Personal Research Database

Full Text: 2007\J Haz Mat147, 997.pdf

Abstract: The adsorption of three basic dyes (Rhodamine B (RB), Crystal Violet (CV), and Methylene Green (MG)) and two acid dyes (Acid Red 1 (AR1) and Erioglaucine (EG)) onto MCM-41 was studied to examine the potential of MCM-41 for the removal of dyes from water solution. The revolution of pore structure and surface chemical characteristics of MCM-41 induced by dyes adsorption was characterized based on the analyses of XRD patterns, FTIR spectra, and nitrogen adsorption-desorption isotherms. The adsorption capacity of MCM-41 for the five dyes followed a decreasing order of RB > CV > MG > EG similar to AR1. It was experimentally concluded that if the dyes adsorption did not introduce a serious disorder on the pore structure of MCM-41 (such as RB adsorption), MCM-41 might be a good adsorbent for the removal of basic dyes from water solution. The fitness of both Langmuir and Freundlich adsorption model on describing the equilibrium isotherms of three basic dyes was examined. The suitability of both pseudo-second-order kinetic model and the intraparticle diffusion model for the description of the kinetic data was investigated, from which the adsorption mechanism was examined. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Acid, Acid Dyes, Activated Carbon, Adsorbent, Adsorption, Adsorption, Adsorption Capacity, Adsorption Mechanism, Adsorption Model, Adsorption-Desorption, Azo-Dye, Basic Dyes, Capacity, Characteristics, Chemical, Color Removal, CV, Diffusion, Diffusion Model, Dyes, Dyes Adsorption, Equilibrium, Equilibrium Isotherms, Fitness, Freundlich, FTIR, Intraparticle Diffusion, Intraparticle Diffusion Model, Isotherms, Kinetic, Kinetic Model, Langmuir, Low-Cost Adsorbents, MCM-41, Mechanism, Methylene-Blue, Mg, Model, Molecular-Sieves, Nitrogen, Order, Pore, Pore Structure, Pore Structure Stability, Potential, Pseudo Second Order, Pseudo Second Order Kinetic, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Removal, Removal of Dyes, Rice Husk, Sorption, Structure, Surface, Wastewater, Water, XRD

? Nasir, M.H., Nadeem, R., Akhtar, K., Hanif, M.A. and Khalid, A.M. (2007), Efficacy of modified distillation sludge of rose (Rosa centifolia) petals for lead(II) and zinc(II) removal from aqueous solutions. Journal of Hazardous Materials, 147 (3), 1006-1014.

Full Text: 2007\J Haz Mat147, 1006.pdf

Abstract: Removal of Lead(II) and zinc(II) from aqueous solutions was studied using chemically modified distillation sludge of rose (Rosa centifolia) petals by pretreatment with NaOH, Ca(OH)₂, Al(OH)₃, C₆H₆, C₆H₅CHO and HgCl₂. The adsorption capacity of biomass was found to be significantly improved. NaOH pretreated biomass showed remarkable increase in sorption capacity. Maximum adsorption of both metal ions was observed at pH 5. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. The overall adsorption process was best described by pseudo second order kinetics. The thermodynamic assessment of the metal ion-Rosa centifolia biomass system indicated the feasibility and spontaneous nature of the process and G was evaluated as ranging from -26.9501 to -31.652 KJ mol^-1 and -24.1905 to -29.8923 KJ mol^-1 for Lead(II) and zinc(H) sorption, respectively, in the concentration range 10-640 mgL^-1. Distribution coefficient (D) showed that the concentration of metal ions at the sorbent-water interface is higher than the concentration in the continuous aqueous phase. Maximum adsorption capacity of biomass tends to be in the order Pb(II) (87.74 mgg^-1) > Zn(II) (73.8 mgg^-1) by NaOH pretreated biomass. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Capacity, Adsorption Process, Aqueous Phase, Aqueous Solutions, Assessment, Bakers-Yeast, Biomass, Biosorption, Biosorption, Ca(OH)₂, Cadmium, Capacity, Cell-Walls, Concentration, Distribution Coefficient, Experimental, Experimental Data, Freundlich, G, Heavy-Metals, Interface, Ions, Isotherms, Kinetics, Langmuir, Langmuir Isotherms, Lead, Lead(II), Metal, Metal Ions, Modified, Mucor-Rouxii, NaOH, Nickel, Order, Pb(II), pH, Pretreated, Pretreatment, Process, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second-Order, Range, Removal, Rosa Centifolia, Second Order, Second Order Kinetics, Sludge, Solutions, Sorption, Sorption Capacity, Spontaneous, Thermodynamic, Zinc, Zinc(II), Zn(II)

? Wu, X.B., Wu, D.C. and Fu, R.W. (2007), Studies on the adsorption of reactive brilliant red X-3B dye on organic and carbon aerogels. Journal of Hazardous Materials, 147 (3), 1028-1036.

Full Text: 2007\J Haz Mat147, 1028.pdf

Abstract: organic aerogels (AGs) and carbon aerogels (CAs) as adsorbents were successfully fabricated by a sol-gel polymerization method. The BET specific surface area and pore size distribution of the samples were analyzed by N-2 adsorption measurements. The adsorption efficiency of prepared samples towards reactive brilliant red X-3B dye (RBRX) was investigated. The adsorption of dye was found to follow the Langmuir and Freundlich models. The thermodynamic parameters, such as the change of free energy, enthalpy and entropy were calculated from equilibrium constants. Kinetic studies indicated that the adsorption of CA followed pseudo first and second order kinetic model, but the adsorption of AG only followed pseudo first order kinetic model. Batch adsorption studies were conducted to evaluate the effects of main preparation and adsorption conditions such as R/C (molar ratio of resorcinol (R) to surfactant (CTAB)) of adsorbent, pH, adsorbent dose and adsorbent particle size on the adsorption of RBRX on AG and CA. The results showed that the adsorption capacity of dye increased with the decrease in dose and particle size of the adsorbent. Maximum adsorption of AGs and CAs was observed at R/C = 200. The adsorption capacity of AG and CA would increase largely when pH < 4 or pH > 12. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorbents, Adsorption, Adsorption Capacity, Adsorption Efficiency, Ag, Aqueous-Solutions, BET, Ca, Capacity, Carbon, Constants, CTAB, Distribution, Dye, Effects, Efficiency, Energy, Enthalpy, Entropy, Equilibrium, Equilibrium Constants, First Order, Free Energy, Freundlich, Husk, Kinetic, Kinetic Model, Langmuir, Measurements, Method, Model, Models, N₂, N₂ Adsorption, N₂-Adsorption, N₂, Order, Organic, Organic and Carbon Aerogels, Parameters, Particle, Particle Size, pH, Polymerization, Pore, Pore Size, Pore Size Distribution, Preparation, Pseudo-First-Order, Reactive Dye, Removal, Resorcinol, Second Order, Size, Size Distribution, Sol-Gel, Specific Surface, Specific Surface Area, Surface, Surface Area, Surfactant, Thermodynamic, Thermodynamic Parameters, Wastewaters

? Tsai, W.T., Hsu, H.C., Su, T.Y., Lin, K.Y., Lin, C.M. and Dai, T.H. (2007), The adsorption of cationic dye from aqueous solution onto acid-activated andesite. Journal of Hazardous Materials, 147 (3), 1056-1062.

Full Text: 2007\J Haz Mat147, 1056.pdf

Abstract: The adsorption of cationic dye (i.e., methylene blue) onto acid-activated andesite in aqueous solution was studied in a batch system with respect to its kinetics as a function of agitation speed, initial adsorbate concentration, pH, and adsorbent mass. It was found that the resulting acid-activated adsorbent possessed a mesoporous structure with BET surface areas at around 60 m²/g. The surface characterization of acid-activated andesite was also performed using the zeta-potential measurements, indicating that the charge sign on the surface of the andesite should be negative in a wide pH range (i.e., 3-11). Furthermore, a simplified kinetic model, pseudo-second-order, was tested to investigate the adsorption behaviors of methylene blue onto the clay samples treated under different process conditions. It was found that the adsorption process could be well described with the model. The adsorption capacity parameter of the model obtained in the present work was significantly in line with the process parameters. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Acid Activation, Adsorbent, Adsorbents, Adsorption, Adsorption Capacity, Adsorption Process, Agitation, Andesite, Aqueous Solution, Basic-Dyes, Batch, Batch System, BET, Capacity, Cationic Dye, Characterization, Charge, Clay, Concentration, Diatomaceous-Earth, Dye, Function, In-Line, Kinetic, Kinetic Model, Kinetic Modeling, Kinetics, Mass, Measurements, Mesoporous, Methylene Blue, Methylene-Blue, Minerals, Model, Parameters, pH, Process, Pseudo Second Order, Pseudo-Second-Order, Range, Removal, Sorption, Speed, Structure, Surface, Surface Areas, Surface Characterization, Waste-Water, Zeta Potential, Zeta-Potential

? Iqbal, M., Saeed, A. and Zafar, S.I. (2007), Hybrid biosorbent: An innovative matrix to enhance the biosorption of Cd(II) from aqueous solution. Journal of Hazardous Materials, 148 (1-2), 47-55.

Full Text: 2007\J Haz Mat148, 47.pdf

Abstract: To enhance the metal removing capacity of a fungus biosorbent, a new idea of producing a hybrid biosorbent (HB) matrix by combining two different biosorbents using a simple and low-cost immobilization technique was tested for the sorption of Cd(II). The two biosorbents, used as the building block for the production of HB matrix, were the fungal biomass of Phanerochaete chrysosporium (13 1) and fibrous network of papaya wood (132). Maximum independent biosorption capacity of B I and 132 was noted, respectively, to be 71.36 and 17.62 mg Cd(II) g^-1 biosorbent. However, when two biosorbents were hybridized to form HB matrix, the combined biosorption capacity (141.63 mg Cd(II) g^-1 biosorbent) was increased by 98.47. 703.80%. respectively, as compared to the ability of B I and B2 when used alone, and by 59.17% than the sum of separate individual abilities of biosorbents B I and B2. The kinetics of equilibrium was fast, approximately 88% of Cd(II) biosorption taking place within 30 min. Biosorption kinetics and equilibria followed the pseudo-second order kinetics and Langmuir adsorption isotherms model. HB matrix was also shown to be highly effective in removing Cd(II) from aqueous solution in a continuous flow fixed-bed column bioreactor, both in batch and repeated cycles. (c) 2007 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Isotherms, Aqueous Solution, Batch, Biomass, Bioreactor, Biosorbent, Biosorbents, Biosorption, Biosorption Capacity, Building, Ca-Alginate, Cadmium Removal, Capacity, Carica Papaya, Cd(II), Cd(II) Removal, Cell Immobilization, Column, Copper, Effective, Equilibria, Equilibrium, Fixed Bed, Fixed Bed Column, Fixed-Bed, Fixed-Bed Column, Flow, Fungal, Fungal Biomass, Fungus, Fungus Trametes-Versicolor, Heavy-Metals, Hybrid, Hybrid Biosorbent, Immobilization, Isotherms, Kinetics, Langmuir, Langmuir Adsorption, Matrix, Metal, Metal Biosorption, Model, Order, Papaya, Papaya Wood, Phanerochaete Chrysosporium, Phanerochaete-Chrysosporium, Production, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second Order, Pseudo-Second Order Kinetics, Pseudo-Second-Order, Removing, Sorption, Waste-Water, Wood, Zinc Ions

? Ayranci, E. and Duman, O. (2007), Removal of anionic surfactants from aqueous solutions by adsorption onto high area activated carbon cloth studied by in situ UV spectroscopy. Journal of Hazardous Materials, 148 (1-2), 75-82.

Full Text: 2007\J Haz Mat148, 75.pdf

Abstract: The removal of anionic surfactants, benzene sulfonate (BS), p-toluene suffonate (TS), 4-octylbenzene sulfonate (OBS) and 4-dodecylbenzene sulfonate (DBS) from water and 0.01 M H₂SO₄ Solutions by adsorption onto high area activated carbon cloth (ACC) were studied by in situ UV-spectroscopic technique. The various properties of the ACC were given and the in situ UV-spectroscopic technique was described. Both kinetic and isotherm data were obtained for the adsorption of surfactants. Kinetic data were treated according to intraparticle diffusion, pseudo-first-order, pseudo-second-order and Elovich models. They were found to fit the pseudo-second-order model best. Isotherm data were treated according to well-known Lanamuir and Freundlich models. The regression analysis of the data showed that Freundlich model represents the isotherm data of the surfactants better. The rate and extent of adsorption of surfactants were found to increase in the order BS < TS < OBS similar to DBS. The main type of interaction between the ACC surface and surfactants was found to be of hydrophobic origin in H₂O solutions. The adsorption was found to be enhanced by the presence of 0.01 M H₂SO₄ in the surfactant solution due to electrostatic attractions between the negatively charged surfactant molecules and the ACC surface which acquired a net positive charge in acidic medium. An inert electrolyte such as NaCl was found to decrease the adsorption capacity of the ACC for the anionic surfactants. (c) 2007 Elsevier B.V. All rights reserved.

Keywords: Acid, Activated Carbon, Activated Carbon Cloth, Adsorption, Adsorption Capacity, Analysis, Anionic, Anionic Surfactants, Aqueous Solutions, Behaviors, Benzene, Benzene Sulfonates, Capacity, Carbon, Carbon-Cloth, Charge, Diffusion, Dodecyl Benzene Sulfonate, Electrolyte, Electrosorption, Elovich, Felt Electrodes, Freundlich, Freundlich Model, H₂O, H₂SO₄, Hydrophobic, In Situ, In Situ UV Spectroscopy, Interaction, Intraparticle Diffusion, Isotherm, Isotherm Data, Kinetic, Kinetics, Model, Models, Nacl, Order, Phenol, Properties, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Rate, Regression, Regression Analysis, Removal, Solutions, Sorption, Spectroscopy, Surface, Surfactant, Surfactants, UV, UV Spectroscopy, UV-Spectroscopy, Waste-Water Purification, Water

? Septhum, C., Rattanaphani, S., Bremner, J.B. and Rattanaphani, V. (2007), An adsorption study of Al(III) ions onto chitosan. Journal of Hazardous Materials, 148 (1-2), 185-191.

Full Text: 2007\J Haz Mat148, 185.pdf

Abstract: The adsorption of Al(III) from aqueous solutions onto chitosan was studied in a batch system. The isotherms and the kinetics of adsorption with respect to the initial Al(III) concentration and temperature were investigated. Langmuir and Freundlich adsorption models were applied to describe the experimental isotherms. Equilibrium data fitted very well to the Langmuir model in the entire concentration range (5-40 mg/L). The negative values of free energy (G) and enthalpy (H) for the adsorption of AI(HI) onto chitosan indicated that the adsorption process is a spontaneous and exothermic one. Two simplified kinetic models, based on pseudo first-order and pseudo second-order equations, were tested to describe the adsorption mechanism. The pseudo second-order kinetic model resulted in an activation energy of 56.4 kJ/mol. It is suggested that the overall rate of Al(III) ion adsorption is likely to be controlled by the chemical process. The values of the enthalpy (H) and entropy (S) of activation were 53.7 kJ/mol and -164.4 J/mol K, respectively. The free energy of activation (G) at 30C was 103.5 kJ/mol. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activation, Activation Energy, Adsorption, Adsorption Isotherm, Adsorption Mechanism, Adsorption Models, Adsorption Process, Al(III), Aluminium, Aluminum, Aqueous Solutions, Aqueous-Solutions, Batch, Batch System, Chemical, Chitosan, Concentration, Crab Shells, Cu(II) Ions, Dyes, Energy, Enthalpy, Entropy, Equations, Equilibrium, Exothermic, Experimental, First Order, Free Energy, Freundlich, G, Ion, Ion Adsorption, Isotherms, Kinetic, Kinetic Model, Kinetic Models, Kinetics, Kinetics, Kinetics Of Adsorption, Langmuir, Langmuir Model, Mechanism, Metal-Ions, Model, Models, Process, Pseudo First-Order, Pseudo Second Order, Pseudo Second Order Kinetic, Pseudo Second-Order, Pseudo-First-Order, Pseudo-Second-Order, Range, Rate, Removal, Second Order, Solutions, Sorption, Spontaneous, Temperature, Thermodynamics

? EI-Sikaily, A., El Nemr, A., Khaled, A. and Abdelwehab, O. (2007), Removal of toxic chromium from wastewater using green alga Ulva lactuca and its activated carbon. Journal of Hazardous Materials, 148 (1-2), 216-228.

Full Text: 2007\J Haz Mat148, 216.pdf

Abstract: Biosorption of heavy metals can be an effective process for the removal of toxic chromium ions from wastewater. In this study, the batch removal of toxic hexavalent chromium ions from aqueous solution, saline water and wastewater using marine dried green alga Ulva lactuca was investigated. Activated carbon prepared from U. lactuca by acid decomposition was also used for the removal of chromium from aqueous solution, saline water and wastewater. The chromium uptake was dependent on the initial pH and the initial chromium concentration, with pH similar to 1.0, being the optimum pH value. Langmuir, Freundlich, Redlich-Peterson and Koble-Corrigan isotherm models were fitted well the equilibrium data for both sorbents. The maximum efficiencies of chromium removal were 92 and 98% for U. lactuca and its activated carbon, respectively. The maximum adsorption capacity was found to be 10.61 and 112.36 mg g^-1 for dried green alga and activated carbon developed from it, respectively. The adsorption capacities of U. lactuca and its activated carbon were independent on the type of solution containing toxic chromium and the efficiency of removal was not affected by the replacing of aqueous solution by saline water or wastewater containing the same chromium concentration. Two hours were necessary to reach the sorption equilibrium. The chromium uptake by U. lactuca and its activated carbon form were best described by pseudo second-order rate model. This study verifies the possibility of using inactivated marine green alga U. lactuca and its activated carbon as valuable material for the removal of chromium from aqueous solutions, saline water or wastewater. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Acid, Activated Carbon, Adsorption, Adsorption Capacities, Adsorption Capacity, Aqueous Solution, Aqueous Solutions, Aqueous-Solution, Batch, Biomass, Biosorption, Cadmium, Capacity, Carbon, Chromium, Chromium Ions, Chromium Removal, Concentration, Copper Ions, Decomposition, Effective, Efficiency, Equilibrium, Equilibrium Data, Freundlich, Green Alga, Heavy Metals, Heavy-Metal Biosorption, Hexavalent Chromium, Industry Waste, Isotherm, Isotherm Models, Langmuir, Marine, Marine-Algae, Metals, Model, Models, Part I, pH, Pollution, Process, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Rate, Rate Model, Redlich-Peterson, Removal, Second Order, Solutions, Sorbents, Sorption, Sorption Equilibrium, Tannery Wastes, Toxic, Ulva Lactuca, Uptake, Value, Wastewater, Water

? Mittal, A., Malviya, A., Kaur, D., Mittal, J. and Kurup, L. (2007), Studies on the adsorption kinetics and isotherms for the removal and recovery of Methyl Orange from wastewaters using waste materials. Journal of Hazardous Materials, 148 (1-2), 229-240.

Full Text: 2007\J Haz Mat148, 229.pdf

Abstract: De-Oiled Soya a waste of Soya oil industries and Bottom Ash a waste of thermal power plants have been used as effective adsorbent for recovery and removal of hazardous dye Methyl Orange from wastewater. During the studies effects of amount of dye and adsorbents, pH, sieve sizes, column studies etc. have been carried out. Adsorption of the dye over both the adsorbents has been monitored through Langmuir and Freundlich adsorption isotherm models and feasibility of the process is predicted in both the cases. Different thermodynamic parameters like Gibb’s free energy, enthalpy and entropy of the undergoing process are also evaluated through these adsorption models. The kinetic studies confirm the first order process for the adsorption reaction and also play an important role in finding out half-life of the adsorption process and rate constants for both the adsorbents. It is also found that over the entire concentration range the adsorption on Bottom Ash takes place via particle diffusion process, while that of De-Oiled Soya undergoes via film diffusion process. In order to establish the practical utility of the developed process, attempts have been made for the bulk removal of the dye through column operations. For the two columns saturation factors are found as 98.61 and 99.8%, respectively, for Bottom Ash and De-Oiled Soya with adsorption capacity of each adsorbent as 3.618 and 16.664 mg, g, respectively. The dye recovery has been achieved by eluting dil. NaOH through the exhausted columns.

Keywords: Adsorbent, Adsorbents, Adsorption, Adsorption Capacity, Adsorption Isotherm, Adsorption Isotherm Models, Adsorption Kinetics, Adsorption Kinetics and Isotherms, Adsorption Process, Bottom Ash, Capacity, Column, Column Studies, Concentration, De-Oiled Soya, Diffusion, Dye, Energy, Enthalpy, Entropy, Feasibility, Film Diffusion, First, First Order, Freundlich, Freundlich Adsorption Isotherm, Half-Life, Isotherm, Isotherms, Kinetic, Kinetic Studies, Kinetics, Langmuir, Methyl Orange, Models, NaOH, Particle Diffusion, pH, Plants, Power, Rate Constants, Recovery, Removal, Role, Saturation, Thermodynamic, Thermodynamic Parameters, Utility, Waste, Waste Materials, Wastewater, Wastewaters

? Ozmen, E.Y. and Yimaz, M. (2007), Use of -cyclodextrin and starch based polymers for sorption of Congo red from aqueous solutions. Journal of Hazardous Materials, 148 (1-2), 303-310.

Full Text: 2007\J Haz Mat148, 303.pdf

Abstract: Two starch-based and a P-cyclodextrin (beta-CD)-based polymers were synthesized using 4,4’-methylene-bis-phenyldiisocyanate (MDI) or hexamethylenediisocyanate (HMDI) as a cross linking agent in dry dimethylformamide and used as a sorbent for the removal of Congo red from aqueous solutions. The cross-linked polymers were characterized by Fourier transform infrared spectroscopy, thermogravimetric and differential scanning calorimetric analysis. The dye adsorption experiments were carried out by using batch and recycling column procedure. The effects of initial pH (pH(0)). the contact time and the initial dye concentration were changed to obtain the best experimental conditions. The pH(0) of the dye solution strongly affected the chemistry of both the dye molecules and polymer 3 in an aqueous solution. The effective pH(0) was 7.0 for adsorption on polymer 3. The equilibrium adsorption data were interpreted using Langmuir and Freundlich models. The adsorption of Congo red was better represented by the Freundlich equation. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Agricultural Solid-Waste, Analysis, Aqueous Solution, Aqueous Solutions, Batch, Beta-Cyclodextrin, Biogas Residual Slurry, Calorimetric Analysis, Chemistry, Coir Pith, Color Removal, Column, Concentration, Congo Red, Congo-Red, Contact Time, Cross Linking, Cross-Linking, Crosslinked, Differential, Dye, Dye Adsorption, Dye Molecules, Dye Solution, Dye-Adsorption, Effective, Effects, Equilibrium, Equilibrium Adsorption, Equilibrium Isotherm, Experimental, Experiments, Fly-Ash, Fourier Transform Infrared Spectroscopy, Freundlich, Freundlich Equation, Infrared Spectroscopy, Isotherms, Langmuir, Methanogenic Conditions, Models, pH, Polymer, Polymers, Reactive Azo Dyes, Recycling, Removal, Solutions, Sorbent, Sorption, Sorption : Beta-Cyclodextrin, Spectroscopy, Starch, Thermogravimetric, Time

? Zhang, Z., Shan, Y., Wang, J., Ling, H., Zang, S., Gao, W., Zhao, Z. and Zhang, H. (2007), Investigation on the rapid degradation of congo red catalyzed by activated carbon powder under microwave irradiation. Journal of Hazardous Materials, 147 (1-2), 325-333.

Full Text: 2007\J Haz Mat147, 325.pdf

Abstract: Azo dyestuff-congo red in aqueous solution can be degraded rapidly under microwave irradiation in the presence of activated carbon powder. The results showed that the degradation ratio could reach 87.79% for 25 mL total volume with 50 mg, L congo red and 2.0 g, L activated carbon powder under 1.5 min microwave irradiation. Furthermore, within the same irradiation time, congo red could be degraded fully by increasing addition amount (e.g. 3.6 g, L) of activated carbon powder and the degradation ratio was up to 96.49%. Otherwise, with the same addition amount, congo red also could be degraded completely by prolonging irradiation time (e.g. 2.5 min) and the degradation ratio was up to 97.88%. In addition, the influences of microwave irradiation time, initial concentration of congo red, addition amount and used times of activated carbon powder as well as solution acidity on the degradation were discussed in details adopting UV-vis spectra, FT-IR spectra, ion chromatography, high phase liquid chromatography (HPLC) and TOC analysis technologies. Here, the method using activated carbon powder as catalyst under microwave irradiation shows many advantages including high degradation ratios, short reaction time, low costs, no intermediates and no secondary pollution. Therefore, it may be fit for dealing with various azo dyestuff wastewaters on a large scale.

Keywords: Acidity, Activated Carbon, Activated Carbon Powder, Analysis, Aqueous Solution, Carbon, Catalyst, Chromatography, Concentration, Congo Red, Costs, Degradation, Dyestuff, FT-IR, FTIR, FTIR Spectra, HPLC, Irradiation, Liquid, Liquid Chromatography, Microwave, Microwave Irradiation, Pollution, Rapid Degradation, Scale, Solution, Technologies, TOC, Volume, Wastewaters

? Sarı, A., Tuzen, M., Cıtak, D. and Soylak, M. (2007), Adsorption characteristics of Cu(II) and Pb(II) onto expanded perlite from aqueous solution. Journal of Hazardous Materials,