研究了蛋白质在厌氧-缺氧-好氧城市污水处理系统中吸附和降解的特性,分别确定了蛋白质在厌氧、缺氧和好氧条件下的吸附等温线模型,建立了蛋白质在厌氧、缺氧和好氧状态下的降解动力学模型,并对模型预测结果进行了验证分析.结果表明,Freundlich模型可以较好地描述蛋白质在厌氧、缺氧和好氧污泥上的吸附过程,牛血清白蛋白水解成氨基酸是其生物降解过程的控速步骤.序批式动力学降解试验还表明,厌氧降解速率系数K厌、缺氧降解速率系数K缺与好氧降解速率常数的比值分别为0.40和0.98,说明在同一活性污泥系统的厌氧和缺氧条件下,蛋白质也能被较好地降解.模型得到的各池混合液出水中蛋白质的浓度模拟结果与实测结果相一致(相对误差〈10%).无论在厌氧、缺氧还是好氧环境中,酸溶蛋白质没有积累.
The removal characteristics by adsorption and degradation of proteins were studied in anaerobic/anoxic/ oxic (A/A/O) municipal wastewater treatment systems. The adsorption isotherms and the degradation kinetics of proteins by the sludge under anaerobic, anoxic and aerobic conditions were separately determined. The degradation model parameters were calibrated by the experimental data obtained from the performance of A/A/O system. The results showed that the adsorption of proteins onto the three kinds of sludge could be adequately described by Freundlich model. Hydrolysis rate was the key step in the degradation process of proteins. The ratios of protein degradation rate under anaerobic and anoxic conditions to that under oxic conditions were 0.4 and 0.98, respectively, indicating that protein was effectively degraded under anaerobic and anoxic conditions. The model was useful in forecasting the effluent quality of anaerobic, anoxic and oxic tanks in the A/A/O system, and the relative error was less than 10%. The accumulation of acid-soluble protein was not obseved in the anaerobic, anoxic and oxic tanks.