HausdorfProduct Manager Centrifuge, Hans HuberAG, Berching, Germany

➤➤➤ Successful Introduction of the first HUBER Centrifuge in Switzerland!

ROTAMAT® Centrifuge RoD

Page 9

Economical combination of over 2years well-proven methods:

1 Production of thermal energy withheat pumps using the heat potenti-al of clarified wastewater prior todischarge into the recipient.

2 KULT® Low Temperature Dryersupplied with water at 55 °C fromheat pump operation

In the early 1990s, the first district heatingnetwork supplying 186 households was

put into service in Muri-Freiamt, Switzer-land using the high heat potential of thewastewater from the WWTP Muri.

Why not also use the available wastewaterenergy immediately and directly in the newdrying plant at WWTP Mellingen?

This question was investigated by Picatech-HUBER AG, Switzerland at the outset of theproject working in conjunction with theengineers responsible, Kuster+Hager AG,Uznach and Durena AG, Lenzburg.

The constructors, the wastewater authorityof Mellingen, finally selected this innovativesystem (see fig. 1) because of its economi-cal and operational advantages.

With sewage sludge being produced with90% DS a long term contract was agreedfor disposal within the cement industry. Thedry sludge quality produced by the HUBERDryer meets the requirements of thecement industry, in terms of grain size, tem-perature or residual dust content and hasalready been proven by the dryer installedin 2003 at WWTP Schwyz.

Benefits for operators and environ-ment

➤ Compared to drying systems heatedwith fossil fuels 300,000 litres fuel oilcan be saved per year and the CO2emission reduced by 800 tons.

➤ Thermal load reduction in watersthrough cooling of the wastewater bymeans of energy removal prior todischarge (heat exchangers) into thereceiving water course.

➤ No treatment of exhaust air or vapoursrequired

➤ No return loads into the WWTP

➤ Complies with air pollution controllegislation

➤ The simple and reliable plant reducesmaintenance costs to a minimum andguarantees maximum operationalreliability.

➤ 30 % electric energy input into theheat pump produces 100% thermalenergy. This makes for lessdependence upon the fast increasingprimary energy costs.

➤ The three-stage heat pumpautomatically delivers as much energyas is required by the drawn in dryingair for the defined drying performance.Under optimal weather conditions, the

dryer automatically changes fromrecirculation air to fresh air operationwithout the need for additional energyinput.

➤ Fully automatic 24 / 7 operationwithout need of operator attendancehas successfully been achieved on theWWTP Schwyz for two years.

➤ Extremely low fire risk with 40 °Cdrying air.

The operating costs (capital, personnel,maintenance) for energy productionfrom the effluent, sewage sludge dry-ing to 90% DS, including transport anddisposal fees payable to the cementindustry will amount in total to 450CHF (292 Euro) per ton dry mass.

Plant set-up and logistics

The KULT®-60 drying plant, designed for450 kg water evaporation per hour, is tohandle 4500 tons dewatered sewage slud-ge (28-30% DS content) within 6800 ope-ration hours per year.

The major challenge at the project planningstage was to optimally utilise the custo-mer's sludge storage area for integration ofthe energy production and drying plant. Inview of the limited space available, it wasnecessary to find the optimum solution forthe external sewage sludge reception anddryer feeding, as well as dust-free loadingof the dried sludge onto two troughed beltconveyors.

New economical and ecological standardswill now be set following the implementa-tion of this innovative drying project inSwitzerland. With the co-operation andforesight of the constructors, planners andmain contractors the aim is to put the plantinto operation by the end of 2005 and welook forward to the first transportation ofsludge from the WWTP using its own ener-gy source.

Bruno HilsPicatech-HUBER AG, Switzerland

➤➤➤ First sewage sludge drying plant in Switzerland utilisingWWTP effluent to supply thermal energy – made possibleby the KULT® Low Temperature Dryer

sludge storage

loading point

heat exchanger

beld dryer

to cementindustryfresh air

exhaust airdelivery dewatering

30 % ds

on-side-

final clarifier

filter

heatheat

pump

accumulator

55 ° C

electric

Energyproduction

exchanger

per-flooder power

localexternal

90 % ds

drying pland

Sludge dryer with thermal power supply out be a final clarifier

➤➤➤ Ecologically aware and energy-conscious HUBER installs its first combined solar and regenerativesewage sludge drying project

The Hayingen wastewater treatment plantis situated in the idyllic valley of the riverLauter, situated on the long hiking trailfrom the Black Forest into the Allgaeu. Thewastewater treatment facility blends per-fectly into the local landscape.

Whilst it is accepted that the need for largesurface areas is required for a pure solardrying plant, the local topography made itnecessary to position the plant on the pla-teau next to the wastewater treatmentplant. The new dewatering unit was instal-led to dewater the sewage sludge to 440t/a with approx. 22 % DR. This resultantsludge would then be transported to thenew drying plant via the municipality's roadnetwork.

The HUBER SRT sewage sludge drying sys-tem with combined solar and regenerativedrying provides for sewage sludge dewate-ring and drying in one place.

Only solar radiation available at site is usedfor drying. The additional regenerativecomponent consisting of a heat pumpassists the replacement of solar drying at

times of little or no solar radiation. For thispurpose the pump uses the heat of thewastewater treatment plant effluent anddelivers it into the dryer.

The HUBER drying plant consists of a pur-pose built structure containing the dewate-ring unit, separate electric measuring andautomatic control devices for the completeplant, and the subsequent dryer. The dryercover is of a double plate construction usedwithin the greenhouse industry. Inside thedryer the sludge is placed onto the perfora-ted bottom, transported and mixed by aturning device. The air that has been hea-ted by the heat pump then flows throughthe sludge layer. The dried sewage sludgesautomatically leaves the plant and is trans-ported into a granulate collecting tank.With the integral design, manual feedingwith sewage sludge or dryer evacuation bymeans of a wheel loader is unnecessary,which results in a safer working environ-ment for the operating staff.

The plant is at present in the test run phaseand achieving the required drying result of90 % DR. Further adjustment and optimisa-

tion of the process will be tailored to suitthe local conditions and plant require-ments.

Stefan WahlProduct Manager Sludge Drying, HansHuber AG, Berching, Germany

KULT® Solar Active Dryer SRT in Hayingen

Page 10

Equipment for preliminary and secon-dary sedimentation tanks

The inflow into the preliminary clarifi-cation tank consists of a sludge/watermixture from the grit trap where the coar-se sludge and mineral solids are separatedby sedimentation. As the wastewater tre-atment plant effluent quality must meetthe Waste Water Levy Act standards, asmuch as possible of the floating and sett-ling material should be removed from theactivated sludge/water mixture within thesecondary clarification tank. Peak loadoperation is critical under storm condi-tions and when the sludge blanket andhydraulic load are increasing, there is arisk of sludge overflow. This most certain-ly must be prevented from occurring asthe limit values will be significantly excee-ded in most cases. The inlet conditions ofa secondary sedimentation tank will beand are a determining factor for the inter-nal tank conditions. An inappropriateinlet design may compound and causeseveral problems that can lead to highoutlet concentrations of suspendedsolids. A major problem is the high inflowenergy within centrally fed tanks thatleads to high internal flows and thus to areduced separation efficiency of the enti-re tank. It is possible to significantly redu-ce the inflow energy by feeding the tankover the full circumference as with theHUBER Opti-Flow System. A furtherdetermining factor for optimal sedimen-tation tank operation will be the uniformclarified water discharge over the fulltank circumference, which can be achie-ved with the HUBER Submerged Pipe.

A channel is theoretically only able tomeet these requirements as it implies thatno installation inaccuracies occur, thewater level remains unaffected by windand no structure subsidence takes place.However the discharge of clarified waterwill have already been influenced even ifonly one of these conditions are not met.This means that in a channel, in worstcase, the clarified water will be dischar-ged only on one side whilst no water at allis discharged on the opposite side. If thisoccurs, the flow in the circular tank will beimpaired to such a degree that onlyapprox. 50 % of the tank volume is stillbeing utilised for sedimentation, leadingto hydraulic tank overload which will inturn result in a poor settling performanceand sludge overflow.

The HUBER Scum Scraper consists in afloating paddle mechanism that will gua-rantee enforced removal of any floatingmaterial from the tank surface.

As the system is floating, it will be self-adjusting to suit varying water levels. Thecomplete system can be retrofitted intonew or existing circular tanks with scraperbridges, or into rectangular tanks.

Clarified water discharge for SBR sys-tems

The SBR system is a variant of the activa-ted-sludge process. The difference whencompared to a conventional wastewatertreatment plant is that the individual pro-cess steps take place in a chronologicalorder rather than a cascade. This meansthat all of the steps required of a SBR sys-tem for biological wastewater treatment

takes place one after the other within onetank and not separate reaction tanks (pre-liminary clarifier, preceding denitrificationfill-and-draw reactor, aeration tank,secondary clarifier). A basic installationdevice is therefore the clarified waterdischarge that will discharge the clearwater into the receiving watercourse both

during and after the sedimentation pro-cess. The HUBER SBR Clarified WaterDischarge KWA is a floating constructionwhich optimally utilises sedimentationtime. Sludge draw-off is assured throughweighted valves in the mixing phase andthrough low erosion below the flaps.

➤➤➤ Sedimentation

HUBER SBR Clarified Water Discharge KWA

HUBER water discharge for circular clarifiers TRRU

Sandfiltration

The CONTIFLOW® Sandfilter is an upflowfilter with a filter bed, which is being cle-aned continuously making shutdownsfor backwashing of the filter bed unne-cessary. The feed is introduced at the topof the filter and flows downwardthrough an opening between the feedpipe and airlift housing. The feed is intro-duced into the bed through a series offeed radials that are open at the bottom.As the influent flows upward throughthe moving sand bed, the solids are retai-ned within the filter sand and filtrateexits via a weir at the top of the filter.Simultaneously, the sand bed, along withthe accumulated solids, is drawn down-ward into the airlift pipe, which is locatedwithin the centre of the filter. The typical-ly used filter bed height for municipalapplications will be 1 metre (2 metres for CONTIFLOW® Sandfilter CFSF

➤➤➤ Clarified water discharge for the SBR tank on WWTPRiezlern, Austria

Due to the seasonally greatly varyingpopulation in the municipality Riezlern,Austria they ultimately selected a systemthat

➤ is able to handle varying hydraulicflows

➤ and allows for a high nitrogendegradation performance.

The previous conventional system, consis-ting of an aeration tank and secondary cla-rifier, was replaced by a Sequencing BatchReactor SBR designed for 10,000 PE whichwas started up in 2004.

Two new tanks, each of 22 metre diameterand 7 metre deep, had to be built for thenew SBR plant. Each of them is needed forthe processes of aeration, sedimentationand clarified water discharge which takeplace cyclically one after the other.

HUBER supplied the clarified waterdischarge unit which is able to meet themunicipality's requirements, such as

➤ Prevention of sludge ingress into theaeration and mixing phase

➤ Prevention of erosion of sedimented

sludge during the water dischargephase

➤ Guaranteed average discharge of600 m3 per hour

➤ Automated operation due to acontrolled outlet valve

Thomas KimmenauerProduct Manager Sedimentation, Hans Huber AG, Berching, Germany

Installation of the HUBER Clarified WaterDischarge

phosphorus removal / denitrification) anddependent upon the plant size, the filtertank will be of a steel or concrete basindesign. As the sand falls through the was-her, which consists of several concentricstages, a small amount of filtered waterpasses upward, washing away the dirt,while allowing the heavier, coarser sand tofall through to the bed. By the setting of thereject weir at a lower level than the filtrateweir, a steady stream of wash water is ensu-red. The continuous reject water exits nearthe top of the filter to enable it to exit bygravity. Due to the increase in requirementsof the effluent quality of wastewater treat-ment plants – both for direct and indirectdischarge – the operators of municipal andindustrial plants are forced to implementadditional treatment steps to ensure therequired effluent standards are met. Sand-filters are a solution to achieving the des-

ired effluent standards within variousapplications.

Typical sandfilter applications

➤ Tertiary filtration after secondaryclarifiers

➤ Phosphorus elimination throughprecipitation filtration

➤ Biological denitrification

➤ Algae removal

➤ Drinking water treatment

➤ Process water treatment

➤ Industrial wastewater

➤ Treatment of exhaust gases frompower plants

➤➤➤ Filtration

Responsible, modern wastewater treat-ment should be aimed at the protectionof waters and the environment. For thisreason, domestic wastewater is collectedin sewer systems and treated within acentral wastewater treatment plant. Fre-quently, however, it can be ecologicallyand economically more sensible to treatthe wastewater as close to its source aspossible and without the need to buildextensive and often expensive sewer sys-tems. The wastewater problem is as weknow a worldwide problem and solutionsfrequently need to be easy and quick toimplement, affordable and adaptable toallow for tailored solutions to be offered.Decentralised wastewater treatment sys-tems are therefore a requirement andnecessity in most cases. When Huberstarted with its new products for decen-tralised wastewater treatment, Huberfocused on the innovative membranetechnology and developed two different

systems, the VRM® and VUM®. In bothsystems the membrane reliably retains allsolids and bacteria along with virtually allgerms as the diameter of the membraneopenings is 1,500 times smaller than thediameter of a human hair. This thereforeallows for the treated water to be reusedwith the filtrate meeting the EU standardsfor bathing water quality.

For decentralised wastewater treatmentin rural areas HUBER have developed theHUBER MembraneClearBox®, which is asmall wastewater treatment plant for upto 150 PE. The plant can be supplied as aretrofit or as an installation set that caneasily be installed into both existing tanksor newly built multi-compartment septictanks, or indeed any other technically sui-table tank. The addition of the optionalHuber Teleservice minimises the require-ment for operator attendance.

HUBER MembraneClearBox®

➤➤➤ Decentralised Wastewater Treatment

➤➤➤ Advanced Wastewater Treatment

➤➤➤ Drinking Water Treatment

DeSa/R, the abbreviation for Decentrali-sed Sanitation and Reuse, relates to themethods of decentralised wastewater tre-atment that provide for the reuse of was-tewater treated in a technical processesand/or reuse of the nutrients containedwithin such wastewater. With the conti-nuous population growth, huge amountsof water required for the irrigation ofagricultural land and finally the use ofcommon fertiliser resources all demand anew way of thinking in terms of waste-water treatment. Exceptional circumstan-ces required special solutions that have tobe not only affordable but easy and quickto implement. After disinfection, mecha-nically treated nutrient-containing waste-water can for example be utilised for irri-gation purposes without the need for anypreceding separation. However, DeSa/Rconcepts frequently start right at thesource, as already common place withinwaste management, with separate collec-

tion of the different wastewater flowsproduced in a household. Faeces from uri-ne and greywater are separated and then

collected separately (wastewater fromwash basins, showers, bathtubs, washingmachines, etc.) in order to provide for the

optimal treatment and reuse of each indi-vidual material flow according to its speci-fic characteristics. The purpose of suchconcepts is the reuse of water andnutrients to as high as possible degreewithout negative effects on the popula-tion and the environment.

The future begins with ourselves …

To be able to assess the acceptance, appli-cability and benefit of such new concepts,Huber implemented within its own newoffice building special sanitary facilitiesfor approx. 200 employees with the sys-tem separating the yellow, brown andgreywater flows. After intermediate sto-rage the separated flows are each direc-ted to specific treatment facilities wherefertiliser, biogas, humus and service waterare produced. Also available are solutionsand products for the treatment of loadedrainwater to enable it to be suitable forgroundwater regeneration.

Fertiliser production from urine

Huber's commitment is not limited towastewater technology but also includesdrinking water treatment. With its trade-mark SafeDrink® Huber focuses on thesmall to medium decentralised plants (upto 5000 m3/h) for surface water treat-ment or partial desalination in arid areas.The plants are designed and developed byHuber from engineering to commissio-ning by means of conventional techni-ques such as membrane technology.

For example within the scope of this acti-vity Huber delivered in 2002 two conven-tional plants into the Sudan. The twoidentical drinking water treatment plantswere installed in the cities of Dongola andEldebba for which Huber engineers hadto consider specific local conditions thatwere reflected within the selected processtechnology.

The project demanded the recovery ofdrinking water from the river Nile for70,000 people.

The treated water had to meet the WHOstandards and furthermore, a simple andreliable technology was an absolute pre-requisite for this project due to the absen-ce of technicians on site.

The plant was designed for a nominalflow of 3500 m3/d and consisted of thefollowing process steps:

1. Coarse preliminary treatment withinthe inlet channel;At the same time coagulant agentsare added in order to allow colloids(such as humic or particulate material)to settle.

2. The settleable material (flocks andsolids) settle within the sedimentationtank. The sludge produced is removedby a belt scraper and deposited into asludge lagoon.

3. Solids that do not settle within thesedimentation tank are filtered in acontinuous sandfilter. Owing to a ful-ly automatic principle these fast filterscan be operated with minimum main-tenance. The wash water is thenreturned into the above mentionedsludge lagoon.

4. The filtrate passes a chlorine gas disin-fection stage where microorganismsand pathogenic germs are eliminated.

5. The treated water is stored within astorage tank.

6. The water is then pumped into an ele-vated reservoir in order to achieve theoperating pressure necessary.

The plant has been additionally equippedwith HUBER stainless steel products, suchas manhole covers, pipelines, doors, rai-lings.

Benefits

➤ Surface water treatment

➤ Reliable operation due to atechnologically simple system

➤ Minimum maintenance requirements

➤ WHO standards are met.

➤ Solution for decentralised watersupply

Page 11

Page 12

➤➤➤ Water reuse – a burning issue Jerusalem's wastewater treatment system

Jerusalem

As water shortage is a problem in many areasof the world, wastewater is a valuable resour-ce and is therefore reused in such countries.

The water and nutrients required for irrigationare made available through reuse of wastewa-ter.

Hans HuberMember of the Board, Hans Huber AG

Wastewater reused for irrigation

Wastewater treatment processes

Nutrients contained in the wastewater A main step: fine screening with HUBER ROTAMAT® Wedge Section Screens

Settling pond Resevoir

Irrigated palm grove Irrigation of roots

Page 13

There is no mountain too high for us toclimb: We consider wastewater, processwater and sludge generated by thevarious industrial sectors as opportunitiesfor successful HUBER Technology installa-tions. So what is industrial wastewater? Itis any sort of wastewater that is producedin the course of industrial production andprocessing. Cooling water produced inthe cooling towers of power plants is usu-ally discharged into rivers without priortreatment (with the result of river waterwarming). Industrial wastewater fre-quently contains difficult to decomposeorganic substances, oils, grease, heavymetals, salts, toxins or caustic substances.Particularly high loads are contained inwastewater from the chemical, textileand food industries. The wastewater pro-duced requires pre-treatment prior tobeing discharged into public wastewatertreatment plants. If industrial wastewateris to be discharged directly into surfacewaters, multi-stage treatment of thewater is required. It is therefore becomingincreasingly important for us to be able tooffer our customers complete solutions.Simply supplying chemical, physical andbiological treatment equipment for was-tewater and process water would not besufficient if in the end the customer is leftwith an unresolved sludge issue.

Hans Huber AG is one of only a handful ofsuppliers worldwide who are able to sup-ply not only the equipment for wastewa-ter and process water treatment but alsosludge treatment technology includingsludge drying.

Our customers will experience the profes-sionalism when working with their assig-

ned individual HUBER specialists, witheach able to select from a large variety ofdifferent treatment technologies choo-sing the most efficient and economicsolution for each individual customer and

application. This we feel is of great bene-fit to our customers when compared toworking with a company only able tooffer part of the solution. Industrial was-tewater is different from municipal was-

tewater and individual industrial sectorsneed individual solutions. HUBER hadalways been aware of this fact and becau-se of this established the special IndustralBusiness Unit.

This young, dynamic team consists of spe-cialists resonsible for different industrialsectors who have gathered their specificknowledge and experience over the yearsand will be competent partners for ourcustomers. It is our pleasure to offer ourexperience to the market and would likethe oportunity to prove to you how wecan solve the challenges facing the mar-ket.

Whenever you need innovative, commer-cial and practicable solutions to solve yourproblem with industrial wastewater orsludge, HUBER will be your partner –worldwide.

➤ Problem identification

➤ Conceptional design

➤ Laboratory analysis

➤ Pilot testing and evaluation

➤ Engineering

➤ Project management

➤ Start up

➤ Installation and service

➤ Process optimisation

➤ Technical support

➤ Training

➤ Trouble shooting

➤➤➤ Solutions for Industrial Wastewater

Wastewater collection tank

➤➤➤ 64 HUBER SSV Step Screens for River Water Screening in South Africa

The 54 HUBER SSV Step Screens, size 4300x 776 x 3 mm, delivered last year to SASOL,South Africa for river water screening havebeen working to the full satisfaction of thecustomer so that they placed a follow-uporder for another 10 HUBER Step Screenswhich were delivered in mid July 2002.This was the largest individual order formechanical preliminary treatment equip-ment for HUBER. SASOL is one of the tenlargest private enterprises in South Africa,with 35,000 employees and 15,000 share-holders.

During the oil shock years, SASOL beganto produce synthetic fuels from carbon,starting a very successful production,amounting to a total of 700 million barrelproduced since 1980. This enormousamount enables South Africa to remainfairly independent of the OPEC. The syn-thetic oils are produced according to theFischer-Tropsch process. Fischer andTropsch were German chemists who inven-ted a method for synthetic production ofaliphatic hydrocarbons around the turn ofthe century. This process converts a gasmixture (water gas, synthetic gas) thatconsists of coke and hydrogen into liquidhydrocarbons, under the influence of cata-lyzers and at a slightly increased pressureat 200°C (high or low temperature). Thistype of fuel is mainly used for motors inSouth Africa.

It is very important for heat exchangeduring the high-temperature process tohave a lot of water available to cool therecirculation water. The cooling watercomes from a nearby river and has to beclarified in front of and behind the coolingtowers and heat exchangers. This task is

successfully achieved by HUBER StepScreens with 3 mm openings. Due to thehuge water amounts, 7 SSV units of size4300 x 776 x 3 mm are required for eachcooling tower.

The investment has saved millions, preven-ting blockage of heat exchangers andinterruptions in production. Installation ofthe first 54 screens has ensured a stableproduction process and saved SASOL mil-lions of Euro per year for expensive clea-ning and repair work.

Peter Brechtelsbauer Head of Business Unit Industry, HansHuber AG

SASOL, South Africa: SSV in-channel installations

28 HUBER Step Screens stored in the HUBER yard before shipment

➤➤➤ The ISKA® ConceptThe ISKA® Concept offers new ways ofmechanical biological waste treatment

The TASi as well as the EU Directive inter-dict landfilling of untreated municipal was-te from 2005/2006 on. As a result alterna-tive concepts have been developed for tre-atment of household and municipal waste.The mechanical-biological waste treat-ment concept of ISKA® GmbH offers aninnovative, flexible and convincing solu-tion. The ISKA® concept is targeted on sig-nificant reduction of residual waste bymeans of percolation – an innovativemechanical-biological waste treatmentmethod. With this method utilisable mate-rials (metals, minerals) are separatedthrough aerobic and anaerobic biologicaldecomposition and intensive watering anddewatering. A part of the remaining solidscan be utilised as a fraction with a highcalorific value. After additional treatmentthe achievable mass reduction can beimproved through further dehydration(drying, composting). The main advanta-ges of this process are the high massreduction, minimum space requirements,high automation degree, energy autarky(to a great extent), and the low emissionsdue to the innovative air management.The ISKA® concept allows to use any pres-ently available reutilisation and disposalpossibilities provided the adequate secon-dary treatment methods are selected andapplied. Customer requests and existingdisposal structures can be integrated intothe concept.

Material flows

When residual waste is treated with theISKA® concept, several different materialflows are produced, the quantities ofwhich depend on the composition of theoriginal waste. Varying input compositionslead to varying output flows. If secondarytreatment follows, the rate of disposalmaterial is further reduced through techni-cal drying and separation of inert materialand metals. Additional reduction can beachieved through optional composting forfurther biological decoposition and waterevaporation.

Coarse material

Material that could lead to operationaltroubles or damage of the plant (such asmattresses, big pieces of wood, stones, bigmetal parts, etc.) is removed already by amechanical coarse screen. Such waste canbe utilised in scrap and wood processingplants or disposed of in waste incinerationplants.

Metals

The residual waste contains several diffe-rent metals. Iron metals (Fe metals) areremoved in the preliminary and secondarytreatment stage by means of magnets andcan then be passed on to scrap traders.Removal of non-iron metals is additionallypossible in the secondary treatment stage.

Wastewater

After treatment and conditioning the was-tewater complies with the limits specifiedin appendix 23 of AbWV standards.Depending on the plant conception thewastewater is used for wetting of compostor introduced into the sewer system.

Ammonium sulphate

The end product of nitrogen removal isammonium sulphate.

Carbon dioxide

The carbon dioxide produced during per-colation and secondary treatment is part ofthe exhaust air and therefore passed on tofurther treatment along with the exhaustair.

Electricity

The energy of the high-quality biogas(70% methane) produced during fermen-tation is utilised in a block heat and powerplant. The electric energy is used in theplant. Usually the percolation process pro-duces excess energy. The heat recovered inthe block heat and power unit is used toheat buildings or the process water and forsecondary drying of material.

Minerals

The inert mineral material (sand, stones,glass, etc.) is removed from the processwater after percolation. In case of a ther-mal utilisation an additional grit removaltakes place in the secondary treatment sta-ge.

Compost

It is not permitted in Germany to use com-post from household and municipal waste.In other countries, however, (such as Aus-tralia) such compost is used for recultiva-tion and landscaping.

Geostabilat®

The material obtained after percolationand composting is a stabilised, virtuallyinert material that complies with the stabi-lity parameters of the EU Directive andAbfAblV so that it can be passed on tolandfills.

C-plus®

The pressed out percolator output can beincinerated in a waste incineration plantwithout any other prior treatment. If it isfurther treated (comminuted, dried, com-pacted) and the fraction with the highcalorific value from the mechanical prelimi-nary treatment unit added, substitute fuel

for energetic utilisation can also be produ-ced.

Huber technology in the ISKA® con-cept

After percolation the separated substratemust be further treated. With a solids con-tent below 10% the percolation waterflows into the size 3 or 2 RoSF4 Grit Was-her that is especially modified for this pur-pose. The perforated plate installed in thestandard units is replaced by a special one-ring system for the upflow water. This sys-tem allows to use even 1 mm screenedsubstrate as upflow water so that the sub-strate is not diluted while it is treated. Thisis very important at this is within the wastetreatment stage the stage before anaer-obic treatment. The substrate serves thereas an energy source and any entry of cleanwater would increase the required fermen-

ter volume.

The substrate is fed into the plant by gravi-ty where coarse material is separated, suchas stones or coarse grit. But also glass andmetal material is found in the dischargedfraction. After the first treatment stage thesubstrate is passed into the Ro 2 WedgeSection Screen Ro 2, size 1800, with 1 mmbar spacing. The screen basket is again notcleaned with clear water as usual but witha partial flow of the substrate that has furt-her been treated in a Ro Mesh® Screen,size 1600, with 0.5 mm perforated plate.This requires a higher pressure (approx. 8bar) and more wash water, but what isagain most important is to avoid substratedilution. Also the Ro 2 Screen used is modi-fied for this special purpose. Its feed anddischarge area and the spray bars areadjusted to suit the specific requirements.

The data for layout and specific adaptionof the plant could be won in a pilot planton WWTP Buchen. The throughput perGrit Washer lies at approx. 30 m3/h, plusthe wash water demand of 15 m3/h. TwoGrit Washers serve one Wedge SectionScreen which is to handle a throughput of90 m3 per hour. A percolator with approx.330 m3 volume per unit is allocated toeach of the installed Grit Washers.

The scope of items supplied by HUBER wasnot limited to mechanical equipment butincluded also perhipheral equipment, suchas process control, pumps and pipelines.HUBER is also responsible for the construc-tion management and commissioning ofthe complete plant. The supply limits wereclearly defined, we had to supply every-thing in between the two transfer points.

The screenings separated by the RoSF4and Ro 2 are transported into containersby conveying systems and passed on tocomposting or landfilling. The screeningsseparated by the RoMesh® Screen arereturned into the substrate flow and pas-sed into the fermenter. Optimal conditio-ning and utilisation of the screenings isinsured in this way.

HUBER Berching has received the ordersfor the plants in Buchen and Heilbronn. Fora plant in Australia HUBER supplied themechanical equipment while the imple-mentation and supply of other equipmentwas the responsibility of Australian part-ners.

Other projects are presently in the plan-ning stage, both in Germany and abroad.

Rüdiger DalhoffDivision Manager, Hans Huber AG, Ber-ching, Germany

Ro 2 - 1 mm screen for fibre removal

BiowasteInterior of the perculator

HUBER RoMesh® Screen for wash water conditioning

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HUBER stainless steel products are regar-ded as the best solution for water andwastewater treatment applications –municipal and industrial. So, why notchoose a material that satisfies the hig-hest requirements.

➤ Unrivalled asset life

➤ Maximum corrosion protectionthrough acid treatment within apickling bath

➤ Standardised products provide easeof planning and associated costadvantages.

➤ High level hygienic conditionsprovide safety for the population andthe environment.

It is our goal to offer the highest standardproducts to our customers and hencewhy we feel it necessary to utilise corres-pondingly modern technologies for theirproduction. Production of the products isundertaken by well-trained, highly moti-vated employees working in combinationwith the most modern up to date machin-ery. To ensure continuously high qualityfor our customers, our company pursuesthe philosophy of a high vertical integra-tion in production. As our company philo-sophy is to excel in the field of manufac-

ture of products in stainless steel this haslead us to make the decision to standardi-se on this material. It should be noted thatthe material requires very special equip-ment for its mechanical treatment as wellas the expertise and know how on how toprocess the stainless steel properly. Aspotable water is our most importantresource and should be available to all,Huber considers it particularly importantto offer innovative treatment techniques

within this field.

Drinking water must be free of pathoge-nic germs, potable and pure and theseconditions can only be fulfilled where theentire process of water recovery, treat-ment and distribution complies with themost up to date standards. Since manyplants do not now meet these standardsand are therefore a risk to us and ourenvironment, it is all the more important

to identify and eliminate damage, defi-ciencies and weak points as early in theprocess as possible.

Huber have developed treatment systemsparticularly for the water supply sectorwhich ensure that the resultant drinkingwater quality is hygienically perfect, forexample the air filter plant. Due to thepermanently varying water level in drin-king water reservoirs air is continuouslysucked in or blown out. In the course ofthis process oxygen, nitrogen and otherparticles contained in the air will pass intothe water chamber and the resultantorganisms like germs, spores, pollen orfungi can lead to pollution of the drinkingwater. The air filter plant with integratedfilters for fine particles and suspendedmatter within the cover will remove suchorganisms from the air within the waterchamber.

The Huber product range includes ofcourse additional products manufacturedin stainless steel that will meet the mostup to date standards for all fields as thematerial stainless steel allows for all possi-bilities to be catered for. Combined withits careful and professional pretreatmentof the stainless steel products they willguarantee for an unsurpassed asset lifewith optimal equipment performance.

➤➤➤ Stainless Steel Equipment

HUBER manhole cover

➤➤➤ Case History: Drinking Water Recovery Project Dongola City

HUBER is a supplier of drinking water andwastewater treatment equipment world-wide, offering for the drinking water sec-tor a wide range of products, such asscreens, sedimentation tank equipment,sand filtration, sludge treatment and stain-less steel products.

Under the brand SafeDrink® HUBER usesits long-term experience for recovery ofdrinking water from surface water in deve-loping countries. The concept includes thecomplete mechanical equipment and engi-neering, both from one source.

Two identical drinking water recoveryplants are installed in Dongola City andEldebba, Sudan for which the HUBER engi-neers had to consider specific local condi-tions which are reflected in the selectedprocess technology.

The requirements:

The project demanded the recovery ofdrinking water from the river Nile for70,000 people. The treated water had tomeet the WHO standards. Furthermore, asimple and reliable technology was an

absolute prerequisite for this project due tothe absence of technicians on site.

The solution:

The plant designed for a nominal flow of3500 m3/d consists of the following pro-cess steps:

1. Coarse preliminary treatment in theinlet channel; at the same time coagu-lant agents are added in order to allowcolloids (such as humic or particulatematerial) to settle.

2. The settleable material (flocks andsolids) settle in the sedimentation tank.The produced sludge is removed by a

belt scraper and deposited in a sludgelagoon.

3. Solids that did not settle in the sedi-mentation tank are filtered in a conti-nuous sandfilter. Owing to a fullyautomatic principle these fast filterscan be operated with minimum main-tenance. The wash water is returnedinto the sludge lagoon.

4. The filtrate passes a disinfection stagewith chlorine gas where microorga-nisms and pathogenic germs are elimi-

nated.

5. The treated water is stored in a storagetank.

6. Finally, the potable water is pumpedinto an elevated reservoir (high tower).

The plant is additionally equipped withHUBER stainless steel products, such asmanhole cover, pipelines, doors, railings.

Thomas KimmenauerProduct Manager Sedimenation, HansHuber AG, Berching, Germany

Filled sedimentation tank

Interior of a Sandfilter

Sedimentation tank before start-up

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Membrane bioreactors with VRM®and VUM® technology

Bacterial-free water at low cost

The clarification process on municipal andindustrial plants has been associated withlarge surface area requirements, big struc-tures, odour containment and poordegradation and retention efficiency incase of varying loads. This results in a hea-vy environmental burden in the form ofemissions and impairment of nature, highbuilding costs and plant maintenancecosts. The utilisation of VRM® and VUM®

systems allow for size reduction of thestructures required by a factor of up to70 % and will even increase the perfor-mance of wastewater treatment plants.Associated problems with scum or sludgeoverflow that occur with normal sedimen-tation systems are no longer an issue withfiltration along with existing structuresbeing able to be retrofitted and the asso-ciated capacity increased. Existing prelimi-nary and secondary clarification tanks canbe modified and further used as storageand stand-by tanks.

Furthermore, the effluent quality of suchplants complies with all present applicablestandards and will allow direct reuse ofthe bacteria-free and germ-free effluentas service water (e.g. for irrigation).

Vacuum Upstream Membrane VUM® –The stationary ultrafiltration system

The characteristic feature of the VUM®

technology is the VUM® module installedwithin the bioreactor (aeration tank). TheVUM® module consists of several vertical-ly arranged stationary membrane plates.Each of the membranes have the effect ofvery fine filters with 0.04 µm pore sizethrough which the wastewater is suckedand discharged.

Air is introduced below the VUM® modu-le and streams upwards between the ver-tically installed plates. The resultant gene-rated upflow removes any covering layersthat are respectively produced by the fil-tration process and prevents the produc-tion of further covering layers. Membranebioreactors with VUM® technology allowcost-efficient high-performance waste-water treatment, and are also utilised wit-hin the HUBER MembraneClearBox® sys-tems for small wastewater treatmentplants.

VacuumRotationMembrane VRM® –The rotating ultrafiltration system

The VRM® system is presently the onlyavailable membrane system that does notuse stationary membranes but utilise tra-pezoidal membrane plates installedaround a stationary hollow shaft with acentral cleaning system.

The advantage of this design is its veryefficient and flexible cleaning conceptwith only one individual membrane seg-ment being high-intensity cleaned at atime, which consequently demands only aminimum energy requirement. The redu-ced space requirements achieved by therotation-symmetrical installation of themembrane plates is unequalled by otherplate systems. A further advantage withthe VRM® system is that a 3 mm screen issufficient as a preliminary treatment sta-ge.

The VRM® system combines the advanta-ges of plate systems (preliminary clarifica-tion, no problems with tressing, efficientmembrane cleaning) with the advantagesof hollow fibre systems (with reduced spa-ce requirements) and as such provides asolution that is ideally suited for a vastrange of applications.

➤➤➤ Membrane Technology

HUBER Bioreactor Membranes VRM®

➤➤➤ Latest orders for VRM® Membrane plants!VRM® Membrane Technology on Lan-zarote – Award of contract for themunicipal WWTP La Santa

The supply of clean drinking water is atechnological and logistical challenge inthe Canary Islands. Drinking water is eitherproduced by means of complex andexpensive reverse osmosis plants and deli-vered in pump lines to all regions, or trans-ported onto the Islands from the mainlandby huge tankers. Extensive secondary tre-atment steps (sandfiltration and disinfec-tion) have been necessary to recycle thewastewater so that it can be reused as ser-vice water. These treatment facilities couldnot be established in all the necessary loca-tions.

This is now possible, however, as membra-ne-activated sludge systems are now avai-lable which combine the well-known acti-

vated sludge process with separation ofthe clarified wastewater by means of sub-merged ultrafiltration membranes. Activa-ted sludge plants, which are very commonin the Canaries, can now be upgraded byadding membrane fil