A rapid and simple electrochemical method for evaluating the electron transfer capacities of dissolved organic matter
A rapid and simple electrochemical method for evaluating the electron transfer capacities of dissolved organic matter
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DOI：
10.1007/s11368-010-0332-1
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发表时间：
2011-02
影响因子：
3.6
通讯作者：
Tian Yuan;Yong Yuan;Shungui Zhou;Fangbai Li;Zhi Liu;L. Zhuang
中科院分区：
文献类型：
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作者：
Tian Yuan;Yong Yuan;Shungui Zhou;Fangbai Li;Zhi Liu;L. Zhuang
目的研究DOM的电子传递能力（ETC）对了解其在微生物活性、污染降解和金属迁移中的作用具有重要意义。目前用于定量ETC的那些方法，例如Zn和Fe 3+测定，通常是耗时的，并且通常需要经验和技能来实现可再现的结果。本文的目的是发展一种快速、简单的方法来准确、直接地定量DOM的ETC。材料与方法DOM从污水污泥堆肥中提取。采用循环伏安法研究了污泥堆肥中DOM的氧化还原行为。采用计时电流法（CA）研究了在三电极电解槽中工作电极上施加固定的正、负电位时的吸电子容量（EAC）和给电子容量（EDC）。为了比较，还采用Zn为还原剂、Fe 3+为氧化剂的化学法测定了DOM的EAC和EDC。采用多电位阶跃技术，采用电化学方法研究了DOM的可逆电子转移过程，结果与讨论污泥DOM的CV显示出一对准可逆的氧化还原峰，形式电位为-0.866V（vs. Ag/AgCl），表明DOM具有可逆电子转移能力。在电位为-0.6 V（vs. Ag/AgCl）时，EAC的值由CA测定为361.6 μmole−（g C）− 1，在电位为+0.4 V（vs. Ag/AgCl）时，初始EDC的值为5.0 μmole−（g C）− 1。EAC和EDC的值都依赖于工作电极上的施加电位。所提出的方法测定的结果与那些通过使用化学methods.ConclusionsA快速电化学方法进行了调查的EAC和EDC的DOM提取污泥堆肥。所获得的EAC和EDC值与使用锌作为还原剂和三价铁作为氧化剂的化学方法测量的值相当。该方法可在几十秒内完成测定，比传统的化学方法更快、更直接。
PurposeThe evaluation of the electron transfer capacities (ETC) of DOM is important to understand their roles in microbial activity, pollution degradation, and metal mobility. Those currently used methods to quantify ETC, such as Zn and Fe3+assays, are normally time consuming and usually require experience and skills to achieve reproducible results. The aim of this paper is to develop a rapid and simple approach to accurately and directly quantify the ETC of DOM.Materials and methodsDOM was extracted from sewage sludge compost. Cycle voltammetry (CV) was used to investigate the redox behavior of DOM derived from sludge compost. Chronoamperometry (CA) was employed to study the electron-accepting capacities (EAC) and electron-donating capacities (EDC) by applying fixed positive or negative potentials to a working electrode in a conventional three-electrode cell. For comparison, the EAC and EDC of DOM were also determined by chemical methods using Zn as the reductant and Fe3+as the oxidant. The reversible electron transfer of DOM was studied electrochemically by CA with a multi-potential step technique.Results and discussionThe CV of sludge DOM displayed that a couple of quasi-reversible redox peaks with a formal potential of –0.866 V (vs. Ag/AgCl), demonstrating that the DOM was capable of reversibly transferring electrons. The value of EAC was determined by CA to be 361.6 μmole−(g C)−1at a potential of −0.6 V (vs. Ag/AgCl), and the value of initial EDC was 5.0 μmole−(g C)−1at a potential of +0.4 V (vs. Ag/AgCl). Both the values of EAC and EDC depended on the applied potentials on the working electrode. The results determined by the proposed method were comparable with those by using chemical methods.ConclusionsA rapid electrochemical approach was employed to investigate the EAC and EDC of DOM extracted from sewage sludge compost. The acquired values of EAC and EDC were comparable with those measured by chemical methods using zinc as the reductant and ferric iron as the oxidant. The determination could be completed in tens of seconds, which was faster and more direct than conventional chemical methods.