投加粉末活性炭强化好氧颗粒污泥的稳定性

Enhancement of Stability of Aerobic Granules by Powdered Activated Carbon Addition

好氧颗粒污泥系统稳定运行一段时间后,往往会发生颗粒污泥解体现象,系统内水力选择压与基质选择压之间的平衡失调,是导致颗粒污泥解体、系统失调的内在诱因.采用了投加粉末活性炭(PAC)强化好氧颗粒污泥稳定性的调控措施.结果发现,PAC的投加对污泥物理性状及微生物生长动力学方面影响明显:投加PAC可以强化系统内水力选择压,提高污泥的湿密度和强度,降低污泥生长速率和产率,调节污泥浓度和粒径大小,降低粒径分布分散化的趋势,避免因传质阻力引起的颗粒内部分裂,保证好氧颗粒污泥系统持久维持稳定.PAC的投加对污泥化学性状影响甚微:不管投加PAC污泥与否,在颗粒污泥形成过程中均伴随着胞外蛋白浓度的增加及污泥表面相对疏水性的上升.

Due to the disorder of balance between hydraulic and substrate selective pressures, a great quantity of aerobic granules began to break down into flocculent sludge after a while of stable operation period. Powdered acti- vated carbon （PAC） was used to regulate the hydraulic selective pressure and strengthen the stability of aerobic gran- ules. Experimental results showed that PAC addition had great effects on the physical properties of sludge and micro- bial growth kinetics： PAC addition could enhance granular wet density and strength, slow down the sludge growth rate and yield rate, moderate the sludge concentration and size, and reduce the dispersion trend of size distribution, so as to avoid internal segmentation of granule and improve the stability of aerobic granular sludge system. PAC addition had little effect on the chemical properties of sludge： the aerobic granulation process was accompanied with increments of extracellular protein content and surface relative hydrophobicity, whether PAC was added or not.