Study On Absorption Of Phenolic Compounds Using Charcoal-Based Solid Sulfonic Acid

As is known to all, phenolic compounds is a carcinogens and hazardous chemical, and the quantity of phenol in treated wastewater fully conforms to the national permitted criterion. In this work, we studied the preparation of bamboo char sulfonic acids, which is a novel carbon-base adsorbent, using bamboo as raw materials by carbonization and sulfonation reaction respectively. To optimize its carbonization and sulfonation conditions, it is necessary that take phenol adsorption as a main line to impenetrate in it. Structural characteristic of samples were made by FT-IR and BET. At the same time, the regeneration properties and adsorption dynamics of bamboo char sulfonic acid are studied. The results are as follows:The optimistical charring conditions are concentration of sulfuric acid being80%, charring temperature being80℃, mass ratio of sulfuric acid and bamboo being1:8and charring time being4h; The optimistical sulfonation conditions are sulfonation temperature being80℃, sulfonation time being2h and mass ratio of sulfuric acid and bamboo charcoal being1:8. The smaller the partical size of bamboo char sulfonic acid, the greater its adsorption capacity of phenol. Bamboo char sulfonic acid, which is prepared in optimistical charring and sulfonation conditions, had reached the maximum adsorption capacity in which are adsorption time being2h, adsorption temperature being10℃and usage of adsorbent being0.008g. With increased nitial concentration of phenol, bamboo char sulfonic acid can adsorbs more phenol. Acid capacities and specific surface areas of bamboo charcoal and bamboo char sulfonic acid can reach as much as0.902,2.056mmol/g and209.35,576.63m2/g. Bamboo char sulfonic acid’s adsorption capacity of phenolic compounds were2,4-dinitrophenol> p-nitrophenol>2,4,6-trichlorophenol>2,4-dichlorophenol>p-chlorophenol>phenol>p-methylphenol.Strong alkaline medium is conducive to the regeneration of bamboo char sulfonic acid. Bamboo char sulfonic acid is regenerated by sodium hydroxide, which optimal concentration is0.1mol/L. Bamboo char sulfonic acid can keep high adsorption property after regenerating.The dynamics of adsorption phenol on bamboo char sulfonic acid was discussed. Two equations were tested to interpret the experimental data, compared with the pseudo-first order kinetic model, the pseudo-second order kinetics model was more suitable for describing the process of adsorption phenol on bamboo char sulfonic acid. And its maximum adsorption capacity can reach as much as159.9mg/g; with adsorption temperature rising, its rate constant also increase. Adsorption phenol on bamboo char sulfonic acid is the result of physical adsorption combined with chemical adsorption. And its activation energy was46.28kJ/mol.