Abstract:Two chemical phosphates (AlPO4 and FePO4) were usually generated during chemical phosphorus removal processes in wastewater treatment plant. To investigate the release of chemical phosphates and biological phosphorus when each chemical phosphate was mixed with surplus active sludge (biological sludge) respectively for anaerobic fermentation, the two chemical phosphates were used. The results showed that in pure water, phosphorus could be released from AlPO4under either strong acid or strong alkaline conditions, and be released from FePO4only under strong alkaline conditions. For anaerobic fermentation of mixed sludge containing AlPO4at 35±1℃, more chemical phosphate could be dissolved under strong acid but microbial activity was inhibited, which was unfavorable to volatile fatty acid (VFA) production. Under alkaline conditions (pH=10~11), 28%~55% of the chemical phosphate and 43%~49% of the biological phosphorus were released and the total released phosphorus amount was 17.5%~62.7% higher than those under neutral condition. Alkaline conditions were also beneficial to VFA production; at pH=10 and pH=11, VFA production was 233% and 117% higher than those under neutral conditions, respectively. For anaerobic fermentation of the mixed sludge containing FePO4, 40% of chemical phosphate and 50% of the biological phosphorus in sludge could be released under neutral condition, which were higher than those under alkaline condition (pH=11).
张丽丽, 李咏梅. pH值对化学-生物混合污泥厌氧发酵释磷的影响[J]. 中国环境科学, 2014, 34(3): 650-657.
ZHANG Li-Li, LI Yong-Mei. Effect of pH on phosphorus release from chemical-biological mixed sludge during anaerobic fermentation. CHINA ENVIRONMENTAL SCIENCECE, 2014, 34(3): 650-657.