Effect of Base Type on Waste Activated Sludge Alkaline Fermentation and Dewaterability

摘要

Base type impacts significantly on waste activated sludge alkaline fermentation. Therefore, this paper investigated the hydrolysis, acidification characteristics and dewaterability of waste activated sludge under four types of anaerobic alkaline conditions, which were KOH, NaOH, Ca (OH) 2 and Na2CO3. Temperature was controlled at 35 °C, pH values were controlled at 10. It was concluded that (1) Under the KOH and NaOH condition, the hydrolysis ability of waste activated sludge was equivalent, and the concentration of solubilized SCOD and NH4+-N and PO43--P released were almost the same. Besides, the dewaterabiliy of the waste activated sludge under the KOH and NaOH condition were also equivalent, which were the worst of the four types of base. (2) Under the NaOH condition, the volatile fatty acid (VFA) production and total suspend solids (TSS) reduction were the best of the four types of base. (3) Under the Ca(OH)2 condition, the dewaterability of waste activated sludge is the best, and NH4+N and PO43--P released were the least, but the hydrolysis ability, acidification ability and sludge reduction were the worst. (4) Under the Na2CO3 condition, the hydrolysis ability and volatile suspend solids (VSS) reduction were the best, but NH4+-N and PO43--P released were the most.