SBR反应器处理番茄酱生产废水的污泥颗粒化过程

Sludge Granulation in SBR Reactor for Treatment of Tomato Paste Processing Wastewater

针对新疆番茄酱生产废水排放量大、污染严重的现状,在SBR反应器中接种絮状活性污泥,研究了逐步提高COD浓度条件下,污泥除污性能、外观形态、微生物活性与胞外聚合物(EPS)组成的变化规律。反应器运行38 d后,出现了粒径为427～502μm的椭球状颗粒污泥,颗粒污泥周围生物相丰富。颗粒形成后对COD、NH_4^+-N、PO_4^(3-)-P的平均去除率分别为96. 0%、97. 3%、95. 2%。培养50 d的颗粒污泥浓度、污泥体积指数(SVI5)、MLVSS/MLSS、沉降速率分别达到6. 1 g/L、23. 4 mL/g、93. 2%、33～44 m/h。在颗粒化过程中,PN/PS值由1. 82增至3. 17;激光共聚焦显微镜观察显示,蛋白质均匀贯穿整个颗粒截面且增加的速度明显大于多糖;α-多糖、β-多糖主要分布在颗粒外层,蛋白质和多糖共同构成了颗粒骨架。

A large amount of wastewater was produced during the production of tomato paste in Xinjiang,which caused serious pollution. In order to find a suitable treatment process,flocculent activated sludge was inoculated in SBR reactor,and its pollutants removal performance,appearance morphology,microbial activity and the composition of extracellular polymer substance (EPS) were studied under the condition of gradually increasing COD concentration. The results showed that ellipsoidal aerobic granular sludge (AGS) with the size of 427-502 μm appeared after 38 days of operation,and it was rich in biofacies after aerobic granulation. The average removal rates of COD,NH4+-N and PO43--P were 96. 0%,97. 3% and 95. 2%,respectively. The sludge concentration (MLSS),sludge volume index (SVI5),MLVSS/MLSS ratio,sedimentation rate were 6. 1 g/L,23.4 m L/g,93.2%,33-44 m/h after 50 days. During the granulation process,the ratio of protein to polysaccharide (PN/PS) increased from 1. 82 to 3. 17. Observation by confocal laser scanning microscopy revealed that protein was evenly distributed throughout the particle cross section and increased at a significantly faster rate than polysaccharides;α-polysaccharides and β-polysaccharides were mainly distributed in the outer layer of particles,and both protein and polysaccharide constituted the framework of AGS.