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WATER AND WASTEWATER TREATMENT

IN HOSPITALMohd Razman Salim

Institute of Environmental and Water Resource Management, Faculty of Civil Engineering,

Universiti Teknologi Malaysia,

Presented at

2nd International Seminar on Environmental Health Water and Green Hospital

December 3 – 4, 2011Singgasana Hotel, Surabaya

EPA information:

http://www.epa.gov/esd/chemistry/pharma/

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• Intensive consumers of water –HIGHER wastewater flow (400–1200 L/bed/d)

• Effluents – pathogens (patients with enteric disease), heavy metals, PPCPs, toxic chemicals and radioactive elements.

• Difficult to remove even after treatment – cause pollution (biological imbalance putting negative effects on environment)

Status of Hospital Wastewater

Status of Hospital Wastewater

• Hospitals are too dangerous for the biodiversity as their wastewater can contaminate the food chain.

• Two kinds of wastewater –hazardous and non-hazardous wastewater.

• Mostly non hazardous and can be treated as domestic wastewater.

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• Direct discharge into urban sewerage systems without pretreatment – risk to environment.

• Cause pollution – acute infection and latent characteristics that are harmful.

• Releasing into sewer or river –outbreaks of waterborne infectious diseases, serious threat to people's health.

Status of Hospital Wastewater

Pollutants UnitsConcentrations

in U.C.EConcentrations

in H.E.

Suspended Solid Matters

mg/L 300 225

BOD5 mg/L 220 603

TOC mg/L 160 211

COD mg/L 500 855

Total Phosphorous mg/L 8 8.80

Chlorides mg/L 50 188

Table 1- Comparison of the average concentrations in pollutants of hospital effluents (H.E.) and urban classic effluents (U.C.E) [Emmanuel et al., 2001]

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Excerpt from Newspaper

Expired Drugs – Where Do They Go?

Kuspis and Krenzelok. 1996. “What happens to expired medications? A survey of community medication disposal.” Vet Hum Toxicol. 38(1):48-9

Returned to Pharmacy

TrashedFlushed

Did Not Dispose

Used All Prior to

Expiration

500 patients surveyed:

54% disposed of medications in the trash

35.4% flushed drugs down the toilet or sink

7.2% did not dispose of medications

2% used all medication prior to expiration

1.4% returned medications to the pharmacy

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PPCPs in Wastewater

Sources:

Pharmaceutical industries

Hospitals, medical facilities

Households

medicines

Personal care products

Farm animals

Pharmaceuticals and Personal Care Products

• Rapid degradation in the environment

• Low bioaccumulation in biota

• No “biomagnification” through food chains

• Not acutely toxic

BUT

• Have biological effects

even at low doses

• Are “pseudo-persistent”

contaminants

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Chemicals in the aquatic environment can result in continuous, multigeneration exposure.

Fish Feminization (estrogen exposure?)

e.g.: Boulder Creek, CO: female white suckers outnumber

males by > 5 to 1; 50% of males have female sex tissue

(David Norris, Univ. of Colorado at Boulder)

Antidepressants affect to growth of fish and frog?

e.g.: Low levels of anti-depressants (Prozac, Zoloft, Paxil and Celexa) – development problems in fish, and metamorphosis

delays in frogs (Marsha Black, Univ. of Georgia)

How Contamination Affect Aquatic Ecosystem

How Can Wastewater Be Reduced?

• Segregate – toilets and kitchen wastewater from laboratory and operation theatre wastewater.

• About 90% wastewater reduction –lesser quantity to be treated (smaller volume of pollutants).

• Wastewater treatment technologies such as physical, chemical and biological can be easily applied.

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Other Approaches:

Control what gets in environment:

• Source control (medical disposal practices)

• Design more environmentally friendly drugs

• Minimize over use or misuse of drugs/chemicals

• Point of use treatment of drugs

• Add advance waste and water treatment technologies and source control at point of entry into environment.

Treatment System Options

Study the LCA of the WWT Systems

• Economically viable, eco-friendly and

sustainable

(most of the times is ignored).

Develop guidelines for LCA of WWT

systems.

• Pros and cons of the systems e.g:

Energy usage, Residual pollution,

Environmental degradation, cause of

global warming etc..

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Effluents from Hospital Activities (PPCPs, pathogens etc.

Urban Wastewater

Domestic and Hospital Wastewaters

Hospital Sewerage System

Urban Sewerage System

Wastewater Treatment Plant

Groundwater

Surface Water

Option for Hospital WWTOption 1 Merits DemeritsDirectDischarged

No investment, maintenance cost and process control

Potential risk of contaminations surface water drinking water human body. If epidemic, raw sewage should be disinfected causing environmental damages

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Option for Hospital WWT

Option 2 Merits Demerits

Sewer and co-treatment with municipal WWTP

Direct discharge to the environment is eliminated

Dilution by stormwateroverflow hinders the biological degradation in the WWTP

Option for Hospital WWTOption 3 Merits Demerits

On-SiteWWTP

Reduction of loading by approximately 90%

Requires stringent monitoring and process control by the operators and also the local authorities

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Option for Hospital WWTOption 4 Merits DemeritsOn-Site andsubsequentmunicipalWWTP

Dual treatment processes allowing for optimum safety

Expensive and complex

Municipal STP Connection

• Area without epidemics of enteric disease – sewer discharge is acceptable but need to meet requirements below:

• Efficient STP connection available (with 95% bacterial removal)

• Proper sludge treatment (anaerobic digestion)

• Effective waste management system – eliminating pollutants in discharged sewage

• Separate treatment of excreta of hospital patients

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Aerobic Processes

Type Treatment Process Application

Suspended Growth

Activated-Sludge Process (es)

Aerated Lagoons

Aerobic Digester

Membrane Bioreactor (MBR)

Carbonaceous BOD Removal, Nitrification

Stabilization, Carbonaceous BOD Removal

Fixed Film (Attached Growth)

Trickling Filters

Rotating Biological Contactor (RBC)

Biotowers

Aerobic Filter Bed

Carbonaceous BOD Removal, Nitrification

Hybrid (Combined) Attached and Suspended Growth Processes

Aerobic Filter Bed/ Activated Sludge

Carbonaceous BOD Removal, Nitrification

Activated Sludge Process

Influent

1) Preliminary Treatment

2) Primary sedimentation

3) Biological Process: Conversion to settleable solids

4) Secondary sedimentation

5) Sludge solids to further treatment and disposal 5) Sludge solids to

further treatment and disposal

Rece

ivin

g w

ate

r

Wastewater Treatment

Process steps

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Anoxic processes

Type Treatment Process Application

Suspended Growth

Suspended-Growth Denitrification

Denitrification

Fixed Film (Attached Growth)

Attached-Growth Denitrification

Denitrification

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Anaerobic ProcessesType Treatment Process Application

Suspended Growth

Anaerobic Contact Processes

Anaerobic digestion

Carbonaceous BOD Removal, Stabilization, Solids Destruction, Pathogen Removal

Attached Growth

Anaerobic Filter and Fluidized Bed

Carbonaceous BOD Removal, Waste Stabilization Denitrification

Sludge Blanket

Upflow Anaerobic Sludge Blanket (UASB)

Carbonaceous BOD Removal, (High-Strength Waste)

Hybrid (Combined)

UASB/Attached Growth

Carbonaceous BOD Removal

Aerobic, Anoxic and Anaerobic

Processes

Type Treatment Process Application

Suspended Growth

Single- or Multistage Processes,

Various Fabricated Processes

Carbonaceous BOD Removal, Nitrification, Denitrification and Phosphorus Removal

Hybrid (Combined)

Single- or multistage processes with packing for attached growth

Carbonaceous BOD Removal, Nitrification, Denitrification and Phosphorus Removal

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MBR

SETTLE

IDLE

FILL

influent

DRAIN

effluent

REACT

air

SBR

SBR and MBR

Conventional Vs MBR

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Process Basics

SS

Deni Nitri

SS

SCT

discharge

conventional technologymembrane technology

NDN

effluentUF notSec. Clarif.

Assessment of MBR Technology

• Advantages

– High effluent quality

– No sludge settling problems

– Reduced volume requirements

• Disadvantages

– Membrane fouling

– Increased operational costs

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Constructed Wetlands

• Constructed wetlands (CW), are now widely used as an accepted method of treating wastewater (Gopal, 1999; Kivaisi, 2001; Vymazak, 2007; Rousseau et al, 2008) and are cheaper than traditional wastewater treatment plants.

• CW is appealing to developing nations in the tropics due to the high rate of plant growth (Kivaisi, 2001).

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Sumiani Yusoff, Universiti Malaya