Preparation Of Carbon Materials Loaded Metal Oxide And Its Adsorption Of Heavy Metal Ions

Heavy metal pollution has become a serious global problem. Based on theadvantages of adsorption method, a serial of nanocomposites were prepared for thetreatment of heavy metals contaminated water. The key contents includes: severalnanocomposites were prepared for effective removal of Cu(II) Cd(II) Cr(VI) fromwastewater. They are briefly as follows:(1) Magnetic nanocomposites (Fe3O4/GO) were synthesized by in-situ growthmethod, then polyethylenimine (PEI) was modified onto their surface to obtain theadsorbent PEI-Fe3O4/GO. The adsorbent was used to remove Cu(II) in water. TEMand FTIR were used to characterize the morphology of as-prepared materials. pH5.0isthe optimum value for Cu(II) removal in this study. Adsorption equilibrium wasreached within10hours. Kinetics study showed that the adsorption process was wellfitted with pseudo-second-order model. The maximum adsorption capacity was150.2mg/g, based on Langmuir adsorption isotherms. Moreover, PEI-Fe3O4/GOnanocomposites can be recycled by magnetic separation. After five cycles, the removalefficiency remained84%. The absorption mechanism was discussed and PEI acted as achelator for Cu(II) removal.(2) Carbon nanospheres (CNs) were synthesis by hydrothermal process,afterwards magnetic nanocomposites Fe3O4/CNs were synthesized by in-situ growthmethod to obtain the adsorbent. The adsorbent was used to remove Cr(VI) Cd(II) Cu(II)in water. SEM, FTIR and XRD were used to characterize the morphology ofas-prepared materials. pH3.0is the optimum value for Cr(VI), pH6.0is the optimumvalue for Cd(II), pH6.0is the optimum value for Cu(II) removal in this study.Adsorption equilibrium was reached within10hours. Kinetics study showed that theadsorption process was well fitted with pseudo-second-order model. The maximumadsorption capacity was7.87mg/g (Cr(VI)),66.68mg/g (Cd(II)), and44.08mg/g(Cu(II)), respectively, based on Langmuir adsorption isotherms.(3) Carbon nanospheres were synthesis by hydrothermal process, and then layereddouble hydroxides (LDH) were anchored on CNs by ultrasound method, the obtainLDH/CNs nanocomposites were used as adsorbent for removal Cr(VI) Cd(II) Cu(II) in water. SEM and TEM were used to characterize the morphology of as-preparedmaterials. pH5.0is the optimum value for Cu(II) removal in this study. Adsorptionequilibrium was reached within10hours. Kinetics study showed that the adsorptionprocess was well fitted with pseudo-second-order model. The maximum adsorptioncapacity was66.28mg/g (Cr(VI)),55.03mg/g (Cd(II)),38.16mg/g (Cu(II)),respectively.