Adsorptive Removal Of Pb(?) By Magnetic Nanocomposites From Aqueous Solution

Recent industrial and urban activities have led to a rapid expansion of a wide range of pollutant in surface and groundwater.Water pollution has become a global environmental pollution.Heavy metals releasing to the environment cause serious environmental and health risks.Consequently,the need for contaminants removal has become a must.Fe₃O₄ magnetic nanoparticles attracted much attention and brought new platforms for water treatment take advantage of the surface effect and strong adsorption of heavy metals and it had an incomparable advantage that it could be very readily separated from aqueous solution by permanent magnet.In our study,Fe₃O₄ was successfully prepared by the immobilization of SiO₂ and L-Cysteine,which was confirmed by ESEM and FTIR.So the adsorption result was much more better and the immobilization process did not significantly result in the phase change of Fe₃O_4.Showd by external magnetic field,Fe₃O₄@SiO₂@CysNPs can separate from the solution quickly.The effect of various parameters such as pH,adsorption dosage,contact time and initial Pb???concentration on the efficiency of adsorption process were evaluated.The adsorption kinetics fitted well to the pseudo-second-order model with correlation coefficients greater than 0.999.The best interpretation for the equilibrium data were given by Langmuir isotherm.The thermodynamic analysis of equilibrium suggested that the adsorption of Pb???was spontaneous and endothermic in nature.Compared with other several kinds of heavy metal ions like Cu???Cd???and Zn???,the adsorbent showed the better adsorption capacity for Pb???.The desorption and regeneration studies indicated that Fe₃O₄@SiO₂@Cys could be employed repeatedly.In addition,a novel ternary magnrtic consisting of reduced graphene oxide,L-Cysteine and Fe₃O_4.The influence of pH value,dosage of adsorbent,initial concentration and contact time were investigated via batch experiments.The results show thatnot only the adsorption of GO@Fe₃O₄@Cys very strong,but also easy to be separated.