The effectiveness of electrodialysis (ED) in removing inorganic arsenic (As) from aqueous solution was investigated. A tailor-made ED stack was used to perform current-voltage and optimization experiments in a recirculating batch mode. Samples were pre-oxidized with NaClO using 1:2 sample to oxidant weight ratio (R-S:O) to transform 100% of As(III) to As(V) in 180 seconds. A high feed water conductivity of 1500S/cm and a low feed water conductivity of 800S/cm had limiting currents of 595mA and 525mA, respectively. Optimum experimental conditions that provided maximum As separation were applied potential (E) of 12V, feed flow rate (Q) of 0.033 L/s, feed concentration (C) of 662.0g L-1, and operating time (t) of 45min, the most significant ones were applied potential, feed concentration and operating time. Model confirmation experiments showed a good agreement with experimental results with only 0.031% error. The total As in the diluate stream was 4.0g L-1, consisting of an average of 3.0g L-1 As(V) and 1.0g L-1 As(III).
關聯:
Journal of Environmental Science and Health Part A-Toxic/Hazardous Substances & Environmental Engineering, v.49 n.5, pp.545-554
