Removal of Ni(II) and Cr(VI) ions from electroplating wastewater using ferrous sulfate

Document Type : Original Article

Authors

1 Department of the Environment, College of Basic Sciences, Hamedan Branch, Islamic Azad University, Hamedan, Iran

2 Department of Chemistry, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran

10.22102/jaehr.2021.260836.1203

Abstract

In this study, the ferrous sulfate was used to remove Cr(VI) and Ni(II) ions from a real Ni-Cr plating industry wastewater. This is an applied study. The type of sampling was composite by three 5 L containers. Wastewater chemical and physical characteristics were measured in accordance with the standard methods book 14. The concentration of un-removed metal ions was estimated by ICP-OES. The Jar test type experiment was used to carry the chemical coagulation experiment. The results indicated that the rate of removal would depend on the pH estimation of 1.5-11, the diverse contact time in the range of 30-120 min and the coagulant measurement in the range of 0.5-2 g/l. The optimum Cr(VI) ions removal was gotten at a pH of 7 up to 83.88% in 0.5 g/l of coagulant dose in 40 min. While the optimum Ni(II) ions removal was found to occur at a pH of 5 up to 56.33 % in 0.5 g/l of coagulant measurements in 40 min. The scanning electron microscopy results reveal the difference between the coagulant surface when coagulation. Also, the energy-dispersive x-ray spectroscopy (EDX) analysis shows the presence of Cr(VI) and Ni(II) ions on the surface of the ferrous sulfate after coagulation. Ultimately, the outcomes indicated that ferrous sulfate could be an operative chemical coagulant to remove Cr(VI) and Ni(II) ions from the plating industry wastewater, especially for Cr(VI) particles. The outcome of this study can be a useful guide to the real plating industry wastewater treatment operators.

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