人工湿地处理四环素类抗生素废水时有机碳源的影响

Effects of different organic carbon sources on removal efficiency of tetracyclines from wastewater in constructed wetlands

研究了以葡萄糖和乙酸钠为碳源的条件下,垂直流人工湿地对四环素（TC）、土霉素（OTC）和金霉素（CTC）等3种四环素类抗生素（TCs）的去除效果。结果表明,在试验条件下,乙酸钠与葡萄糖两种碳源均能有效促进人工湿地系统对3种TCs的去除;在相同碳源条件下COD质量浓度越高,TCs的去除率越高,当COD质量浓度大于400mg/L时,对3种TCs的去除率均达到90%以上;垂直流人工湿地对TCs的去除过程包括2个阶段：前2 h为湿地基质吸附作用下的快速去除阶段,2-24 h为缓慢去除阶段。乙酸钠与葡萄糖两种碳源对TCs去除率的提高,主要发生在2h之后的第二个阶段,分析认为发生了微生物共代谢作用,促进了湿地系统对基质吸附富集之后的TCs的进一步降解。

The removal efficiency of three kinds of tetracyclines （ TCs ） including tetracycline （ TC ）, oxytetracycline （ OTC）, and chlortetracycline （CTC） from wastewater in the vertical-flow constructed wetlands （CWs） were investigated under the conditions of two different carbon sources （i. e. , glucose and sodium acetate）. The results show that both glucose and sodium acetate were highly efficient in the removal of TCs in the CWs. The removal rates of TCs were enhanced with the increase of COD concentration with the same carbon source. When the COD concentration was greater than 400 mg/L, the removal rates of TCs were above 90%. The removal process of TCs by vertical-flow constructed wetland included two stages： during the first two hours, TCs concentrations had a sharp decrease mainly due to the adsorption of the wetland substrate,and during the following 22 hours, the TCs concentrations continued to decline slowly. The improvement effect of sodium acetate and glucose on the TCs removal rate mainly occurred in the second stage after 2 hours. It is considered that cometabolism occurred in the CWs,which promoted the further degradation of TCs adsorbed to the wetland substrate.