Lakes and Ponds: Pollution Abatement and Environmental Sustainability National Environmental Engineering Research Institute Dr. Rakesh Kumar, Chief Scientist and Head, Mumbai Regional Center Email: [email protected]; [email protected] Phone: +91-22-24973521/24974607 Urban Lakes: Under Constant Threat What has gone wrong!!! — Degradation of quality – — — — — — Untreated sewage discharge Solid waste disposal Eutrophication Floating weeds PROTECTION METHODS — Degradation of quantity – — — — — Abstraction of Water for variety of usages Encroachment Drainage & Alternate Land Use Silt influx from degradation of catchment area Water Bodies – Current Status-Across India Ground water Recharge: Lakes Help! Qualities of a Healthy Lake.. High Water Clarity [ No floating matter ] No Stench No Floating Weeds No Floating Solid Waste High Dissolved Oxygen (D. O.) High Biodiversity 1st Step: Prevent — Prevent – v Municipal and/or Industrial Effluent disposal v Solid waste disposal v Idol Immersion v Introduction of exotic and/or invasive species v Encroachments v Over-exploitation of resources like fish, water v Catchment Area degradation v Slope Instability Cure is Necessary.. Eutrophication Floating Treatment Wetlands Floating weeds Removal Brine Spray Physical Removal Introduction of biological predator (insects, fungi, herbivorous fish) Sedimentatio n Dredging: When and Where?? Low D.O. Does Aeration always Help?? A Healthy Ecosystem in the Lake = A Healthy A Lake 2nd Step: Treatment of Inputs — Any unwarranted flow of solids and liquids need to be treated and suitably discharged — Liquid Waste can become an additional source of water — Achieve discharge standards: Below 10 ppm of BOD INPUT TREATMENT USING CONSTRUCTED WETLAND 11 3rd Step: Peripheral and In-situ Treatment — Water bodies (lake or impounded water in dam) need peripheral arrangement for: — prevention of silt and sediments — Prevention of nutrient from rainy runoffs — In-situ removal of contaminants 13 14 The Shahadara Lake Rejuvenation Project Sewage Water will be treated by the “Phytorid Technology” based on constructed wetland and will be used for Rejuvenating the lake in the Shahadara locality of East Delhi Floating Treatment Wetland: In-situ treatment Advantages.. — Low Cost — No Power Requirement — Low on maintenance — Eco-friendly Lake/Pond Status Bhujale Ongoing Lonar Completed Telebandha Phase I Kot Lake On progress Shahdara Under implementation Eco-Unfriendly Activities — Solid waste disposal — Nirmalya disposal — Fish feeding — Idol Immersion Environmental Issues — Pre-monsoon water quality poor; water was high in — — — — suspended solids, floating debris, foul smell, BOD and COD It appeared faint yellow-green in color and the clarity was poor Local fishermen around complained of itching when their skin came in contact with the water No aquatic plants or birds observed Fishes like magur and guppy have been introduced Some Work of NEERI’s Technology for Lakes and Nalla Waste Water Treatment NEERI’s Floraft Technology Pilot scale implementation of NEERI's Floraft technology, which is our improvised version of the Floating Treatment Wetland technology has been undertaken at the Bhujavale Talao in Malad (W), Mumbai Common native aquatic plants planted in Florafts Phragmites karka Typha latifolia Justicia americana Eleocharis Alternanthera Bhujale Talao: Location of Study Area ØDimensions: 71.43 m, 73. 1 m, 18.54 m, and 32.23 m ØApproximately 1618 feet deep at the center ØRoughly bowl shaped Mumbai Reels under Water Pollution Stress Florafts are made of PVC pipes and plastic nets of about 5ft by 5ft size Florafts are given adequate thickness through thermocol paddings and double net layers so that plants are adequately supported Florafts can be tethered to nearby trees or poles Or, allowed to float freely Idol-in-Net Technology Water Quality of Bhujale Pond Pre-Monsoon Am-N Pre-Monsoon DO Post-Monsoon 6 Pre-Immersion 5 Post-Immersion 4 (mg/l) (mg/l) Post-Monsoon 3 2 6 Pre-Immersion 5 4 Post-Immersion 3 2 1 0 1 0 1 2 3 1 4 3 4 Sampling stations Sampling stations Pre-Monsoon Post-Monsoon Pre-Immersion Post-Immersion TSS 70 60 50 40 30 20 10 0 Pre-Monsoon Post-Monsoon Pre-Immersion Post-Immersion TDS 2000 1500 (mg/l) (mg/l) 2 1000 500 1 2 3 Sampling stations 4 0 1 2 3 Sampling stations 4 Pre-Monsoon Post-Monsoon Pre-Immersion Post-Immersion BOD 50 (mg/l) 40 30 20 10 0 2 3 Sampling stations 4 Pre-Monsoon Post-Monsoon Pre-Immersion Post-Immersion COD 200 (mg/l) 1 150 100 50 0 1 2 3 Sampling stations 4 OPERATION & MAINTENANCE ØLittle or no maintenance required on a daily basis as the system is biological and requires no electricity or sophisticated set-up ØManpower is required for harvesting excess emergent biomass every few months ØLocal wetland plants will be needed for re-populating floating rafts ØBriquetting and sale of harvested biomass ADVANTAGES ØIn-situ method of water treatment ØLow cost, aesthetic and ecofriendly ØNo electricity requirement ØNo skilled manpower required ØNatural Oxygen production ØReduction in BOD, NO3-N, TSS and coliforms has been reported ØNew land mass for use by all kinds of creatures including fish and aquatic birds ØSequestration of carbon and other greenhouse gases ØHarvested biomass can be sold as briquettes Nabi Lake Under Consideration Lonar Lake Lake Area: 3 Ha Phytorid Capacity 500 KLD Plant commissioned Entire Sewage from Lonar Lonar Lake (under threat), Maharashtra Phytorid Plant on Nabi Lake Telibandha Lake, Raipur Lake Area: 11 Ha Phytorid Capacity 2 MLD Proposed to develop 3 plant at periphery Second Phase started Kot Lake Brahmapuri, Maharashtra Phytorid capacity 450 kld project design initiated Shahadara Lake, Delhi 3 MLD Capacity Phytorid Beds for Rejuvenation of an 8 acre surface area Lake – which is currently totally dried up Existing Conditions Proposed Outlay Proposed design of Phytorid for Nag Nadi (Nalla) Already 500,000 lit/day already being treated and used (Punjab Rao Krishi Vidyapeeth) Estimated land area required: 2563 m2 For a plant capacity of 1000 m3/day Entire length of the plant: 267m For a plant capacity of 1000 m3/day Length of the Phytorid bed: 184 m Dimension: 1.5m depth X 184m length X 8m width Project completion period: 12 months The Result…. More varieties of fish Birds among visitors Clean waters and no stink No itch for swimmers Study Area — Thane: One of the cities in Mumbai Metropolitan Region — Lat – Long: 900 12’ N 730 92’ E — Also known as “City of Lakes” (35 lakes in the city) Sampling Site: Siddheshwar Lake ü Location: Near Uthalsar Ward Office ü Area: 3 Hectares ü Type of settlement: Completely urbanized water body Ref: TMC’s ESR, 2009 -2010 Water Quality Index Seasonal Variation in WQI Values 350 295 300 WQI Values 250 248 200 200 166 150 100 50 0 W S M PM Season W= Winter, S =Summer, M= Monsoon, PM= Post Monsoon ü Based on the seasonal WQI values for Siddheshwar lake, it can be concluded that the water quality of this lake is very poor in all the seasons ü Water is unsuitable (based on drinking standards) Conclusions — Without understanding the social connectivity with water bodies, its difficult to solve issues — Protection methods (modern) are actually harming them — Input control technologies (sustainable and power free) — In-situ Control — Continuous monitoring with local participation Dream or Reality?!
© Copyright 2024 ExpyDoc
