Uboczne produkty dezynfekcji wody

Three oxidants have found wide acceptance in water disin-fection-chlorine, chlorine dioxide and ozone. Of these, chlorine has been preferred for the past decades. Unfortunately, chlorine has the inherent disadvantage of reacting with the micropollu-tants present in the water to produce derivatives of the halogen group, which are all cancerogenic or mutagenic compounds. Thus, in order to overcome the problem of chlorine derivative formation, the use of ozone as disinfectant has become more and more frequent. But it soon became obvious that the reaction of ozone with water pollutants yielded equally hazardous pro ducts, mostly carbonyl derivatives and bromoacetonitriles. Although ozone is a strong biocide, it is seldom used singly because of its instability. The most frequent use of ozone as disinfectant is in combination with chlorine or chlorine dioxide, which, again leads to the formation of a number of toxic by-products. The mechanisms tfiat govern the production of these toxic species or are responsible for their toxicity have not been satisfactorilyexplainedyet. The authors of the present paper provide adetailed account of the chemical compounds produced in a variety of Poland's waterworks in the course of the disinfection process. Particular consideration is given to the water treatment plants of the city of Warsaw, where use is made of chlorine, ozone and chlorine dioxide as disinfectants. Presented are also the potentialities for determining the by-products in potable water.