Role of micronutrients in activated sludge-based biotreatment of industrial effluents.

Industrial processes often produce wastewaters that resist biological treatment owing to the unfamiliarity of some components to biological systems. Availability of nutrients determines the community structure of the activated sludge and hence the efficiency of the degradation process. Micronutrients influence the bacteria involved in waste degradation and also the species diversity within the sludge. The requirements for and toxicity of different micronutrients vary according to the nature of the waste and the ecology of the sludge. Adding micronutrients to biological treatment processes is one possible approach to upgrading an existing facility in order to deal with increasing volumes and strengths of industrial wastewaters and the tightening discharge legislation.