合流污水固形物自然沉降性能研究

Sedimentation property study on suspended solids of combined sewage

采用累积沉降法对合流污水悬浮固体(SS)进行自然沉降试验研究及与化学需氧量(COD)、总氮(TN)、总磷(TP)、氨氮(NH4+-N)相关性分析,研究结果表明:合流污水沉降30 min,SS的去除率即达到88.69%,在沉降初期可去除大部分污染物;经沉降120 min,SS的去除率即可达96.14%,COD、TN、TP和NH4+-N的去除率分别为90.63%、54.22%、66.95%和4.1%;在自然沉降过程中,合流污水中的污染物COD、TN、TP浓度变化规律与SS的浓度变化规律有极显著的正相关性,线性方程分别为y=79.99+0.66x、y=21.58+0.65x、y=5.44+0.17x,相关系数R2分别达到0.974、0.961、0.989,而NH4+-N在合流污水中基本上都是以溶解态存在,与SS的沉降关联不大,去除率随SS的去除变化较小;初始SS浓度对合流污水沉降性能影响显著,初始浓度越高,一定时间内去除率越高,并通过对各污染物沉降规律的函数拟合得出COD、TN、TP、SS自然沉降规律函数分别为y=1020.61e(–x/10.05)+92.49、y=28.2e(–x/6.92)+22.56、y=13.24e(–x/10.0)+5.69、y=1533.22e(–x/8.58)+47.03,相关系数分别为R2=0.972、R2=0.936、R2=0.938、R2=0.914。

Natural sedimentation experiments on suspended solids（SS） of combined sewage were conducted through accumulative sedimentation, as well as relative analysis with chemical oxygen demand（COD）, total nitrogen（TN）, total phosphorus（TP） and ammonia nitrogen（NH4＋-N）. Results showed that most pollutants can be removed with 88.69% removal of SS in initial stage after sedimentation for 30 min. After 120 min removal of SS amounted to 96.14% and that of COD, TN, TP and NH4＋-N was 90.63%, 54.22%, 66.95%, 4.1%, respectively. In the process of the sedimentation, concentrations change rules of COD, TN, TP had positive correlations with that of SS. Linear equations were y=79.99＋0.66 x, y=21.58＋0.65 x, y=5.44＋0.17 x and correlation coefficients were 0.974, 0.961, 0.989. However, NH4＋-N was just on the contrary for its dissolving property. We also studied influence on the removal rate of the initial concentration of SS and removal rate was high with high initial concentration. We got sedimentation laws of COD, TN, TP, SS through function fitting of experimental data and fitting functions were y=1020.61e（–x/10.05）＋92.49, y=28.2e（–x/6.92）＋22.56, y=13.24e（–x/10.0）＋5.69, y=1533.22e（–x/8.58）＋47.03 with correlation coefficient of 0.972, 0.936, 0.938, 0.914 respectively.