功能化水葫芦生物吸附剂的制备及其对铀的吸附机理

采用氢氧化钠预处理—柠檬酸热改性的两阶段处理方法,对水葫芦(water hyacinth,WH)通过酯化反应引入外来羧基,制备成一种新型的功能化水葫芦生物吸附剂(modified water hyacinth,MWH).利用批次静态吸附实验,研究了pH、铀初始质量浓度、WH/MWH投加量、吸附时间等因素对WH/MWH吸...

Preparation of Functional Water Hyacinth Biological Adsorbent and its Adsorption Mechanism for Uranium

The modified Water Hyacinth MWH was prepared by sodium hydroxide pretreatment and thermal modification with citric acid. The effects of pH, initial uranium concentration, WH/MWH dosage, adsorption time and other factors on the adsorption of uranium by WH/MWH were studied by batch static adsorption experiment. The mechanism of WH/MWH adsorption of uranium-containing wastewater was studied by SEM, EDS, FTIR characterization and adsorption kinetics. The results showed that when the initial concentration of uranium-containing wastewater was 1 mg/L, the pH value of the solution was 7, the dosage of WH /MWH was 0.2 g/L and the adsorption time was 4 hours, the adsorption equilibrium was reached, and the maximum adsorption capacity was 4.06 mg/g. Compared with WH, the adsorption rate of MWH to uranium increased by 34.03%, and the adsorption capacity increased by 1.7 mg/g. The uranium adsorption process of MWH is more in line with the quasi-second-order kinetic model, indicating that adsorption of uranium-containing wastewater with MWH is mainly chemical adsorption, accompanied with surface adsorption and ion exchange.