Study On The Preparation Of Straw-sludge Adsorbent And The Adsorption Properties

Along with the environmental problem getting acute in our country and people’sincreasing awareness of protecting environment, the adsorbent used for the treatment ofsewage and waste gas purification is increased. As a cheap, readily available and certaincarbon content waste, municipal sludge and straw can be used as adsorbent materialspreparation. This subject was to utilize municipal sludge and corn straw as raw materialsfor the preparation of the adsorbent by chemical activation. And the adsorbent preparedwas used to treat the leachate for adsorption purpose.The optimum technological conditions of preparing adsorbent were studied by usinga orthogonal matrix experimental method. The results showed that the prepared adsorbentwas with good effect when ZnCl₂was used as an activator, and the carbonization wasconducted under a temperature of600℃for1.5hours with a impregnation ratio of1:4. Inthis case, the iodine adsorption value of the adsorbent was426.4mg/g, and the surfacearea of BET was546.5m²/g. Besides, the pore size mainly ranged from2nm to50nm,mainly in hole, and the average pore size was4.71nm with a pore volume of0.64cm³/g.After our range analysis and variance analysis, four factors influencing theexperimental results are listed according to the importance as follows:activator>impregnation ratio>carbonization time>carbonization temperature.Analysis of TG/DTA and FTIR for the best adsorbent was carried out, which wasmainly for the study of the adsorbent surface structure and thermodynamic characteristics.Carbonization process of raw materials mainly includes evaporation stage of water andorganic matters, and then activation stage.The adsorption experiments of leachate were carried out with the best adsorptionagent, and the results showed that the method could effectively remove the color and CODof leachate. After studying the adsorption conditions, we found that the best value fordosage ratio, adsorption time and pH was3.5%,70min,3.50, respectively. Under theconditions of best adsorption, the removal rate of color and COD in the leachate was98.6%and29.4%, respectively. The GC-MS of the leachate before and after adsorptionwas investigated, and better adsorption results of refractory organic matter were achieved.