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Rural Sanitation, DEWATS, Decentralized Treatment of Wastewater,
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Earthizenz ecofriendly systems
Appropriate Technologies Appropriate Technologies for Rural Sanitation: for Rural Sanitation:
Recovery Recycle & Reuse Recovery Recycle & Reuse of GHGs, Water & Nutrientsof GHGs, Water & Nutrients
M.P. Singh M.P. Singh B. Tech.(Civil); M.I.E. (Mech.)B. Tech.(Civil); M.I.E. (Mech.)
Earthizenz Ecofriendly SystemsEarthizenz Ecofriendly Systemsemail: [email protected]: [email protected]
Made and presented on behalf of Village Life Improvement Foundation
Earthizenz ecofriendly systems
Need for this WorkshopNeed for this Workshop Last Year questions were raised on the Simplified Sewerage
Technology being used by the NRI NGOs. A presentation was given in a similar workshop The General opinion of the panel present was that choice choice
between settled or simplified sewerage depended on ground between settled or simplified sewerage depended on ground realities of individual villagesrealities of individual villages
A team of departmental Engineers visited the villages with Simplified Sewerage was operational.
There was hardly any comment on Simplified Sewerage, meaning that the carriage o sewage was satisfactory.
There were comments on the quality of effluent, which had nothing to do with Sewerage systems.
Moreover, the panel asked about the treatment system. A decision treedecision tree was presented to Zero downZero down on
Appropriate Technology
Earthizenz ecofriendly systems
Is Simp. Sew. Cheaper than Onsite Sanitation?
YES
Is minm. 40LPD per Cap water available?
YES
Do most houses have Safe Septic tanks?
NO
Simplified Simplified SewerageSewerage
Can balance houses have septic tanks? Keeping safe distances from specified Structures?
YES
YES
Settled (Small Settled (Small Bore) SewerageBore) Sewerage
NO
NO
Is Water Supply Augmentation Feasable?YES NO
Go For Go For onsite San.onsite San.
Decision Tree Sewerage SystemDecision Tree Sewerage System
Earthizenz ecofriendly systems
Our Dream Treatment of Rural Our Dream Treatment of Rural WasteWaste
Energy Neutral SystemEnergy Neutral System
No Random Methane EmissionNo Random Methane Emission
Carbon Neutral SystemCarbon Neutral System Maximum wastewater Maximum wastewater
Reuse/RechargeReuse/Recharge
Rainwater Filtration & Rainwater Filtration & HARVESTHARVEST
Recovery of Energy via Recovery of Energy via Biomethanation of Solids and LiquidsBiomethanation of Solids and Liquids
Fertilizer & Energy from Sludge Fertilizer & Energy from Sludge
Self Self SustaininSustaining Processg Process
No Nitrous Oxide EmissionNo Nitrous Oxide Emission
Earthizenz ecofriendly systems
fertilizer production from finite resources
foodfood
Mixing of flow streams, Mixing of flow streams, misuse of drinking misuse of drinking water for transportwater for transport
90% 90% untreateduntreated
waste disposal in waste disposal in water bodieswater bodies
sewage sewage sludgesludge
Overexploitation of Overexploitation of groundwatergroundwater
Current ScenarioCurrent Scenario
Courtesy gtz
GH
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GH
G
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iss
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Earthizenz ecofriendly systems
Dream ScenarioDream Scenario
Restoring Soil Fertility
Treatment / Hygienization / Energy Recovery
Water ReuseWater Reuse
NO Waste Disposal in Water Bodies
Rainwater HarvestingRainwater Harvesting
food
OrganicOrganic WasteWaste
FaecesFaeces
UrineUrine
GreywaterGreywater
Energy and Fertilizer Recovery through Biomethanation
Agricultural Use
Courtesy gtz
GH
G
GH
G
Em
iss
ion
sE
mis
sio
ns
NN22OO
CCHH44CC
OO22
Emis
sion
Reduct
ion
Earthizenz ecofriendly systems
The System Hitherto @ VLIFThe System Hitherto @ VLIF
Earthizenz ecofriendly systems
Secondary Treatment/ Disposal
Primary/ Secondary Treatment
Primary Treatment
The System Hitherto @ VLIFThe System Hitherto @ VLIF
1) Septic Tank HRT = 72 Hrs2) Recirculating Filter ensures minimum
clogging chances.3) Being Centralized, the septic tank is
preceded by a collecting chamber and a pump house for dosing Raw Sewage
4) Both Septic Tank And Filter are power dependent
5) Quality of treatment dependant on Power continuity
Recirculating Recirculating Sand FilterSand Filter
Maturation/ Maturation/ Storage PondStorage Pond
Centrlized Centrlized Septic TankSeptic Tank
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The System Hitherto @ GoPThe System Hitherto @ GoP
1)1) The advantage of cost saving in The advantage of cost saving in sewerage is lost by having a settler sewerage is lost by having a settler in every house.in every house.
2)2) Cannot maintain mandatory Cannot maintain mandatory distances in congested placesdistances in congested places
3)3) Lift Station requires Energy for Lift Station requires Energy for pumpingpumping
4)4) Aeration Tanks are Energy Aeration Tanks are Energy dependant.dependant.
Primary Primary Intercepter/ settler Intercepter/ settler
at Household at Household LevelLevel
Lift StationLift Station
Secondary Secondary TreatmentTreatment
Aeration Tanks and then to polishing Aeration Tanks and then to polishing pondpond
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1. Waste water from building
2. Sedimentation chamber
3. Pressure pipe sludge
4. Liquid pipe siphon action
5. Settlement chamber
6. Liquid to filtration
7. Infiltration system
8. Composting plant
9. Irrigation/secondary treatment
Post Kyoto Changes in EI Nolson’s (Inventor of System) Concept of Small Bore System
Not to have a Not to have a septic tank in septic tank in every house but every house but one for a cluster one for a cluster of several housesof several houses
Use the small Use the small bore sewerage bore sewerage system after system after settlementsettlement
A truly Hybrid A truly Hybrid SystemSystem
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Current System (Under Current System (Under Discussion) @ VLIFDiscussion) @ VLIF
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Decentralised Decentralised Wastewater Wastewater ManagementManagement
Decentralised Decentralised Wastewater Wastewater ManagementManagement
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The Systems Now in Use @ VLIFThe Systems Now in Use @ VLIF Decentralised Wastewater Treatment Systems (DEWATS)
DEWATS is based on different natural treatment techniques
put together in different combinations according to need.
In this method the reed bed/Root Zone system acts as a secondary treatment unit,
Vetiver grass forms part of the Collage of plants
This is preceded by a baffled reactor where most of the treatment takes place.
The treated water from the reed bed system is stored in a polishing pond for the aerobic process. Vetiver Floats naturally aerate the pond
Earthizenz ecofriendly systems
Decentrlised Hybrid SystemDecentrlised Hybrid System
DEWATS is based on four basic treatment modules, which are combined according to specific requirements
Pre-treatment and sedimentation in settlement tank or inseptic tank
Secondary anaerobic treatment in baffled reactors
Aerobic/ anaerobic treatment in reed bed system.
Aerobic treatment in ponds
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Primary TreatmentPrimary Treatment
• A unit called a settling tank is used for this phase. It is A unit called a settling tank is used for this phase. It is aa
• sedimentation tank in which settled sludge is stabilised sedimentation tank in which settled sludge is stabilised by anaerobic digestion. by anaerobic digestion.
• Dissolved and suspended matter leaves the tank Dissolved and suspended matter leaves the tank untreated. untreated.
• The treatment efficiency of a septic tank is in the The treatment efficiency of a septic tank is in the range of 30 per cent BOD removal. range of 30 per cent BOD removal.
• A settling tank can also be incorporated into an A settling tank can also be incorporated into an anaerobic baffled tank as the first section of a settler anaerobic baffled tank as the first section of a settler device.device.
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Secondary TreatmentSecondary Treatment Baffled reactor is used for this phase.
Several tanks (upflow chambers) are built in a series to digest degradable Matter.
Baffles guide WW between the chambers from top to bottom and up againfrom top to bottom and up again.
During the process the fresh influent is mixed and inoculated for digestion with the active blanketactive blanket deposit of suspended particles and microorganisms microorganisms occurring naturally at the bottom of each chamber in such conditions.
Because of the physical separation of Chambers, various microorganisms are present at different stages, allowing high treatment efficiency
Earthizenz ecofriendly systems
Secondary TreatmentSecondary Treatment
• At the end of the treatment device a chamber can be set aside as an anaerobic filter in order to improve further the treatment efficiency.
• A filter media allowing contact with the sewage stream is used, which is very efficient in retaining and digesting the remaining pollutants.
• The problem of encountering clogging is minimised due to the digestion and treatment in the baffled reactor.
• The primary and secondary treatment systems are constructed below ground level and are built together as a single and compact setup.
• Nearly 90 per cent of the original pollution load is removed at this stage.
Anaerobic filter
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Anaeroobic Filter
Planted Filter
Primary/ Secondary treatment
The Systems Now in Use @ VLIFThe Systems Now in Use @ VLIF
Anaerobic Filter Anaerobic Filter (Attachable to (Attachable to
BR.BR.
Anaerobic Anaerobic Baffled ReactorBaffled Reactor
Horizontal Planted Horizontal Planted Filter/ Root Zone/ Filter/ Root Zone/
WetlandWetland
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Combined into One UnitCombined into One Unit
The Settling tank, The Settling tank, Baffled upflow reactor Baffled upflow reactor and Anaerobic Filter can and Anaerobic Filter can be plugged together,be plugged together,
The whole system is The whole system is underground and has a underground and has a total Hydraulic Residence total Hydraulic Residence time of 8 t0 14 hrs. like the time of 8 t0 14 hrs. like the UASB reactorUASB reactor
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The whole System can The whole System can fit in any place and is fit in any place and is always undergroundalways underground
Small surfaces become available for Small surfaces become available for treatment (sidewalks, private yards, treatment (sidewalks, private yards, parking lots, alleys, parks, etc.)parking lots, alleys, parks, etc.)
In a Street
In a Street
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The right combination and dimension of Modules The right combination and dimension of Modules is important.is important.
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Tertiary TreatmentTertiary Treatment• A horizontal planted gravel filter acts through the combined
effect of the filter material and plants growing on the filter media.
• Usage of sand as the main filter materials was replaced by pebbles and granite stones.
• The wastewater is resupplied with oxygen while passing through the planted gravel filter.
• The effluent is odour free. Since baffled reactor is being used to provide secondary treatment the size of the planted filter is reduced.
• This leads to a cost reduction, less needed space above ground
• The use of Vetiver grass alongwith other plants further increases the efficiency and hence the size.
• Moreover, the issue of N2O emission is effectively taken care of.
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Planted Gravel Filter
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Vetiver and Decentralized Treatment System
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Tertiary treatment
Earthizenz ecofriendly systems
Figure 11: Anaerobic treatment and final polishing in constructed wetland producing tertiary quality effluent. (Journey, W. K. and S. McNiven. 1996.)
Earthizenz ecofriendly systems
Vetiver in Planted Filter
Earthizenz ecofriendly systems
Vetiver In Tertiary TreatmentVetiver In Tertiary Treatment
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Earthizenz ecofriendly systems
Vetiver In Treatment in PondsVetiver In Treatment in Ponds
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Case HistoriesCase Histories
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Locations for Final treatment next to existing ponds
Location for Storage of Filtered Rainwater Runoff, to form a lake
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Original Site for centralized treatment with pump house etc
Nullah
Water Course
Four Decentralized sites chosen for Primary Treatment, 2 along Nullah & 2 along water course
Earthizenz ecofriendly systems
Baffled Reactor 1, along Nullah
Baffled Reactor 2, along Nullah
Baffled Reactor 3
Baffled Reactor 4
Natural Wetland to be modified with Vetiver for
sec.& Ter trtmnt.
Vetiver plantation for
final Nutrient uptake,
in water course
Narur Contd.
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Effluent is Effluent is currently currently discharging here discharging here into the Beininto the Bein
It is proposed to It is proposed to pump the raw pump the raw Sewage across the Sewage across the Bein for treatment Bein for treatment herehere
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Section of Section of the Beinthe Bein
Treatment along Treatment along the acquired area the acquired area
long the Beinlong the Bein
Earthizenz ecofriendly systems
The BeinThe Bein
Pedestrian Pedestrian PathwayPathway
Green Cover Green Cover (Vetiver and (Vetiver and other plants)other plants)
Fruit trees Fruit trees and soil and soil
protecting protecting HedgerowsHedgerows
Total treatment can be along the Total treatment can be along the length of the Bein.length of the Bein.
The baffled Reactor can be The baffled Reactor can be under the pathwayunder the pathway
The Wetland can be in the green The Wetland can be in the green beltbeltThe water can be absorbed by The water can be absorbed by the green belt and rows of vetiver.the green belt and rows of vetiver.
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Original Location of Original Location of Baffled Reactors and Baffled Reactors and
collection cum treatment collection cum treatment pondpondThe water table was too
high.
The depth of the Baffled Reactor had to be reduced.
A waterproof liner was installed.
Treatment with a special enzyme that will produce bacteria to reduce Sludge.
Enzyme will also produce Oxygen producing bacteria in the pond.
New position of New position of 9 chamber 9 chamber reactorreactor
Water body Water body with enzyme with enzyme treatment and treatment and Vetiver floatsVetiver floats
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Decentralized Wastewater Decentralized Wastewater System in the Author’s HouseSystem in the Author’s House
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Four Chamber Baffled Reactor in my House
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Earthizenz ecofriendly systems
Earthizenz ecofriendly systems
Earthizenz ecofriendly systems
Earthizenz ecofriendly systems
Earthizenz ecofriendly systems
Earthizenz ecofriendly systems
Earthizenz ecofriendly systems
Earthizenz ecofriendly systems
Earthizenz ecofriendly systems
Planted Filter
Earthizenz ecofriendly systems
Water collected in an Water collected in an underground water underground water tank and pumped up tank and pumped up in an overhead tank in an overhead tank as per need.as per need.