Conclusions from Ufa, Russia, drinking water dioxin cleanup experiments involving different treatment technologies

The city of Ufa, in the Bashkortostan Republic of Russia, is believed to have dioxin contamination of its water supply from 30 years of gas ejections, sewage and buried sludge from the Chimprom industrial factory, and possibly other sources. A project was developed to provide technology at relatively low cost for treating dioxin contaminated water in routine and also in emergency situations. This paper describes the results of the 15-year research project to remove dioxins from drinking water. Three different methods were experimentally tested for efficiency at removing dioxins from tap water. The methods used were: (1) ozonization plus filtration through powder sorbents, (2) filtration through sand, and (3) filtration through granulated sorbents. It was found that the method of filtration through granulated sorbents was most effective at removing dioxins from water: 90-95% of all PCDD and PCDF isomers were removed from water samples. This research also shows that the most toxic congener, 2,3,7,8-TCDD, can be removed effectively and efficiently. In addition, there are no significant differences between the extractability of PCDDs and PCDFs. Reductions in exposure to humans from contaminated drinking water can be accomplished via sorptive water treatments for relatively reasonable cost, making this a practical approach. This method of decreasing toxic chemicals is being implemented in Ufa, Russia.