产甲烷改良UASB启动试验及最优水力条件研究

在中温两相厌氧工艺处理玉米酒精废水的基础上,进行产甲烷改良UASB的启动试验和颗粒污泥的培养,考察水力条件对反应器处理效果的影响。试验采用低负荷启动方式,通过增大处理量和提高进水COD浓度逐级提高容积负荷,通过强制内回流控制反应器中水力条件,使产甲烷改良UASB在最佳条件下运行。63 d后反应器中形成的污泥床颗粒化程度高,粒径>0.7 mm的颗粒污泥占82%以上,产气速率和COD去除率分别达到539 L/d和90%,产甲烷改良UASB启动顺利完成;改良UASB作为两相厌氧工艺的产甲烷相可以自行调节其进水pH,启动时pH的人工调节可以在反应器进入颗粒污泥成熟期时停止;反应器的最佳水力条件为:上升流速为0.62 m/h、回流比300%;最优操作条件下产甲烷改良UASB具有良好的抗冲击负荷能力。

Start-up and Optimum Hydraulic Conditions of Methanogenic Improved UASB

Based on mesophilic two-phase anaerobic reactor treating corn ethanol wastewater,the start-up,cultivation of granular sludge and optimum hydraulic conditions of methanogenic improved UASB were studied.Methanogenic improved UASB was operated under the optimal conditions with start-up at low loading rate,increasing volume loading rate stepwise by increasing treatment capacity and influent COD as well as regulating hydraulic conditions through internal circulation.After 63 d of operation,the granulated degree of the formed sludge bed was high,over 82% of total granular sludge was more than 0.7mm,bio-gas production rate and COD removal rate achieved 539 L/d and 90% respectively.The start-up of methanogenic improved UASB was accomplished successfully.Improved UASB,as methanogenic phase of two phase anaerobic process,can adjust pH value of influent automatically.The manual regulation of pH value during start-up could be stopped when the granular sludge in methanogenic improved UASB going into maturity stage.The optimum hydraulic conditions of methanogenic improved UASB were up-flow velocity 0.62 m/h,return mixed liquid ratio 300%.The methanogenic improved UASB has excellent properties of loading shock resistance under optimum hydraulic conditions.