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Technical aspects of technology transfer from Germany to India

concerning waste water treatment plant

Presented by: Alex Tagbo

Shashank Giridhar Sunil Kumar

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Type of wastewater treatment plantThis plant is a decentralized one since

chennai is a very large city.The plant is designed to serve 55000 people.It is a pilot project and its main purpose is

research and development.The water from the plant is sent to the river

or could later be processed to drinking water.

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Principles of biological elimination of pollution

Elimination of organic matter org. C + O2 →Biomass + CO2 +H2O

Nitrification NH4 →NO3 / NO2

Denitrification NO3 / NO2→N2

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Technical realization of the principle

In the first process we eliminate carbon.The second step is the nitrificaton process

where ammonia is converted into nitrogen di- oxide and nitrogen tri-oxide.

The next stage is the denitrification process, where nitrogen di-oxide and tri-oxide are converted into nitrogen gas.

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ATV 131ATV means Abwassertechnische Vereinigung that is wastewater technical association in

English.

Using ATV 131, we can meet the achievable minimum effluent requirement which correspond with the requirements of the of the German waste water ordinance.

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Main objective of ATV 131Technical regulations for the selection of the

most practical procedure for carbon, nitrogen and phosphorous removal and for the dimensioning of the essential components and facilities of the plant.

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Allgemeine AbwasserVerwaltungvorschrift uber die

Mindestanforderungen an das Einleiten von Abwasser in Gewasser .

English translation of the above sentence is “Administrative rules concerning the discharge of waste water into water bodies based on minimum requirements”.

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Procedure for planning and dimensioning using ATVDesign criteria : flow rates and loads for different design

cases,effluent requirements

Other design constraints : area,subsoil,hyraulics etc

Selection of the process,required sludge age,assumption of sludge volume index

Design of the secondary settling tank

Design of the biological reactor

Optimum matching of reactor and settling tank

Optimised solution

End of dimensioning

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Reactor constructions for biological nitrogen removal

Post denitrification process Post aeration Organic carbon → → → →

•The process is employed if the waste water has a low C/N ratio.

•The denitrification tank is downstream from the nitrification tank.

Nitrification D

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Pre-anoxic zone denitrification process

→ → → → Internal recirculation

Secondary

settling Return sludge

tank

•Waste water, return sludge and internal recirculation flow are mixed in the denitrification tank.

Denl.Nitrificatio

n

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Phosphorous Elimination

→ → → →→

Anaerobic mixing tank secondary

settling

tank

Adenosine tri phosphate is broken down into adenosine di phosphate and adenosine mono phosphate.

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Specification tableCSB BSB Inorganic

NitrogenP

Raw water dirt

120 60 11 2.5

Concentration mg/l

400-1000 200-500 40-90 10-20

Required quality

<1000 EW 150 40

1000-5000 EW

110 25

5000-20000 90 20 18

20000-100000

90 20 18 2

>100000 75 15 18 1

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Differences between German and Indian standards

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Summary of calculation for A-131 Documentation of the project. Size class and treatment objectives.Specification of the process concerning the

technical realization.Overview and selection of loads.Dimensioning loads, flow rates,

concentrations, peak factors.

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Loading with the lowest temperature.Loading with the highest temperature.Selecting the type of sludge thickening,

return sludge and inflow secondary settling.Dimensioning of the tank.Details of the rotating blade scraper.Specifications related to nitrogen balance.

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Details regarding phosphorous removal.Dimensions of activated sludge tank.Operation specifications with lowest

temperature.Operation specifications with highest

temperature.Oxygen demand specifications.Alkalinity

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Important technical aspects of technology transfer

Influence of the volume of basin depending on the size of inhabitants.

Dependence of volume of basin on produced waste water per inhabitant per day.

Influence of temperature on the volume of the basin

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Influence of the volume of basin depending on the size of inhabitants

Graph of Number of inhabitants Vs Loading

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Graph of Total volume of the basin Vs Number of inhabitants

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Dependance of volume of basin on produced waste water per inhabitant per day

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Influence of temperature on the volume of the basin

Membrane technology

Membrane technology utilizes a semipermeable membrane for the

separation of suspended and dissolved solids from water. There are two basic types

of membrane separation processes; pressure-driven and electrically-driven.

Pressure-driven processes use hydraulic pressure to force water molecules through the membranes. In the electrically-driven membrane process, electric current is used to move ions across the membrane.

Types of pressure driven membranes

Settlement tanks are not required if membrane technology is used, hence the space required will be less.

Settlement Tanks are a limiting factor for the concentration for biomass in the aeration basin.

The used basin volume for 100000 inhabitants without membrane technology is 36653m3 , whereas with membrane technology it is 18462m3 .

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