CaCO_3与接种污泥预结合对好氧污泥颗粒化的影响

EFFECT OF PRE-BONDING CaCO_3 WITH SEED SLUDGE ON GRANULATION OF AEROBIC SLUDGE

通过培养前添加Ca^(2+)和CO_3^(2-),使CaCO_3与接种污泥预结合实现好氧污泥快速颗粒化。添加Ca^(2+)和CO_3^(2-)后由真空脱水和网格切割后得到的紧凑污泥颗粒称为物理颗粒污泥(PGS)。物理颗粒污泥进行培养后在15 d内完成颗粒化,具有浓度极高的混合液挥发性悬浮固体(MLVSS),其值可达8 763 mg/L,且具有优良的总氮(TN)去除率。SEM-EDX分析表明:由许多富含Ca的球体构成的PGS可能是CaCO_3和污泥的混合物,在20 d时污泥中还含有丰富的Ca元素,包括CaCO_3。富含Ca的球体发挥了骨架作用,使PGS具有多孔结构,有利于营养转移和保持良好的沉降性,防止生物量的损失,并有助于提供更多的造粒载体。

Numerous researches were carried out to enhance sludge granulation by increasing the concentration of Ca2＋ in feeding water. And we added Ca2＋ and CO2-3 to make CaCO3 pre-bonded with seed sludge before cultivation to realize rapid aerobic granulation in this study. Compact sludge particles named as physical sludge granules （PGS） was obtained by vacuum dewatering and cutting by a 14-mesh after adding Ca2＋ and COl-. Granulation was completed by this method within 15 days, with an extremely high mixed liquor volatile suspended solid （MLVSS） of 8 763 mg/L and preferable removal rate of total nitrogen （TN）. Scanning electron microscope and energy dispersive X-ray detector （SEM-EDX） analysis showed that the PGS constructed by many Ca-rich spherules which could be the mixture of CaCO3 and sludge, and the sludge still contained rich Ca elements including CaCO3 on day 20th. The connected Ca-rich spherules played a role of skeleton to make the PGS was to have porous structure in favor of nutrients transfer, keep well settleability preventing the loss of biomass and help to provide more carriers for granulation.