Kowbel D J, Ramaswamy S, Malaiyandi M, Nestmann E R
Environ Mutagen. 1986;8(2):253-62. doi: 10.1002/em.2860080207.
Aqueous residues of ozonated, chlorinated, and ozonated/chlorinated water fulvic acids (WFA) were tested for induction of His+ reversion in Salmonella typhimurium strain TA100 in fluctuation tests for mutagenicity. The data suggest that ozonation of natural organics present in sources of drinking water can prevent subsequent formation of by-products of chlorination that are mutagenic in bacteria. Ozonation of the WFA at different pH and at varying dose levels produced residues that were not or were only weakly mutagenic. Chlorination of WFA or of previously ozonated WFA led to residues that were highly mutagenic. However, mutagen formation in the ozonated/chlorinated residues could be prevented, depending upon the pH of the WFA solutions during ozonation-mutagenicity decreased as pH increased. This decrease in mutagenicity is associated with previous observations of enhanced ozone decomposition into its highly reactive oxidant species at higher pH. Since ozonation seems to be more effective at alkaline pH, alkaline raw water sources seem to be the best candidates for water treatment that involves ozonation.
在鼠伤寒沙门氏菌TA100菌株的波动试验中，对臭氧化、氯化以及先臭氧化后氯化的水体富里酸（WFA）的水相残留物进行了致突变性测试，以检测其诱导His+回复突变的能力。数据表明，对饮用水源中存在的天然有机物进行臭氧化处理，可以防止后续形成在细菌中具有致突变性的氯化副产物。在不同pH值和不同剂量水平下对WFA进行臭氧化处理，产生的残留物无致突变性或仅具有微弱的致突变性。对WFA或先前臭氧化的WFA进行氯化处理，会导致残留物具有高度致突变性。然而，根据臭氧化过程中WFA溶液的pH值，臭氧化/氯化残留物中的诱变剂形成可以得到防止——随着pH值升高，致突变性降低。致突变性的这种降低与之前在较高pH值下臭氧分解为高活性氧化物种增强的观察结果相关。由于臭氧化在碱性pH值下似乎更有效，碱性原水水源似乎是涉及臭氧化的水处理的最佳选择。
