Study On The Treatment Process Of Corn Ethanol Wastewater

This research was based on a project of Anhui BBCA Biochemical Co., which is one of the four exemplary projects in China.The background of research was a wastewater treatment project of its ethanol plant with 320,000 tons products annually. The fermentation in clarifying solution which was different from the traditional ethanol method was used by BBCA group. According to the characteristic of ethanol wastewater, and the pretreatment -- two anaerobic -- two aerobic process was used to treat ethanol wastewater.First-class and Second-class anaerobic technology processes were 3 MIC (Multi-Internal Circulation reactor) reactors respectively. The volume of every reactor is 4000m3, which is one of the biggest MIC reactor .But production scale of anaerobic reactor need a long cycle of start-up , which restricted anaerobic technology to apply . The digested sludge of municipal sewage treatment factory was used to start-up MIC reactor quickly. Quick start-up for anaerobic technology was solved, BBCA group Group ethanol wastewater reached standards and Smooth operationThe granular sludge cultivate process was divided into three stages: the sludge taming , the granular sludge forming and its maturing .Many factors,such as the COD(Chemical Oxygen Demand),pH of the influent and effluent, the removal rate of COD, the volumetric loading, and VFA et al. were analyzed as time changes in the different training periods .The shape and the color of the particle size of sludge were observed ,and the particle size and distribution and granular sludge settlement were discussed .The MIC reactor was applied to ethanol wastewater treatment successfully.The volumetric loading of MIC reactor influent was about 20kgCOD/ (m3·d), the COD removal rate would remain above 90%. The relationship between Granular sludge sedimentation properties and particle size was close, the larger size of the sludge the better to settle.Sludge diameter rise from the size of the initial training 0.2mm growth to 3mm when it was maturity, a quick start-up was achieved.