Active Biochar Prepared By Papermaking Sludge And Its Application For The Treatment Of Lead (â…¡)

Papermaking sludge is the by-product after the papermaking wastewater treatment, which is composed of inorganic particles, bacteria somatic, colloid, etc of the very complicated heterogeneous body. Sludge not only contains a lot of available nitrogen, phosphorus, potassium, trace elements and organic matter and so on, also contain a lot of pathogens and parasites and so on the many kinds of harmful organic pollutants. If it is not through proper disposal, that will give a lot of pressure to the environment.In this study, biochar was modified and the structure of the modified biochar was characterized. It studied the pyrolysis temperature and the time to the performance of the biochar. The biochar was disposed with sulfuric acid,we also studied the modifiedtemperature and the added quantity of sulfuric acid to the adsorption capacity mflunce of the biochar. Besides, the influence of adsorption time, the pH value of the solution, temperature and the initial solution concentration were discussed during the adsorption. According the adsorption results, the appropriate adsorption conditions was attained. Morever, the kinetics and thermodynamics of the adsorption were investigated, furthermore, the adsorption mechanism of Pb(Ⅱ) was studied. The main conclusion of this study were as follows:(1) We prepared the biochar by the papermaking sludge, which was modified by sulfuric acid;(2) The best conditions for modification:0.1g dry biochar,50mL0.5M of sulfuric acid at550℃under activation0.5h;(3) Based on biochar characterization analysis, we obtained the surface of sulfuric acid activation biochar increased-OH,-COOH,-NH2groups, the specific surface area of the biochar was159m2·g-1,the mean diameter of the pore was20A;(4) The Pb (II) adsorption best condition is:when the biochar was added in the Pb(II) solution as the initial concentration was160mg·L-1, at pH value6and at25℃with an adsorbent dosage of0.2g.L-1, after4hours adsorption, the maximum adsorption capacity was577.8mg·-g-1; (5) When the adsorption temperature was at25℃,35℃and45℃, the experimental kinetic data were conformed to Pseudo-second-order model; when the adsorption temperature is at25℃,35℃and45℃, the data of the equilibrium sorption experiments was accorded with Langmuir isotherm.