Adsorption of reactive brilliant red K-2BP on activated carbon developed from sewage sludge

Abstract

Activated carbon was prepared from the sewage sludge of municipal wastewater treatment plant by chemical activation (activation reagent is ZnCl₂) and was used for the adsorption of dye (reactive brilliant red K-2BP). The impact of adsorbent amount, adsorption time and pH value on adsorption effect, the adsorption kinetics, and the adsorption thermodynamics were discussed according to batch adsorption tests. The results indicated that the activated carbon developed from sewage sludge (ACSS), which was mesoporous, possessed opened porous structures. The iodine number of the ACSS was 326 mg·g^-1. The rate of achievement was 51.31%. The BET surface area was 298 m²·g^-1 and the contents of heavy metals in the leachate didn’t exceed the contents limit. The adsorption kinetics of reactive brilliant red K-2BP on the ACSS was accorded with the two-step kinetics rate equation and pseudo-second-order kinetics equation. Compared to the Freundlich isotherm equation, the Langmuir isotherm equation showed better applicability for the adsorption. The adsorption which was favorable was an endothermic (enthalpy ?H > 0) and spontaneous (free energy ?G < 0) process and was accompanied by an increase in entropy (?S > 0).

References

1. Zhang S G Wu Z C Zhang S F Zhu S Q Study of countermeasuresfor sludge disposal of Shanghai wastewater treatment plantsEnvironmental Engineering 2004 22(1)7578(in Chinese)
2. Gao S Y Chen W Y Elements and Application ofActivated CarbonBeijing: Chinese ForestryPress1984(in Chinese)
3. Yu L L Zhong Q Feng L L Research on preparation and application of activated carbonadsorbent from residual sludgeJournal ofSafety and Environment 2005 5(4)3942(in Chinese)
4. Bian H S Zhang Z Y Liu Z L Use of Sewage Sludge for Manufacturing AdsorbentEnvironmental Science 1999 20(6)5659(in Chinese)
5. Zhang D J Wei X X Zeng G M Zhai Y B Experimentalresearch on sewage sludge ramification adsorbent with chemical activationJournal of Safety and Environment 2003 3(5)4446(in Chinese)
6. Tay J H Chen X G Jeyaseelan S Graham N Optimising thepreparation of activated carbon from digested sewage sludge and coconuthuskChemosphere 2001 444551
7. Nagaoka H Imae T Analytical investigation oftwo-step adsorption kinetics on surfacesJournal of Colloid and Interface Science 2003 264335342
8. Yang X Y Al-Duri B Kinetic modeling of liquid-phaseadsorption of reactive dyes on activated carbonJournal of Colloid and Interface Science 2005 2872534
9. Yeddou N Bensmaili A Kinetic models for the sorptionof dye from aqueous solution by clay-wood sawdust mixtureDesalination 2005 185499508
10. Zhang Y H SorptionShanghai: Shanghai Science and Technology LiteraturePress 1989 50–51(in Chinese)
11. Fu X C Shen W X Yao T Y Physical ChemistryBeijing: HigherEducation Press 1990 201–202(in Chinese)
12. Garcla-Delgado R A Cotouelo-Minguez LM Rodfiguez J J Equilibrium study of single-soluteadsorption of anionic surfactants with polymeric XAD resinsSep Sci Technol 1992 27(7)975987