7种酚类化学物质对活性污泥的呼吸抑制作用

苯酚类化学物质是废水中常见的有机污染物,其对活性污泥的毒性数据对于污水处理厂稳定运行和化学品危害性评估具有重要意义。本研究采用活性污泥呼吸抑制试验(209)测定7种酚类化学物质对活性污泥的呼吸抑制作用。结果显示,2,6-二叔丁基苯酚和对特辛基苯酚对活性污泥未产生明显的毒性效应;2,4-二氯酚、2-苯基苯酚、4-硝基酚、4-氯酚和对甲酚等5种化学物质都对活性污泥呼吸有不同程度的抑制效应,3 h-EC50值分别为49.7、77.6、102、150.1和462 mg·L-1,构效关系分析结果表明-Cl、-NO2等官能团是导致活性污泥呼吸抑制效应增强的关键因素。在化学品生物降解性测试研究中,要确保有毒化学物质的测试浓度低于EC50值的1/10。

Respiratory Inhibition Effect of Seven Phenolic Chemicals on Activated Sludge

Phenolic chemicals are ubiquitous organic contaminants in wastewater. The toxicity data of those compounds on activated sludge is of vital importance to steady operating of sewage treatment plant and performing of chemicals hazard assessment. In this study, respiratory inhibition effect of seven phenolic chemicals on activated sludge was tested by employing the activated sludge respiration inhibition test (TG 209). The experimental results indicated that there is no significant respiratory inhibition effect on activated sludge for 2,6-Di-tert-butylphenol and 4-(1,1,3, 3-Tetramethy(butyl)-phenol. However, significant respiratory inhibition effect on activated sludge was observed for other five tested phenolic chemicals i.e. 2,4-dichlorophenol, 2-phenyl-phenol, 4-nitrophenol, 4-chlorophenol and p-cresol. And their 3 h-EC₅₀ values were 49.7, 77.6, 102, 150.1 and 462 mg·L^-1, respectively. The structure-activity relationship analysis results indicated that the functional groups such as -Cl, -NO₂ are key factors for strong inhibiting of activated sludge respiration. In addition, the results present here also imply that the tested concentration of those toxic compounds should be lower than 1/10 EC₅₀ in their biodegradability test.