Novel insight into the adsorption and co-adsorption of Cd(II) and As(V) by magnetic graphene nanomaterials in water

D. Huanga,b, J. Wua,b and Jianming Xua,b

a Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, China

b Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, China

jmxu@zju.edu.cn

A simple method was employed to prepare stable, magnetic graphene oxide, with few layers (MGO), by loading graphene oxide (GO) onto Fe3O4 nanoparticles. Magnetic chemically reduced graphene (MCRG) and magnetic annealing reduced graphene (MARG) were prepared from the reduction of MGO with hydrazine hydrate and thermal reduction at 500 °C, respectively. The adsorption of Cd(II) and As(V) by MGO, MCRG and MARG were investigated to determine their adsorption properties and molecular mechanisms. The adsorption of Cd(II) and As(V) was pH-dependent and their adsorption capacities followed the order: MGO > MCRG > MARG. Therefore, MGO was selected to systematically study their adsorption behavior in the binary system of Cd(II) and As(V). The maximum adsorption capacities of MGO were 234 mg/g for Cd(II) and 14 mg/g for As(V). The superiority of MGO was mainly attributed to its high dispersibility, thin nanosheets and various O-containing functional groups. The adsorption of Cd(II) and As(V) in the co-adsorption system was increased by 65% and 30%, respectively. This synergistic effect resulted from electrostatic attraction and the formation of type A ternary surface complexes.These new results are valuable for determining the interaction mechanisms, and for designing novel adsorbents, for traditional and emerging pollutants in the environment.

results matching ""

    No results matching ""