模拟人工湿地中基质酶对PhACs的动态响应

Dynamic response of substrate enzymes to PhACs in a simulated constructed wetland

基质酶是催化土壤生物化学反应的重要催化剂,其对有机污染物具有高度敏感性。实验测定了5座人工湿地(CWs)反应器中过氧化氢酶、脱氢酶和脲酶活性的动态变化及其与进水医药活性物质(PhACs)浓度、湿地植物的关系。结果显示:种植植物反应器3种基质酶的活性均高于未种植植物的反应器;随培养时间增长过氧化氢酶的活性逐渐提高,在培养150 d后达到最高;脱氢酶和脲酶的活性随培养时间增长先升高后降低,分别于120 d和90 d时达到最高;不同基质酶对不同PhACs浓度响应不同,脲酶活性均表现为被抑制,而脱氢酶和过氧化氢酶活性在低PhACs浓度时被激活,在高PhACs浓度时被抑制。为CWs应用于去除水环境中存在的PhACs类污染物提供参考。

Substrate enzymes are important catalysts that promote soil biochemical reactions and have high sensitivity to organic pollutants. In this study,dynamic changes in the activities of catalase,dehydrogenase,and urease in five constructed wetland（ CW） reactors and their relationships to the concentration of pharmaceutically active compounds（ Ph ACs） in the water and wetland plants were examined. All three substrate enzymes in reactors with plants demonstrated higher activity compared to that in reactors without plants. Catalase activity increased gradually with longer incubation durations and reached a maximum after 150 days. As the incubation duration increased,the activity of both dehydrogenase and urease increased and reached peaks after 120 d and 90 d,respectively,after which the activity levels declined. The substrate enzymes responded to differences in Ph AC concentration in different ways. Urease activity was suppressed in the presence of Ph ACs,whereas dehydrogenase and catalase were activated at low concentrations of Ph ACs and suppressed at a high concentration. These results provide a reference for the application of CWs to Ph AC pollutant removal in the water environment.