Advantages of low pH and limited oxygenation in arsenite removal from water by zero-valent iron

Making Fe0-Based Filters a Universal Solution for Safe Drinking Water Provision

“…Considered studies were published in various journals between 2000 and 2016 [56,57,[71][72][73][74][75][76][77][78][79]. Tables 2 and 3 show that system design differs in terms of the size of the columns, Fe 0 type, Fe 0 size, Fe 0 elemental composition, Fe 0 mass, Fe 0 ratio in the reactive layer (RZ, reactive zone), initial As concentration, initial pH value, flow rate, and duration of the experiments.…”

“…However, advice and knowledge transfer can be acquired in collaboration with other groups, including scientific ones. Considering the significant advancements made in research on 'Fe 0 for environmental remediation and water treatment' over the past three decades [26][27][28][29][30]52,76,116,146,[222][223][224][225][226][227][228][229] as the cornerstone for a universal sustainable solution to a long-lasting crisis, the universal provision of safe drinking water is no longer an 'elusive goal' [7]; Fe 0 filtration provides a solution, specifically for the developing world [229,230].…”

Removal of arsenate by ferrihydrite via surface complexation and surface precipitation

“…Arsenic (As), one of trace elements in drinking water, is toxic to living organism when its concentration exceeds 10 µg/L [1][2][3]. The distribution and mobility of As in the aquatic environment depend on the stability of aqueous species and solid phases, especially the iron oxides (ferrihydrite) that is widespread in nature to capture arsenic [4][5][6].…”

“…This reveals that arsenate-cation complex directly determined the formation of surface precipitation.Based on above studies, it was evident that surface precipitation of ferric arsenate was formed when arsenate was adsorbed on surface of ferrihydrite under acidic condition (at pH 3.0-6.0). Therefore, the surface precipitation was proposed as a 3-step process: (1) An initial uptake of As(V) via surface complexation;(2) Re-adsorption of Fe 3+ leaching from ferrihydrite on the surface complex; (3) As(V) adsorption via surface complexation again and finally forming the surface precipitate (Fig. 8).…”

Effect of spatial distribution and aging of ZVI on the reactivity of resin–ZVI composites for arsenite removal

“…Application of zero-valent iron (ZVI or Fe 0 ) is an environmental benign approach of remediation/treatment of contaminated groundwater and wastewater, because it is cost-effective and readily available and can remove a variety of organic and inorganic contaminants including chlorinated organic compounds [1,2], nitroaromatic compounds [3,4], dyes [5,6], heavy metals [7,8], arsenic [9,10], nitrate [11,12], and phenol [13]. ZVI system can take advantage of not only the reductive but also oxidative reactions, which may make the ZVI technology more versatile.…”