饮用水消毒过程中剑水蚤对生物稳定性的影响及变化规律

Influence and Change Regularity of Cyclops on Biological Stability during Disinfection of Dringking Water

有机碳是控制饮用水中异养细菌繁殖的最主要营养物质,可同化有机碳(AOC)含量的高低被普遍认为是控制给水管网中细菌再生长的限制因素。该文以可同化有机碳(AOC)作为水质生物稳定性的评价指标,剑水蚤死体溶出物为试验对象,研究在不同影响因素下,氯和氯胺消毒对AOC的去除效果。研究结果表明,采用氯/氯胺消毒能够显著降低AOC浓度,且氯和氯胺消毒均在投量为10 mg/L时AOC为最低值。随着反应时间延长,氯化消毒后AOC浓度呈现先降低后增加再降低的趋势,在12 h这一阶段效果最好,AOC为1.55 mg/L;而氯胺消毒反应速率明显滞后于氯化消毒,在24 h这一阶段效果最好,AOC为3.72 mg/L。混凝烧杯试验结果表明,随着混凝剂投量增加,AOC显著降低,当混凝剂为40 mg/L时,经消毒后AOC浓度不足50μg/L。在反应温度逐渐升高的过程中,氯化消毒的效果明显好于氯胺消毒,随温度升高AOC的浓度降低,当温度为30℃时,氯胺消毒过程中AOC浓度反而增加。

The formation of assimilable organic carbon （AOC） was investigated during the chlorination/chloramination of Cyclops intracellular organic matter （IOM） under different conditions, to determine how the intracellular organic produced by the organisms affected water safety and the formation of AOC. The effects of chlorine and chloramine dosages, coagulant dosage, reaction time and temperature on the formation of AOC were investigated during the disinfection of Cyclops intracellular organic matter （IOM）. With increasing chlorination and chloramination dosages, AOC concentrations are moderated overall and trend to be minimum with 10 mg./L disinfections. Formation of AOC follows a decreasing and then increasing and decreasing pattern with prolonging reaction time. AOC concentration reduces to 1.55 mg/L at 12 hours with chlorine. While chloramine is a less effective disinfectant than chlorine, AOC concentration reaches to 3.72 mg/L the lowest value with 24 hours. The formation of AOC can be suppressed under coagulant condition. And when coagulant dosage is 40 mg/L, AOC concentration is less than 50 μg,/L. Furthermore, temperature by means of chlorination at 30 ℃ and chloramination at 20 ℃, lower AOC levels are displayed.