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>Removal of arsenic from water by electrocoagulation using aluminum-aluminum, iron-iron, aluminum-iron electrode pair systems and characterization of by-products.
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Removal of arsenic from water by electrocoagulation using aluminum-aluminum, iron-iron, aluminum-iron electrode pair systems and characterization of by-products.
Electrocoagulation (EC) has been performed with three different electrode pair systems namely Al-Al, Fe-Fe, Al-Fe, for the removal of arsenic from water. The removal process has been studied with a wide range of arsenic concentration (1-1000 ppm) at various pH (4-10), at different residence times (1-60 min) and at two different voltages (3 V, 14 V). Analysis of the electrochemically generated waste product by XRD, FTIR, and Mossbauer Spectroscopy revealed the expected crystalline iron oxides (magnetite (Fe3O4), lepidocrocite (FeO(OH)), iron oxide (FeO)) and aluminum oxides (bayerite (Al(OH) 3), diaspore (AlO(OH)), mansfieldite (AlAsO4·2(H 2O)), as well as some interaction between the two phases. ICP-AES analysis of EC filtrate showed that the Fe-Fe and Al-Fe electrode pair systems can remove more arsenic than the Al-Al electrode pair system. Arsenic detection in a set of EC (Al-Fe electrode system) samples at different residence times (10, 20, 30, 40, 50, and 60 min) by Anodic Stripping Voltammetry (ASV) showed that 98.78 % arsenic was removed within 10 min residence time and at 50 min residence time, the total arsenic concentration went below the detection limit of ASV (detection limit of ASV is 5 ppb).
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