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“Lake Protection (Bandhwa Talab) through Decentralised
Wastewater Management”
“Lakes Bio-Remediation Project”
WIPRO Corporate Office, Sarjapura, Bangalore
25th November 2014
Presented by Andrews Jacob
Introduction to the Project
Current Sanitation Situation
Wastewater Management
Concept (DEWATS)
2
PRESENTATION OUTLINE
INTRODUCTION TO PROJECT AREA3
BANDHWA TALAB
Surface Area- 23,602 sq.mt.
Maximum depth- 230 cm
Status-
• North Eastern edge- Untreated wastewater flow
from adjacent Residential area, and surface
drains convey solid waste
• South East-an outflow drain present. Mainly
used for laundry washing, fishing and religious
activities
• Western bank- Temple complex
• South Eastern and South Western bank used
for laundry washing
• Fishing activities all around the lake.
View on the eastern bank of Bandhwa Talab with
lake water overrun at the north-eastern edge and
rampant water vegetation.
Bathing activities at the south-eastern bank. This
part is free of water vegetation.
DEMOGRAPHY & LANDUSE4
The catchment covers:
POPULATION- 916 persons
HOUSES-124
HOUSEHOLDS-171
AVERAGE HH SIZE-5
LANDUSE:
Residential-89%
Mixed-5%
Commercial- 5%
Institutional-2%
5
WASTEWATER MANAGEMENT - MAP
6
COVERAGE OF SEPTIC TANKS EFFLUENT DISPOSAL FROM SEPTIC TANK
WASTEWATER MANAGEMENT
CURRENT SANITATION SITUATION…
CONVEYANCE SYSTEM
Wastewater from households discharged into
drains constructed for carrying storm water.
Total drain length in the catchment area
approximately 1000 meters with depth varying
from 0.3 to 0.8 meter
Type of existing drains are as follows:
Open Drains- 45%
Partially covered-26%
Fully Covered-22%
The overall condition of storm water drains is
poor with more than 50% of total drain length
clogged with solid waste.
7
CURRENT SANITATION SITUATION…
8
DETAILS OF WATER BALANCE IN BANDHWA TALAB
CURRENT SANITATION SITUATION…
9
QUALITY OF WASTEWATER
INFLOW AT BANDHUA TALAB:
Chemical Oxygen Demand
(COD) -310 to 1183 mg/l.
Biological Oxygen Demand
(BOD) -103 to 392 mg/l.
AT BYPASS:
COD -734 to 1550 mg/l and
BOD -234 to 512 mg/l
BANDHWA
TALAB
BYEPASS
CURRENT SANITATION SITUATION…
Wastewater quality analysis conducted
during period May-July 2012
CONCEPT FOR WASTEWATER MANAGEMENT10
Finalised Concept
The above mentioned concept was approved by RMC Officials on 20/12/2012
and the decentralised technology for wastewater treatment selected was
DEWATSTM for its low O&M cost in comparison to the other technologies.
11
POTENTIAL OF DIFFERENT TREATMENT OPTIONS
Criteria SBR DEWATS FAB
Performance in Terms of Quality of Treated Sewage
Potential of Meeting the TSS, BOD, and COD
Discharge Standards
Potential of Total / Faecal Coliform Removal
Potential of DO in Effluent
Potential for Nitrogen Removal (Nitrification-
Denitrification)
Potential for Phosphorous Removal
Performance Reliability
Potential of Low Energy Requirement
Potential of Low Land Requirement
Potential of Low Capital Cost
Potential of Low Recurring Cost
Potential of Low Level of Skill in Operation
Potential of Low Level of Skill in Maintenance
Potential Low Medium High Very High
12
Catchment population - 1000 people
Water Supply - 135 lpcd (based on the service level
benchmarks as mentioned in the CSP for Raipur City).
Wastewater generation - 85% of water supply i.e. 114.75 cu.m
per day (say 115 cu.m/day)
Composition of wastewater
67% greywater, 33% blackwater.
Greywater generated - 76.38 cu.m/day (say 77 cu.m)
Blackwater generated - 37.86 cu.m/day (say 38 cu.m/day)
INPUT DATA FOR DPR
13
Wastewater parameters for designing of treatment unit
INPUT DATA FOR DETAILING CONCEPT
Parameter Grey Water
Blackwater
(effluent from
septic tank)
Combined
(grey+black)
Biological Oxygen Demand (BOD)
mg/L
100 - 150 300 - 450 200 - 400
Chemical Oxygen Demand (COD)
mg/L
200 - 300 600 - 900 400 - 800
Total Solids mg/L 500 - 700 800 - 1000 100 - 150
Total Nitrogen mg/L 0.05 - 0.15 0.05 – 0.15 0.15 – 0.20
Phosphates (as P) mg/L 3.00 – 5.00 5.00 – 10.00 10 - 15
Coliform (MPN/100 ml) 1600 > 1600 1000 - 1600
Based on wastewater quality analysis conducted during period May-July 2012
15
locations for installation of
treatment unit
Two potential sites available for
installation of treatment unit.
Preferred location - land identified in
the northern part of Bandhwa Talab
(Site A) close to the inlet point
The other location is a low lying area
in the north eastern part of the lake
(Site B).
DETAILS OF DPR
SITE ‘A’
SITE ‘B’
16
Stakeholder Workshop
“GIZ Support to the NUSP – CSP Implementation” 9th April 2013, Raipur
17
Stakeholder Workshop
“GIZ Support to the NUSP – CSP Implementation” 9th April 2013, Raipur
18
Stakeholder Workshop
“GIZ Support to the NUSP – CSP Implementation” 20 December 2012, Raipur
Proposed Network for Conveying Wastewater
19
Treatment and Disposal
The quantum of wastewater to be treated is estimated to be 115 cu.m.
The wastewater shall be treated using a DEWATSTM technology to a
level prescribed by PCB and shall be discharged into Bandhwa Talab
DETAILS OF FINALISED CONCEPT…
20
Decentralised Wastewater
Treatment System (DEWATSTM)
The wastewater collected through the
SSS shall be conveyed through the
following modules for treatment:
Settler – Primary treatment
Anaerobic Baffled Reactor (ABR) –
secondary treatment and organic reduction
upto 90% can be achieved
Anaerobic Filter (AF) - further 70-90% of the
remaining organic load
Planted Gravel Filter (PGF) –tertiary
treatment for further removal of organic load
and nutrients present in the wastewater
DETAILS OF TREATMENT TECHNOLOGY
Collectio
n Tank
Pump wastewater to Lake
Sedimentation tank for retaining settleable particles
Dissolved and suspended matter passes untreated to
next stage of treatment
Efficiency of 25% - 40%
Desludging period of 2 years as per design for
sludge storage
21
Raw
Sewage
Partially Treated
Wastewater
Sludge Sludge
Scum
Biogas
Gas
TREATMENT MODULE 1 - SETTLER
22
Gas Gas Partially Treated
Wastewater
TREATMENT MODULE 2 – ANAEROBIC BAFFEL REACTOR +
ANAEROBIC FILTER
Activated
Sludge
23
Anaerobic Baffle Reactor (ABR):
• Anaerobic treatment (in the absence of oxygen)
• Wastewater passes a series of up-flow chambers
• Bacteria mass (activated sludge) at bottom of each chamber
• Further treatment (degradation) of suspended and dissolved solids by
anaerobic bacteria
• Efficiency 75% - 85%
Anaerobic Filter (integrated with ABR)
• Wastewater passes in a series of up-flow chambers with carrier
material (filter material)
• The filter is made out of gravel, slag or plastic elements
• To avoid plugging pre-treatment (sedimentation) is necessary.
• Efficiency 75% - 90%
TREATMENT MODULE 2 – ANAEROBIC BAFFEL REACTOR +
ANAEROBIC FILTER…
24
TREATMENT MODULE 3 – PLANTED GRAVEL FILTER
Aerobic treatment (in the presence of
oxygen)
Planted Gravel Filter (PGF) consist of plants
(reeds) & filter materials (graded gravels,
river pebbles)
The filter is permanently soaked (up to 50
cm from bottom) in water
The flow direction is horizontal
Wastewater requires pre-treatment
29
O&M
Desludging of settler Wastewater Monitoring
Cleaning of filter material Plant harvesting for PGF
Treatment is based on physical and
biological (anaerobic and aerobic)
wastewater treatment component
Affordable price
Fulfillment of discharge standards
Treatment of wastewater flows from 1-1000
m3/d
Tolerance to inflow fluctuation
No dependence on external energy
Minimal and easy maintenance
Reliability and long-lasting
Reuse of wastewater
30
ADVANTAGES OF DEWATS TECHNOLOGY
THANK YOU…
Consortium for DEWATS Dissemination (CDD) Society
Survey No. 205, (Opp. Beedi Workers Colony)
Kommaghatta Road, Bandemath
Kengeri Satellite Town
Bangalore 560 060 – Karnataka, India
Tel/Fax: +91-080-28486700 / 28482144
www.cddindia.org
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