Journal of Environmental Analytical Chemistry

Synthesis of Manganese Chloride Activated Carbon Deriving from Wheat Straw and its Adsorption Mechanism for Arsenic and Chromium

Abstract

Ningyuan Zhu, Tingmei Yan, Jun Qiao and Honglei Cao

Manganese impregnated biochar deriving from wheat straw were synthesized to treat heavy metal contamination. Nitrogen adsorption-desorption isotherms, scanning electron microscopy-energy dispersive X-Ray spectroscopy (SEM-EDS), and X-ray diffraction (XRD) were used to determine the characteristics of adsorbents. Batch adsorption experiments demonstrated a fit Langmuir model with the maximum adsorption capacity of 0.216 mmol g-1 for As (III) and a suitable Freundlich model for Cr (VI) respectively. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were measured to explore probable adsorption mechanisms involving As and Cr adsorption, which indicated that the Lewis acid-base interactions play a more important role in arsenic adsorption while electrostatic interaction along with the reduction Cr (VI) to Cr (III) contribute primarily to chromium adsorption.