阴极协同过硫酸盐降解苯酚的研究

发布时间：2018-01-01 19:15

本文关键词：阴极协同过硫酸盐降解苯酚的研究　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

更多相关文章： 过硫酸盐 苯酚阴极 Fe~(2+) Fe~(3+)

【摘要】：基于过硫酸盐(S2O82-,PS)活化的高级氧化技术(Advanced oxidation processes,AOPs)以其氧化能力强、价格低廉、稳定性好、反应产物温和等优点成为一种非常有发展前景和应用潜力的除污染技术。本文以来源广泛、毒性较高的典型酚类污染物苯酚为目标污染物,探讨了以低浓度Fe2+(Fe3+)为活化剂,并且引入阴极的Cathode(Pt)/PS/Fe2+(Fe3+)体系对苯酚降解的可行性,较系统全面地考察和分析了各实验因素对降解效果的影响,提出了表征过硫酸钠和电流利用率的参数△[PS]/[e-],并简要分析了该体系的作用机理。通过对照实验结果分析可知,以低浓度的Fe2+(Fe3+)为活化剂的Cathode/PS/Fe2+(Fe3+)体系能有效降解苯酚,并且较传统的过渡金属活化体系和电化学强化体系更加节能省料。影响因素实验分析表明,苯酚的降解速率随电流密度的增大先增大之后趋于稳定,而过大的电流密度下,体系会由于pH的升高使溶解性铁元素浓度迅速降低而崩溃;苯酚的降解速率与初始Fe2+浓度正相关;与支持电解质(硫酸钠)浓度负相关;而随过硫酸钠浓度的增大先增大再减小,在初始过硫酸钠浓度为14.17 mmol L-1时达到最大。反应过程的化学分析和数学分析说明,。由于阴极条件下过硫酸钠的在阴极还原的必然性,过硫酸钠和电流的利用率无法达到100%,即△[PS]/[e-]总小于1;而该值,即过硫酸钠和电流的利用率与电流密度负相关,与初始Fe2+浓度和过硫酸钠浓度正相关,随支持电解质浓度的增大先增大后减小,在支持电解质浓度为50 mmol L-1时达到最大。机理研究反映出该体系的核心是Fe2+/Fe3+循环,一切影响到该循环的因素都会影响到苯酚的降解;该体系降解苯酚的中间产物有苯二酚(对苯二酚、邻苯二酚、间苯二酚)、苯醌和马来酸等,而降解苯酚的活性自由基既有硫酸根自由基,也有羟基自由基;苯酚的降解在主要时间段内符合零级反应动力学方程。
[Abstract]:Advanced oxidation processes (AOPs), an advanced oxidation technology based on the activation of S _ 2O _ 82-O _ (2) P _ (2) O _ (2) O _ (2) O _ (2), is characterized by its high oxidation ability. The advantages of low price, good stability and mild reaction products have become a promising and potential decontamination technology. Phenol, a typical phenolic pollutant with high toxicity, was used as the target pollutant. The low concentration of Fe2 Fe3) was used as activator. The feasibility of phenol degradation by Cathode(Pt)/PS/Fe2 Fe3 (cathode) system was investigated and analyzed systematically and comprehensively. The parameters to characterize the utilization of sodium persulfate and current were proposed. [PS] /. [The mechanism of the system was analyzed briefly, and the results were compared with the experimental results. Phenol can be effectively degraded by Cathode/PS/Fe2 Fe _ 3) system with low concentration of Fe2 _ (Fe _ 3) as activator. The experimental results show that the degradation rate of phenol increases firstly with the increase of current density and then tends to be stable. However, when the current density is too high, the system will collapse because the concentration of dissolved iron decreases rapidly with the increase of pH. The degradation rate of phenol was positively correlated with the initial Fe2 concentration. Negative correlation with the concentration of supporting electrolyte (sodium sulfate); However, with the increase of sodium persulfate concentration, the initial concentration of sodium persulfate increased first and then decreased, and reached the maximum when the initial concentration of sodium persulfate was 14.17 mmol L-1. The chemical analysis and mathematical analysis of the reaction process showed that. Because of the inevitability of cathodic reduction of sodium persulfate under cathodic conditions, the utilization ratio of sodium persulfate and current cannot reach 100%. [PS] /. [E-] is always less than 1; However, the utilization ratio of sodium persulfate and current was negatively correlated with current density and positively correlated with initial Fe2 concentration and sodium persulfate concentration, and increased first and then decreased with the increase of supporting electrolyte concentration. The results show that the core of the system is the Fe2 / Fe _ 3 cycle when the supporting electrolyte concentration is 50 mmol 路L ~ (-1). All factors affecting this cycle will affect the degradation of phenol; The intermediate products of degradation of phenol include hydroquinone, catechol, resorcinol, benzoquinone and maleic acid, etc. The degradation of phenol obeys the zero order reaction kinetics equation in the main time period.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703

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