四环素对活性污泥系统抑制性及其去除效果研究

Inhibitory Effect of Tetracycline on Activated Sludge System and Its Removal Efficiency

考察了四环素(TC)对活性污泥系统降解COD及污泥产率的影响,并研究了活性污泥系统对TC的去除效果。结果表明,TC对活性污泥产率及其降解底物的能力具有显著的抑制作用,其抑制性随着TC浓度的增大、MLSS的降低而愈加明显。当TC浓度由零升至20 mg/L时,系统对COD的去除率由89.2%降至39.1%,污泥表观产率由0.53 gMLSS/gCOD降为零,污泥停止生长;好氧活性污泥系统主要通过快速吸附作用去除水中的TC,在TC初始浓度分别为5、10和20mg/L时,系统对水相中TC的去除率分别达95%、91.24%和90.54%。随着TC浓度的升高和MLSS的降低,活性污泥对TC的吸附平衡时间延长,单位吸附量增大,吸附去除率降低。活性污泥对TC的吸附符合伪二级反应动力学模型(R2>0.999)。

The influence of tetracycline （TC） on COD removal and sludge yield in activated sludge system was investigated, and the removal efficiency of TC by activated sludge was studied. The resuits showed that the TC had significant inhibitory effect on the sludge yield and its ability in substrate removal. With the increase of TC concentration and the reduction of MLSS, the inhibitory effect became apparent. When TC concentration was increased from 0 to 20 mg/L, the removal rate of COD was decreased from 89.2% to 39.1%, the apparent sludge yield was decreased from 0.53 to 0 gMLSS/gCOD, and sludge growth stopped. The removal of TC from wastewater was achieved mainly via rapid adsorption on the sludge, and the removal rates of TC were 95%, 91.24% and 90.54% when its initial concentrations were 5, 10 and 20 mg/L, respectively. With the increase of TC concentration and the reduction of MLSS, the equilibrium time was prolonged, adsorption capacity increased and adsorption rate reduced. The adsorption of TC by activated sludge fit a pseudo second-order kinetics model （R^2 〉 0. 999）.