MnO2-Al2O3对氟离子的吸附性能及机理研究

摘要

以y-Al2O3为前驱体,利用原位生长及氧化还原法合成了MnO2-Al2O3吸附剂.研究了MnO2-Al2O3对氟离子的吸附选择性、循环利用性及除氟机理.结果表明,阴离子对MnO2-Al2O3除氟率的影响大小顺序为PO43-＞Cl＞SO42＞NO3-＞HCO3-;MnO2-Al2O3经5次吸脱附之后其除氟率下降至15.01％,循环利用性能有待进一步提高;吸附机理与吸附剂表面的zeta电位有关,主要包括静电吸引、配体交换和离子交换作用.%MnO2-Al2O3 was successfully fabricated using the in-situ growth and redox technology with gamma-alumina as a precursor.The adsorption selectivity,recycling performance,and adsorption mechanism towards fluoride ions were systematically studied.The results showed that some anions had significant effect on the fluoride removal,and the influence order was pO4Cl-＞SO42-NO3＞HCO3-.The fluoride removal rate fell to 15.01％ after five adsorption and desorption cycles,which indicated the recycling utilization performance of MnO2-Al2O3 was needed to be further improved.The value of zeta potential of MnO2-Al2O3 had significant effect on the fluoride removal,and the adsorption mechanism mainly included the electrostatic attraction,ligand exchange and ion exchange actions.