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

Introduction The chemical group O demand (COD) is a verse of the amount of oxygen consumed by the ingrained material at bottom a water system taste that is oxidized by a upstanding chemical oxidant, much(prenominal) as potassium bichromate (K2Cr2O7). Its of import use is as an indicator of the constitutional and inorganic military issue indoors water and wastewater enter giving a valued value of water quality. in that respect argon early(a) rivulets that are in like manner employ to measure the organic topic of a water body, such as the biological oxygen demand exam. The biological oxygen demand (BOD) and quite a little be found by collecting a try on from the watercourse and incubating it at 200C for quintuplet days, and calculating the oxygen apply oer the pensiveness conclusion (Harrison 1996). The COD is frequently utilise when early(a) methods are not as effective to be used. virtuoso advantage of the COD canvass over other tests, such as the BOD test is that it is relatively fast to cause back come forth, for congresswoman the BOD test takes correct over a five-day incubation period whilst the COD tests buttocks be carried out in 2 hours; hence provides a much speedy index of water quality. This property of the test has resulted in a abundant range of usage when supervise and controlling the organic message of industrial waste from effluent systems and the receiving water bodies.

Dichromate is often used as the oxidizing agent when determine the COD cod to its might to oxidise most materials and relaxation of manipulation (Chapman 1996). raise allows the organic matter within a sample to depress the bichromate; 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 turn into a salt by the addition of sulfuric loony toons (Na2Cr2O7), this produces... If you want to get a full essay, ordination it on our website: Orderessay

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