Acute toxicity and relationship between metabolites and ecotoxicity during the biodegradation process of non-ionic surfactants: fatty-alcohol ethoxylates, nonylphenol polyethoxylate and alkylpolyglucosides
Acute toxicity and relationship between metabolites and ecotoxicity during the biodegradation process of non-ionic surfactants: fatty-alcohol ethoxylates, nonylphenol polyethoxylate and alkylpolyglucosides
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DOI：
10.2166/wst.2009.266
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发表时间：
2009-01-01
影响因子：
2.7
通讯作者：
Lechuga, M.
中科院分区：
文献类型：
--
作者：
Jurado, E.;Fernandez-Serrano, M.;Lechuga, M.
用荧光细菌法测定了脂肪醇乙氧基酯、壬基酚聚氧基酸酯和烷基多糖苷的毒性值。此外，还确定了生物降解过程中代谢物与生态毒性的关系。生物降解试验是根据经合组织301 E现成生物降解性试验进行的。在这些试验中，作为微生物唯一碳源的表面活性剂溶液在矿物培养基中进行试验，在黑暗的有氧条件下接种和培养。表面活性剂的毒性与其分子结构有关（定量结构活性关系，QSAR）。对于烷基多糖苷，以EC50表示的毒性与表面活性剂的临界胶束浓度（CMC）、亲水性平衡（HLB）和疏水性烷基链(R)有关。结果表明，随着CMC的减少、疏水性的增加和R的增大，毒性增大。对于脂肪醇乙氧基醚，研究了HLB、环氧乙烷单位数和烷基链长度等参数。所发现的关系与增加烷基链长导致较低的EC50，而增加乙氧基化导致较低的毒性这一事实一致。对毒性和HLB行为的分析再次表明，HLB较小的表面活性剂毒性更大。在生物降解过程中研究了毒性的演变，以抑制百分比表示。除壬基酚聚氧乙酸酯外，所有非离子表面活性剂的毒性在生物降解试验的头几天和所有测试浓度下都有明显下降。
The toxicity values of fatty-alcohol ethoxylates, nonylphenol polyethoxylate, and alkylpolyglucosides have been determined by applying assays with luminescent bacteria. Also, the relation between metabolites and ecotoxicity during the biodegradation process has been determined. The biodegradation tests were carried out according to the OECD 301 E test for ready biodegradability. In these tests a solution of the surfactant, representing the sole carbon source for the microorganisms, was tested in a mineral medium, inoculated and incubated under aerobic conditions in the dark. The toxicity of surfactants is related to their molecular structure (Quantitative Structure Activity Relationships, QSAR). For the alkylpolyglucosides, toxicity expressed as EC50 is related with the critical micelle concentration (CMC), the hydrophiliclipophilic balance (HLB) of the surfactant, and the hydrophobic alkyl chain (R). The results indicate that toxicity increased as the CMC decreased and as the hydrophobicity increased and R rose. For fatty-alcohol ethoxylates, parameters characteristic studied have been HLB, number of units of ethylene oxide and the alkyl chain length. Relationships found are in agreement with the fact that increasing the alkyl chain length leads to a lower EC50, whereas increasing ethoxylation leads to a lower toxicity. An analysis of the behaviour of the toxicity and HLB again indicates that the toxicity was greater for surfactants with a smaller HLB. The evolution of the toxicity was studied over the biodegradation process, expressed as a percentage of inhibition. For all the nonionic surfactants assayed, except for the nonylphenol polyethoxylate, a major decline was found in toxicity during the first days of the biodegradation assay and at all the concentrations tested.