Chemical oxygen demand, pollution evaluation

A measure of the total organic material present in slurries can be obtained by determining chemical oxygen demand (COD) or biological oxygen demand (BOD) (3) and the latter measure is used by Water Authorities in relation to the pollution of water courses where oxygen tension in the water is a prime concern. In studies to evaluate aerobic digestion as a means of odour reduction, the dissolved volatile fatty acids are a useful measure of the potential odour nuisance (2). 

Ozonolysis can be applied for assessing the pollution level of potable and wastewaters, by determining the ozone demand in an apparatus including an ozone generator and UVD for measuring the amount of O3 supplied. A correlation can be established between the ozone demand and the chemical oxygen demand, which is a standard method for pollution evaluation. The advantage of the ozonolysis route is its speed (a few minutes for sample... 

The following is an example of a typical chemical process (in a schematic form) used for the analysis of a wastewater sample in order to determine the presence of organic matter or oxidizable fraction through the measurement of the chemical oxygen demand (COD), a very common parameter in the evaluation of water pollution ... 

The presence of pollutants in environmental waters may be detected by the measurement of the chemical oxygen demand (COD). This parameter which represents the oxygen required for complete oxidation of the organic matter, is, likewise to the batch procedure, evaluated in a flow system as the consumption of a strong chemical oxidant (namely, permanganate, dichromate, or cerium(IV)). The intrinsic drawback of making the COD determination fully automated in flow assemblies owing to the short... 

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