École Polytechnique de Montreal, Civil, Mineral and Mining Engineering Department, P.O. Box 6079, Station Centre-ville, Montreal, Quebec, Canada, H3C 3A7.
Environ Sci Technol. 2010 Dec 1;44(23):9055-61. doi: 10.1021/es102130b. Epub 2010 Nov 4.
Surface water sources are increasingly subject to proliferation of toxic cyanobacteria. Direct chlorination of source water containing toxic cyanobacterial cells for different treatment purposes might cause cell damage and toxin release. There is limited information available on chlorination of saxitoxins (STXs: saxitoxin, C-toxins, and gonyautoxins) produced by Anabaena circinalis. This work: (1) investigated the impact of chlorination on cell lysis and toxin/odor compound release in natural waters; (2) assessed the rates of chlorination of total STXs, and (3) estimated apparent rate constants for STX oxidation in ultrapure and natural waters. With a chlorine exposure (CT) value of 7.0 mg x min/L all cells lost viability causing toxin release. Cell-membrane damage occurred faster than released STXs oxidation. All saxitoxin and more than 95% of other STX analogues were subsequently oxidized. Kinetic analysis of the oxidation of STX analogues revealed significant differences in the susceptibility to chlorine, saxitoxin being the easiest to oxidize. Also, concentrations of trihalomethanes, haloacetic acids, and N-nitrosodimethylamine as chlorination byproducts were respectively <50 μg/L and 11 ng/L even at the highest CT value (50.3 mg x min/L).
地表水水源越来越容易受到有毒蓝藻的大量繁殖的影响。为了不同的处理目的，将含有有毒蓝藻细胞的原水直接氯化可能会导致细胞损伤和毒素释放。目前关于节旋藻产生的沙克毒素（STX：石房蛤毒素、C 毒素和冈田酸毒素）氯化的信息有限。这项工作：（1）研究了氯化作用对天然水中细胞裂解和毒素/气味化合物释放的影响；（2）评估了总 STX 的氯化速率，（3）估计了超纯水和天然水中 STX 氧化的表观速率常数。在氯暴露（CT）值为 7.0 mg x min/L 时，所有细胞均失去活力导致毒素释放。细胞膜损伤的速度快于释放的 STX 氧化速度。所有石房蛤毒素和超过 95%的其他 STX 类似物随后被氧化。STX 类似物氧化的动力学分析表明，它们对氯气的敏感性存在显著差异，石房蛤毒素最容易被氧化。此外，即使在最高 CT 值（50.3 mg x min/L）下，三卤甲烷、卤乙酸和 N-亚硝基二甲胺作为氯化副产物的浓度分别<50 μg/L 和 11 ng/L。
