CaO2投加量及投加方式对剩余污泥厌氧发酵产生短链脂肪酸的影响

以污水处理厂剩余活性污泥作为研究对象，在中温条件下，按照不同投加量和投加方式投加过氧化钙（CaO₂）进行预处理，考察其对污泥发酵产酸和产甲烷的影响，以期确定CaO₂最佳投加量和投加方式.结果表明，在（35±1）℃条件下，投加CaO₂可提高剩余污泥发酵液pH值，从而促进有机物的快速溶出.在同样投加剂量条件下，一次性投加比多次投加更有利于污泥的溶解以及短链脂肪酸的积累.当一次性投加0.2g CaO₂/g VSS时，发酵液中乙酸浓度在第7d达到最高值（169mg COD/g VSS），同时乙酸在6种主要酸中所占比例达到最大（71.0%）.与一次性投加方式相比较，多次投加CaO₂对产甲烷的抑制作用较小，不利于SCFAs的积累.

Effects of the dosage and dosing methods of CaO2 on the production of short-chain fatty acids produced during anaerobic fermentation of waste activated sludge

CaO₂ was added under mesophilic conditions for the pretreatment of waste activated sludge (WAS) obtained from wastewater treatment plants (WWTP). The effects of CaO₂ dosage and dosing methods on the acidification and methane production during anaerobic fermentation were evaluated. The aim was to find the optimum dosage and dosing method of CaO₂ for obtaining short chain fatty acids (SCFAs) from WAS. The results indicated that at (35±1)℃, CaO₂ addition could remarkably increase pH of the supernatant, thus accelerating the release of organic matters. Given the constant dosage, the once-and-for-all dosing of CaO₂ could enhance the solubilization of WAS and the accumulation of SCFAs much more effectively than multiple dosing of CaO₂. When CaO₂ was dosed at 0.2g/g VSS for once, the acetic acid concentration witnessed its highest level (169mg COD/g VSS) on day 7 and accounted for 71.0% of the total SCFAs, eclipsing all the other acids. Compared with the once-and-for-all dosing method, multiple dosing of CaO₂ resulted in less accumulation of SCFA due to weaker inhibition of methane production.