| With the striking development of some industries in our country such as steel production, electroplateing, dyeing and printing industry etc., there exists a severe water resource crisis due to a large amount of water contaminated by heavy metals and dye. metals. The heavy metals and dye contained in waste water not only causes the harm of health for environmental biological but also influences the survival of human. Therefore, the research on disposing heavy metal ions and dye molecules in waster water has quite practical application significance for resolving the water resource crisis and promoting the intensive development of industry, such as leather tanning, mining, smelting, electroplating, etc. The conventional processes were sometimes restricted by the technique, economy and secondary pollution. Recently, the utilization of biomass and agricultural waste materials for the research object, chemically modifield, special properties nanometer materials to removal heavy metal ions and dye molecules has been research hotspot.In the experiment the magnetic Fe3O4 baker's yeast biomass (FB) was prepared by combining baker'syeast biomass and nano-Fe3O4 using glutaraldehyde as a cross-link agent, and was chemically treated with ethylene-diaminetetraacetic dianhydride(EDTAD). The magnetic Fe3O4 baker's yeast biomass (FB) and EDTAD-magnetic Fe3O4 baker's yeast biomass(EFB) were utilized as biosorbents to adsorb heavy metal ions(Ca2+, Cd2+, Pb2+) and dye molecules in the aqueous solution. All the effect condition on adsorption, such as pH value, contact time, initial concentration of heavy metal ions(Ca2+, Cd2+, Pb2+) and dye molecules, coexisting ions, temperature and ehtion experiment were discussed.The adsorption properties of EFB for Pb2+, Cd2+, and Ca2+ions were evaluated. The results showed that the uptakes of EFB for the three metal ions were higher than that of FB, and the adsorption capability of Pb2+, Cd2+, andCa2+ions increased with an increase in pH. The adsorption process was followed by the pseudo-second-order kinetic model and Langmuir isotherm equation. The maximum adsorption capacities of 99.26mg/g for Pb2+ at pH5.5,48.70mg/g for Cd2+ at pH6.0, and 33.46mg/g for Ca2+at pH6.0 were observed at 30℃. The coexisting ions experiments were indicate that the EFB combined with metal ions followed the order:Na+, K+< Mg2+< Ca2+<<Cd2+< Pb2+<Ni2+< Cu2+. The adsorption properties of EFB and FB for methylene blue were also evaluated. The results showed that the adsorption capacities of EFB were two times for FB. The maximum adsorption capacities were 223.66 mg/g for EFB, and 110.00 mg/g for FB. The adsorption capacities of EFB and FB for methylene blue increased with an increase in pH<4, but the the adsorption capacities of EFB for methylene blue keeping stability with an increase in 4<pH<9. The adsorption process of EFB and FB were followed by the pseudo-second-order kinetic model and Langmuir isotherm equation. The uptakes weren't influenced by a rise reaction temperature from 5 to 40℃. The regeneration experiments showed that the EFB and FB could be successfully reused. The uptakes of EFB and FB for the three metal ions and dye molecules after three consecutive adsorption/desorption cycles keep above 80%.The FB and EFB were investigated by IR, SEM, XRD, Zeta potential, potentiometric titration and magnetic response analysis. The results revealed that the FB and EFB possessed not only a favorable superparamagnetism, but also those surface were tough. The number of carboxyl and amino groups which were magnificent relevant to the three metal ions and dye molecules on surface of EFB was increased by chemically treated with EDTAD. |
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