THE INFLUENCE OF WATER DISINFECTANTS ON INACTIVATION OF VIRUSES AND FORMATION OF VOLATILE AND NONVOLATILE ORGANIC COMPOUNDS

A comparative study was conducted to remove indicator bacteria and viruses and reduce carcinogenic and mutagenic substances in drinking water between simulated in lab and on site at Donghu Lake Water Works by such disinfectants as chlorine, chlorine dioxide, the combination of chlorine and chlorine dioxide, and ozone. The results showed that Escherichia coli was easily killed by chlorine than poliovirus and coliphage f 2 . Further research demonstrated that when initial concentration of poliovirus and coliphage f 2 was n (PFU)≈1×10 5 mL -1 in water, the threshold doses of various disinfectants for complete inactivation of viruses were obtained. They were 16.0 mg/L of chlorine, 8.0 mg/L of chlorine dioxide, and a combination of equal doses of 5.0 mg/L chlorine and 5.0 mg/L chlorine dioxide, and 1.22 mg/L of ozone for poliovirus; 8.5 mg/L of chlorine, 5.0 mg/L of chlorine dioxide, and a combination of equal doses of 2.5 mg/L chlorine and 2.5 mg/L chlorine dioxide and 0.67 mg/L of ozone for coliphage f 2 , respectively. With reference to the above results the threshold doses of each disinfectant were also applied to the water source of Donghu Lake Water Works and the formation of chloroform (CHCl 3 ) and tetrachloride (CCl 4 ) were quantified. The amount of CHCl 3 produced by chlorination was greatly larger than that treated by other disinfectants. Tetrachloride was not found in all of samples. The organic in water treated by each individual disinfectant were extracted through a porous resin and then used for Ames test and GC/MS detection. The rusults showed that the water treated by chlorination had the highest mutagenicity among all of samples. A total of 118 organics were detected by GC/MS. The specific compounds identified were polycyclic aromatic hydrocarbon, alkyl benzene, phthalic esters, and so on. The phthalic esters were dominant compounds, most of which were known as U.S. EPA prior pollutants including some carcinogens, mutagens and teratogens. Tab 6, Ref 7