SEWAGESEWAGE TREATMENT TREATMENT

BASIC CONSIDERATIONSBASIC CONSIDERATIONSIN DESIGN & OPERATIONIN DESIGN & OPERATION

Dr. Ananth S. KodavasalDr. Ananth S. KodavasalEcotech Engineering Consultancy Pvt. Ltd.Ecotech Engineering Consultancy Pvt. Ltd.

11As presented in “The Water Workshop” organized by As presented in “The Water Workshop” organized by ApartmentADDA.com ApartmentADDA.com

FEBRUARY 2012FEBRUARY 2012

CONTENTS

1. WASTEWATER POLLUTANTS/ IMPACT

2. PHYSICAL, CHEMICAL, BIOLOGICAL UNIT OPERATIONS

3. BIOLOGICAL TREATMENT VARIANTS

4. PROS AND CONS

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1.WASTEWATER POLLUTANTS/ IMPACT

WHY WASTEWATER TREATMENT ?

- COMPLIANCE WITH LAW

- WASTE MINIMISATION / RESOURCE RECOVERY

- IMPROVED SURFACE/ GROUND WATER QUALITY

- IMPROVED PUBLIC HEALTH

- IMPROVED FLORA & FAUNA

- LONG TERM SUSTAINABILITY

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POLLUTING INDUSTRIES

DOMESTIC ( BPO/ SOFTWARE/ RESIDENTIAL)

METALS / MINERALS PROCESSING

FOOD PROCESSING INCL. FERMENTATION

OIL & PETROCHEMCALS

CHEMICALS, BULK DRUGS

TEXTILES

PULP & PAPER

ETC., ETC. 4

TYPES & EFFFECTS OF POLLUTION

O&G : TREATMENT EFICIENCY

AESTHETICS

HEAVY METALS : TOXICITY

ORGANIC CMPDS. : TOXICITY

BOD/ COD : OXYGEN DEPLETION

N, P : EUTROPHICATION

PATHOGENS : DISEASES

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THREE CARDINAL RULESTHREE CARDINAL RULESFOR A GOOD WWT PLANTFOR A GOOD WWT PLANT

PROPER DESIGN OF TRTMNT PLANTPROPER DESIGN OF TRTMNT PLANT

PROPER ENGG. OF TRTMNT PLANTPROPER ENGG. OF TRTMNT PLANT

PROPER O&M OF TREATMENT PLANTPROPER O&M OF TREATMENT PLANT

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WASTEWATER CHARACTERISATION

• PHYSICAL PROPERTIES

• CHEMICAL PROPERTIES

• BIOLOGICAL PROPERTIES

1. TO ASSESS COMPLIANCE

2. TO DETERMINE TREATMENT REQUIRED

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SOME PHYSICAL CHARACTERISTICSpH

COLOUR

ODOUR

TURBIDITY

SOLIDS – SUSPENDED/ DISSOLVED

TEMPERATURE

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SOME CHEMICAL CHARACTERISTICSORGANIC CONTENT

SPECIFIC ORGANIC COMPOUNDS

TOXIC COMPOUNDS

HEAVY METALS

REACTIVITY

( CONVENTIONAL MEASURES SUCH AS COD

TOD, TOC )

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BIOLOGICAL CHARACTERISTICS

RELATIVE BIODEGRADEABILITY

TYPE OF BIOLOGICAL TREATMENT

(COMMON MEASURE IS BOD )

REFRACTORY ORGANICS

INHIBITORY COMPOUNDS

TOXIC COMPOUNDS 10

WASTEWATER QUANTITY, DISCHARGE PATTERN

• DAILY AVERAGE

• HOURLY AVG./ PEAK HOUR

•CONTINUOUS / INTERMITTENT

•BATCH DUMP

•NO. OF SHIFTS

• WEEKEND FLOW

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MICROBES

FOOD

O2

NUTR.

+ ENERGY

+ GASES

+ PRODUCTS

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BASIC BIOLOGICAL REACTION

MORE

MICROBES

22. . PHYSICAL, CHEMICAL & BIOLOGICAL PHYSICAL, CHEMICAL & BIOLOGICAL UNIT OPERATIONS IN WWT UNIT OPERATIONS IN WWT

PHYSICAL TREATMENT METHODSPHYSICAL TREATMENT METHODS

SCREENING, GRIT REMOVALSCREENING, GRIT REMOVAL O&G REMOVALO&G REMOVAL EQUALISATION/ HOMOGENISATIONEQUALISATION/ HOMOGENISATION SEDIMENTATIONSEDIMENTATION FILTRATIONFILTRATION ADSORPTIONADSORPTION OTHER TERTIARY TREATMENT METHODSOTHER TERTIARY TREATMENT METHODS

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CHEMICAL TREATMENT METHODS

•NEUTRALISATION

•OXIDATION/ REDUCTION

•COAGULATION / COLOUR REMOVAL

•PRECIPITATION

•DEEMULSIFICATION

•CHLORINATION – OZONATION

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BIOLOGICAL TREATMENT METHODS

• ANAEROBIC BIOLOGICAL METHODS

• AEROBIC BIOLOGICAL METHODS

• FACULTATIVE BIOLOGICAL METHODS

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3. 3. AEROBIC BIOLOGICAL TREATMENT AEROBIC BIOLOGICAL TREATMENT VARIANTSVARIANTS

CONVENTIONAL ACTIVATED SLUDGE ( EAAS)CONVENTIONAL ACTIVATED SLUDGE ( EAAS)

MOVING BED/ FIXED BED BIOLOGICAL REACTORMOVING BED/ FIXED BED BIOLOGICAL REACTOR ( MBBR / FBR / SAFF / %#@+)( MBBR / FBR / SAFF / %#@+)

SEQUENCING BATCH REACTOR (SBR)SEQUENCING BATCH REACTOR (SBR)

MEMBRANE BIOREACTOR (MBR)MEMBRANE BIOREACTOR (MBR)

OTHERSOTHERS

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EAAS – EAAS – SUSPENDED M.OSUSPENDED M.O

EQ. TNK

AER.TNK

INT SUMPPSF

ACF

SET. TNK

SLUDGE HNDLNG

FNL TNK

CL 2 AIR BLOWERS

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MBBR – MBBR – ATTACHED M.OATTACHED M.O

SAME AS EAAS - EXCEPT SAME AS EAAS - EXCEPT

1. NEED TO HAVE PRIMARY 1. NEED TO HAVE PRIMARY SEDIMENTATIONSEDIMENTATION

2. PLASTIC MEDIA INTRODUCED IN 2. PLASTIC MEDIA INTRODUCED IN AERATION TANK TO INCREASE AERATION TANK TO INCREASE SURFACE AREA FOR MICROBES TO SURFACE AREA FOR MICROBES TO ATTACHATTACH

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VIEW OF MBBR TANKVIEW OF MBBR TANK

PLASTIC MEDIA FLUIDISED IN TANKPLASTIC MEDIA FLUIDISED IN TANK

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SBR – BATCH REACTORSBR – BATCH REACTOR

20

MBR – MEMBRANE MBR – MEMBRANE BIOREACTOR - IMMERSEDBIOREACTOR - IMMERSED

21

MBR – MEMBRANE MBR – MEMBRANE BIOREACTOR - SIDESTREAMBIOREACTOR - SIDESTREAM

2222

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EAASEAASPROS CONS PROS CONS

TIME TESTEDTIME TESTED AREA REQMNTAREA REQMNT

PROVEN – PROVEN – CONSISTENT QLTYCONSISTENT QLTY

POWER CONSMPTNPOWER CONSMPTN

OP. FLEXIBILITYOP. FLEXIBILITY

GOOD SLUDGE GOOD SLUDGE QUALITYQUALITY

EASY MONITORING EASY MONITORING CONTROLCONTROL

LOW SKILL LVLSLOW SKILL LVLS23

SBRSBRPROS CONSPROS CONS

LESS NO. OF UNITSLESS NO. OF UNITS SOPHISTICATED SOPHISTICATED DECANTER REQD.DECANTER REQD.

LESS POWERLESS POWER NUMBER OF BATCHES NUMBER OF BATCHES – LIMITS– LIMITS

NOT SUITED FOR NOT SUITED FOR HIGH PEAK FLOWSHIGH PEAK FLOWS

MORE LOAD ON MORE LOAD ON FILTERSFILTERS

SLUDGE HANDLING SLUDGE HANDLING ISSUESISSUES

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MBBRMBBRPROS CONSPROS CONS

NONE KNOWNNONE KNOWN NEED PRIMARY NEED PRIMARY SETTLINGSETTLING

POOR ENERGY POOR ENERGY EFFICIENCYEFFICIENCY

SLUDGE HANDLING SLUDGE HANDLING ISSUESISSUES

MONITORING, MONITORING, CONTROL DIFFICULTCONTROL DIFFICULT

DIFFUSERS MTCE. DIFFUSERS MTCE. ISSUESISSUES

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MBRMBRPROS CONSPROS CONS

GOOD QUALITY GOOD QUALITY WATERWATER

HIGH INITIAL & HIGH INITIAL & REPLCMNT COSTSREPLCMNT COSTS

HIGH POWERHIGH POWER

HIGH CHEMICALSHIGH CHEMICALS

UNRESOLVED OP. UNRESOLVED OP. ISSUESISSUES

HIGH SKILLSHIGH SKILLS

HIGH LVL PRETRTMNTHIGH LVL PRETRTMNT26

SUMMARY, CONCLUSIONSUMMARY, CONCLUSION

- EAAS STILL REMAINS THE EAAS STILL REMAINS THE WORKHORSE OF THE INDUSTRYWORKHORSE OF THE INDUSTRY

- TIME TESTED, PROVEN, CONSISTENT TIME TESTED, PROVEN, CONSISTENT RESULTSRESULTS

- FLEXIBLEFLEXIBLE- LOW LIFETIME COSTSLOW LIFETIME COSTS- EASY MTCE, MONITORING, CONTROLEASY MTCE, MONITORING, CONTROL

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DESIGN BASIS FOR BIOLOGICAL TREAMTMENT

AEROBIC TREATMENT

• pH

• TEMPERATURE

• FOOD

• OXYGEN REQUIREMENTS

• TYPE OF WASTE

• FOOD TO MICROORGANISMS ( F/M)

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• SLUDGE AGE

• MLSS LEVEL

• SLUDGE RETURN RATE

• EXCESS SLUDGE PRODUCTION

• DISSOLVED OXYGEN LEVEL

• MIXING IN AERATION TANK

• SETTLING CHARACTERISTICS OF SLUDGE

•TYPE OF MICROORGANISMS

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SECONDAY CLARIFIER DESIGN

• OVERFLOW RATE

• WEIR RATE

• SLUDGE LOADING RATE

• RETENTION TIME

• MECHANICAL RAKE ARM DESIGN

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SLUDGE HANDLING

• PRIMARY, SECONDARY, TERTIARY SLUDGE

• SLUDGE THICKENING

• SLUDGE CONDITIONING

• SLUDGE DEWATERING

DRYING BEDS,

FILTER PRESS, VAC. FILTER

CENTRIFUGE

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TYPICAL INTEGRATION OF TREATMENT UNITS/ STAGES

• PRELIMINARY TREATMENT

• PRIMARY TREATMENT

• SECONDARY TREATMENT

• TERTIARY TREATMENT

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TYPICAL FLOWSHEET OF TREATMENT

SCREEN GRIT/GRSE EQLSTN SETTLING

AN. REACTORAER. TANKSEC. CLRFR

SAND FILTER AC FILTER SLDGE HNDLNG

SEC. TRTMENT

PR. TRTMENT

TERT. TRTMENT

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ADVANCED WWT TREATMENT ( TERTIARY)

• ACTIVATED CARBON ADSORPTION

• NUTRIENT REMOVAL

• AIR STRIPPING

• CHEMICAL COAGULATION/ SETTLING

• CHEMICAL OXIDATION

• MICRON/ ULTRA FILTRATION

• REVERSE OSMOSIS

• UV RADIATION 34

4. OPERATION & MAINTENANCE PROBLEMS

SCREEN : CLOGGING, ODOUR

GRIT CHAMBER : POOR SEPARATION

PRMRY CLRFIER : FLOATING SLUDGE

LOW SOLIDS IN SLUDGE

AERATION TANK : FOAMING, MIXING,

OVER/ UNDER AERATION

SEC. CLRFIER : BULKING SLUDGE

PIN POINT FLOCS 35

SEC. CLRFIER : NO CLARITY IN WATER

POOR SLUDGE SETTLING

PR. SAND FILTER : INSUFFICIENT CLARITY

BACK PRESSURE HIGH

ACT. CARB. FLTR : NO IMPROVEMENT

ETP OPERATOR : UNTRAINED

UN MOTIVATED

UN SUPERVISED

INDISCPLINED

DESIGN FAULTS : REDESIGN/ REENGINEER

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IMP. ACTS AND RULES ON ENV. PROTECTION

• Water (Prevention & control of pollution) Act, 1974

• Air (Prevention & control of pollution) Act, 1981

• Environment (Protection) Act, 1980

• Factories Act, 1948

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• The Water (Prevention & control of pollution) Cess Act, 1977

• The Indian Boilers Act, 1923

• The Water (Prevention & control of pollution) Rules, 1975

• The Air (Prevention & control of pollution) Rules, 1982

• The Environment (Protection) Rules, 1980

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• Scheme on Labelling of Environment friendly products (Eco-mark)- criteria for packaging materials (G.S.R. 621 (E) dt. 6 Sept. 1995

• Hazardous Waste (Management & Handling) Rules, 1989

• Manufacture, Storage and import of Hazardous Chemicals Rules, 1989

• Chemical Accidents (Emergency planning, preparedness & Response) Rules, 1996

• The Public Liability Insurance Act, 1991 39

• The Hazardous Waste (Management & Handling) Amendment Rules, 2000, 2003

• The Batteries (Management & Handling) Rules, 2001

• The Environment (Protection) Amendment Rules, 2000

• The Noise Pollution (Regulation & control) Act, 2000

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ECOTECH COMPANY PROFILE

•ESTABLISHED IN 1986

•DESIGN, ENGINEERING OF TREATMENT PLANTS

•COMMISSIONING, UPGRADATION, O&M

•REIA, WATER, WASTEWATER, ETP AUDIT

•OVER 600 PROJECTS HANDLED ALL OVER INDIA

•OVER 80 O&M AMC CONTRACTS AT PRESENT

•QUALIFIED, EXPERIENCED AND DEDICATED STAFF

•3 ENV. SCIENTISTS/ ENGINEERS

•8 FIELD, QUALITY & TRAINING OFFICERS

•8 MECHANICS/ ELECTRICIAN

•OVER 80 EXPERIENCED SUPERVISORS

THANK YOU

ECOTECH ENGG. CONSULTANCY PVT LTD