连续流CSTR反应器中好氧污泥的颗粒化及其特性

AEROBIC ACTIVATED SLUDGE GRANULATION AND ITS CHARACTERISTICS IN A CONTINUOUS-FLOW COMPLETELY STIRRED TANK REACTOR(CSTR)

采用连续流完全混合反应器(CSTR)对好氧污泥的颗粒化进行试验研究。以乙酸盐作为碳源、由营养和微量元素配制的人工配水作原水(COD=150~500 mg/L、pH=6~7)、以污水处理厂活性污泥接种,在常温(25~30℃)条件下,经过20多天的运行,培养出外观为淡黄色、颗粒粒径为1~5 mm(平均为2~3 mm)的好氧颗粒污泥。污泥颗粒化过程由EPS作用下的自絮凝、大量丝状菌的缠裹及细颗粒间的黏附结合等作用产生,经过絮凝核的形成、絮凝核的黏附、颗粒的形成和颗粒的成熟等几个阶段。反应器运行稳定高效,在水力停留时间为2.82 h、COD有机负荷为4.24 kg/(m3.d)的条件下,COD、NH4+-N和PO43--P的去除率分别为85%~90%、90%和50%~70%。颗粒污泥具有极好的沉降性能,沉降速度达30~58 m/h。

The laboratory-scale study was carried out on the granulation and characteristics of aerobic activated sludge in a continuous-flow completely stirred tank reactor with a cetates as the carbon source and a prepared water by nutrients and other micro-elements as raw water(COD=150～500 mg/L,pH=6～7),which was inoculated with activated sludge from a municipal wastewater treatment plant. The results showed that the stramineous aerobic granule sludge of 1～5 mm in diameter(average 2～3 mm) was formed after 20 d operation at normal temperature(25～30℃).The granulation was accomplished via such consecutive processes as EPS self-flocculation,filamentous binding and attachment among the small-sized granules,and four steps including inner nucleus formation and flocculation,granule formation and maturation were found during the aerobic sludge granulation.The reactor was operated stably and efficiently,and the removal rates of 85%～90%,90% and 50%～70% for COD,NH^+_4-N and PO^3-_4-P respectively were obtained under the conditions of HRT being 2.82 h and organic loading rate 4.24 kg/(m^3·d).The aerobic granules show excellent settling performance with settling velocity of 30～58 m/h.