两级微氧EGSB同步处理焦化废水和剩余污泥

Simultaneous Treatment of Coking Wastewater and Excess Sludge Using Two-phase Oxygen-limited EGSB Reactor

为实现焦化废水和剩余污泥的同步高效处理,采用两级微氧EGSB反应器系统,通过交叉回流的运行方式,对COD、挥发酚、CN^-、SCN^-、NH_3-N、NO_3^--N和TN的去除效果及反应器内污泥量和污泥活性的变化情况进行了研究。结果表明:交叉回流两级微氧EGSB反应器系统能同步高效处理焦化废水和剩余污泥,对焦化废水中COD、挥发酚、CN^-、SCN^-、NH_3-N、NO_3^--N和TN的平均去除率分别为86. 7%、100. 0%、96. 6%、97. 3%、96. 5%、92. 2%和74. 3%。在稳定运行阶段,获得高污染物去除率的EGSBⅠ内的污泥处理率达到51. 19%～147. 81%。污泥表观产率平均为0. 01 kgMLVSS/kgCOD,处于较低水平,MLVSS/MLSS值从0. 36提高到0. 47,污泥中惰性难降解部分被有效去除,污泥能够保持较高的产甲烷活性。微氧所形成的厌氧/好氧交替或共存条件能够促进污泥中惰性难降解有机物的去除,反应器内长期处理焦化废水所形成的特殊菌群也能促进污泥中惰性成分的高效降解。

A cross-reCirculation two-phase oxygen-limited EGSB reactor system was employed to treat eoking wastewater and excess sludge simultaneously and efficiently. The removal efficiencies of COD, phenol, CN-, SCN-, NH3 -N, NO3- -N, and TN in coking wastewater were investigated, and the changes in sludge quantity and sludge activity were analyzed. The results showed that the system could simultaneously and efficiently treat the coking wastewater and excess sludge. The average removal rates of COD, phenol, CN- , SCN- , NH3 - N, NO3- - N and TN in coking wastewater was 86.7% , 100.0% , 96.6% , 97.3% , 96.5% , 92.2% , and 74.3% , respectively. In the stable operation stage, the removal efficiency of excess sludge was as high as 51.19% - 147.81% in EGSB I which achieved high pollutant removal rate. The average apparent yield of sludge was at a low level of 0.01 kgMLVSS/kgCOD. The MLVSS/MLSS value increased from 0.36 to 0.47, the inactive refractory organics was re- moved, and the methanogenic activity was kept at a high level. The microenvironment of anaerobic and/ or aerobic introduced by the oxygen-limited method strengthened the removal of bioinert refractory organ- ics in the sludge. Moreover, some special species of organisms existed in the sludge after treating coking wastewater for a long time promoted the efficient removal of bioinert refractory organics in the sludge.