Abstract

The aim of the study is to examine the possibility of removing nickel, as a heavy metal, from waters of different origins using an environmentally friendly tetra-oxy ferro(VI) ion. As a strong oxidizing agent, ferrate(VI) decomposes complexes of organic compounds with heavy metal ions, which make efficient coagulation and removal of heavy metal ions from the solution difficult. With the use of ferrate(VI), the formation of toxic by-products, which is often a side effect of conventional methods, is avoided. The paper presents new results that confirm the advantages of application of ferro(VI) ion salts in water treatment as environmentally favorable, strong oxidants and coagulants. Ferate(VI) was applied in the form of Na₂FeO₄ salt synthesized by an electrochemical method in a laboratory pilot plant composed of a two-part flow-through electrochemical cell and based on the transpassive anodic dissolution of iron alloys in a 10 M NaOH solution. The concentration of synthesized and applied ferrate was 8 g/L. The treatment was performed using the Jar test, pH 9 and T = 25°C. During the research, it was shown that the method of water treatment, removal of pollutants and even removal heavy metals, in situ, would enable more efficient use of ferrate and prevent its decomposition. This paper shows the results for nickel removal from waters of different origins: copper refinery wastewater, industrial wastewater effluent and raw drinking water which contained far higher concentrations of nickel than it’s maximum allowed (0.01 mg/L). In the displayed results, apart from the efficiency of nickel removal, the results of the removal of other ions present in the test samples are also given. The results showed the removal of nickel from 87.5 to 99.0%.

中文翻译：

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使用铁 (VI) 离子在镍样品上去除不同来源水中重金属的可能性

摘要

该研究的目的是研究使用环境友好的四氧铁 (VI) 离子从不同来源的水中去除作为重金属的镍的可能性。作为一种强氧化剂，高铁酸盐 (VI) 会分解有机化合物与重金属离子的络合物，这使得有效凝聚和去除溶液中的重金属离子变得困难。使用高铁酸盐 (VI) 可以避免有毒副产物的形成，而这通常是常规方法的副作用。该论文提出的新结果证实了铁 (VI) 离子盐在水处理中作为对环境有利的强氧化剂和凝结剂的应用优势。Ferate(VI) 以 Na ₂ FeO ₄的形式应用在实验室中试设备中通过电化学方法合成的盐，该设备由两部分流通式电化学电池组成，并基于铁合金在 10 M NaOH 溶液中的被动阳极溶解。合成和应用的高铁酸盐浓度为 8 g/L。使用 Jar 测试、pH 9 和T= 25°C。研究表明，原位处理水、去除污染物甚至去除重金属的方法可以更有效地利用高铁酸盐并防止其分解。本文展示了从不同来源的水中去除镍的结果：铜精炼废水、工业废水和原饮用水中的镍含量远高于最大允许浓度 (0.01 mg/L)。在显示的结果中，除了去除镍的效率外，还给出了去除测试样品中存在的其他离子的结果。结果表明，镍的去除率为 87.5% 至 99.0%。