铝钛改性MCM-41材料对污水中铅镉的吸附研究

Use of MCM-41 Modified with Al and Ti Ions to Remove Cd^(2+) and Pb^(2+) from Wastewater through Adsorption

研究了改性MCM-41材料对污水中重金属铅、镉离子的吸附行为。在MCM-41材料中加入Al、Ti两种诱因金属离子来合成新的Al-Ti-MCM-41及Ti-Al-MCM-41改性材料,通过氮气吸附-脱附等温线对Al-Ti-MCM-41(Al/Ti=1∶1)及Al-Ti-MCM-41(Al/Ti=2∶1)样品进行了表征,并采用改性后的MCM-41材料为吸附剂对含有二价铅、镉离子的溶液进行吸附实验,考察了吸附剂投加量,Pb2+、Cd2+初始质量浓度和吸附温度对吸附的影响。结果表明:改性Al-Ti-MCM-41(Al/Ti=1∶1)材料的最可几孔径和比孔容分别为16.68 nm和0.046 cm3/g,由BJH计算得到的平均孔径为17.02 nm;Al-Ti-MCM-41(Al/Ti=2∶1)的最可几孔径和比孔容分别为16.88 nm和0.083 cm3/g,由BJH计算得到的平均孔径为17.08 nm。Al-Ti-MCM-41(Al/Ti=1∶1)对Cd2+的吸附率为99.8%;Al-Ti-MCM-41(Al/Ti=2∶1)对Pb2+的吸附率为99.96%;Pb2+和Cd2+的吸附容量随吸附剂投加量的增加而降低,随离子初始浓度的增大而增加;温度越高越有利于吸附。该研究重点考察改性MCM-41材料在重金属铅镉离子污染治理中的性能,从而为解决重金属铅镉的污染,加强环境保护提供理论支撑和技术支持,具有明确的现实意义。

Al-Ti-MCM-41 and Ti-Al-MCM-4,the new adsorbing materials made by modifying MCM-41 with aluminum and titanium ions,were prepared and used as adsorbents to remove Cd2＋ and Pb2＋ from wastewater at a bench-scale level.The adsorption behavior of the modified MCM-41 was investigated and the results revealed the data of pore diameters and specific pore volumes of the new modified adsorbents and reported the adsorption ratios of Cd2＋ and Pb2＋ ions onto Al-Ti-MCM-41 i.e.,99.8% and 99.96% respectively.According to the investigation,generally adsorption capacity of Cd2＋ and Pb2＋ decreased with the increased adsorbent dosage while increased with increased initial concentrations of the ions;in addition,as to the effect of temperature on adsorption： the higher the better.