DANSK DS/EN 1899-2 PDF

This standard specifies determination of the biochemical oxygen demand of waters of undiluted samples. This standard is applicable to all waters having biochemical oxygen demands greater than or equal to the limit of determination 0,5 mg/l of oxygen and not exceeding 6 mg/l of oxygen. The results obtained are the product of a combination of biochemical and chemical reactions. They do not have the rigorous and unambiguous character of those returning from, for example, a single, well-defined, chemical process. Nevertheless, they provide an indication from which the quality of waters can be estimated. The test can be influenced by the presence of various substances. Those which are microorganisms, for example bactericides, toxic metals or free chlorine, will inhibit biochemical oxidation. The presence of algae or nitrifying microorganisms can produce high results.