Aluminum-based chemically enhanced primary sedimentation has seen increasing use in wastewater treatment plants. However, the derived sludge (Al-sludge) has low biodegradability due to the inhibition of Al-coagulants on organic hydrolysis, which increases the difficulty of sludge treatment and limits the potential for resource recovery. In this study, the effects of pH adjustment on the pretreatment and fermentation of Al-sludge was investigated, with a focus on sludge hydrolysis and production of volatile fatty acids (VFAs). The effects of abiotic and biotic hydrolysis on sludge disintegration, organics solubilization, and hydrolytic enzyme activity were also evaluated. The results show that adjustment of the pH to between 8.0 and 10.0 was more effective than adjustment to between 2.0 and 6.0 for sludge hydrolysis and subsequent VFA production. The enzymatic activities of protease and α-glucosidase showed a positive correlation with the pH values, leading to the highest VFA yield (275 mg-COD/g-VS) for the initial pH 10.0 condition, with 46% improvement over the control reactor (without pH adjustment). Semi-continuous fermentation was found to be more effective than batch fermentation for the biotic hydrolysis rate, k_H. Little phosphorus (<0.1 mg/L) was released from the Al-sludge into the fermented sludge liquor, so P removal was not necessary before the VFAs were used. The wastewater treatment process with Al-based chemically enhanced primary sedimentation and pH adjustment for enhanced sludge fermentation can recover 24% of organic carbon from domestic wastewater.

铝基化学增强的初次沉淀已在废水处理厂中得到越来越多的使用。然而，由于Al-凝结剂对有机水解的抑制作用，衍生的污泥（Al-污泥）具有较低的生物降解性，这增加了污泥处理的难度并限制了资源回收的潜力。在这项研究中，研究了pH调节对铝污泥的预处理和发酵的影响，重点是污泥的水解和挥发性脂肪酸（VFA）的产生。还评估了非生物和生物水解对污泥分解，有机物溶解和水解酶活性的影响。结果表明，对于污泥水解和随后的VFA生产，将pH调节至8.0至10.0比调节至2.0至6.0更有效。α-葡萄糖苷酶与pH值呈正相关，导致在初始pH 10.0条件下VFA产量最高（275 mg-COD / g-VS），比对照反应器提高了46％（无需调节pH）。发现半连续发酵在生物水解速率k _H方面比分批发酵更有效。铝污泥中几乎没有磷（<0.1 mg / L）释放到发酵污泥液中，因此在使用VFA之前无需去除P。采用基于Al的化学增强的初级沉淀和pH调节的污泥处理工艺可增强污泥发酵，可从生活污水中回收24％的有机碳。