Amino-functionalized core-shell magnetic mesoporous composite microspheres for Pb(II) and Cd(II) removal.
Amino-functionalized Fe3O4@mesoporous SiO2 core-shell composite microspheres NH2-MS in created in multiple synthesis steps have been investigated for Pb(II) and Cd(II) adsorption. The microspheres were characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), N2 adsorption-desorption, zeta potential measurements and vibrating sample magnetometer. Batch adsorption tests indicated that NH2-MS exhibited higher adsorption affinity toward Pb(II) and Cd(II) than MS did. The Langmuir model could fit the adsorption isotherm very well with maximum adsorption capacity of 128.21 and 51.81 mg/g for Pb(II) and Cd(II), respectively, implying that adsorption processes involved monolayer adsorption. Pb(II) and Cd(II) adsorption could be well described by the pseudo second-order kinetics model, and was found to be strongly dependent on pH and humic acid. The Pb(II)- and Cd(II)-loaded microspheres were effectively desorbed using 0.01 mol/L HCl or EDTA solution. NH2-MS have promise for use as adsorbents in the removal of Pb(II) and Cd(II) in wastewater treatment processes.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, China. tangyulin@tongji.edu.cn
Yulin
Y
Tang
Song
S
Liang
Juntao
J
Wang
Shuili
S
Yu
Yilong
Y
Wang
D000327:Adsorption; D000588:Amines / Q000737:chemistry*; D002104:Cadmium / Q000302:isolation & purification*; D006812:Humic Substances / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007854:Lead / Q000302:isolation & purification*; D060328:Magnetic Phenomena; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D016062:Porosity; D059027:Recycling; D012996:Solutions; D055672:Static Electricity; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D000588:Amines; D006812:Humic Substances; D012996:Solutions; D014874:Water Pollutants, Chemical; D002104:Cadmium; D007854:Lead