摘要
为评价某石化混合废水的毒性,采用活性污泥耗氧速率抑制试验研究不同φ(石化废水)对活性污泥中不同菌群的抑制及其影响因素.结果表明,所用石化废水对活性污泥中的硝化细菌具有明显毒性,其EC_(50)(半抑制效应浓度,以φ计)为9%左右;同时,该废水对异养菌的耗氧具有较强的促进作用,φ(石化废水)为100%时IH(异养菌耗氧速率抑制率,131%)最高,这种促进作用对R_T(总耗氧速率)测定有显著影响(R=0.991,P<0.05),因此,仅以RT评价废水毒性容易造成对废水真实毒性的低估.5种常见易降解基质(乙酸钠、葡萄糖、甲醇、生活污水、丙酸钠)中,ρ(甲醇)为15 mg/L时对异养菌促进效果显著(P<0.05),促进率达50%以上;而在高浓度条件下,乙酸钠、葡萄糖、甲醇、丙酸钠对异养菌均有显著促进作用(P<0.05),R_H(异养菌耗氧速率)最高提高了182%.研究显示,石化废水中的乙酸盐等易降解成分是活性污泥耗氧速率抑制试验的重要干扰因素.
An activated sludge oxygen uptake inhibition test was used to evaluate the toxicity of a petrochemical wastewater after biological treatment. Anomalies were found that oxygen uptake could be inhibited in low concentrations and promoted in high concentrations. The causes of interference were analyzed in this study. The petrochemical wastewater had severe toxicity on the nitrifying bacteria in activated sludge, with its EC50 being about 9%. The oxygen consumption of heterotrophic bacteria was accelerated by the petrochemical wastewater. IH（promoting rate） even reached 131% by 100% wastewater. As the influence of acceleration was greater, total oxygen uptake rate showed a promotion of 47%. Therefore, the total oxygen uptake rate of the whole activated sludge would lead to underestimation of the toxicity. The influence of readily degradable substances on the oxygen consumption by heterotrophic bacteria in activated sludge was also analyzed. Methyl alcohol promoted the rate of 50% at low concentration（15 mg/L） of readily degradable substances, while sodium acetate, glucose, methanol and sodium propionate had the most obvious effects at high concentrations, and the promoting rate was about 182%. The effect of readily degradable substance, such as acetate and propionate, on the RT showed that the readily degradable substance such as acetate in the petrochemical wastewater used in this study was responsible for promoting the heterotrophic oxygen consumption.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2016年第1期92-98,共7页
Research of Environmental Sciences
基金
国家水体污染控制与治理科技重大专项(2012ZX07201-005)
关键词
石化废水
耗氧速率
异养菌
硝化细菌
易降解基质
petrochemical wastewater
oxygen uptake rate
heterotrophic bacteria
nitrifying bacteria
readily degradable substance
