序批式气提生物反应器(SABR)处理氯苯胺类有机废水好氧污泥颗粒化研究

Granulation of aerobic sludges in sequencing airlift bioreactor(SABR) for the treatment of chloroanilines-containing organic wastewater

研究了序批式气提生物反应器(SABR)处理氯苯胺类(CAs)有机废水过程中好氧污泥的颗粒化.SABR运行15d后,反应器内出现细小污泥颗粒,通过缩短循环时间与污泥沉降时间,并逐步提高COD与CAs进水负荷,SABR运行48 d后污泥颗粒化明显;反应器在循环时间为12 h、污泥沉降时间为6 min、表面气速为2 4 cm·s-1、COD负荷为1.0～3.6 kg·m-3·d-1、CAs负荷逐步提升至800 g·m-3·d-1的条件下继续运行50d,SABR污泥颗粒化趋于成熟,COD、CAs去除率稳定在90%、99.9%以上.根据污泥形态、最小沉降速率、SVI和目标污染物降解性能的变化,好氧污泥颗粒化过程可分为启动期、颗粒污泥形成期、生长期和成熟期.成熟好氧颗粒污泥粒径为0.9～2.5 mm,平均颗粒密度为64 g·L-1(以MLVSS计),污泥最小沉降速率为68.4 m·h-1,SOUR为167 mg·g-1·h-1;颗粒污泥外形为圆形或椭圆形,呈橙黄色,结构较致密,颗粒内外分布有丰富的类球菌、类短杆菌,与胞外多聚物交织共存.

The granulation of aerobic sludges in Sequencing Airlift Bioreactor （SABR） for the treatment of chloranilines（ CAs）-containing organic wastewater was investigated. Aerobic granules were observed after start-up for 15 days. The granulation of aerobic sludges was apparently developed after 48 days of operation along with gradual increases COD and CAs loadings, as well as the decreases of cycle time and settling time. Since then and within the subsequent 50 days, the granulation of aerobic sludge tended to mature while the removal efficiencies of COD and CAs were maintained around 90% and 99.9%, respectively. When SABR was continuously operated in 12h cycle time with settling time of 6 min, superficial air velocity of 2.4 cm·s^-1 , COD loadings of 1.0 - 3.6 kg·m^- 3·d^- 1 and CAs loadings increased from 560 to 800 g·m^- 3· d^- 1 . The process of sludge granulation could be divided into four different stages such as startup, granules formation, growth and maturation, based on the changes of sludge morphology, minimal settling velocity, SVI and CAs-degrading performance. Mature granules in this study featured with diameter of 0.9 - 2.5 mm, average biomass density of 64 gMLVSS·l^-1 , minimal settling velocity of 68.4 m· h^-1 and SOUR of 167 mgDO· gMLVSS^-1 · h^-1 . The aerobic granules were found in shape of rotundity and/or ellipse with colour of orange and comparably dense structure, which consisted of a wide variety of heterotrophic bacteria （including rods-like and cocci-like）, interlacing with extraeelluar polymers. Results demonstrated that aerobic sludge granulation was feasible in SABR for treatment of CAs-containing organic wastewater, and could be exploited to increase stability and efficiency of bioreactors.