DECENTRALIZED WASTEWATER TREATMENT SYSTEMS

Dr. SHIRISH NAIK, Chairman and Managing Director,Naik Enviro, Mumbai, IndiaFormer Faculty, Indian Institute of Technology , Mumbai , Indiawww.naikenviro.com

Sewage Treatment Facilities & disposal system

Pumping stations

Sewer network

COMPONENTS OF WASTEWATER MANAGEMENT SYSTEMS

COST DETERMINANTS

• EXCAVATION , BACKFILL & ROAD REINSTATEMENT• PIPES• BEDDING• MANHOLES• PUMPING STATIONS• SEWAGE TREATMENT PLANTS• TREATED SEWAGE DISPOSAL/ REUSE SYSTEM

KEY COST DETERMINANTS

DEPTH

DIAMETER

S

FUNDAMENTAL PRINCIPLE

SOURCE

REUSETREATMENT

PROXIMITY ECONOMY

NAIKENVIRO THE HEART-N-SCIENCE OF ENVIRONMENTAL ENGINEERING

DECENTRALIZED CONFIGURATIONS FOR COST EFFECTIVENESS

Drastic reduction in pipe sizes

Reduction in manhole depths

Reduction in depths and excavations

NAIKENVIRO THE HEART-N-SCIENCE OF ENVIRONMENTAL ENGINEERING

NAIK ENVIRO’S APPROACH– DECENTRALIZED CONFIGURATIONS

sources

treatmentReuse/recyclelocations

CENTRALIZEDDE-CENTRALIZED

DRASTIC REDUCTION IN CAPEX AND OPEX

CAPEX/OPEX

KEY DECISIONS

KEY DECISIONS

NUMBER OF ZONES &

DEMARKATION

PHASED EXPANSION

TREATMENT TECHNOLOGIES

REUSE/ RECYCLE OPTIOSN

NUMBER OF ZONES AND DEMARKATION

ZONING CONFIGURATION

DECISION

TOPOGRAPHY & POPULATION

DENSITY PROFILE

SENSITIVE ZONES, SOIL PARAMETERS

ADMINISTRATIVE BOUNDARIES &

AVAILABLE SITES

DIVIDERS LIKE

RAILWAY LINES,

RIVERS ETC

PHASED EXPANSION

PHASE 1

PHASE 2

PHASE 3

TIME HORIZON

PHASED EXPANSION

VARIATIONS IN POPULATION DYNAMICS NEED TO BE ADDRESSED

PHASED EXPANSION

POTENTIAL STP ZONES

PHASED EXPANSION

ZONING WILL DEPEND ON AVAILABLESITES FOR STPs

PHASED EXPANSION

ZONING WILL DEPEND ON PHYSICAL FEATURESLIKE RIVERS FLOWING THROUGH CITY OR RAILWAY LINES

DIVIDING THE CITY INTO ZONES

STP SITE SELECTION CRITERIA• Space availability• Land Acquisition constraints • Land cost• Potential future uses of candidate sites• Growth dynamics• Sensitive receptors• Soil mechanics • Topography• Treated sewage reuse zones• Feasibility of laying sewer lines upto STP• Invert depths of sewers at STP site

CANDIDATE SITES FOR STPS• Sewage Pumping station premises

• Old STP premises

• Parks & Playgrounds (underground STPs)

• Reclaimed Landfill sites

• Span across Natural Drains

STP TECHNOLOGY SELECTION CRITERIA• Foot print needed• Environmental Impacts• Sound• Odour & aerosol contamination• Land value impacts • Complexity and extent of civil works• Economic decision variables• CAPEX• OPEX• Present Worth• Technology Track Record, especially low flow Handling capability

PRESENT WORTH ANALYSIS

• F= (1+(1+I)^n/((I*(1+I)^n

Capital costO&M cost

Convert O&M costTo present worth

Present worth Of capital cost

Pres

ent w

orth

Time horizon

TRIAXIAL TRADE-OFF

Optimal Solution

Phased expansion

DecentralizationSystem Synthesis and process optimization

HEURISTIC CONSIDERATIONS IN PHASED EXPANSION OPTIMIZATION

200 TIME HORIZON 0 TIME HORIZON 20

EXCESS CAPACITIESEXCESS CAPACITIES

EXCESS (IDLE) CAPACITIES REDUCE COST EFFECTIVENESS

ECONOMY OF SCALE CONCEPTC

OST

PER

UN

IT O

F C

APAC

ITY

CAPACITYCO

ST P

ER U

NIT

OF

CAPA

CITY

CAPACITY

WEAK ECONOMY OF SCALE

INDICATES PREFERENCE OF MODULAR EXPANSION

STRONG ECONOMY OF SCALE

INDICATES PREFERENCE OF LONG TERM DESIGN HORIZON

TECHNOLOGY SPECTRUM

CAPITAL INTENSIVE

OPEX INTENSIVE

LAND INTENSIVE

ALGORITHM FORHEURISTIC OPTIMIZATION OF DECENTRALIZED WASTEWATER MANAGEMENT

• DATA COMPILATION• Road Map of city with contours, land use pattern, physical features etc

• Population and population density overlay on map – present and 5 years time spans till say 20years

• Show per capita water use and sewage generation on plan

• Show treated water reuse/ recyle zones and demands on plan

• Show existing sewerage system, pumping stations and STPs on plan

• Show candidate STP and pumping station sites with plot areas and tabulate soli data

• Show sensitive zones

• Show traffic density on road network and alternative routes

ALGORITHM FORHEURISTIC OPTIMIZATION OF DECENTRALIZED WASTEWATER MANAGEMENT

• DATA COMPILATION

• Tabulate cost data for system components and develop rate analysis chart, example..

• a) Cost per m of sewer line v/s dia and depth (all inclusive)

• b) Cost of manholes v/d depth and size

• c) Cost of u/g tanks v/s capacity and depth below GL

• d) Cost of pumping machinery v/s discharge and head

• e) Cost of substations v/s KVA

• f) Cost of various technologies-- v/s design flow for various use options

ALGORITHM FORHEURISTIC OPTIMIZATION OF DECENTRALIZED WASTEWATER MANAGEMENT

• DATA COMPILATION

• g) Cost of Power per Kwhr

• h) Manpower costs for various technologies v/s capacity

• i) Maintenance costs for various technologies v/s capacity and equipment age

• j) Compile land costs at pumping station and STP sites

ALGORITHM FOR HEURISTIC OPTIMIZATION OF DECENTRALIZED WASTEWATER MANAGEMENT

• Mark candidate STP locations and demarkate zones considering cotours, roads, sensitive zones, population densities etc

• Mark main and sub main sewer networks terminating at STPs and decide on number of zones and their demarcation. This is the first option. Take the maximum number of zones you would like to consider.

• Mark and compute drainage areas and multiply these by population densities applicable and per capita sewage generation. Use CPHEEO criteria to compute peak flows. Insert the peak flow numbers on the networks

• Input the data for various zones into to a sewerage design software or carry out the design using an excel template

ALGORITHM FOR HEURISTIC OPTIMIZATION OF DECENTRALIZED WASTEWATER MANAGEMENT

• Plots invert level profiles on road map and decide on intermediate pumping stations … compute CAPEX and OPEX of sewerage system

• Decide on time horizon for each zone based on flow estimates over 5 year intervals up to 20 years

• Compute space requirement for pumping stations and STPSs for the ultimate stage. Check adequacy of space and find options. Make note of space inadequacies for next iteration.

• Compute CAPEX including land costs and OPEX of zone STPs for selected technologies

• Compute overall CAPEX, OPEX and present worth of the overall system.

• Now you are ready for the next iteration in which you may merge some zones and repeat the exercise.

ECONOMY OF DECENTRALIZATION

NUMBER OF ZONES

PRES

ENT

WO

RTH

1 2 3 4 5

NETWORKING & AUTOMATION OF DECENTRALIZED STPS

• Control through SCADA (Supervisory Control and Data Acquisition) Alerts on mobile phones of control team.

• Central control hub with mobile squad

• Visual observation and control through cameras, DVDs and desktops

• Complete automation through Programmable Logic Controls (PLCs)

NAIKENVIRO THE HEART-N-SCIENCE OF ENVIRONMENTAL ENGINEERING

E-CONNECTIVITY--- ECOBIOPACK ONLINE

NAIKENVIRO The Heart-N-Science of Environmental Engineering

Raw sewage tank

Rotating Media Bio Reactors

Dual Media filters

Settlement tankSludge DewateringSystems

Raw sewage Pumps

9MLD COMPACT STP AT WADALA TRUCK TERMINUS

RMBR- 1,2,3

SETTLING TANK- 1,2,3

FILTERS

TREATED WATER TANKS

RAW SEWAGE

TANK

3-D DRAWING OF 1.5 MLD STP

1.5 MLD NAIK ENVIRO SCADA CONTROLLED COMPACT SEWAGE TREATMENT PLANT– 3D MODEL

PROCESS FLOW DIAGRAMRaw waste water pumpScreen

RMBR

Flocculation Channel

Settling Tank

Filter Feed TankPressure Sand Filter

Activated Carbon Filter

Meters:1] Flow meter2] pH meter3] Temperature meter4] DO meter

Treated Water Tank

Ozone Dosing System

Sludge Dewatering System

Backwash/Rinse

Sludge

Treated Water Tank

NAIKENVIRO

BEFORE

AFTER

SCADA •The operating system at site is SCADA, which stands for supervisory control and data acquisition. It is an industrial control system where a computer system monitors and controls the ongoing operation/process.•The software gives various information's like details of pump operation, breakdown details, energy consumption, treated water quality parameters, historical trends etc.

Main Screen NAIKENVIRO

SCADA –Home Screen NAIKENVIRO

DECENTRALIZED STP FOR GATED COMMUNITY IN PUNE INDIA

NAIKENVIRO The Heart-N-Science of Environmental Engineering

DECENTRALIZED STP FOR MUNICIPAL CORPORATION OF MUMBAI 1 MLDAT BANDRA, MUMBAI SEWAGE PUMPING STATION

NAIKENVIRO The Heart-N-Science of Environmental Engineering

DECENTRALIZED STP BASED ON ROTATNG MEDIA BIO REACTOR TECHNOLOGY FOR

MUNICIPAL CORPORATION OF MUMBAI 1 MLDAT BANDRA, MUMBAI SEWAGE PUMPING

STATION– ELEVATION VIEW

DECENTRALIZED STP BASED ON ROTATNG MEDIA BIO REACTOR TECHNOLOGY FOR

MUNICIPAL CORPORATION OF MUMBAI 1 MLDAT BANDRA, MUMBAI SEWAGE PUMPING

STATION– BIRDS EYE VIEW