Essay On Biochemical Oxygen Demand

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Biochemical Oxygen Demand (BOD) Biochemical Oxygen Demand is a standard test used to find the degree of organic pollution of water. Biochemical Oxygen Demand is defined as the amount of oxygen absorbed by microorganisms to decompose organic matter such as such as plant residues, lawn clippings, leaves, corn stalks and straw, manures, sludge, wood and food processing wastes, and green manures. For example, bacteria will decompose organic matter by consuming the dissolved oxygen in the water. If there is a large amount of organic waste, there will eventually be a lot of bacteria present to decompose the waste. A Biochemical Oxygen Demand test is conducted on 2 samples of water. The dissolved oxygen level of the first sample is noted immediately taken upon collection of the water. The second sample is placed during a specified period of 5 days at a temperature of 20°C in an incubator. After 5 days, a dissolved oxygen reading is…show more content…
Suspended solids are present mostly at point sources of water pollution include municipal sewage treatment plant discharges and industrial plant discharges, non-point sources such as soil erosion from agricultural sites and many types of industrial waste water. In laboratory, the total suspended solid is determined by first recording the weight of a filter paper. Then, one liter of sample of water is passed through the initially weighed filter paper. The filter paper is then allowed to dry and reweighed. The change in weight is the weight of the total suspended solids. Waste water which are naturally low in suspended solid do not require treatment. Another way of knowing how contaminated a waste water is, is to collect a sample of the waste water and leave it for 2 days. If the sludge present in the water remain suspended, then it is highly contaminated, but if less sludge is suspended, then the contamination of the waste water is

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