Sludge anoxic dermentation and denitrification (SAFD) system was established by adding NO3 -N into the typical sludge anaerobic fermentation system. In SAFD, denitrifiers can utilize the carbon source generated in waste activated sludge (WAS) fermentation for denitrification. This system was aimed at dealing with the carbon source shortage and WAS treatment difficulties in waste water treating plants (WWTPs). The results indicated that suspended solid (SS) and volatile suspended solid (VSS) decreased by 63.8% and 74.7%, respectively, presenting a remarkable effect in sludge reduction when SRT = 60d. At the meantime, it showed a good denitrifying performance with complete removal of NO3 -N in the early period of the cycle. SAFD could achieve simultaneous fermentation and denitrification, indicating a better performance than typical anaerobic fermentation. Investigations into the denitrification rate during the cycle demonstrated that denitrification rate was higher in the early period (the 5th day) , while decreased gradually and denitrification was accompanied with the accumulation of volatile fatty acids (VFAs). Besides, pH and oxidation reduction potential (ORP) curves reflected the process capability level of fermentation and denitrification in SAFD system. Conclusions of this study could provide reference for technological upgrading of WWTPs.%引言rn城市污水生物处理系统反硝化的顺利进行通常需要足够的碳源保证[1],而我国大部分污水厂存在碳源不足的问题,许多工艺中外加碳源的投加[2-3]大大增加了运行成本及控制系统的复杂性.剩余污泥的处理处置是城市污水处理厂的另一重点和难点[4].为了实现剩余污泥的减量化和资源化[5-6],通常将其发酵产物作为生物碳源强化脱氮除磷,已有研究表明此种污泥内碳源相比乙醇等单一碳源更易被微生物利用[7-8].因此,利用污泥内碳源进行反硝化能够解决碳源不足和剩余污泥处理的双重问题.
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