IJSRD - International Journal for Scientific Research & Development| Vol. 3, Issue 04, 2015 | ISSN (online): 2321-0613 All rights reserved by www.ijsrd.com 1077 Comparative Study of Wastewater Treatment Technologies for a Township Gulhane M. L. 1 Pawar S.V. 2 1 Associate Professor 2 P.G Student 1,2 Department of Civil Engineering 1,2 Government College of Engineering, Amravati, Maharashtra, India Abstract— The paper presents comparison among the most frequently used waste water systems in developing countries. Various physico-chemical and biological techniques have been used for the treatment of domestic wastewater. The wastewater is conventionally treated either by suspended growth system, by attached growth system or combined suspended and attached growth system. The system studied were oxidation pond, activated sludge, upflow anaerobic sludge blanket, trickling filter and constructed wetland. All the above systems were designed and analysed based upon the various factors such as BOD removal efficiency, land required, power required, HRT, quantity of sludge to be handled, initial, operational & maintenance cost. The main summary table for quantitative analysis is prepared based on per capita values. It also includes the advantages and disadvantages of the treatment processes. Key words: attached growth system, suspended growth system, removal efficiency, sludge handling I. INTRODUCTION The community waste water carries organic as well as inorganic impurities. Direct discharge of waste water into the river or any fresh water source leads to its pollution. Inappropriate use of water resources and poor management of waste water has an increasingly negative effect on economic growth on social welfare and on the world‟s eco- systems. Nowadays there is a wide variety of systems which can be applied for wastewater treatment. In developed countries the number of alternatives may be somewhat more limited due to the more stringent effluent quality standards usually applicable, while in developing countries as a whole the breadth of choices to be analysed may be higher. This fact stems from the diversity of effluent standards encountered throughout these countries. Also the cost component and the operational requirements, while important in the industrialised countries, play a much more decisive role in the developing countries. All these points make the preliminary selection of the more appropriate systems for the intended application a critical step, many times overlooked in less careful designs. In developed countries, critical items which are to taken into consideration are efficiency, reliability, sludge disposal aspects and land requirements, environmental impact, etc. Where as in developing countries, these parameters have secondary importance, but have a smaller magnitude, compared to developed countries. In developing countries, critical parameters for selection of treatment system are cost of construction, cost of operation, sustainability, simplicity, etc. These items are also important for developed countries, but cannot be considered to be critical. The objective of the paper is to present elements for a preliminary comparison among the systems most frequently used for treatment of domestic wastewater, with a particular view to developing countries, under different conditions. The items analysed should help the consultant or even members of the organised community to make a first evaluation and preliminary selection of the treatment systems which could present a higher potential applicability for each case under consideration. For this some applicable systems were designed for next three decades and analysed for various parameters for the township generating 3500 m3/day of sewage (peak flow). II. THE SYSTEMS ANALYSED - Oxidation Pond (OP) - Activated Sludge Process (ASP) - Trickling Filter (TF) - Upflow Anaerobic Sludge Blanket (UASB) - Constructed Wetland (CW) All the above systems are analysed based upon the various factors such as BOD removal efficiency, land required, power required, HRT, quantity of sludge to be handled, initial, operational & maintenance cost. A. Oxidation Pond Waste stabilization ponds are biological treatment systems, which processes and operations are highly dependent on the environmental conditions such as temperature, wind speeds and light intensity which highly variable and any given combination of these environmental parameters is usually unique to a given location. An oxidation pond is a shallow pond designed specifically to treat sewage by natural purification processes under the influence of air and sunlight. The stabilization process consists largely of the interactions of bacteria and algae. Bacteria digest and oxidize the constituents of sewage and render it harmless and odor free. Algae utilize carbon dioxide and other substances resulting from bacterial action and through photosynthesis produce the oxygen needed to sustain the bacteria in the treatment process. During the detention period, the objectionable characteristics of the sewage largely disappear. Wastewater is first subjected to preliminary treatment (screening and grit removal) to remove large and heavy solids. Basically, primary treatment is carried out in anaerobic ponds, secondary treatment in facultative ponds, and tertiary treatment in maturation ponds. Anaerobic and facultative ponds are for the removal of organic matter and maturation ponds for the removal of faecal viruses, faecal bacteria.