ZETA-POTENTIAL ANALYSIS OF COAGULATION AND BIOFILTRATION OF WATER-SUPPLY

Organic contaminants present in drinking water sources can change the water electrodynamic characteristics significantly. Such change may co mplicate the coagulation processes. Zeta potential analysis based on c oagulation tests indicated that the trend of zeta potential changes in the coagulation of organic-contaminated water sources is different fr om the classic coagulation process. In this case, the conformation of organic molecules may play an important role. The effect of biological treatment on the zeta potential was also investigated within a biofil ter in the scale of 10,000 m(3)/day. The results showed that the biolo gical process can change the zeta potential of turbidity particles, re ducing the stability of the turbidity particles probably through biode gradation and bioflocculation, leading to the improvement of the coagu lation process.