Selective removal of arsenic in water: A critical review

Lakshika Weerasundara, Yong Sik Ok, Jochen Bundschuh

Research output: Contribution to journalReview articlepeer-review

10 Citations (Scopus)

Abstract

Selective removal of arsenic (As) is the key challenge for any of As removal mechanisms as this not only increases the efficiency of removal of the main As species (neutral As(III) and As(V) hydroxyl-anions) but also allows for a significant reduction of waste as it does not co-remove other solutes. Selective removal has a number of benefits: it increases the capacity and lifetime of units while lowering the cost of the process. Therefore, a sustainable selective mitigation method should be considered concerning the economic resources available, the ability of infrastructure to sustain water treatment, and the options for reuse and/or safe disposal of treatment residuals. Several methods of selective As removal have been developed, such as precipitation, adsorption and modified iron and ligand exchange. The biggest challenge in selective removal of As is the presence of phosphate in water which is chemically comparable with As(V). There are two types of mechanisms involved with As removal: Coulombic or ion exchange; and Lewis acid-base interaction. Solution pH is one of the major controlling factors limiting removal efficiency since most of the above-mentioned methods depend on complexation through electrostatic effects. The different features of two different As species make the selective removal process more difficult, especially under natural conditions. Most of the selective As removal methods involve hydrated Fe(III) oxides through Lewis acid-base interaction. Microbiological methods have been studied recently for selective removal of As, and although there have been only a small number of studies, the method shows remarkable results and indicates positive prospects for the future.

Original languageEnglish
Article number115668
JournalEnvironmental Pollution
Volume268
DOIs
Publication statusPublished - 2021 Jan 1

Keywords

  • Arsenic
  • Competitive ions
  • Cost reduction
  • Removal methods
  • Selective removal
  • Waste reduction

ASJC Scopus subject areas

  • Toxicology
  • Pollution
  • Health, Toxicology and Mutagenesis

Fingerprint

Dive into the research topics of 'Selective removal of arsenic in water: A critical review'. Together they form a unique fingerprint.

Cite this