Fe-Mn binary oxide incorporated into diatomite as an adsorbent for arsenite removal: preparation and evaluation.
Fe-Mn binary oxide incorporated into diatomite (FMBO-diatomite) was prepared by a simple coating method, and exhibited high oxidation and adsorption ability for arsenite [As(III)]. After being incorporated by Fe-Mn binary oxide, the surface area of diatomite increased 36%, and the pore volume increased five times. The pHzpc of FMBO-diatomite was determined to be 8.1. These characteristics are responsible for the increased As(III) adsorption efficiency. The adsorption equilibria of As(III) on FMBO-diatomite were described well by a Langmuir isotherm model due to the homogeneous distribution of Fe-Mn binary oxide on a diatomite surface. As(III) was oxidized into As(V), and then adsorbed by FMBO-diatomite. The oxidation and adsorption efficiencies for As(III) depended deeply on the pH of solution. When the pH was raised to 8.1, the As(III) adsorption efficiency of FMBO-diatomite was almost equal to the As(III) oxidation efficiency. Silicate and phosphate had negative effects on As(III) adsorption. Also the influence of silicate and phosphate with the pH variation was different.
Chang
Fangfang
F
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Qu
Jiuhui
J
Liu
Huijuan
H
Liu
Ruiping
R
Zhao
Xu
X
D000327:Adsorption; D000838:Anions / Q000737:chemistry; D018053:Arsenites / Q000737:chemistry* / Q000302:isolation & purification*; D007692:Diatomaceous Earth / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D008345:Manganese / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010316:Particle Size; D011199:Potentiometry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature
D000838:Anions; D018053:Arsenites; D010087:Oxides; D008345:Manganese; D007692:Diatomaceous Earth; C033787:diatomite; D007501:Iron; C015001:arsenite