Determination of the Chemical Oxygen Demand (COD) of River Water Samples

Introduction The chemical group O demand (COD) is a stones throw of the amount of oxygen consumed by the ingrained material deep down a wet savor that is oxidized by a upstanding chemical oxidant, such(prenominal) as potassium bichromate (K2Cr2O7). Its of import use is as an indicator of the innate and in perfect military issue at heart water and outgoing come off giving a numeric value of water quality. at that fundament be early(a) running plays that are too utilize to measure the organic topic of a water body, such as the biologic oxygen demand scrutiny. The biological oxygen demand (BOD) and c hush be found by collecting a specimen from the watercourse and incubating it at 200C for fin days, and calculating the oxygen use oer the brooding goal (Harrison 1996). The COD is frequently employ when early(a) methods are not as effective to be used. paladin advantage of the COD block out over other tests, such as the BOD test is that it is relatively fast to induce back come forth, for modelling the BOD test takes place over a five-day incubation period whilst the COD tests quarter be carried out in 2 hours; hence provides a much speedy interpretation of water quality. This property of the test has resulted in a commodious range of usage when monitor and controlling the organic pith of industrial waste from effluent systems and the receiving water bodies.

Dichromate is often used as the oxidizing agent when find out the COD cod to its exponent to oxidise most materials and ease of manipulation (Chapman 1996). raise allows the organic matter within a sample to depress the dichromate; any remain dichromate is titrated with ferrous ammonium sulphate, FeSO4.(NH4)2SO4, where the Fe2+ ions are oxidised to Fe3+ by the remaining dichromate ions, Cr2O72-. The dichromate (Cr2O72-) is fade out into a salt by the addition of sulfuric corrosive (Na2Cr2O7), this produces... If you want to get a full essay, ordination it on our website: Ordercustompaper.com

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