Adsorptive characteristics of modified talcum powder in removing methylene blue from wastewater

Abstract

Modified talcum powder prepared by physical purification and 50% (w/w) HNO3 acid activation was characterised by X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry. The modified talcum powder was used for the methylene blue adsorption in wastewater. Adsorption contact time, pH, adsorption temperature, initial mass concentration, and solid content were investigated. The adsorption mechanism was described by the Weber-Morris equation. Experimental results showed that above pH 7, increasing the initial dye concentration and the temperature improved the adsorption, and also that the adsorption capacity of modified talcum powder for methylene blue was superior to the initial unmodofied talcum powder. The modification processes improved the talcum powder purity. The kinetics of the sorption of methylene blue on the modified talcum powder fitted well to the pseudo-second-order model. From these experimental results, it is concluded that the talcum powder could be employed as an efficient adsorbent for the removal of textile dyes from effluents.