UASB处理纤维素乙醇废水的启动运行研究

以厌氧UASB反应器处理纤维乙醇废水为研究对象,探讨分析了UASB的启动和稳定运行过程。结果表明,采用城市污水处理厂的厌氧消化污泥作为接种污泥,在COD有效容积负荷为0.33~1.11 kgCOD/(m3·d)的条件下,UASB反应器成功启动,COD的去除率达到70%以上。启动初期,出水pH会明显高于进水,污泥呈先减少后增加的趋势,当增加进水SO42-浓度到7 250 mg/L,COD/SO42-比值2.7∶1时,会导致纤维素乙醇废水UASB处理系统的崩溃。UASB反应器运行稳定后,污泥浓度增至30~40 g/L,MLVSS/MLSS比值也达到90%左右,在HRT为14~41 h,回流比3∶1~13∶1,有效容积负荷3.45~14.67 kg COD/(m3·d)的条件下,对纤维乙醇生产废水均能保持90%以上的COD去除率,出水COD小于1 000 mg/L。

Study on Start-up Process of UASB Reactor For Treating Cellulosic Ethanol Wastewater

Taking treatment of cellulosic ethanol wastewater by UASB reactor as a researching object,the start-up process of UASB reactor was analyzed and discussed. The results show that, taking anaerobic digestion sludge from urban sewage treatment plants as started sludge, under the effective volumetric loading rate 0.33-1.11 kg COD/（m3.d） conditions,the UASB reactor can be successfully started, and COD removal efficiency can reach more than 70%. At the initial period of start-up,the effluent pH value is significantly higher than the influent pH value ,and the sludge decreases at the beginning and then increases. As the concentration of SO42-is increased to 7 250 mg/L and COD/SO42-ratio is 2.7：1, UASB treatment system for cellulosic ethanol wastewater will collapse. As the UASB reactor is in stable operation,the sludge concentration increases to 30-40 g/L, MLVSS/MLSS ratio reaches about 90%.Under the conditions of HRT 14-41 h, reflux ratio of 3：1 to 13：1 and effective volumetric loading rate 3.45-14.67 kg COD/（m3.d）, UASB reactor can maintain more than 90%COD removal rate for cellulosic ethanol wastewater, effluent COD is less than 1000 mg/L.