A environment-friendly utilization of flue gas desulfurization residue for removing hexavalent chromium from electroplating wastewater

Abstract

A novel environment-friendly utilization manner of the flue gas desulfurization residue from wet magnesia flue gas desulfurization process and semi-dry calcium flue gas desulfurization process was proposed. In this article, the wet magnesia flue gas desulfurization residue and the semi-dry calcium flue gas desulfurization residue were respectively regarded as a high price-performance water treatment agent to detoxify the hexavalent chromium in the electroplating wastewater. The main technological mechanism and optimal parameters of the hexavalent chromium removal process were investigated. When the detoxification process was performed by using a residue from wet magnesia flue gas desulfurization process, the residual pollutant concentration in treated wastewater under the optimal experimental parameters was as follow: the hexavalent chromium residue decreased to 0.035 mg/L, total chromium residue decreased to 0.08 mg/L and magnesium residue was 73.5 mg/L. When the detoxification process was performed by using a residue from semi-dry calcium flue gas desulfurization process, the residual pollutant concentration in treated wastewater under the optimal experimental parameters was as follow: the hexavalent chromium residue decreased to 0.021 mg/L, total chromium residue decreased to 0.085 mg/L and calcium residue was 227 mg/L. The present work not only provided a new resource utilization approach of desulfurization residue from wet magnesia desulfurization technology and semi-dry calcium desulfurization technology, but also provided a high price-performance, efficient and environmentally friendly detoxification process for the electroplating wastewater which give attention to economic benefit and environmental factors.