Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China; College of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China.
Water Res. 2021 Feb 15;190:116704. doi: 10.1016/j.watres.2020.116704. Epub 2020 Nov 28.
Cationic polyacrylamide (cPAM) is a widely used flocculant to dewater sewage sludge (SS) for high-solids anaerobic digestion (AD), and its degradation is crucial since it would release toxic acrylamide (AM) once entering environment. Hydrothermal treatment (HTT) is an efficient method to enhance the AD efficiency of SS. However, the effects of cPAM on AD of SS and the degradation of cPAM during HTT-AD process have not be studied. The study showed cPAM at 20 mg/g TS increased methane yield of SS from 127.0 to 138.9 ml CH/g TS in HTT-AD process, and the biodegradability of cPAM was 76.3%, which was much higher than that (7.4%) without HTT. In HTT-AD process, the enrichment of certain microbes (e.g. Gelria sp.) was observed, which might be related with cPAM degradation. HTT decreased the molecular weight (MW) of cPAM, and resulted in the production of 2-hydroxy-ethyl-trimethylammonium, ammonia, trimethylamine, and ethanol. Methane potential tests of the main HTT products also showed they were easily to be degraded. Overall, HTT-AD integrated process was an efficient method to reduce environmental risk of cPAM as well as increase energy output (biogas), and the study also provided insights into the degradation mechanism of cPAM during HTT.
阳离子聚丙烯酰胺（cPAM）是一种广泛应用于污水污泥（SS）脱水的絮凝剂，用于高固体厌氧消化（AD），由于其一旦进入环境会释放出有毒的丙烯酰胺（AM），因此其降解至关重要。水热处理（HTT）是提高 SS 的 AD 效率的有效方法。然而，cPAM 对 SS 的 AD 以及 cPAM 在 HTT-AD 过程中的降解的影响尚未得到研究。研究表明，在 HTT-AD 过程中，20mg/g TS 的 cPAM 使 SS 的甲烷产量从 127.0 增加到 138.9ml CH/g TS，cPAM 的生物降解率为 76.3%，远高于未经 HTT 的 7.4%。在 HTT-AD 过程中，观察到某些微生物（如 Gelria sp.）的富集，这可能与 cPAM 的降解有关。HTT 降低了 cPAM 的分子量（MW），并导致 2-羟乙基-三甲基铵、氨、三甲胺和乙醇的产生。主要 HTT 产物的甲烷潜力测试也表明它们很容易被降解。总体而言，HTT-AD 集成工艺是一种减少 cPAM 环境风险和增加能源产出（沼气）的有效方法，该研究还提供了对 cPAM 在 HTT 过程中降解机制的深入了解。
