Assessment of a colorimetric method for the measurement of low concentrations of peracetic acid and hydrogen peroxide in water
Assessment of a colorimetric method for the measurement of low concentrations of peracetic acid and hydrogen peroxide in water
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DOI：
10.1016/j.talanta.2018.02.078
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发表时间：
2018-06-01
期刊：
影响因子：
6.1
通讯作者：
Antonelli, Manuela
中科院分区：
文献类型：
--
作者：
Dominguez-Henao, Laura;Turolla, Andrea;Antonelli, Manuela
近年来，人们对过氧乙酸(PAA)作为废水处理消毒剂的兴趣与日俱增，这就要求有可靠和容易获得的方法来测定它。具体地说，污水处理厂对PAA的监测需要一种简单、准确、快速、廉价的测量方法。本文对美国环保局总氯比色法的低浓度PAA分析方法进行了评价。在过量碘存在的磷酸盐缓冲体系中，该方法使用N，N-二乙基-对苯乙二胺(DPD)。粉红色物种的产生与样品中PAA的浓度成比例。考虑到PAA在商业上可以作为PAA和过氧化氢(H_2O_2)的平衡溶液，还研究了一种测定H_2O_2的方法。该方法与测定PAA的方法一样，也是以碘化物氧化成碘为基础，不同之处在于加入钼酸铵钼(VI)催化H_2O_2和I_2的氧化反应，定量测定总过氧化产物(PAA+H_2O_2)。这两种方法适用于对苯二胺和过氧化氢的浓度范围分别为0.1mgL-1和0.3mgL-1。此外，工作还阐明了操作条件、动力学和H_2O_2可能对PAA测定的干扰等方面的相关问题。
The recent growing interest in peracetic acid (PAA) as disinfectant for wastewater treatment demands reliable and readily-available methods for its measurement. In detail, the monitoring of PAA in wastewater treatment plants requires a simple, accurate, rapid and inexpensive measurement procedure. In the present work, a method for analyzing low concentrations of PAA, adapted from the US EPA colorimetric method for total chlorine, is assessed. This method employs N,N-diethyl-p-phenylelnediamine (DPD) in the presence of an excess of iodide in a phosphate buffer system. Pink colored species are produced proportionally to the concentration of PAA in the sample. Considering that PAA is available commercially as an equilibrium solution of PAA and hydrogen peroxide (H2O2), a measurement method for H2O2 is also investigated. This method, as the one for the determination of PAA, is also based on the oxidation of iodide to iodine, with the difference that ammonium molybdate Mo(VI) is added to catalyze the oxidation reaction between H2O2 and iodide, quantifying the total peroxides (PAA + H2O2). The two methods are suitable for concentration ranges from about 0.1-1.65 mg L-1 and from about 0.3-3.3 mg L-1, respectively for PAA and H2O2. Moreover, the work elucidates some relevant aspects related to the operational conditions, kinetics and the possible interference of H2O2 on PAA measurement.