This study comparatively investigated the different effects of Fe2(SO4)3 coagulation-filtration and FeCl3 coagulation-filtration on the removal of Mo(VI). In addition, the authors examined the influence of calcium, sulfate, silicate, phosphate and humic acid (HA). The following conclusions can be obtained: (1) compared with the case of FeCl3, Fe2(SO4)3 showed a higher Mo (VI) removal efficiency at pH 4.00-5.00, but an equal removal efficiency at pH 6.00-9.00. (2) The optimum Mo (VI) removal by Fe2(SO4)3 was achieved at pH 5.00-6.00; (3) The presence of calcium can reduce the removal of Mo (VI) over the entire pH range in the present study; (4) The effect of co-existing background anions (including HA) was dominated by three factors: Firstly, the influence of co-existing background anions on the content of Fe intercepted from water (intercepted Fe). Secondly, the competition of co-existing anions with Mo (VI) for adsorption sites. Thirdly, the influence of co-existing background anions on the Zeta potential of the iron flocs.
Full Source: Zhang X, Ma J, Lu X, Huangfu X, Zou J. ;Full Source: Journal of Hazardous Materials. 2015 Aug 20;300:823-829. doi: 10.1016/j.jhazmat.2015.08.026. [Epub ahead of print] ;