Hunan Engineering Research Center of Water Security Technology and Application, College of Civil Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Hunan University, Changsha, 410082, PR China.
Hunan Engineering Research Center of Water Security Technology and Application, College of Civil Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, Hunan University, Changsha, 410082, PR China.
Chemosphere. 2022 Nov;307(Pt 4):136083. doi: 10.1016/j.chemosphere.2022.136083. Epub 2022 Aug 18.
β-N-methylamino-l-alanine (BMAA) is a cyanobacterial neurotoxin associated with human neurodegenerative diseases, and its removal in drinking water is receiving increasing attention. In this study, the degradation of BMAA in UV/peracetic acid (UV/PAA) system was investigated. BMAA degradation followed the pseudo-first-order kinetic model. The synergistic effect of UV and PAA exhibited a great potential for BMAA degradation, which was attributed to the generation of a large number of reactive radicals, of which R-C was the most dominant contributor. We also explored the effects of different factors on BMAA degradation. The results showed that there was a positive correlation between BMAA degradation and PAA dosage, and the optimal effect was achieved at pH 7. Notably, the existence of water matrices such as bicarbonate (HCO－), chloride ion (Cl－), humic acid (HA) and algal intracellular organic matter (IOM) all inhibited the degradation of BMAA. Based on the identified intermediates, this study suggested that reactive radicals degraded BMAA mainly by attacking the carbon-nitrogen bonds on BMAA. Besides, comparing the effect of Cl－ on disinfection byproduct (DBP) formation in UV/PAA-post-PAA oxidation and UV/chlorine-post-chlorination systems, it was found that the former was more sensitive to the presence of Cl－.
β-N-甲基氨基-L-丙氨酸（BMAA）是一种与人类神经退行性疾病有关的蓝藻神经毒素，其在饮用水中的去除越来越受到关注。本研究考察了 UV/过氧乙酸（UV/PAA）体系中 BMAA 的降解情况。BMAA 的降解符合准一级动力学模型。UV 和 PAA 的协同作用对 BMAA 的降解具有很大的潜力，这归因于大量活性自由基的产生，其中 R-C 是最主要的贡献者。我们还探讨了不同因素对 BMAA 降解的影响。结果表明，BMAA 降解与 PAA 剂量之间呈正相关，在 pH 值为 7 时达到最佳效果。值得注意的是，水基质如碳酸氢根（HCO－）、氯离子（Cl－）、腐殖酸（HA）和藻类细胞内有机物质（IOM）的存在均抑制了 BMAA 的降解。基于鉴定出的中间产物，本研究表明活性自由基主要通过攻击 BMAA 上的碳-氮键来降解 BMAA。此外，比较了 UV/PAA-后过氧乙酸氧化和 UV/氯气-后氯化系统中 Cl－对消毒副产物（DBP）形成的影响，发现前者对 Cl－的存在更为敏感。
