Study on characterization of mercury sorption by natural and thiol modified zeolites
天然和巯基改性沸石吸附水溶液中重金属Hg~(2+)的特征研究

This work, using cysteamine hydrochloride to modify natural clinoptilolite zeolites, results in great enhancement of absorption capacity. The effects of absorber dosage, pH values, temperature, adsorption time and Hg2+ concentration on Hg2+ adsorption and adsorption mechanism are researched. The result shows that the mercury retention by the modified zeolite is attributed to the metal-chelating S functionality, while the one by the natural zeolite is cation exchange. The pH and temperature factors that have slightly effect on the modified zeolite adsorption could significantly affect the natural zeolite; the higher the temperature is, the lower the sorption rate is. Within a high rate of the adsorption process, the modified zeolite takes 0.5 h to reach the adsorption equilibrium, while the natural zeolite takes 1 h. The Langmuir isotherm model and the adsorption conditions experiment both indicate that the modification has greatly enhanced the adsorption capacity for Hg2+, the maximum capacity is increased by 146.65%, from 8.06 mg/g to 19.88 mg/g Hg.