Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, PR China.
Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental & Applied Chemistry, Central China Normal University, Wuhan 430079, PR China.
J Hazard Mater. 2018 Sep 5;357:408-414. doi: 10.1016/j.jhazmat.2018.06.029. Epub 2018 Jun 15.
This study systematically compared the degradation of atrazine (ATR) with aerobic zero-valent aluminum (ZVAl/Air) and zero-valent iron (ZVI/Air) systems. By comparing the ATR degradation curves and rate in the ZVAl/Air and the ZVI/Air systems, a significant induction period was observed in the ZVAl/Air system, and the pseudo-first-order rate constant of ATR degradation in the second stage by ZVAl was 6.4 times faster than that by ZVI. The differences in ATR degradation patterns of the two systems stemmed from the different redox nature and electrical conductivity of aluminum (oxide) and iron (oxide). Reactive oxygen species measurement and electron spin spectra analysis indicated that more hydroxyl radical was generated through molecular oxygen activation in the ZVAl/Air system, leading to enhanced ATR degradation in the ZVAl/Air process. By analyzing the intermediates of atrazine degradation, we found that ATR underwent an oxidative dealkylation and hydroxyl-dechlorination degradation pathway, and the low toxicity cyanuric acid was the final product in both systems. However, aluminum ions released in the ZVAl/Air system exceeded the regulated standard value, which might cause environmental pollution. Finally, the pros and cons of potential environmental remediation of the ZVAl/Air and ZVI/Air processes were evaluated.
本研究系统比较了莠去津（ATR）在有氧零价铝（ZVAl/Air）和零价铁（ZVI/Air）系统中的降解情况。通过比较 ZVAl/Air 和 ZVI/Air 系统中 ATR 的降解曲线和速率，在 ZVAl/Air 系统中观察到一个明显的诱导期，并且 ZVAl 对 ATR 的第二阶段的伪一级降解速率常数比 ZVI 快 6.4 倍。两个系统中 ATR 降解模式的差异源于铝（氧化物）和铁（氧化物）的不同氧化还原性质和电导率。活性氧物种测量和电子自旋谱分析表明，ZVAl/Air 系统中通过分子氧活化生成了更多的羟基自由基，从而增强了 ZVAl/Air 过程中的 ATR 降解。通过分析莠去津降解的中间产物，我们发现 ATR 经历了氧化脱烷基和羟基脱氯降解途径，并且在两个系统中低毒性的三聚氰胺都是最终产物。然而，ZVAl/Air 系统中释放的铝离子超过了规定的标准值，可能会造成环境污染。最后，评估了 ZVAl/Air 和 ZVI/Air 工艺对潜在环境修复的优缺点。
