壳聚糖-聚乙烯醇复合水凝胶对水体和土壤中总砷的吸附性能研究

Study on adsorption ability of arsenic in wastewater and soil by chitosan-polyvinyl alcohol composite hydrogel

采用水热法制备壳聚糖-聚乙烯醇复合水凝胶,利用扫描电镜观察其表面形态,通过吸附试验和解吸试验分别考察其对水溶液及土壤溶液中总砷的吸附及解吸性能.结果表明:所制壳聚糖-聚乙烯醇复合水凝胶是一种比表面积较大且具有较多孔隙的材料,孔隙直径为10~60μm;该水凝胶对水溶液及土壤溶液中的总砷均有较好的去除能力,对水溶液,每g水凝胶吸附3.976 mg砷,对土壤溶液,每g水凝胶吸附3.480 mg砷;该水凝胶对总砷的解吸率较高,可重复利用,对水溶液和土壤溶液中的总砷解吸率分别为74.7%~81.4%和64.1%~77.0%.这说明,利用壳聚糖-聚乙烯醇复合水凝胶可以有效去除水体和土壤中的总砷.

Chitosan-polyvinyl alcohol composite hydrogel was prepared using the hydrothermal method and scanning electron microscope （ SEM ） was used to detect the surface morphology of the composite hydrogel. Then the adsorption ability was detected through static adsorption experiments and desorption tests in water solution and soil digestion solution, respectively. Results suggested that the chitosan-polyvinyl alcohol composite hydrogel ,as material with large surface area and more pores 10 ~ 60 μm in diameter, could effectively remove arsenic from both wastewater and soil. The adsorbing capacity were 3. 976 mg arsenic/g hydrogel and 3. 480 mg arsenic/g hydrogel, respectively. The desorption efficiency of this composite hydrogel to arsenic was higher,and the hydrogel could be reused. The desorption efficiency were 74.7% -81.4% and 64. 1% 77.0%, respectively for wastewater and soil. So the chitosan/polyvinyl alcohol composite hydrogel could effec- tively remove arsenic from both wastewater and soil.