Study On Combined Biological Treatment Process Of High Concentrations Butyl-acrylate-producing Wastewater

According to the degradation properties of main organic pollutants in butyl-acrylate-producing wastewater, the enhanced removal of acrylic acid and p-toluenesulfonic acid in a microaerobic biological fluidized bed reactor was investigated. The influence of p-toluenesulfonic acid on methanogenic process was evaluated. A novel process for butyl-acrylate-producing wastewater treatment, which is combined of microaerobic biological fluidized bed and up-flow anaerobic sludge blanket (UASB) reactor and aerobic biological fluidized bed, is proposed in this study.It is indicated that, after sludge acclimation, the microaerobic biological fluidized bed reactor removed more than98.5%of acrylic acid, with effluent acrylic acid concentration below100mg/L under optimized operation conditions (hydraulic retention time (HRT) of12h, aeration rate of140L/h, the influent acrylic acid concentration of1000-6000mg/L, the influent p-toluenesulfonic acid concentration of50-1000mg/L). The rates of p-toluenesulfonic acid, COD and TOC were approximately10%,20%and30%respectively. Addition of Fe, Co and Ni of5mg/L,0.5mg/L and0.1mg/L, respectively, enhanced the removal of acrylic acid and p-toluenesulfonic acid.The removal of acrylic acid mainly occurred in the1st cell of the reactor, which contributed about95%of average removal rate. The main intermediate products of acrylic acid degradation by microbiological degradation are acetic acid and propionic acids. In the1st cell of the reactor can transform each1.00mol acrylic acid into0.227mol acetic acid and0.418mol propionic acid.The combined process was used for the treatment of high-concentration butyl-acrylate-producing wastewater. Acrylic acid and p-toluenesulfonic acid were removed completely. The removal rate of COD and TOC are approximately93%and97%with the effluent concentration are lower700mg/L and50mg/L, respectively, under the following conditions:total HRT of36h, the influent acrylic acid concentration of5500-7000mg/L, the influent p-toluenesulfonic acid concentration of800-1100mg/L. the acrylic acid volume load of11.0-14.0kg/(m3·d), the p-toluenesulfonic acid volume load of1.6-2.2kg/(m3·d).