The Study Of Adsorption Of Phenol Onto Dried Activated Sludge And Its Modified Products

Adsorption of phenol in water by dried activated sludge and pyrolysis dried activated sludge, which made from the material of discarded activated sludge of municipal wastewater treatment plant, were studied. The work included adsorption equation of dried activated sludge and pyrolysis dried activated sludge, adsorption saturation curve and influenced facters include time,temperature,pH and so on. Furthermore, flood organ of dried activated sludge and pyrolysis dried activated sludge were studied, and provided the theoretical basis for surplus activated sludge recycle.Because of different temperatures, the component of sludge was different, the organ in dried activated sludge was more than in pyrolysis dried activated sludge. Then, the ability of adsorption of phenol was different. Under the same condition, the adsorption quantities of dried activated sludge was as twice as pyrolysis.Adsorption equilibrium time of dried activated sludge: in temperature 25℃and 30℃, was 48h; in temperature 40℃and 45℃, it was 24h. Adsorption equilibrium time of pyrolysis dried activated sludge: in temperature 25℃and 30℃, was 6h; in temperature 40℃and 45℃it was 48h.The results showed that in temperature 30, adsorption of phenol on to dried activated sludge: the uptake process of the phenol has proven to follow the second-order kinetic model, and can be described by the first-order Lagergren equation, and its first-order equation was ln(10.371-q) = 2.339-0.9487t, second-order kinetic equation was t/q = 15.296 + t/15.949; in temperature 25, adsorption of phenol on to pyrolysis dried activated sludge: the uptake process of the phenol has proven to follow the second-order kinetic model, and can be described by the first-order Lagergren equation, and its first-order equation was ln(155.5294-q) = 5.0468-1.8974t, second-order kinetic equation was t/q = 0.7322+t/2.8506.In temperature 25℃, adsorption the kinetic equation of phenol to dried activated sludge and pyrolysis dried activated sludge conformed to Langmuir type isotherm primely. Adsorption the kinetic equation of phenol to dried activated sludge was G =909.091x0.0031 Ce/(1+0.0031 Ce), and the greatest adsorption amount was 909.091 mg/g, k=0.0031; Adsorption the kinetic equation of phenol to pyrolysis dried activated sludge was G=117.6471x0.0263Ce/(1+0.0263 Ce), and the greatest adsorption amount was 117.6471 mg/g, k=0.0263. In other temperature, the relative coefficient was no more than in temperature 25℃.In the scale of pH 4～9, adsorption of phenol on dried activated sludge was better; and in the scale of pH weak acidic or neutral, adsorption of phenol on pyrolysis dried activated sludge was better. Whether dried activated sludge or pyrolysis dried activated sludge, in water, its organ of it would flood. The percentage of flood organ of pyrolysis dried activated sludge was more than dried activated sludge, however, the organ in pyrolysis dried activated sludge was less in dried activated sludge, so the flood organ in dried activated sludge was more. Besides, the flood organ in dried activated sludge was endothermic reaction, and the flood organ in pyrolysis dried activated sludge was exothermic process.