Polyelectrolyte treatment – an approach for water quality improvement

Contamination of industrial water by suspended materials such as mud, dirt, turbidity, organic matter and decaying vegetation can be a serious operational problem besides reducing its aesthetic quality. The clarity of water is affected due to overloading of the clarifier and during the rainy season when turbidity is high. The operational problems encountered during alum and lime treatment programme and the improvement of clarification of raw water by using diallyl dimethyl ammonium chloride (DADMAC), a hetero-ally-cyclic organic polymer are discussed. This paper discusses the chemistry of coagulation and benefits of polyelectrolytes. Treatment recommendations and dosage of polyelectrolyte are discussed in terms of an overall system approach. The use of this organic polymer could improve the overall efficiency of raw water treatment plant with increased throughput, reduced plant maintenance and better water quality. The replacement of alum treatment is cost effective with a substantial cost savings of 25 to 30%.