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Hospital Wastewater Management
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Transcript of Hospital Wastewater Management
Jaldhara Technologies
Changing the way the World treats Wastewater and Effluent
HOSPITAL WASTEWATER MANAGEMENT
PRESENTED BY : AMIT CHRISTIAN AREA MANAGER
JALDHARA TECHNOLOGIES PVT LTD
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
Laundry 5%
Misc 9%
HVAC 22%
Sanitary 41%
Med-ical
Process
14%
Food Services 9%
water use in hospital
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)
•
CHEMICALS, PHARMACEUTICALS AND RADIO ACTIVE SUBSTANCES
• 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 faeces• 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
CHEMICALS, PHARMACEUTICALS AND RADIO ACTIVE SUBSTANCES
• 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
CHEMICALS, PHARMACEUTICALS AND RADIO ACTIVE SUBSTANCES
• 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 MANAGEMENT AND ABATEMENT OF EMISSIONS
• Water Use Efficiency :• Main areas to be considered:• Water Leakages :• Sanitary / Amenities • HVAC system • Medical Processes • Cafeteria /dining places/kitchens • Laundry
WATER MANAGEMENT AND ABATEMENT OF EMISSIONS
• 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)
WATER MANAGEMENT AND ABATEMENT OF EMISSIONS
• 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
WATER MANAGEMENT AND ABATEMENT OF EMISSIONS
• 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
WATER MANAGEMENT AND ABATEMENT OF EMISSIONS
• 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)
SEQUENCING BATCH REACTOR
• Suspended growth biological wastewater treatment system • Fill and Draw type reactor where all the treatment steps take place
in the same reactor. • Wastewater is treated in batches rather than continuously • Phases of SBR: • a) Fill • b) Mix • c) React • d) Settle • e) Decant •
SBR PHASES
ADVANTAGES OF SBR
• Smaller foot print compared to conventional plants • Operational stability against shock loading due to equalization • Settling occurs under ideal conditions so better removal of suspended solids • Can be configured to nitrification-de nitrification without adding additional
tanks • Compact and stabilized sludge • No sludge recirculation and thus can be operated at higher SRTs and MLSS
concentrations compared to CAS. • Offers automation facility • Complete operational and process flexibility due incorporation of VFDs and
PLCs for its operation. • Energy efficient operation due to automation and VFDs • Minimal operator intervention required
ADVANTAGES FOR HOSPITAL WWT
• Removal of estrogens is associated with nutrient removal, higher sludge age (SRT) and long hydraulic retention time.
• Nitrifying bacteria have a key role in the biodegradation of pharmaceuticals in WWTP that are operate at higher SRT
• Longer SRTs provides 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 equalization of flow and pollutant loadings.
PROCESS LAYOUT FOR SBR SYTEM
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
GREWA-RSingle Tank Sequential Biological Reactor (SBR)
Modularly expand up to 300% of original capacity
Silent Operation
Plug-n-Play
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Grewa-R
Decentralized Wastewater Treatment Product
Pre-engineered and pre-fabricated (in a container); - Plug and Play : Ready to Install with no civil / fabrication
work at site- Fully Automatic : No dedicated Operator required- No odour : No Emmissions or Gases
Low Footprint > 40 % savings on space compared to others in range
Efficient Treatment Achieves 4 log reduction in organic and bacteriological contaminants
Nutrient Reduction Converts nitrates into nitrogen
Scalable and modular Can easily meet growth requirements
Low Power Consumption 0.75 - 0.85 KW/m3 as against 1.4 - 1.8 KW/m3 in conventional plants
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