hospital wastewater management

HOSPITAL WASTEWATER MANAGEMENT

PRESENTED BY : AMIT CHRISTIAN

HOSPITALS : HEALTH CARE CENTRES OR POLLUTION SOURCES?

• hospitals are significant consumers of water • generates considerable amount of wastewater which

consists of • pathogens and harmful bacteria, virus • pharmaceuticals and its metabolites • radio active elements • toxic chemicals , heavy metals

IMPACT ON ENVIRONMENT

• pathogens can spread disease, adversely affect the biodiversity, • microbial resistant strains to antibiotics can spread resistance

vertically and horizontally • persistent, non biodegradable, hydrophilic chemicals pass wwtp

and pollute water bodies •

WATER USE IN HOSPITALS

• average water consumption 750 l/p/d/b

• principal areas of usage: • sanitary/amenities (taps,

showers, toilets)• HVAC system • medical purpose • cafeteria/dining

places/kitchen • laundry

POLLUTION SOURCES IN HOSPITAL

Administered drugs to patients

Excretion of patients containing

pharmaceuticals, drugs and their

metabolites

Hospital Sewer Network

Wastewater from care activities, medical

research

Domestic Wastewater + Industrial Wastewater

POLLUTANTS IN HOSPITAL WASTEWATER

hospital wastewater

microbial contaminantsand clinical discharges (e.g. blood, biological samples)

heavy metals

and rare earth

elements

chemicals , pharmaceuticals and radio active

substances

domestic wastewater

and suspended

solids

MICROBIAL CONTAMINANTS

• 3 x 105 per 100 ml bacterial flora • markers of viral pollution adenovirus and enterovirus• HIV agents • prions • multiple antibiotic resistant strain (MARS) • concentration of MARS 2 to 10 times higher than domestic wastewater • resistance to antibiotic can be transferred horizontally as well as vertically • resistance gene transfer would occur at high cell densities and high

selective pressures (e.g. high concentration of antibiotics) • may cause ecological imbalance in the environment • may accumulate in the sewer and in case of epidemic require complete

elimination using chlorination

HEAVY METALS AND RARE EARTH ELEMENTS

• Mercury (Hg) • Persistent, bio accumulative, potent neuro toxin • Found in health care devices (thermometers, blood pressure

cuffs), laboratory chemicals, measurement devices, fixatives, cleaning agents

• Can pass wastewater treatment plant and may end up in river sediments and may bio accumulate in fish and other biological life in aquatic environment

HEAVY METALS AND RARE EARTH ELEMENTS

• Silver(Ag) • Potentially toxic to aquatic environment • Mainly used in radiology labs for X-ray film processing • Concentrated in fix and bleach-fix solutions and wash waters • Used in dental amalgam and in some chemicals used for chloride

analysis • Zinc (Zn) • Originates from Laboratory reagents used for glucose test and

household cleaning products like floor waxes, wax strippers, stainless steel cleaners

• Gadolinium and Indium : Used for MRI and non-biodegradable • Platinum : Used in Oncological treatment with cis-platinum and

carbo platinum or other cytostatic agents

CHEMICALS, PHARMACEUTICALS AND RADIO ACTIVE SUBSTANCES

• Hospitals are major contributors of chemicals and pharmaceuticals in wastewater but not exclusive.

• Major Categories : • Cytostatic agents • Anesthetics • Antibiotics • Disinfectants • Iodinated Contrasting Media (ICM)• Analgesic and anti-inflammatories • Absorbable Organic substances (AOX)

•


• Cytostatic agents:• Mainly used for cancer therapy• known for their carcinogenic, mutagenic and toxic effects• Excreted by the patients undergoing chemotherapy• Highly polar and non volatile . Thus bound to stay in water phase • Varying biodegradability • Antibiotics: • Of total consumption 26% are used in hospitals • Antibiotics along with their metabolites end up in Wastewater due to

human excretion in urine and faece• no serious threat to human health for 2L of water consumption per day

and 70 years life span at present concentrations • Cause antibiotic resistant to bacteria which may imbalance ecological life

in aquatic environment


• Iodinated Contrasted Media (ICM) :• Used for X-ray imaging of soft tissues • For one treatment about 100g is used • About 30g of it represents Absorbable Organic Iodinated Media (AOI) • Biologically inert and stable towards metabolism thus easily pass from

body and end up in wastewater • Hydrophilic in nature thus persist in water phase for longer time • Poor sorption and bio accumulation properties • Fate and impact on environment unknown• Risk of ending up in groundwater


• Adsorbable Organic Halogen Compounds (AOX): • Derived as byproducts of disinfectants application • ICM are significant source of AOX and radiology department

contributes maximum to AOX concentrations • Persistent in environment • Accumulate in food chain • Poor bio degradability

QUANTITATIVE CHARACTERISTICS OF HOSPITAL WASTEWATER

• Macro Pollutants :

Parameter HWW Urban Wastewater

pH 7.7-8.1 75.-8.5

BOD₅ (mg/l) 300-400 200-300

COD (mg/l) 800-1000 600-800

SS (mg/l) 400-600 150-300

TKN (mg/l) 5-80 20-70

Total – P (mg/l) 0.2-13 4-10

Fat, oil and Grease(mg/l) 5-60 50-100

Total Surfactant 3-7.2 4-8

E.Coli MPN/100 ml 10ᶟ- 10⁶ 10⁶-10⁷

Faecal coliform 10ᶟ-10⁷ 10⁶-10⁸

Total Coliform 10⁵-10⁸ 10⁷-10⁹

QUANTITATIVE CHARACTERISTICS OF HOSPITAL WASTEWATER

• Micro- Pollutants:

Therapeutic Class HWW (Avg. Value) UWW (Avg. Value)

Analgesic (µg/l) 100 11.9

Antibiotic 11 1.17

Cytostatic 24 2.97

Β- blockers 5.9 3.21

Hormones 0.16 0.10

ICM 1008 6.99

AOX 1371 150

Gadolinium 32 0.7

Platinum 13 0.155

Mercury 1.65 0.54

DISCHARGE STANDARDS

• no specific standards for hospital wastewater • Indian Standards :

Parameter Limit

pH 6.5-9.0

TSS 100 mg/l

BOD 30 mg/l

O & G 10 mg/l

COD 250 mg/l

Bio-assay test 90% survival of fish after 96 hrs in 100% effluent

DISCHARGE STANDARDS • WHO (World Bank) guidelines :

Parameter Limit

pH 6-9

BOD₅ 50 mg/l

COD 250 mg/l

TSS 20 mg/l

Oil and grease 10 mg/l

Cadmium 0.1 mg/l

Chromium 0.5 mg/l

Lead 0.1 mg/l

Mercury 0.01 mg/l

Chlorine (Total residue) 0.2 mg/l

Phenols 0.5 mg/l

Fecal Coliforms 400 MPN/ 100 ml

WATER MANAGEMENT AND ABATEMENT OF EMISSIONS

• Hospital wastewater a complex matrix

• Water Use efficiency • Source Reduction/

Segregation • Recycle/reuse • Treatment and disposal


• Water Use Efficiency :• Main areas to be considered:• Water Leakages :• Sanitary / Amenities • HVAC system • Medical Processes • Cafeteria /dining places/kitchens • Laundry


• Do ward wise water audit and identify major users • Continuous staff training, education, campaigns • Water Management committee • Assess water and energy demands for equipment when they are purchased • Sanitary/Amenities:• Reduce wastage through regular maintenance of taps, shower heads and

replacement with efficient ones (e.g. aerated taps) • Use toilets with efficient flush models • HVAC systems: • Reduce waste in cooling towers, use close loop system rather than open loop • Efficient pumps and chillers • Recycling of wastewater for cooling , toilets and irrigation (30% of usage)


• Medical equipment and Processes: • Efficient management of steam sterilizers • Cold water is used to bring down the temperature of hot water . Instead

use heat exchanger to reduce the temperature of hot water • X-ray machines: Constant flow of water is used to cool the machine and

develop films • Shift to digital processing • Use of stop valve to control the flow of machine when not in use


• Source Reduction and Segregation:• Mercury :• Conduct a mercury assessment survey• Collect mercury containing wastes for hazardous waste disposal • Substitute mercury containing chemicals and reagents • Replace mercury containing measuring instrument with digital ones • Waste containing mercury from dental surgery collected separately • Silver: • Install silver recovery unit • Employ digital processing • Substitute low silver film


• Iodinated Contrast Media (ICM):• Separate collection of urine for the patients undergoing X-ray

imaging • Treat it as hazardous waste in incinerator • Avoid residual quantities while preparation and separate collection

for the residuals

DISPOSAL AND TREATMENT OF HOSPITAL WASTEWATER

Option Advantages Disadvantages Direct Disposal No investment,

maintenance cost.

A Major danger of pollution spread in the environment due to harmful bacteria and virus. Serious threat to aquatic life and contamination of aquatic bodies. In case of epidemic complete chlorination of wastewater required which can further harm environment

Co- treatment in municipal WWTP

No direct discharge to environment

Not viable option as based on dilution rather than pollutant segregation. Toxic substances may severely harm processes

Onsite WWTP 90% reduction in pollutant load

Additional cost of investment and maintenance

Onsite + Municipal Double treatment Costly

TREATMENT TECHNOLOGIES

• Much of the hospital wastewater has similar characteristics as domestic wastewater

• Biological Wastewater Treatment Technologies most sustainable and cost effective option.

• Chemical treatments add up harmful byproducts. • Available Technologies :• Conventional Activated Sludge (CAS) • Sequencing Batch Reactor (SBR)• Membrane Bio reactor(MBR) • Moving Bed bio reactor (MBBR) • Constructed Wet lands • Submerged Aerated Fix Film Reactor(SAFF)

BIOLOGICAL WASTEWATER TREATMENT• Principle: • Biochemical oxidation processes • Under controlled conditions Micro-organism utilize organic matter for the

production of energy for cellular respiration and new biomass production • Types of processes on the basis of kinetics : a) aerobic , b) anaerobic • Aerobic Process: • Presence of oxygen • Aerobic micro organisms • Production of new cells and CO₂ , H₂O • Anaerobic Process:• Absence of oxygen • Certain slow growing micro organisms utilize oxygen bound to inorganic

compounds like nitrate and sulfate

•

BIOLOGICAL WASTEWATER TREATMENT

• Two Types of Processes : a) Suspended Growth , 2) Attached Growth • Suspended growth: • Micro organisms responsible for degradation are maintained in liquid suspension • Influent is allowed to come in contact with the suspension • Utilization of organic matter by micro-organisms for cellular respiration and new

cell growth • Conventional Activated Sludge System (CAS), Sequencing batch reactor (SBR),

Oxidation ditch ponds, Contact Stabilization • Attached Growth:• Micro- organisms responsible for degradation are allowed to grow on fixed , inert

plastic media • Influent is allowed to flow past the fixed film • Micro organisms utilize it as food source and for cell growth • Percolating filter, Moving Bed Bio Reactor (MBBR), Fluidized Media Reactor

(FMR) , Rotating Biological Contactor (RBC)

MBBR/IFAS PROCESS • A combination of suspended growth

as well as fixed film based technology • Utilize specialized carriers in

suspension for biomass retention • MBBR : • Once through process • No sludge is recycled back • Separate reactors for BOD,COD ,

nitrification removal • IFAS : • Sludge is recycled back to aeration

basin • Additional biomass in suspended

phase as well • A truly hybrid system

ADVANTAGES OF MBBR/IFAS PROCESS

• A combination of suspended growth as well as fixed film based technology • Utilize specialized carriers in suspension for biomass retention • Offers advantages of both technologies which includes : • Growth of specialized biomass for the desired treatment goals• Continuous flow and thus eliminating need of backwashing unlike other fixed

film processes • Same flexibility and flow sheet simplicity as suspended growth based systems • Additional biomass in the reactor without increasing solids loading to clarifiers • Flexibility in separation technologies thus achieving better SS removal • Reduced sludge production (0.3 g VSS/gCOD compared to 0.4-0.6 for CAS) • High rate treatment and thus offers space saving due to smaller foot print • Improved process stability and faster recovery from shock loads • Better settling properties of sludge reducing handling costs •

Biofilm Tech GmbH• About Us: • A specialized company providing innovative solutions for the

treatment of wastewater and polluted air • A team with more than 40 years of experience in research and

development of fixed film based technologies for industrial and difficult to treat wastewater and polluted air

• What We do : • Problem analysis for the treatment of high strength industrial and

municipal wastewater treatment • Define treatment goals and conceptual process design • Development of optimal process and parameters • Manufacturing of high performance tailor made bio carriers for the

application • Process Start up and trouble shooting

LEVAPOR CARRIERS • First synthesized Bio

Carrier • Porous, Flexible, Durable

PU foam impregnated with surface active pigments with high surface area

• Due to variability of foam and pigment type and their ratios, tailor made carriers can be produced with varying properties

Unique Properties

PROPERTIES • High Adsorbing Surface

• High Porosity

• Fast wetting and water binding

• High surface Area • Higher fluidization ability

ATTRIBUTES• Adsorption of inhibitory

substances and fast colonization • Protection of biomass against

shear, anoxic zone formation • Homogenization of media and

maintenance of bio activity • Lower Degree of Filling (12-

15%)• Less Power consumption

Advantages of Levapor based MBBR/IFAS

• Reversible adsorption of inhibitory substances and slowly bio degradable pollutants

• Short process start up and higher performance compared to suspended mass based systems (100 to 300%)

• Colonization of carrier by more active bio mass and simultaneous nitrification-de nitrification

• Higher process stability and lower sludge yield • Lower degree of filling (12 to 15% compared to 40-65%

for plastic based media) • Remarkable lower power consumption compared to

conventional MBBRs

ADVANTAGES FOR HOSPITAL WWT

• Adsorption of disinfection by products (AOX) on activated carbon which stabilizes the process and their subsequent biodegradation

• Removal of pharmaceutical micro pollutants possible due to adsorption and higher SRTs compared to conventional systems

• Development of specialized biomass providing more diverse community of micro- organisms with broader physiological properties, enhanced metabolic and co-metabolic processes affecting removal of recalcitrant compounds providing more complete mineralization

• Better process stability towards shock loadings due to adsorption and internal porosity

TREATED WATER QUALITY

Parameter Treated Water at the outlet of Reactor Tank

Treated water at the outlet of Post treatment

pH 6.5-8 6.5-8

SS < 30 mg/l < 2 mg/l

BOD <20 mg/l < 5 mg/l

COD <100 mg/l < 50 mg/l

TKN < 10 mg/l < 3 mg/l

Total P < 2 mg/l < 0.5 mg/l

Oil and Grease < 10 ppm Nil

APPLICATION OF TREATED WATER

• Cooling Water • Gardening • Irrigation • Toilet Flushing

THANK YOU

hospital wastewater management

Healthcare