化学品快速生物降解性经典测试方法的要点比对

Comparisons of Classical Test Methods of Ready Biodegradability for Chemicals

通过分析六种经典快速生物降解性测试方法的试验原理、操作特点以及限制因素,指出最好根据受试物对活性污泥呼吸抑制的EC50和EC20值,选择试验方法、受试物浓度和接种物浓度。比对了各方法在受试物适用浓度范围、接种物来源和前处理、无机培养基的配制和预处理、质量控制等方面的要求,指出快速生物降解性测试严禁接种物在接种前接触受试物;接种微生物的来源可能对试验结果影响很大;各方法需要的接种物浓度不同,建议采用平板计数方法确定并调整细菌数;对接种物和培养基进行有效的预处理,可减少空白值。应注意防止滤膜过滤和离心过程产生的有机碳干扰DOC的分析。列举了测试过程中常见的问题,强调应根据降解曲线分析试验结果;尽快研发跨区域、多来源的标准接种物。

By of ready biod analyzing the experimental principle, operating feature and limited factors of six classical test methods egradability, it was pointed out that the suited test method, test substance concentration and inoculum concentration had better be selected according to the values of ECso and ECho of activated sludge from respiration inhibition test. After comparing the requirement on concentration ranges of test substances, source and pre- condition of inoculum, preparation and preliminary treatment of mineral medium, and validity of quality control of the six test methods, it was indicated that inoculum was forbidden to contact test substances before inoculating in all test methods of chemicals for ready biodegradability; different sources of inoculum might impact on test results greatly. Each method required different concentrations of inoculum, and it was suggested that bacteria should be enumerated by using plate-counting techniques and microbial cell densities controlled accordingly. The effective preliminary treatment of inoculum and mineral medium could reduce blank values. It was important to avoid organic carbon generated from filter membrane or centrifugation influence on analyzing DOC concentration. Frequent questions in test process were listed, and it was emphasized that test results should be estimated from degradation curve, and that trans-areas and multi-source standard inoculum should be researched and developed as soon as possible.