制革废水处理过程中磺胺类抗生素和抗性细菌的分布特征

针对两家制革厂废水处理过程中3种磺胺类抗生素和磺胺类抗性细菌的丰度和分布特性以及两个不同工艺污水处理厂对抗生素的去除规律做了相关研究.结果表明,3种抗生素在两家制革污水处理过程中均有检出,水样中3种抗生素的总质量浓度在59.1~706.7 ng·L~(-1)之间;两家制革厂废水处理剩余污泥中3种抗生素的总含量分别为4 388 ng·kg~(-1)和2 979.4ng·kg~(-1),与市政污水处理厂中的抗生素含量相差不大.不同的污水处理工段对3种抗生素去除效果不同,但去除效率均大于70%.生物处理单元对抗生素的去除率相对较高,而厌氧池是去除抗生素的主要阶段(去除率50%).两个制革厂的进出水和剩余污泥中共筛选出8株抗性细菌,这8个分离菌株可分为5个菌属.进出水中的抗性细菌含量介于9.37×10~3~5.08×10~5CFU·mL~(-1)之间,剩余污泥中的磺胺类抗性细菌含量较高分别为1.17×10`7CFU·g~(-1)和7.2×10~6CFU·g~(-1).两个制革污水处理厂对磺胺甲唑抗性细菌的去除率分别达到了1.34 log和2.15 log.

Distribution Characteristics of Sulfonamides and Sulfamethoxazole-Resistant Bacteria in Tannery Wastewater Treatment Processes

The study investigated abundance and distribution of three sulfonamides and sulfonamide-resistant bacteria in the wastewater treatment processes of two tannery wastewater plants, as well as the extent of their removal in different treatment units of the plants. Results showed that the three sulfonamides were detected in two different tannery wastewater treatment processes, with total content in water samples of 59.1-706.7 ng·L^-1. The content of sulfonamides in excess sludge samples from the two plants was 4388 ng·kg^-1and 2979.4 ng·kg^-1, respectively. Antibiotic content was therefore similar to that in municipal wastewater treatment plants. The three sulfonamides were removed in two different sewage treatment processes; both led to removal extents>70%. Antibiotic removal extent was relatively high in the biological unit, especially in anaerobic tanks (removal extent>50%). Eight strains of resistant bacteria were screened out from influent, effluent, and excess sludge samples of the two plants. These were identified as five kinds of sulfonamide-resistant bacteria. The content of resistant bacteria in influent and effluent was between 9.37×10³-5.08×10⁵ CFU·mL^-1and the content of sulfonamides was 1.17×10⁷ CFU·g^-1and 7.2×10⁶ CFU·g^-1in excess sludge samples. The removal extent of sulfamethoxazole-resistant bacteria in the two plants was 1.34 log and 2.15 log, respectively.