Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing, 210095, China.
Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing, 210095, China; State Key Laboratory of Bioelectronics, Southeast University, Nanjing, 210096, China.
Chemosphere. 2019 Dec;236:124835. doi: 10.1016/j.chemosphere.2019.124835. Epub 2019 Sep 12.
In this contribution, the electrocatalytic abatement of bisphenol A (BPA) with boron-doped diamond (BDD) anode had been conducted in NaNO electrolytes. Central composite design was used as statistical multivariate method to optimize the operating parameters adopted (applied current density, flow rate, concentration of NaNO and initial pH). The results from response surface analysis indicated that pH was the most influential factor for TOC decay, and a maximum TOC decay of 63.7% was achieved under the optimized operating conditions (9.04 mA cm of applied current density, 400 mL min of flow rate, 10 mM of NaNO, 4.0 of initial pH and 60 min of electrolysis time). Besides, LC/MS technique was applied to identify the main reaction intermediates, and plenty of nitrated oligomers were detected at the end of the degradation. These by-products were generated via the coaction of coupling reaction of nitrated phenol and electrophilic substitution mediated by nitrogen dioxide radicals. Moreover, our results showed that the degree of nitration depended heavily on the employed initial nitrite concentration. This was one of the very few investigations dealing with nitrophenolic by-products in nitrite medium, and thus the findings exhibited important implications for electrochemical degradation of BPA and its related phenolic pollutants.
在这项贡献中，使用掺硼金刚石（BDD）阳极在 NaNO 电解液中进行了双酚 A（BPA）的电催化降解。中心复合设计被用作统计多元方法来优化所采用的操作参数（施加电流密度、流速、NaNO 浓度和初始 pH）。响应面分析的结果表明，pH 是 TOC 降解的最主要影响因素，在优化的操作条件（施加电流密度 9.04 mA cm、流速 400 mL min、NaNO 浓度 10 mM、初始 pH 4.0 和电解时间 60 min）下，TOC 的最大去除率达到 63.7%。此外，还应用 LC/MS 技术来鉴定主要的反应中间体，并在降解结束时检测到大量的硝化低聚物。这些副产物是通过硝化苯酚的偶联反应和二氧化氮自由基介导的亲电取代作用共同作用生成的。此外，我们的结果表明，硝化程度严重依赖于所采用的初始亚硝酸盐浓度。这是少数涉及亚硝酸盐介质中硝基酚类副产物的研究之一，因此这些发现对 BPA 及其相关酚类污染物的电化学降解具有重要意义。
