UASB+MBBR组合工艺处理城市污水减量剩余污泥的试验研究

TREATING MUNICIPAL WASTEWATER AND REDUCING EXCESS SLUDGE BY COMBINED PROCESS OF UASB +MBBR

以西安市邓家村污水处理厂污水为进水,研究了上流式厌氧污泥床反应器(UASB)与紊动床生物膜反应器(MBBR)组合工艺在常温条件下处理城市污水的运行效果及其在污泥减量化方面的优势。连续4个多月的运行结果表明,当UASB和MBBR水力停留时间分别为7.7h和10.3h时,组合工艺对TCOD和SS的平均去除率分别达到77.8%和92.5%,出水平均值分别为75.7mg·L-1和17.3mg·L-1;对氨氮的去除率平均达到98.7%,最终出水氨氮质量浓度小于1mg·L-1,均可达到二级排放要求。另一方面,组合工艺污泥的表观产率为0.32kgVSS·kgCOD-1,与常规活性污泥法相比剩余污泥减量可达20%～40%。

The removal efficiency of pollutant and reduction of excess sludge by a combined process of UASB and MBBR were studied. The wastewater from Dengjiacun Sewage Treatment Plant in Xi＇an was adopted as influent. The experiment result of continuous operation for 4 months showed that the average removal efficiency of TCOD and SS reached 77.8% and 92.5% respectively with the average effluent concentration of TCOD and SS being 75.7 mg·L^-1 and 17.3 mg·L^-1 under the condition of HRT in the UASB and MBBR being 7.7 h and l 0.3 h respectively. At the same time, the average removal efficiency of ammonia nitrogen reached 98.7%with the average effiuent concentration of NH4^＋ -N below 1mg·L^-1. So the average concentration ofcarbon and ammonia nitrogen in the effluent attained the discharge standard of Ⅱ grade. On the other band, the observed yield of sludge was 0.32 kgVSS·kgCOD^-1 in this combined system which made the reduction of excess sludge reached 20%-40% compared with the activated sludge process.