Preparation and performance of coal based chelating adsorbent

In order to improve the adsorption capacities of coal for heavy metal ions,triethylenetetramine was grafted on the surface of Shenfu coal particles with 71. 55 μm average diameter using γ-aminopropyltriethoxysilan as the coupling reagent. Then the grafted coal particles reacted with carbon disulfide and sodium hydroxide to form dithiocarbamate on the surface of coal particles. The adsorptive properties and mechanism of Ni2+onto coal based chelating adsorbent were investigated. The results show that the adsorption isotherm of Ni2+onto coal based chelating adsorbent can be described by Langmuir model. The adsorption capacity of Ni2+onto coal based chelating adsorbent is104. 17 mg / g,which is founded to be much higher than that of original coal of 32. 23 mg / g. The negative values ofΔH and ΔG illustrate the process is spontaneous and exothermic. FTIR spectrum analysis illustrate that the dithiocarbamate is grafted onto the surface of the coal particles successfully and reacte with Ni2+from the aqueous solution. The saturated chelating adsorbent is stable at higher p H. The desorption rate of the saturation chelating adsorbent for Ni2+can reach to 90. 74% by 0. 1 mol / L acetic acid.