Sewage Treatment Processes Sewage Treatment Processes in Haryanain Haryana

Public Health Engineering Department, Haryana

by by

SFC Environmental Technologies SFC Environmental Technologies Pvt.Pvt. Ltd.Ltd.

Contents

• Introduction

• Sewage Characterisation

• Treated Sewage Discharge Standards

• Treatment units in Sewage Treatment• Treatment units in Sewage Treatment

• Basics of Biological Process

• Overview of Sewage Treatment Technologies

• Technology Pros and Cons

• Discussion

Introduction

POPULATION

TOTAL POPULATION AS PER 2011 CENSUS

121,01,93,422

URBANURBAN

RURAL

URBAN POPULATION

60

80

100

120

Urban Population in crores

0

20

40

2011 2021 2031 2041 2051

Year

SEWAGE GENERATION

60000

80000

100000

120000

Estimated sewage generation, MLD

0

20000

40000

60000

2011 2021 2031 2041 2051

Year

STP Capacity as on 2009 - 11553

GA

P

Status of Most Sewage

Treatment Plant in India

Sewage generation & TreatmentSewage generation & Treatment

RefRef :: CPCBCPCB ReportReport onon PerformancePerformance EvaluationEvaluation ofof STPs,STPs, 20132013

Over Exploiting & Indiscriminate Disposal Of

Polluted Water Into Limited Water Resources Is

Further Aggravating The Problem

Sewage discharge into river

State of Yamuna river

Polluted Yamuna

Dal Lake, Srinagar

Powai Lake, Mumbai

Usual scenes of water bodies

Haryana Scenario

2001 2011 2021

Urban Population 2,964,678 4,755,000 10,504,000

Sewage generation, MLD 374 599 1342

Sewage Treated, MLD 164 199

Gap, MLD 200 400

Ref : National Capital Region Planning Board (NCRPB) Report, Ministry of Urban Development, GoI

400 MLD sewage goes untreated into water bodies / drains / rivers

About SETPL....

Proper & efficient treatment technology is required

for providing Sustainable & Economical Solution to

this problem …

Sewage Characteristics

Types of contaminants in SewageTypes of contaminants in Sewage

ORGANIC - Decays INORGANIC

• Sugar

• Milk

Suspended Dissolved SuspendedDissolved• Vegetable matter

• Food residue

• Floating

�Plastic bags

• Settling

�Sand

�Grit

• Salt

Biological treatmentPrimary

treatmentNo

treatment

SEWAGE CHARACTERISTICS

Floating material/ Large

suspended matter

Sand/ Grit

Oil & Grease

Chokes pumps/ pipes

Silting in tanks/ receiving bodies

Floating scum/ sticking to tanks

RAW SEWAGE CONTAINS

Oil & Grease

Suspended Solids

Organic matter (BOD/COD)

Nitrogen

Phosporous

Floating scum/ sticking to tanks & pipes

Silting & septicity

Septicity/ odour/ depletion of DO

Growth of aquatic plants

Growth of aquatic plants

BOD / CODBOD / COD

BODBiological Oxygen Demand

CODChemical Oxygen Demand

• Sugar

• Milk

Suspended Dissolved SuspendedDissolved• Vegetable matter

• Food residue

• Chemicals

• Oil

• Sulphides

BOD is amount of oxygen required by bacteria to degrade organic matter

COD is amount of oxygen required by chemicals to degrade organic matter

TREATMENT STANDARDS

Parameter Raw CPCB

BOD5, mg/L 250-300 < 30

COD, mg/L 400-550 < 250

TSS, mg/L 300-600 < 100

Turbidity, NTU -- --

NH4-N, mg/L 35-45 < 50

State PCB

< 30

< 250

< 100

--

< 50

MoUD

< 10

--

< 10

--

--

US EPA

< 10

--

--

< 2

--NH4-N, mg/L 35-45 < 50

TN, mg/L 40-50 --

TP, mg/L 5-8 < 5

pH 5.5 to 8.5 5.5 to 9.0

FaecalColiforms (MPN/100 ml)

106 --

Residual Chlorine, mg/L

-- < 1

< 50

--

< 5

5.5 to 9.0

--

< 1

--

< 10

< 2

--

< 230

--

--

--

--

6-9

Nil

< 1

Sewage Flows

100

150

200

250

% D

esi

gn

Flo

w

DAILY FLOW VARIATIONS OF RAW SEWAGE

Peak Flow – 2.25 times

Peak Flow

Average Flow

0

50

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Hrs

Lean Flow – 0.5 times

Pumps have to be designed to cater to both peak and average flow.

Typical Flow Diagram of Sewage Treatment PlantTypical Flow Diagram of Sewage Treatment Plant

FINE

SCREENING

GRIT REMOVAL

GRITRAW

SEWAGE INLET CHAMBER

RAW SEWAGE

PUMPING

COARSE

SCREENING

RAW SEWAGE PUMPING STATION PRIMARY TREATMENT

AERATION TANK

SECONDARY

CLARIFIER

TREATED

WATER

DISINFECTION

CHLORINE

SLUDGE

RECIRCULATION

AIR BLOWER

RAW SEWAGE PUMPING STATION PRIMARY TREATMENT

SECONDARY TREATMENT

TERTIARY TREATMENT

SLUDGE

SUMPCENTRIFUGE

SLUDGE

SLUDGE DEWATERING SURPLUS SLUDGE

CENTRATE

TO AT

Basics of Biological Treatment

BASICS OF AEROBIC BIOLOGICAL

PROCESS

ORGANIC MATTER + BACTERIA + OXYGEN ����ORGANIC MATTER + BACTERIA + OXYGEN ����

NEW BACTERIA + CO2 + H2O

BOD/COD

SURPLUS

SLUDGE

MLSS

CO2, H20

NEW

ORGANIC

MATTER

NEW

CELLS

(SLUDGE)

TO MEET THE OBJECTIVE OF ORGANIC MATTER

REMOVAL, BIO-MASS FORMED (WHICH ITSELF IS

ORGANIC IN NATURE) SHOULD ALSO BE SEPARATED.

USUALLY, A SETTLING TANK IS PROVIDED TO

SEPARATE BIO-MASS FORMED DURING ORGANIC

MATTER DEGRADATION.

ORGANIC

MATTER

(FOOD)

O2NUTRIENTS

(N/P)

AERATION BASIN

TEMP. MIXING

BACTERIA

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Biological Treatment TechnologiesBiological Treatment TechnologiesBiological Treatment TechnologiesBiological Treatment Technologies

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