Tobajas Montserrat, Verdugo Verónica, Polo Alicia M, Rodriguez Juan J, Mohedano Angel F
a Sección de Ingeniería Química, Facultad de Ciencias , Universidad Autónoma de Madrid , C/Francisco Tomás y Valiente, 7, 28049 Madrid , Spain.
Environ Technol. 2016;37(6):713-21. doi: 10.1080/09593330.2015.1079264. Epub 2015 Sep 11.
Several methods for evaluating the toxicity and biodegradability of hazardous pollutants (chlorinated compounds, chemical additives and pharmaceuticals) have been studied in this work. Different bioassays using representative bacteria of marine and terrestrial ecosystems such as Vibrio fischeri and Pseudomonas putida have been used to assess the ecotoxicity. Activated sludge was used to analyse the effect of those pollutants in a biological reactor of a sewage treatment plant (STP). The results demonstrate that none of the compounds is toxic to activated sludge, except ofloxacin to P. putida. The additives tested can be considered moderately toxic according to the more sensitive V. fischeri assays, whereas the EC50 values of the pharmaceuticals depend on the specific microorganism used in each test. Regarding the biodegradability, respirometric measurements were carried out for fast biodegradability assessment and the Zahn-Wellens test for inherent biodegradability. The evolution of the specific oxygen uptake rate (SOUR) showed that only diethyl phthalate was easily biodegradable and acetylsalicylic acid was partially biodegradable (98% and 65% degradation, respectively). The persistence of dichloromethane, ofloxacin and hidrochlorothiazide was confirmed along the 28 days of the Zahn-Wellens test whereas 1,1,1-trichloroethane showed inherent biodegradability (74% removal). Most of the chlorinated compounds, pharmaceuticals, bisphenol A and ethylenediaminetetraacetic acid were partially degraded in 28 d with total organic carbon (TOC) reduction ranging from 21% to 51%. Sulphamethoxazole showed certain biodegradation (50% removal) with TOC decrease around 31%, which indicates the formation of non-biodegradable by-products.
本研究探讨了几种评估有害污染物（氯代化合物、化学添加剂和药物）毒性及生物降解性的方法。采用不同的生物测定法，利用海洋和陆地生态系统中的代表性细菌，如费氏弧菌和恶臭假单胞菌，来评估生态毒性。活性污泥用于分析这些污染物在污水处理厂生物反应器中的影响。结果表明，除氧氟沙星对恶臭假单胞菌有毒外，其他化合物对活性污泥均无毒。根据更敏感的费氏弧菌测定法，所测试的添加剂可被视为中等毒性，而药物的半数有效浓度（EC50）值则取决于每次测试中使用的特定微生物。关于生物降解性，进行了呼吸测量以快速评估生物降解性，并采用赞恩-韦伦斯试验评估固有生物降解性。特定氧摄取率（SOUR）的变化表明，只有邻苯二甲酸二乙酯易于生物降解，乙酰水杨酸部分可生物降解（分别降解98%和65%）。在赞恩-韦伦斯试验的28天中，二氯甲烷、氧氟沙星和氢氯噻嗪的持久性得到证实，而1,1,1-三氯乙烷显示出固有生物降解性（去除率74%）。大多数氯代化合物、药物、双酚A和乙二胺四乙酸在28天内部分降解，总有机碳（TOC）减少21%至51%。磺胺甲恶唑有一定的生物降解（去除率50%），TOC下降约31%，这表明形成了不可生物降解的副产物。
