The breakdown of synthetic organic compounds in biological processes

Abstract

Industry may discharge effluents from manufacturing processes either direct to rivers (usually after suitable pretreatment), to waters to which quality standards are not applied, or to public sewers. The significance of that part which receives conventional biological waste treatment is discussed in relation to the ultimate disposal of waste waters to the sea. An account is given of the removal of certain synthetic organic chemicals during biological treatment. Over 200 substances have been selected on the basis of the inquiries received by the Information Service on Toxicity and Biodegradability of the Water Pollution Research Laboratory since 1966, and these substances have been broadly categorized as easily destroyed during biological treatment, degradable only after suitable acclimatization of the microflora concerned, or resistant. The importance of acclimatization is stressed. Some particularly resistant compounds are discussed in more detail. The possibility of predicting from its chemical structure the ease of removal of an organic compound by biological processes is considered to be remote, but some practical guidelines are suggested. Since living systems are both complex and variable, generalizations are to be avoided and information on particular compounds must be considered in relation to the circumstances.