School of Environmental and Chemical Engineering, Shanghai University, No.99 Shangda Road, Shanghai, 200444, China.
School of Environmental and Chemical Engineering, Shanghai University, No.99 Shangda Road, Shanghai, 200444, China.
Chemosphere. 2021 Apr;268:129391. doi: 10.1016/j.chemosphere.2020.129391. Epub 2020 Dec 21.
The anaerobic fermentation (AF) of waste activated sludge (WAS) with an electrochemical pretreatment (EPT) was investigated to determine its correlation with the release of phosphorus and the disintegration of WAS. The sludge was pretreated by holding under 4.5 V for 60 min, followed by AF for 9 days. Untreated sludge was used as the control group (no-EPT). Results showed that, with pretreatment, the total dissolved P (TDP), orthophosphate (PO-P) and organic P (OP) reached the maximum values of 7.30 mg/L, 4.77 mg/L and 2.35 mg/L on day 8, respectively, which were approximately 5.3, 9.2 and 2.7 times greater than that in the control group. The analysis of soluble chemical oxygen demand (SCOD), protein and polysaccharides showed that the EPT promoted the disintegration of sludge, thereby enhancing the P release. The SCOD reached 1625 mg/L on day 6 in pretreatment experiment, which was about 9.8 times greater than that in control group. Additionally, the EPT contributed to fewer metal ions in sludge supernatant. This mechanism might have been due to the anions accumulating in the supernatant from the greater degree of sludge collapse after EPT, which caused the released metal ions to combine with anions to form insoluble compounds. In conclusion, EPT could be a promising method for the dissolution of sludge and the recovery of phosphorus from WAS under AF. Besides, the economic benefit evaluation showed the potential value of EPT for P recovery.
采用电化学预处理（EPT）对剩余活性污泥（WAS）进行厌氧发酵（AF），以确定其与磷释放和 WAS 解体的相关性。将污泥在 4.5 V 下保持 60 min 进行预处理，然后进行 9 天的 AF。未处理的污泥用作对照组（无 EPT）。结果表明，预处理后，总溶解磷（TDP）、正磷酸盐（PO-P）和有机磷（OP）在第 8 天分别达到 7.30mg/L、4.77mg/L 和 2.35mg/L 的最大值，分别约为对照组的 5.3、9.2 和 2.7 倍。对可溶化学需氧量（SCOD）、蛋白质和多糖的分析表明，EPT 促进了污泥的解体，从而增强了磷的释放。预处理实验中 SCOD 在第 6 天达到 1625mg/L，约为对照组的 9.8 倍。此外，EPT 有助于减少污泥上清液中的金属离子。这种机制可能是由于 EPT 后污泥解体程度更大，导致上清液中阴离子积累，使释放的金属离子与阴离子结合形成不溶性化合物。总之，EPT 可以成为一种很有前途的方法，可用于在 AF 下溶解污泥并从 WAS 中回收磷。此外，经济效益评估显示了 EPT 回收磷的潜在价值。
