SFBR中好氧颗粒污泥的培养及特性研究

Research on Cultivation of Aerobic Granular Sludge and Its Characteristics in Sequencing Fed Batch Reactor

接种自行培养的活性污泥,以模拟废水为基质,采用连续进水、间歇出水及厌氧/好氧交替的运行模式,尝试了在SFBR中进行好氧颗粒污泥的培养,并研究了好氧颗粒污泥的特性及反应器对污染物的去除效果.结果表明,通过逐步缩短沉降时间,28 d时成功培养出好氧颗粒污泥,所形成的好氧颗粒污泥呈黄色、形状不规则,且粒径较小(平均粒径0.56 mm),正常情况下的SVI保持在70 mL·g-1以下,EPS在59 d时达到最大值(以MLVSS计)373.24 mg·g-1,较培养初期增加了约2.5倍,运行后期由于颗粒出现解体,导致EPS急剧下降;反应器在运行过程中未能保持较高的污泥量,中后期MLSS始终在3 000mg·L-1以下;在63 d的运行时间里,除异常波动外,反应器对COD的去除率基本维持在90%左右,正常情况下出水COD小于100 mg·L-1,反应器对NH+4-N、TIN的去除效果波动较大,去除率分别为44.45%~94.72%及43.87%~93.13%,反应器对TP的去除率在44.50%~97.40%之间,正常情况下TP去除率可维持在60%以上;限于自动控制水平,夜间长时间的好氧饥饿期容易造成丝状菌过度生长,使得AGS在生长竞争中处于劣势,最终导致了AGS的解体.

Aerobic granular sludge was cultivated in the sequencing fed batch reactor,and granules' characteristic and reactor's performance to the pollutants were studied. The SFBR was operated under the conditions as: inoculated with activated sludge former self-cultivated,fed with simulated wastewater,and continuous feed / intermittent discharge and alternately anaerobic / aerobic operation mode. The results showed that through gradually decreasing the settling time,aerobic granular sludge was successfully cultivated in 28 days,which was yellow,irregular shape,and small particle size( the average particle size was 0. 56 mm). Under normal circumstances,the SVI stayed under 70 mL·g- 1. EPS( as MLVSS) reached the maximum 373. 24 mg·g- 1on the 59 d,which increased about 2. 5 times over the inoculums. However,EPS decreased sharply during the later period due to the disintegration of aerobic granular sludge. MLSS was always below 3 000 mg·L- 1during the middle and later periods in the reactor. During the 63 days' operation,the removal rate of COD by the reactor maintained at about 90% except the abnormal circumstances,and the effluent COD was less than 100 mg·L- 1. TIN and ammonia nitrogen's removal efficiency by the reactor fluctuated greatly,and the removal rates were 44. 45%-94. 72% and 43. 87%-93. 13% respectively. The removal rate of TP was between 44. 50%-97. 40%,which could remain above 60% under normal circumstances. Limited to the automatic control level,AGS was disadvantage in the competition with filamentous bacteria that overgrew easily during the long time aerobic starvation period at night,which eventually led to the collapse of AGS.