Defluoridation of tap water by electrocoagulation and fluoride adsorption on aluminum hydroxide flocs

Water Supply Pub Date : 2024-04-09 DOI:10.2166/ws.2024.079

Sirin Dhifallah, Anis Attour, Christophe Vial, Fehti Zagrouba, F. Audonnet

{"title":"Defluoridation of tap water by electrocoagulation and fluoride adsorption on aluminum hydroxide flocs","authors":"Sirin Dhifallah, Anis Attour, Christophe Vial, Fehti Zagrouba, F. Audonnet","doi":"10.2166/ws.2024.079","DOIUrl":null,"url":null,"abstract":"\n \n Overload of fluoride ions in water is observed in several regions of southern Tunisia, mainly the regions close to the mining basin of Gafsa: Metlaoui, Omlarayes and Redayef. This study concerns fluoride removal from Metlaoui's tap water by electrocoagulation (EC) using aluminum electrodes in a batch reactor. This water contains 3.5 mg·L−1 of fluoride, the highest concentration observed in these basins. The effect of the operating conditions of EC treatment on tap water defluoridation was analyzed, namely, current density, temperature and interelectrode distance. Hydroxide aluminum flocs, formed with different durations of EC, were used as sorbents in fluorinated deionized water ([F−] = 3.5 mg·L−1) and Metlaoui's tap water. Flocs formed after 30 min of EC, produced by dissolving (79 ± 1) mg·L−1 of aluminum and adjusted at pH = 6.5, allowed the adsorption of (98 ± 1)% of fluoride ions from deionized fluorinated water. Flocs adjusted at different pH, from 5 to 9, were used as sorbents in fluorinated deionized water and Metlaoui's tap water. Acidic and neutral flocs allowed the best yields of fluoride adsorption. Contrary to the literature, this work highlighted the absence of ion exchange of hydroxide anion by fluoride anion in water, highlighting a mechanism of physical adsorption on aluminum hydroxide flocs.","PeriodicalId":509977,"journal":{"name":"Water Supply","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Supply","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2166/ws.2024.079","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 0

Abstract

Overload of fluoride ions in water is observed in several regions of southern Tunisia, mainly the regions close to the mining basin of Gafsa: Metlaoui, Omlarayes and Redayef. This study concerns fluoride removal from Metlaoui's tap water by electrocoagulation (EC) using aluminum electrodes in a batch reactor. This water contains 3.5 mg·L−1 of fluoride, the highest concentration observed in these basins. The effect of the operating conditions of EC treatment on tap water defluoridation was analyzed, namely, current density, temperature and interelectrode distance. Hydroxide aluminum flocs, formed with different durations of EC, were used as sorbents in fluorinated deionized water ([F−] = 3.5 mg·L−1) and Metlaoui's tap water. Flocs formed after 30 min of EC, produced by dissolving (79 ± 1) mg·L−1 of aluminum and adjusted at pH = 6.5, allowed the adsorption of (98 ± 1)% of fluoride ions from deionized fluorinated water. Flocs adjusted at different pH, from 5 to 9, were used as sorbents in fluorinated deionized water and Metlaoui's tap water. Acidic and neutral flocs allowed the best yields of fluoride adsorption. Contrary to the literature, this work highlighted the absence of ion exchange of hydroxide anion by fluoride anion in water, highlighting a mechanism of physical adsorption on aluminum hydroxide flocs.

查看原文本刊更多论文

通过电凝和氢氧化铝絮凝体吸附氟化物对自来水进行除氟处理

在突尼斯南部的几个地区，主要是靠近加夫萨矿业盆地的地区，发现水中氟离子超标：Metlaoui、Omlarayes 和 Redayef。本研究涉及在间歇式反应器中使用铝电极，通过电凝（EC）去除 Metlaoui 自来水中的氟化物。自来水中的氟含量为 3.5 mg-L-1，是在这些盆地中观察到的最高浓度。分析了电解处理的操作条件对自来水除氟的影响，即电流密度、温度和电极间距离。在含氟去离子水（[F-] = 3.5 mg-L-1）和梅特劳伊自来水中使用了不同电解时间形成的氢氧化铝絮凝物作为吸附剂。通过溶解（79 ± 1）mg-L-1 的铝并在 pH = 6.5 的条件下调节，在电解质作用 30 分钟后形成的絮凝体可以吸附去离子水中（98 ± 1）%的氟离子。在含氟去离子水和 Metlaoui 自来水中使用不同 pH 值（5 至 9）的絮凝体作为吸附剂。酸性和中性絮凝物的氟吸附率最高。与文献报道相反，这项研究强调了氢氧阴离子与水中的氟阴离子不存在离子交换，突出了氢氧化铝絮凝体的物理吸附机制。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Water Supply

自引率

0.00%

发文量