National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China; College of Environment and Resources, Chongqing Technology and Business University, Chongqing, 400067, China.
National Research Base of Intelligent Manufacturing Service, Chongqing Technology and Business University, Chongqing, 400067, China; College of Environment and Resources, Chongqing Technology and Business University, Chongqing, 400067, China; Chongqing South-to-Thais Environmental Protection Technology Research Institute Co., Ltd., Chongqing, 400069, China.
Chemosphere. 2022 Mar;290:133209. doi: 10.1016/j.chemosphere.2021.133209. Epub 2021 Dec 8.
In this study, fly ash and hydrogen peroxide (HO) assisted hydrothermal carbonization (HTC) was used to improve the removal efficiency of nitrogen (N) and sulfur (S) from sewage sludge (SS). The removal rate and distribution of N and S in hydrochar were evaluated, and properties of the aqueous phase were analyzed to illustrate the N and S transformation mechanism during fly ash and HO assisted HTC treatment of SS. The results suggested that during HTC process assisted by fly ash (10% of raw SS), dehydration, decarboxylation and hydrolysis of SS were strengthened due to the catalysis effect. The N and S removal were promoted marginally. For hydrochar achieved from HTC process with HO addition, the N and S removal were improved slightly due to the biopolymer oxidization by ‧OH released from HO decomposition. While for HTC treatment with fly ash and HO supplementation, a positive synergistic effect on N and S removal was observed. The N and S removal obtained from fly ash (10% of raw SS) and HO (48 g/L) assisted HTC increased to 81.71% and 62.83%, respectively, from those of 69.53% and 49.92% in control group. N and S removal mechanism analysis suggested that hydroxyl radicals (‧OH) produced by HO decomposition will destroy SS structure, and the biopolymers such as polysaccharides and proteins will be decomposed to release N and S into the liquid residue. In addition, the fly ash acts as the catalyst will decrease the energy need for denification and desulfartion. Consequently, N and S removal efficiency was enhanced by fly ash and HO assisted HTC treatment.
在这项研究中，采用粉煤灰和过氧化氢（HO）辅助水热碳化（HTC）来提高污水污泥（SS）中氮（N）和硫（S）的去除效率。评估了水热炭中 N 和 S 的去除率和分布，并分析了水相的性质，以说明在粉煤灰和 HO 辅助 SS 的 HTC 处理过程中 N 和 S 的转化机制。结果表明，在粉煤灰（占原始 SS 的 10%）辅助的 HTC 过程中，由于催化作用，SS 的脱水、脱羧和水解得到加强。N 和 S 的去除略有促进。对于添加 HO 进行 HTC 得到的水热炭，由于从 HO 分解释放的·OH 氧化生物聚合物，N 和 S 的去除略有改善。而对于粉煤灰和 HO 补充的 HTC 处理，观察到对 N 和 S 去除有积极的协同作用。从粉煤灰（占原始 SS 的 10%）和 HO（48 g/L）辅助 HTC 获得的 N 和 S 去除率分别从对照组的 69.53%和 49.92%提高到 81.71%和 62.83%。N 和 S 去除机制分析表明，HO 分解产生的羟基自由基（·OH）会破坏 SS 结构，多糖和蛋白质等生物聚合物将被分解，将 N 和 S 释放到液体残渣中。此外，粉煤灰作为催化剂将降低氮化和脱硫所需的能量。因此，通过粉煤灰和 HO 辅助 HTC 处理提高了 N 和 S 的去除效率。
