MnO_2基复合吸附剂制备及去除水中重金属性能

采用共水热法和分步水热法分别制备了δ-MnO_2/MCM-41和δ-MnO_2/ZSM-5-n复合吸附材料,利用X射线衍射仪、透射电镜、N_2吸附/脱附仪等对复合吸附剂进行了表征,并考察了其去除水中Cu²⁺和Ni²⁺的性能。结果表明,δ-MnO_2具有海胆状形貌,单个颗粒直径大约在200 nm;其与分子筛复合后仍能保持原来的晶型和介孔结构。对δ-MnO_2/MCM-41复合吸附剂,当MCM-41添加质量分数为30%时,其对溶液中重金属Ni²⁺吸附能力最大,约为44.61mg/g;对δ-MnO_2/ZSM-5-n复合吸附剂,其对重金属离子的吸附量随ZSM-5-n硅铝比的增大而降低;且复合吸附剂对溶液中的重金属离子以单层物理吸附为主。

Preparation of Silico-Manganese Based Composite Adsorbents and Its Performance for Heavy Metal Ions Removal from Water

The δ-MnO2/MCM-41 and δ-MnO2/ZSM-5-n composite adsorbents were prepared by co-hydrothermal method and stepwise hydrothermal method,respectively.The performance of obtained adsorbents for Cu^2+ and Ni^2+ removal from water were characterized using X-ray diffractometer,transmission electron microscope,and N2 adsorption-desorption instrument.The results showed that,δ-MnO2 had a sea urchin-like morphology with a single particle diameter of about 200 nm.After being compounded with the molecular sieve,the δ-MnO2 could still maintain its original crystal structure and microporous structure.For δ-MnO2/MCM-41 composite adsorbent,when the dosage of mass fraction of MCM-41 was 30%,its adsorption capacity for Ni2^+ was the largest,about 46.61 mg/g;For δ-MnO2/ZSM-5-n,its adsorption capacity of heavy metal ions decreased with increase of silica-alumina ratio of ZSM-5-n,and the heavy metal species were absorbed onto the composite adsorbents surface by forming a continuous monolayer of adsorbate molecules.