Abstract：Experiments were carried out to investigate phosphate release mechanism according to the variations of phosphate and related parameters during anaerobic fermentation of enhanced biological phosphorus removal (EBPR) sludge in the presence of different initial acetate concentrations. The results indicated that the initial acetate concentration did not significantly affect the maximum level of the released phosphate concentration. During the fermentation, (73.1±2.2) % of total phosphorus (TP) could be released in the form of phosphate into liquid phase, and it was mainly from the decomposition of polyphosphate. The decomposition pathways of polyphosphate include: 1) Anaerobic biological phosphorus release mechanism that polyphosphate accumulating organisms (PAOs) take up acetate and store it as polyhydroxyalkanoate (PHA); 2) direct decomposition of polyphosphate due to PAOs maintenance. When the initial acetate was insufficient, biological phosphorus release was limited and polyphosphate was decomposed in a relatively slow rate. When the acetate concentration increased, the biological phosphate release rate increased. Moreover, the increased content of PHA accelerated sludge hydrolysis and acidification. PO43--P and Mg2+ concentrations slightly decreased after their maximum levels were reached, because they were precipitated probably in the form of struvite. According to the above results, strategy for recovering phosphorus from phosphorus-rich sludge is proposed: adding some carbon source before sludge anaerobic digestion so as to recover phosphate from the separated supernatant within 24h of anaerobic fermentation. Thus, it can not only speed up and maximize phosphate release and minimize the block of pipes due to precipitation, but also avoid the inhibition of high phosphate concentration on anaerobic digestion.
陈文玲, 王如意, 李咏梅. 富磷污泥厌氧发酵过程中乙酸浓度对磷释放的影响[J]. 中国环境科学, 2015, 35(6): 1763-1770.
CHEN Wen-Ling, WANG Ru-Yi, LI Yong-Mei. Effect of acetate concentration on phosphate release during anaerobic fermentation of phosphorus-rich sludge. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(6): 1763-1770.
