Synthesis And Characterization Of Magnetic Poly(Acrylamide-co-maleic Anhydride) Grafted Gelatin As A Heavy Metal Ions Wastewater Treatment Agent

Due to the high chemical toxicity,bio-accumulative effect,persistence,the heavy metal pollution has brought a serious threat to the ecological environment,human survival and living conditions.Therefore,removing heavy metal ions from effluents is an important problem of global concern.However,most of the agents show low water solubility,environmentally unfriendly,slow precipitation separation rate and other defects.In order to overcome the disadvantages of the existing chemical precipitants,a magnetic metal-organic macromolecule complex with many anionic functional groups,was prepared as heavy metal ions wastewater treatment agent which has excellent removal efficiency and rapid solid-liquid separation performance.In this paper,the development of magnetic nanomaterials and anionic poly?AM-co-MA?was first studied.Anionic poly?AM-co-MA?was prepared by aqueous solution polymerization.The synthesis conditions of anionic poly?AM-co-MA?were studied and the optimum preparation conditions were determined.The monomer concentration of 40%,initiator dosage of 0.6%,AM/MA mass ratio of 10:1 and reaction time of 30 min were employed for optimizing the polymerization conditions of anionic poly?AM-co-MA?.At the optimum condition,intrinsic viscosity extended the maximum of 0.401 mL·g^-11 and the molecular weight 1.905×10⁶ g·mol^-1.The optimum conditions for the preparation of magnetic anionic poly?AM-co-MA?-g-gelatin were obtained by orthogonal experiment.The results show that the optimized strategy was achieved with 7.6%gelatin,15.2%Fe₃O₄ and 3.8%citric acid.The obtained magnetic composite was characterized,which showed a core/shell structure and good magnetic properties.The effect of heavy metal ions wastewater treatment agent on heavy metal ion treatment in water was investigated further.The best condition parameter of heavy metal ion experiment were investigated by the single factor experiment on the Cr³⁺removal efficiency.It was proved that the optimum parameter for the preparation were pH of 9,the settling times of 10 min,and the heavy metal ions wastewater treatment agent dosage of 5 mL.Under the optimum condition,Cr³⁺removal efficiency was95.5%.The effect of the initial concentration of simulated wastewater on the removal efficiency was studied.The removal efficiency was reduced as the initial concentration of Cr³⁺,Cu²⁺,Zn²⁺increased,and the removal rate was Cr³⁺>Zn²⁺>Cu²⁺.In order to assess the advantages of heavy metal ions wastewater treatment agent,the separation speed of poly?AM-co-AM?and magnetic poly?AM-co-AM?-g-gelatin were compared.The results showed that the Cr³⁺removal efficiency reached 90.1%within 2 min when treated with magnetic poly?AM-co-AM?-g-gelatin,and it was 75.3%higher than that of conventional non-magnetic anionic polyacrylamide.These results demonstrate that the magnetic poly?AM-co-AM?-g-gelatin can remove heavy metal ions from water in shorter settling time and has high practicability.