Removal of cadmium in Water Using TCAS-adsorbed resin

摘要

A adsorbent for cadmium had been prepared by loading an anion-exchange resin with a novel supramolepblar compound named thiacalix[4]arenetetrasulfonate (TCAS). The adsorption properties of Cd2+ on TCAS-adsorbed resin had been studied and the effects of varying temperature, pH value, adsorption time and initial conentration. Batchwise extraction studies had revealed a high adsorption ability of the TCAS-adsorbed resin toward this heavy metal ion with high selectivity. The maximum adsorption capacitiy of the TCAS-adsorbed resin toward Cd2+ was 14.45 mg·g-1.The removal rate of Cd2+ in water was up to 99% after 60min at 20°C when a 50mL aqueous solution of Cd2+ (10 mg·L-1) was adsorbed by 0.5g TCAS-adsorbed resin. The desorption rate steadily retained above 98% when the pH value was in the range of 7 to 11.The data obtained from sorption isotherms of metal ions at different temperatures fit to linear form of Langmuir sorption equation. These results not only could theoretically provide the approach to use the new type of TCAS-adsorbed resin to enhance the capacity of desorption of Cd2+ from liquid media, but also could extensively be used in the technique for low concentration Cd2+ contaminated water.