Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5759085 | Water Research | 2017 | 25 Pages |
Abstract
Electrocoagulation with an iron-air fuel cell is an innovative arsenate removal system that can operate without an external electricity supply. Thus, this technology is advantageous for treating wastewater in remote regions where it is difficult to supply electricity. In this study, the possibility of real applications of this system for arsenate treatment with electricity production was verified through electrolyte effect investigations using a small-scale fuel cell and performance testing of a liter-scale fuel cell stack. The electrolyte species studied were NaCl, Na2SO4, and NaHCO3. NaCl was overall the most effective electrolyte for arsenate treatment, although Na2SO4 produced the greatest electrical current and power density. In addition, although the current density and power density were proportional to the concentrations of NaCl and Na2SO4, the use of concentrations above 20Â mM of NaCl and Na2SO4 inhibited arsenate treatment due to competition effects between anions and arsenate in adsorption onto the iron hydroxide. The dominant iron hydroxide produced at the iron anode was found to be lepidocrocite by means of Raman spectroscopy. A liter-scale four-stack iron-air fuel cell with 10Â mM NaCl electrolyte was found to be able to treat about 300Â L of 1Â ppm arsenate solution to below 10Â ppb during 1 day, based on its 60-min treatment capacity, as well as produce the maximum power density of 250Â mW/m2.
Related Topics
Physical Sciences and Engineering
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Authors
Jung Hwan Kim, Hubdar Ali Maitlo, Joo Yang Park,