铝离子和钛离子化学改性MCM-41介孔材料的制备及其对污水中镉离子的吸附性能

摘要

通过在MCM-41材料中引入Al3+和Ti4两种诱因金属离子合成了化学改性介孔材料Al-Ti- MCM-41和Ti-Al-MCM-41；评价了两种介孔材料对污水中镉离子的吸附行为.利用氮气吸附-脱附等温线对Al-Ti-MCM-41(1∶1)样品的吸附行为进行了详细分析,考察了吸附剂投加量、Cd2初始质量浓度和吸附温度对其吸附行为的影响.结果表明:改性Al-Ti-MCM-41(1∶1)介孔材料的最可几孔径和比孔容分别为16 nm和0.04cm3/g,由BJH法计算得到的平均孔径为17.02 nm;其对污水中Cd2+的吸附率达99.8％.Cd2+的吸附率随Al-Ti-MCM-41(1∶1)介孔材料投加量的增加先增加而后降低最终达到平衡,吸附容量随Cd2+初始浓度的增大而增加；吸附温度对吸附行为基本无影响.%Chemically modified mesoporous materials Al-Ti-MCM-41 and Ti-Al-MCM-41 were prepared by incorporating Als+ and Ti4+ ions as inducement ions into MCM-41.The adsorption behavior of the two kinds of mesoporous materials for Cd2+ in wastewater was evaluated.Particularly,the adsorption performance of sample Al-Ti-MCM-41 (1 ∶ 1) was analyzed in detail based on nitrogen adsorption and desorption isotherms,with which the effects of adsorbent dosage on the adsorption rate and initial concentration of Cd2+ on the adsorption capacity were highlighted.However,the adsorption behavior was not affected by temperature.Results show that the most probable pore diameter and specific pore volume of Al-Ti-MCM-41(1 ∶ 1) are 16nm and 0.04 cm3/g,respectively.Its average diameter determined by the BJH method is 17.02nm,and it is able to adsorb Cd2+ in wastewater at a rate of up to 99.8%.Moreover,the adsorption capacity of Cd2+ decreased with increasing adsorbent dosage but increased with increasing initial concentration of Cd2+.