Utilization from Cement Kiln Dust in Removal of Acid Dyes

Problem statement: The growth of industries and day to day changes in human activities has resulted in an increase in the volume and complexity of wastewater to the environment. Textile industry is one of the most water consumers industries of Egypt, thus discharges large amounts of wastewater effluents during processing, especially, in the coloring and washing steps. Cement kiln dust is a solid waste in cement manufacturing. Approximately 2.5-3.0 (6-9%) million tons of cement kiln dust is produced annually in Egypt and that cause significant environmental problems. Approach: This study aims to investigate removal of some acid dyes from aqueous solution using cement kiln dust and monitoring the dye in colored cement kiln dust. Solution with 0.4 g L^-1 concentration was treated with cement kiln dust until the color of dye disappears. The colored cement kiln residue was separate by filtration and dried. The concentration of dye was measured before and after treatment by UV-Vis spectroscopy as well as after washing of colored residue. Also, the colored residue was investigated with, XRD, IR and DSC techniques as well as the loss on ignition at 450°C. Results: The results found that the cement kiln dust has the power to remove all existing acid dyes and the residue has the same color of dye. When colored residue was washed with water, there was no back diffusion of dye in to water. This may be mainly due to chemical reaction that took place between cement kiln dust and dye. Thus analysis such as IR, XRD and DSC are in agreement with these results. Conclusion: CKD is efficient in the processes of dye removal from aqueous solutions. The interaction between acid dye and CKD is fast (just minutes). So, we suggest using spent CKD for dye removal of waste water.