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WASTE WATER- MANAGEMENT AND TYPES. SHANKAR GURU S G 20M246.

INTRODUCTION - WASTE WATER TREATMENT. Wastewater treatment is a process used to remove contaminants from wastewater and convert it into an effluent that can be returned to the water cycle . Once returned to the water cycle, the effluent creates an acceptable impact on the environment or is reused for various purposes . There are several kinds of wastewater which are treated at the appropriate type of wastewater treatment plant . The term "wastewater treatment" is in the literature often used to mean "sewage treatment. The main by-product from wastewater treatment plants is a type of sludge which is usually treated in the same or another wastewater treatment plant..

TYPES OF WASTE WATER TREATMENT PLANT. Wastewater treatment plants may be distinguished by the type of wastewater to be treated . There are numerous processes that can be used to treat wastewater depending on the type and extent of contamination . The treatment steps include physical, chemical and biological treatment processes. Types of wastewater treatment plants include: 1.Sewage treatment plants 2.Industrial wastewater treatment plants 3.Agricultural wastewater treatment plants 4.Leachate treatment plants.

BENEFITS OF WASTE WATER TREATMENT. Provides clean, safe water processed. Saving you money. Beneficial to the environment. Saving water. A way to minimize waste ..

STEPS INVOLVED IN WASTE WATER TREATMENT.

INDUSTRIAL WASTE WATER. Industrial wastewater treatment describes the processes used for treating wastewater that is produced by industries as an undesirable by-product . After treatment, the treated industrial wastewater (or effluent) may be reused or released to a sanitary sewer or to a surface water in the environment. Some industrial facilities generate wastewater that can be treated in sewage treatment plants . Most industrial processes, such as petroleum refineries , chemical and petrochemical plants have their own specialized facilities to treat their wastewaters..

SOURCES OF INDUSTRIAL WASTE WATER. Iron and steel industry Mine and quarries Food industry Textile industry Nuclear industry Complex organic chemical industry Dairy industry.

POLLUTANTS PRESENT. Suspended solids Colloidal solids Inorganic compounds and salts Oil and grease Ammonia and phosphate Cyanide Heavy metals and coloring agents Refractory substances resistant to biodegradation.

Industrial water reuse and recycling is the process by which wastewater produced from one source is treated to be reused in the same process or recycled for another. General wastewater recycling Cooling tower blowdown Boiler blowdown RO reject Once through cooling water Ion exchange rinse waters Collected rain waters Various methods for recycling or reusing industrial water are available, depending on water quality requirements, space constraints, and budgetary considerations..

DOMESTIC WASTEWATER. Wastewater is the water which is disposed from homes, offices and industry. It comes from toilets, sinks, showers, washing machines and industrial processes and was historically called sewage. The strength and composition of the domestic wastewater changes on hourly, daily and seasonal basis, with the average strength dependent on per capita water usage, habits, diet, living standard and life style Households in developed countries use more water than those in developing countries..

Direct Reuse: Even though water for direct reuse may be relatively free of contaminants, the future reuse of rainwater and greywater must be appropriate for the level of contaminants present. Appropriate purposes for direct reuse can include: -Washing (cars, etc.) -Flushing toilets -Gardening and food production can be done with greywater towers, vertical gardens, fertigation, drip-irrigation, and subsurface drip irrigation.

TREAT AND REUSE WASTEWATER (RECYCLING): If wastewater is not suitable for direct reuse, household wastewater treatment options may be employed to reduce the level of contaminants to a level that is safe for reuse. Some possibilities for household wastewater treatment systems include: -Constructed wetlands (see free-surface, horizontal, vertical, and hybrid constructed wetlands) -Biogas settlers -Anaerobic baffled reactors -Septic tanks -Leach fields - Evapo -transpiration beds -Surface or subsurface groundwater recharge.

BOD measures the amount of dissolved oxygen (DO) required by the aerobic organisms in order to break down the organic materials that are present in a water sample at particular temperature and time. I t is not a precise quantitative test , Since BOD is a biochemical process But, BOD is a widely used test method, indicating the organic quality of water..

The sources of BOD are leaves, woody debris, , animal manure, food-processing plants, feedlots, failing septic systems, urban stormwater runoff, and effluents from pulp and paper mills. T he temperature, pH, present in microorganisms, and the type of organic material in water determines the the rate of the oxygen consumption If the BOD is greater in a particular water body, oxygen is lesser available for the aquatic life forms. D ue to high BOD , Aquatic life forms would be stressed, suffocate and ultimately die.

COD measures the amount of the dissolved oxygen which is required by the decomposition of the organic matter as well as the oxidation of inorganic chemicals which includes ammonia and nitrite. COD is done with the samples of wastewater or natural water , in which they are contaminated by domestic and industrial wastes. COD is the only method to measure the amount of industrial wastes in water, which cannot be measured under BOD. The amount of cellulose in water is only measured by COD. The plants which treat wastewater from the commercial operations measure COD.

SIMILARITIES BETWEEN BOD AND COD COD and BOD can be indicated as mg/L or ppm (parts per million). Both parameters measure the amount of oxygen needed to oxidize pollutants in water. Also, both measurements indicate the intensity of water pollution. Furthermore, both BOD and COD are critical in wastewater , which is used for measuring the amount of waste in the water.

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