Presentation on theme: "S.C.Santra Department of Environmental Science University of Kalyani Kalyani – 741 235, Nadia West Bengal, India. AQUATIC MACROPHYTE BASED WASTE-WATER."— Presentation transcript:
S.C.Santra Department of Environmental Science University of Kalyani Kalyani – 741 235, Nadia West Bengal, India. AQUATIC MACROPHYTE BASED WASTE-WATER TREATMENT IN TOWNS AND MUNICIPALITY
Background:- Proper treatment, utilization and safe disposal of wastewater are the hallmarks of the modern civilization. Our environment is under constant threat from our own activities. Expanding population, industrialization and intensive agriculture are responsible for damage to our environment. However, technological development for treating wastewater has not kept pace with the changes in the complexity of effluents created through the growth of different industries and emerging of new complex problems owing to the addition of various toxic and hazardous substances to the water system. In India, most of the surface water bodies e.g. river lakes, pond are polluted due to discharge of untreated wastewater from municipalities, industries, surface run- off carrying insecticides, pesticides from agriculture field etc. However, every water body has a limit of pollution control capacity, beyond which if it is loaded then it will result in degradation of aquatic ecosystem resulting an adverse impact on the water management. In India, out of total wastewater generated in the metro cities hardly 30% is treated in the treatment plants before disposal.
Present Scenario of Wastewater Treatment in India PlantPlant Capacity (in MLD) Unit Operation and Process Preliminary/Primary Treatment Secondary Treatment 1163.00S, GR, PSASP, SS 227.00S, GR,PSTF, SS 390.00-OP 427.00S, GR, PSASP, SS 55.70S, GR, PSGTF,SS 69.10S, GR, PSASP, SS 745.5S, GR, PSTF,SS 8136.40S, GR, PSASP, SS 980.00S, GR, PSTF,SS 1034.00S, GR, PSASP, SS 1123.00S, GR, PSASP, SS 1220.00S, GR, PSASP, SS 1311.40S, GR, PSTF,SS 1427.00S, GR,PSTF, SS 1522.50S, GR, PSASP, SS 1610.90S, GR, PSTF,SS 17181.80S, GR, PSASP, SS 18181.80S, GR, PSASP, SS 195.50S, GROP 208.0S, GR, PSASP, SS S – Screening, GR – Grit Removal, OP – Oxidation Pond TF – Trickling Filter SS - Secondary Settling, PS – Primary Settling ASP – Activated Sludge Process
Status of Sewage Treatment plants of India (Classification based upon Design Capacity )
Status of Sewage Treatment plants of India (Classification based upon Treatment Plant)
Status of Sewage Treatment plants of India (Classification based upon O& M Agency)
Probable causes of failure Hydraulic/organic over loading of the system Inadequate oxygenation due to frequent power failure and mechanical failure of the aerators. Poor F/M ratio and low MLSS concentration Uneven distribution of sewage over trickling filter Ponding in the trickling filter bed. Interrupted operation due to frequent power failure/non availability of sewage. Others Non-cooperation between the different wings of engineering department Untrained operators Electrical and mechanical fault Improper sewerage systems
Status Aquaric Macrophytes in Tropics Over 100 species viz’ floating from Submerges forms party submerged & party emerged (Reeds)
CONSTRUCTED WETLAND (CW) Historical back ground Treating wastewater for about 90 years 1 st initiated in the year 1950 at Max Plank Institution in Germany In 1973 full scale experiment developed by Robert Kablee, Principle of wetland Management Several research efforts initiated between 1970 – 1980 in USA In the year 1993 EPA presented O&M of sub-surface flow wetland In Europe at present there are 11,370 nos. officially registered wetland In Australia about 40CW have been installed in the last 10 years China, Korea, Pakistan also started to treat wastewater by CW In India demonstration project on community-based wastewater treatment started in the districts Roper & Patiala at Punjab. Also in Delhi and Vellor CW system initiated
BOD/ Carbon Pathways Legend DM Dissolved Matter PM Particular Matter # Denotes dissolved or in solution Se Sedimentation Re Resuspension of bed particulates Bu Biofilm Uptake Rs Respiration by algal biofilm and Ao Aerobic decomposition phytoplankton An Anaerobic decomposition Fb Bio film fall and deposition Fm Microphyte litter Di Dilution of O at water/air interface
Carbon Transformations in Free Water Surface Wetland
Nitrogen Transformations in Free Water Surface Wetland ■ PON= Particulate organic nitrogen ■ DON= Dissolved organic nitrogen ■ NH + 4 = Associated ammonia nitrogen ■ NH 3 = Non associated ammonium gas ■ O 2 = Oxygen ■ NO - 2 = Nitrite nitrogen ■ NO - 3 = Nitrate nitrogen ■ N 2 = Nitrogen
Why constructed wetland? Eco-friendly way of treatment Less area requirement Minimum power consumption Sun light does not affect in treatment unlike WSP More shelter to the birds and water animals Can be used at source or in centralized manner Less capital and O&M cost Existing wetlands can be utilized after certain modification Already established in America, Europe,Australia and other advance countries.
Evaluation of the existing treatment plants in KMA Study on the performance of conventional and low cost treatment system Cost evaluation of the different types of treatment plants Performance study of a Constructed Wetland through pilot-plant investigation Suitability study of different aquatic plants used in pilot- plant of Constructed Wetland. Designing of Constructed Wetland and evaluation of the cost Comparative study of the area requirement of Constructed Wetland with that of Waste Stabilization Pond (WSP) for treatment of equal quantity of wastewater is also contemplated Case Study:-
Conclusion…...... From the present study it is evaluated that none of the existing treatment plants is functioning well, but WSP being low-cost and easily manageable, is working satisfactorily in most of the cases.. Moreover, the WSP is good from the view point of pond ecologies. The application of primary treated sewage in the pond takes advantages of the complex ecologies of the meadow and underlying soil. But in spite of many advantages, the main stringency lies in the fact that WSP needs large area, which is very scarce in the urban areas. From the view point of efficiency and land requirement constructed wetland treatment system may be considered effective alternative of the wastewater treatment.