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

In the past few decades, discharging thousands of organic, inorganic, and biological pollutants into environment has severely deteriorated water quality especially the heavy metals pollution which could be concentrated in organisms and, thus, harmful to most plants and animals not only at a high dose but also in relatively low concentration [1]. The continuous existence of heavy metal contaminant in the water environment, such as the high toxic arsenic and chromium, has been threaten seriously to water resource. Many studies have applied various methods such as ion exchange, solvent extraction, chemical precipitation and adsorption to reduce the concentration of these kinds of metal ions [2,3]. Among these methods, adsorption has been proved to be the most commonly used technique due to its simplicity of design, high efficiency, ease of operation and heavy metal adsorbents like polymeric hybrid sorbent, manganese oxide modified biochar and akaganeite nanoparticles have been well investigated [4-6]. Pacheco et al. [7] prepared alumina silica nanoparticles with hydroxyl, alkoxy, and oxy groups, which could remove cadmium efficiently by cationic exchange from wastewater samples. Banerjee and Chen [8] modified magnetic Fe3O4 nanoparticles with gum arabic which could adsorb copper metal ion rapidly from aqueous solution due to carboxylic groups of gum arabic, complexation of the amine group of gum arabic and surface hydroxyl groups of iron oxide.