Preparation and adsorption of Cr(Ⅲ) on thiol functionalized cellulose aerogels

Abstract

In order to effectively treat Cr(Ⅲ) and reduce the contention in tannery wastewater,studied the adsorption of thiol functionalized cellulose aerogels using absorbent cotton as raw material,NaOH/urea /H2O as solvent and CS2 as modifier,hydroxyl groups in cellulose molecules were functionalized,and sulfhydryl functionalized cellulose aerogels (CS2-MCC) were prepared by solvent replacement and freeze drying.Determined the optimum preparation conditions by single factor test and orthogonal test.Analyzed the functional group structure and surface morphology of the material.And then carried out the adsorption experiment of Cr(Ⅲ) on CS2-MCC further.The results showed that,the optimum preparation conditions are as follows:CS2 dosage 0.5 mL/g,magnesium sulfate dosage 20 mL/g,modification time 6 h,modification temperature 40 ℃.And the maximum adsorption capacity of CS2-MCC for Cr(Ⅲ) is 75.792 mg/g.The adsorption process conforms to pseudo-second-order kinetic model and Langmuir isothermal model,ΔGθ</sup><0,indicating that the adsorption of Cr(Ⅲ) by CS2-MCC is spontaneous monolayer adsorption and chemical adsorption,and the content of Cr(Ⅲ) is reduced to 1.470 mg/L after treatment,which can reach the standard of discharge.The prepared thiol functionalized cellulose aerogel material with rich three-dimensional network and excellent adsorption performance was successfully prepared,which solved the shortcomings of cellulosic adsorption materials,such as difficult powder recycling and poor adsorption selectivity.Cr(Ⅲ) can be effectively adsorbed by this material in tannery wastewater,

Keywords

• adsorption and ion exchange; tanning wastewater; cellulose; aerogel; adsorbent; cr[bf]([bfq]ⅲ)