Magnetic Juice Residue Used As New Adsorbents For Removing Heavy Metals And Dyes From Solutions

In this work, we synthesized a novel magnetic adsorbent based on agro-waste juice residue denoted as MJR, and charactered by FT-IR, BET, XRD, Zeta potential, magnetization. The result of FT-IR showed the increase of functional groups of MJR, the BET test showed the decrease of specific surface area. The XRD test showed the iron oxide was composed of magnetite. Additonally, the Zeta potential incicated that the surface of MJR was negatively charged. Moreover, magnetization curve revealed that the MJR has been magnetized.For the removal of Pb(II) and malachite green(MG) from solution, the factors influencing adsorption, such as contact time, adsorbent dosage, and pH were investigated by batch experiments. The maximum adsorption of Pb(II) and MG onto MJR was achieved at a contact time of 120 min, a pH of 6, a dose of 5 g/L and a contact time of 60 min, a pH of 6, a dose of 5 g/L, respectively. The comparison of the adsorption capacity between juice residue and magnetic juice residue was used to indicate the advantagement of MJR as a novel magnetic adsorbent.The experiment mechanism was studied using pseudo-second-order model, Internal diffusion dynamics model, Langmuir, Freundlich and D-R isotherms model based on batch experiments. The result showed that adsorption processes of Pb(II) onto MJR were described well by both Langmuir and Freundlich isotherms. However, The adsorption processes of Pb(II) onto MJR can be just described by Langmuir isotherms. The maximum adsorption capacity of Pb(II) and MG onto MJR was 48.74 mg/g and 106.24mg/g,respectively.The magnetic adsorbent can be separated easily and speedily from solutions in an external magnetic field. The mixed reaction bed model which shows the higher adsorption efficiency in the practical application based on the characteristics of magnetic adsorbent was created, so as to provide important theoretical basis and practical support for the construction of sewage treatment system and the safeguard of the sewage treatment effect.