State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
J Hazard Mater. 2022 Feb 5;423(Pt A):127022. doi: 10.1016/j.jhazmat.2021.127022. Epub 2021 Aug 24.
At present, the bioproduction of short-chain fatty acids (SCFAs) from waste activated sludge (WAS) has attracted worldwide attention due to the demand of carbon neutrality during waste treatment. Calcium peroxide (CaO) has been reported to be an effective method for the solubilization of WAS and the accumulation of SCFAs, but the high reagent cost limits its industrial application. Therefore, free nitrous acid (FNA) was introduced into the WAS pretreatment system to assist with CaO for enhancing the disruption of extracellular polymeric substances (EPS) and the subsequent acidogenesis process. The results showed that FNA and CaO synergistically enhanced EPS decomposition and the release of biodegradable organic compounds during pretreatment. The highest soluble chemical oxygen demand (3.1- and 2.6-fold higher compared to individual pretreatments at the same concentrations) after pretreatment and the highest SCFAs accumulation (2.0- and 6.4-fold compared to individual pretreatments at the same concentrations) after a 2-day fermentation period was observed in the FNA + CaO (0.15 g/g VSS) co-treated group. Therefore, the FNA + CaO (0.15 g/g VSS) co-treatment was determined to be the optimal strategy for ensuring the disintegration of the EPS matrix and enhancing the accumulation of SCFAs in pretreated sludge during anaerobic digestion.
目前，由于在废物处理过程中需要实现碳中和，因此从废活性污泥（WAS）中生物生产短链脂肪酸（SCFAs）引起了全世界的关注。过氧化氢钙（CaO）已被报道是一种有效溶解 WAS 和积累 SCFAs 的方法，但高试剂成本限制了其工业应用。因此，本研究将游离亚硝酸（FNA）引入 WAS 预处理系统中以辅助 CaO 增强细胞外聚合物（EPS）的破坏和随后的产酸过程。结果表明，FNA 和 CaO 协同增强了预处理过程中 EPS 的分解和可生物降解有机化合物的释放。在预处理后，FNA + CaO（0.15 g/g VSS）共处理组的可溶化学需氧量（与单独预处理相同浓度相比提高了 3.1-和 2.6 倍）和 2 天发酵周期后 SCFAs 的积累量最高（与单独预处理相同浓度相比提高了 2.0-和 6.4 倍）。因此，FNA + CaO（0.15 g/g VSS）共处理被确定为确保 EPS 基质解体和增强厌氧消化预处理污泥中 SCFAs 积累的最佳策略。
