Civil and Environmental Engineering Faculty, Technion, Haifa, 32000, Israel.
School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
Environ Res. 2021 Jul;198:111187. doi: 10.1016/j.envres.2021.111187. Epub 2021 May 5.
In this study, a comparative activity assessment of several activated carbon (AC) and AC-FeO composites was performed to evaluate their efficiency and versatility as Fenton-like catalysts. Although many studies have demonstrated the advantages of AC-based materials as Fenton-like catalysts, most have been developed using only one oxidant and/or one pollutant. Here, untreated (AC) and acid-treated AC (AC) iron-oxide composites were synthesized, characterized, and compared in terms of activity to bare AC using several oxidants and pollutants, the activation efficiency of hydrogen peroxide (HO) and ammonium persulfate ((NH)SO), and the subsequent oxidation extent and kinetics of bisphenol-A, atrazine, and carbamazepine by the AC-based materials were studied in depth. The persulfate-based systems showed considerably higher pollutant removal in the presence of the catalysts, despite lower persulfate decomposition rates: atrazine and carbamazepine were partially degraded, mainly through a radical-dependent pathway; the highest removal of atrazine was achieved with the AC-iron composite, whereas carbamazepine was best removed by the AC-iron composite. In contrast, bisphenol A was completely mineralized, probably via a non-radical pathway, in the presence of all AC-based composites, even at very low persulfate concentrations. Furthermore, bisphenol A removal remained high for several consecutive cycles, with the most efficient removal and stability observed in the presence of AC. These findings reveal the high complexity of AC-based systems, with multiple binding sites and degradation pathways unique to each combination of pollutants, catalysts, and oxidants. In general, the composition of the waste stream governs the applicability of these materials. Thus, the structure-function correlations and degradation mechanisms revealed here are crucial for improving sorbent-catalyst design and accelerating the implementation of low-cost remediation and in situ regeneration technologies.
在这项研究中，对几种活性炭 (AC) 和 AC-FeO 复合材料进行了比较活性评估，以评估它们作为类 Fenton 催化剂的效率和多功能性。尽管许多研究已经证明了基于 AC 的材料作为类 Fenton 催化剂的优势，但大多数研究都是使用一种氧化剂和/或一种污染物开发的。在这里，合成了未经处理的（AC）和酸处理的 AC（AC）氧化铁复合材料，并根据几种氧化剂和污染物的活性对其进行了比较，研究了过氧化氢（HO）和过硫酸铵（(NH)SO 的活化效率），以及随后的氧化程度和动力学双酚 A、莠去津和卡马西平在基于 AC 的材料中的研究。基于过硫酸盐的系统在催化剂存在下表现出相当高的污染物去除率，尽管过硫酸盐分解速率较低：莠去津和卡马西平部分降解，主要通过自由基依赖途径；AC-铁复合材料对莠去津的去除率最高，而 AC-铁复合材料对卡马西平的去除效果最好。相比之下，在所有基于 AC 的复合材料存在下，双酚 A 被完全矿化，可能是通过非自由基途径，即使在过硫酸盐浓度非常低的情况下也是如此。此外，双酚 A 的去除率在几个连续的循环中仍然很高，在 AC 的存在下观察到最高的去除率和稳定性。这些发现揭示了基于 AC 的系统的高度复杂性，具有每个污染物、催化剂和氧化剂组合特有的多个结合位点和降解途径。一般来说，废水的组成决定了这些材料的适用性。因此，这里揭示的结构-功能相关性和降解机制对于改进吸附剂-催化剂设计和加速低成本修复和原位再生技术的实施至关重要。
