呼吸测量法测定废水中活性异养菌COD组分

废水中的活性异养菌(XH)会影响废水生物处理过程动力学,过程模拟需要对其定量表征.通过2种方法对城市污水中XH进行呼吸测量,分别结合XH最大比呼吸速率参数(P方法)和细胞生长过程模型拟合(F方法)测定其中的XH-COD组分.结果表明,F方法的测量结果是P方法的0.6～0.9倍,两者存在一定的丰廿关性;对于含高XH、低易生物降解基质(RBCOD)的废水,呼吸测量得不到明显的呼吸速率指数上升段,影响F方法的测定结果,水样稀释和外加RBCOD是可行的改进办法.使用P方法得到某城市污水厂进水的XH-COD占总COD的23%～46%(平均31%),高于多数文献报道结果.

Determination of active heterotrophic biomass-COD in wastewater using respirometry

Active heterotrophic biomass (X_H) in wastewater has influence on wastewater biological treatment process dynamics. So it is necessary to determine X_H in wastewater for process modeling. Two respirometric methods, combining the maximum specific oxygen uptake rate (OUR) of X_H (named P-method) and the fitting of X_H growth model (named F-method), were used to determine X_H-COD in wastewater. The results showed that F-method gives lower X_H than P-method (about 0.6~0.9 times), but the two methods are correlative to some extent. For wastewater with high X_H and/or low readily biodegradable COD (RBCOD), the visible OUR exponential increase phase can not be obtained and so the precise of F-method is affected. Diluting the wastewater samples and adding RBCOD can overcome this problem. The ratios of X_H-COD to total COD in wastewater used in this study are 23%~46% (average 31%), which are higher than those reported in most literature.