Personal Research Database

170 (1), 27-34.

Full Text: 2009\J Haz Mat170, 27.pdf

Abstract: Sahara desert sand (SaDeS) was employed as a mineral sorbent for retaining organic dyes from aqueous solutions. Natural sand has demonstrated a strong affinity for organic dyes but significantly lost its adsorption capacity when it was washed with water. Therefore, characterization of both natural and water washed sand was performed by XRD, BET, SEM and FTIR techniques. It was found that water-soluble kyanite, which is detected in natural sand, is the dominant factor affecting adsorbance of cationic dyes. The sand adsorbs over 75% of cationic dyes but less than 21% for anionic ones. Among the dyes studied, Methylene Blue (MB) demonstrated the strongest affinity for Sahara desert sand (Q(e) = 11.98 mg/g, for initial dye solution concentration 3.5×10^-5 mol/L). The effects of initial dye concentration, the amount of the adsorbent, the temperature and the pH of the solution on adsorption capacity were tested by using Methylene Blue as model dye. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were applied. It was concluded that adsorption of Methylene Blue on Sahara desert sand followed pseudo-second order kinetics. Gibbs free energy, enthalpy change and entropy change were calculated and found -6411 J/mol, -30360 J/mol and -76.58 J/mol K, respectively. These values indicate that the adsorption is an exothermic process and has a spontaneous nature at low temperatures. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Clay, Adsorbent, Adsorption, Adsorption Capacity, Aqueous Solutions, Aqueous-Solution, BET, Capacity, Cationic Dye, Cationic Dyes, Characterization, Concentration, Diffusion, Dye, Dyes, Energy, Enthalpy, Entropy, Exothermic, Fly-Ash, FTIR, Gibbs Free Energy, Intraparticle Diffusion, Kinetics, Mb, Methylene Blue, Methylene-Blue, Mineral Dust, Model, Models, Natural, Organic, pH, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second Order Kinetics, Pseudo-Second-Order, Removal, Rights, Sahara Desert Sand, Sand, SEM, Solution, Solutions, Sorbent, Techniques, Temperature, Waste-Water, Water, Water Treatment, XRD

? Arkas, M. and Tsiourvas, D. (2009), Organic/inorganic hybrid nanospheres based on hyperbranched poly(ethylene imine) encapsulated into silica for the sorption of toxic metal ions and polycyclic aromatic hydrocarbons from water. Journal of Hazardous Materials, 170 (1), 35-42.

Full Text: 2009\J Haz Mat170, 35.pdf

Abstract: Organic-inorganic hybrid silica nanospheres were prepared through a biomimetic silicification process in water at ambient conditions by the interaction of low cost poly(ethylene imine) hyperbranched polymer with silicic acid. The characterization of these nanoparticles by FTIR spectroscopy, scanning electron microscopy (SEM), zeta-potential and dynamic light scattering (DLS) experiments confirmed that the dendritic polymer was incorporated into the silica network. Preliminary experiments show that these hybrid nanoparticles can be employed for the removal of toxic water contaminants. Hybrid nanospheres’ sorption of two completely different categories of pollutants, i.e. metal ions such as Pb²⁺, Cd²⁺ Hg²⁺. Cr₂O₇^2-, and polycyclic aromatic hydrocarbons such as pyrene and phenanthrene, was largely enhanced in comparison with the corresponding polymer-free silica nanospheres. This was attributed to the to the formation of conventional metal-ligand and charge-transfer complexes proving that although integrated into the silica network poly(ethylene imine) retains its chemical properties. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aqueous-Solutions, Dendrimer Complexes, Elsevier, FTIR, FTIR Spectroscopy, Gel, Heavy Metal Ions, Hyperbranched Poly(Ethylene Imine), Interaction, Metal, Metal Ions, Nanoclusters, Nanoparticles, Nanosponges, Organic Pollutants, Polycyclic Aromatic Hydrocarbons, Polymer, Purification, Removal, Sem, Silicification, Sorption, Spectroscopy, Water, Water Treatment

? Opiso, E., Sato, T. and Yoneda, T. (2009), Adsorption and co-precipitation behavior of arsenate, chromate, selenate and boric acid with synthetic allophane-like materials. Journal of Hazardous Materials, 170 (1), 79-86.

Full Text: 2009\J Haz Mat170, 79.pdf

Abstract: Pollution caused by boric acid and toxic anions such as As(V), Cr(VI) and Se(VI) is hazardous to human health and environment. The sorption characteristics of these environmentally significant ionic species on allophane-like nanoparticles were investigated in order to determine whether allophane can reduce their mobility in the subsurface environment at circum-neutral pH condition. Solutions containing 100 or 150 mmol of AlCl₃ center dot 6H₂O were mixed to 100 mmol of Na₄SiO₄ and the pH were adjusted to 6.4±0.3. The mineral suspensions were shaken for 1 hand incubated at 80°C for 5 days. Appropriate amounts of As, B, Cr and Se solutions were added separately during and after allophane, precipitation. The results showed that As(V) and boric acid can be irreversibly fixed during co-precipitation in addition to surface adsorption. However, Cr(VI) and Se(VI) retention during and after allophane precipitation is mainly controlled by surface adsorption. The structurally fixed As(V) and boric acid were more resistant to release than those bound on the surface. The sorption characteristics of oxyanions and boric acid were also influenced by the final Si/Al molar ratio of allophane in which Al-rich allophane tend to have higher uptake capacity. The overall results of this study have demonstrated the role of allophane-like nanoparticles and the effect of its Si/Al ratio on As, B, Cr and Se transport processes in the subsurface environment. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Allophane, Aluminum-Hydroxide, Arsenate, Boric Acid, Capacity, Chromate, Co-Precipitation, Desorption, Elsevier, Ettringite, Goethite, Hydrotalcite, Mechanisms, Nanoparticles, New-Zealand, Oxyanions, pH, Ray-Absorption Spectroscopy, Selenate, Solutions, Sorption, Species, Subsurface Environment, Surface, Transport, Water

? Augulyte, L., Kliaugaite, D., Racys, V., Jankunaite, D., Zaliauskiene, A., Bergqvist, P.A. and Andersson, P.L. (2009), Multivariate analysis of a biologically activated carbon (BAC) system and its efficiency for removing PAHs and aliphatic hydrocarbons from wastewater polluted with petroleum products. Journal of Hazardous Materials, 170 (1), 103-110.

Full Text: 2009\J Haz Mat170, 103.pdf

Abstract: The efficiency of a biologically activated carbon system for treating wastewater polluted with petroleum products was examined and the effects of process parameters on its efficacy were evaluated. In each experiment 17 alkylated and 19 non-alkylated polycyclic aromatic hydrocarbons (PAHs) and total petroleum hydrocarbons (TPHs, C-10-C-40) were extracted using semipermeable membrane devices from wastewater before and after treatment. The acquired data during experiments were analyzed using principal component analysis (PCA). The treatment system robustly removed dissolved PAHs across the studied ranges of the process parameters, providing overall removal efficiencies of 96.9-99.7% for the sum of 36 PAHs. However, the major contributor to their removal was sorption rather than biodegradation, and despite the general efficiency of the process there was up to a 9-fold range in the sums of quantified PAHs in the effluents between experiments. Combinations of long process contact time (24 h) with high temperature (24°C) and moderate oxygen concentration (6-7 mg O-2 L^-1) resulted in good removal of bioavailable PAHs. The removal of TPHs was more dependent on biological activities during the wastewater treatment, and consequently more dependent on the process parameters. In addition, small but significant proportions of PAHs were volatilized and released during the wastewater treatment. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Air, Bioaccumulation, Biodegradation, Carbon, Effluent, Elsevier, High Temperature, Membrane, Multivariate Analysis, Plant, Polycyclic Aromatic Hydrocarbons, Polycyclic Aromatic Hydrocarbons (PAHS), Polycyclic Aromatic-Hydrocarbons, Removal, River, Sediments, Semipermeable Membrane Devices, Semipermeable Membrane Devices (Spmds), Semipermeable-Membrane Devices, Sorbents, Sorption, System, Temperature, Total Petroleum Hydrocarbons (TPHS), Treatment, Wastewater, Wastewater Treatment

? Behnamfard, A. and Salarirad, M.M. (2009), Equilibrium and kinetic studies on free cyanide adsorption from aqueous solution by activated carbon. Journal of Hazardous Materials, 170 (1), 127-133.

Full Text: 2009\J Haz Mat170, 127.pdf

Abstract: Adsorption equilibrium and kinetics of free cyanide onto activated carbon were investigated in the batch tests, and the effects of contact time (1-72 h) and initial cyanide concentrations in the range of 102-532 mg/L were studied. Linear regression was used to determine the best fit of equilibrium and kinetics expressions. The two-parameter models including Freundlich, Dubinin-Radushkevich, Temkin and four different linearized forms of Langmuir and three-parameter models including Redlich-Peterson and Koble-Corrigan were employed for fitting the equilibrium data and it was found that, three-parameter models fitted the data better than the two-parameter models and among the three-parameter models the equilibrium data are best represented by Koble-Corrigan model. A number of kinetic models including fractional power, zero order, first order, pseudo-first order, Elovich, second order, intraparticle diffusion and four different linearized forms of pseudo-second order models were tested to fit the kinetic data. The latter was found to be consistent with the data. Intraparticle diffusion plots show that the adsorption process of free cyanide is a two steps process. In the first step, the adsorption of cyanide is fast while in the second step, cyanide adsorption slows down. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption Equilibrium, Aqueous Solution, Basic Dye, Batch, Batch Tests, Biomass, Biosorption, Carbon, Cyanide, Data, Diffusion, Elovich, Equilibrium, First, First Order, Forms, Freundlich, Intraparticle Diffusion, Isotherm, Kinetic, Kinetic Models, Kinetic Studies, Kinetics, Langmuir, Linear Regression, Methylene-Blue, Model, Models, Nonlinear Method, Power, Pseudo First Order, Pseudo Second Order, Pseudo-First Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second-Order, Redlich-Peterson, Regression, Removal, Rights, Second Order, Second-Order, Solution, Sorption, Sorption Isotherm Models, Thermodynamics, Waste-Water

? Bhatnagar, A., Choi, Y., Yoon, Y., Shin, Y., Jeon, B.H. and Kang, J.W. (2009), Bromate removal from water by granular ferric hydroxide (GFH). Journal of Hazardous Materials, 170 (1), 134-140.

Full Text: 2009\J Haz Mat170, 134.pdf

Abstract: The feasibility of granular ferric hydroxide (GFH) for bromate removal from water has been studied. Batch experiments were performed to study the influence of various experimental parameters such as effect of contact time, initial bromate concentration, temperature, pH and effect of competing anions on bromate removal by GFH. The adsorption kinetics indicates that uptake rate of bromate was rapid at the beginning and 75% adsorption was completed in 5 min and equilibrium was achieved within 20 min. The sorption process was well described by pseudo-second-order kinetics. The maximum adsorption potential of GFH for bromate removal was 16.5 mg g^-1 at 25ºC. The adsorption data fitted well to the Langmuir model. The increase in OH peak and absence of Br-O bonding in MR spectra indicate that ion-exchange was the main mechanism during bromate sorption on GFH. The effects of competing anions and solution pHs (3-9) were negligible. Results of the present study suggest that GFH can be effectively utilized for bromate removal from drinking water. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption Kinetics, Adsorption Mechanism, Anions, Aqueous-Solutions, Bromate, Bromate Removal, Concentration, Data, Diffusion, Drinking Water, Drinking-Water, Equilibrium, Equilibrium and Kinetic Modeling, Experimental, Experiments, Feasibility, GFH, Granular Ferric Hydroxide, Granular Ferric Hydroxide (GFH), Hydroxide, Ion Exchange, Ion-Exchange, Ion-Exchange-Resin, Ionexchange, Irradiation, Kinetics, Langmuir, Langmuir Model, Mechanism, Model, MR, pH, Potential, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second-Order, Pseudo-Second-Order Kinetics, Reduction, Removal, Rights, Solution, Sorption, Sorption Isotherms, Sorption Process, Temperature, Uptake, Water

? Naiya, T.K., Bhattacharya, A.K. and Das, S.K. (2009), Clarified sludge (basic oxygen furnace sludge) - an adsorbent for removal of Pb(II) from aqueous solutions - kinetics, thermodynamics and desorption studies. Journal of Hazardous Materials, 170 (1), 252-262.

Full Text: 2009\J Haz Mat170, 252.pdf

Abstract: The basic oxygen furnace waste generated in steel plant has been used as a low cost adsorbent for the removal of Pb(II) from aqueous solution. The effect of pH, adsorbent dosage, initial metal ion concentration, contact time and temperature on adsorption process was studied in batch experiments. Results of the equilibrium experiments showed that the solution pH was the key factor affecting the adsorption characteristics. Optimum pH for the adsorption was found to be 5 with corresponding adsorbent dosage level of 5 g/L The equilibrium was achieved within 1 h of contact time. Kinetics data were best described by pseudo second order model. The effective particle diffusion coefficient of Pb(II) is the order of 10^-10 m²/s. The maximum uptake was 92.5 mg/g. The adsorption data can be well fitted by Freundlich isotherm. The result of the equilibrium studies showed that the solution pH was the key factor affecting the adsorption. External mass transfer analysis was also carried out for the adsorption process. The thermodynamic studies indicated that the adsorption is spontaneous and endothermic. The sorption energy (10.1745 kJ/mol) calculated from Dubinin-Radushkevich isotherm indicated that the adsorption process is chemical in nature. Desorption studies were carried out using dilute mineral acids to elucidate the mechanism of adsorption. Application studies were carried out considering the economic viewpoint of wastewater treatment plant operations. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorbent Dosage, Adsorption, Adsorption, Analysis, Aqueous Solution, Aqueous Solutions, Atomic-Absorption Spectrometry, Bagasse Fly-Ash, Batch, Batch Experiments, Characteristics, Chemical, Clarified Sludge, Concentration, Cost, Data, Desorption, Desorption Studies, Diffusion, Diffusion Coefficient, Economic, Endothermic, Energy, Equilibrium, Equilibrium Studies, Experiments, Freundlich, Freundlich Adsorption Isotherm, Freundlich Isotherm, Heavy-Metal Ions, Industry Waste, Isotherm, Kinetics, Lead, Low Cost, Low Cost Adsorbent, Mass Transfer, Mass Transfer Analysis, Mechanism, Mechanism of Adsorption, Metal, Metal Ion, Model, Oxygen, Particle Diffusion, Pb(II), pH, Plant, Preconcentration, Pseudo Second Order, Pseudo-Second-Order, Red Mud, Removal, Rights, Second Order, Second-Order, Single, Sludge, Solution, Solutions, Sorption, Temperature, Thermodynamic, Thermodynamic Studies, Thermodynamics, Treatment, Uptake, Waste, Wastewater, Wastewater Treatment, Wastewater Treatment Plant

? Escudero, C., Fiol, N., Poch, J. and Villaescusa, I. (2009), Modeling of kinetics of Cr(VI) sorption onto grape stalk waste in a stirred batch reactor. Journal of Hazardous Materials, 170 (1), 286-291.

Full Text: 2009\J Haz Mat170, 286.pdf

Abstract: Recently, Cr(VI) removal by grape stalks has been postulated to follow two mechanisms, adsorption and reduction to trivalent chromium. Nevertheless, the rate at which both processes take place and the possible simultaneity of both processes has not been investigated. In this work, kinetics of Cr(VI) sorption onto grape stalk waste has been studied. Experiments were carried out at different temperatures but at a constant pH (3±0.1) in a stirred batch reactor. Results showed that three steps take place in the process of Cr(VI) sorption onto grape stalk waste: Cr(VI) sorption, Cr(VI) reduction to Cr(III) and the adsorption of the formed Cr(III). Taking into account the evidences above mentioned, a model has been developed to predict Cr(VI) sorption on grape stalks on the basis of (i) irreversible reduction of Cr(VI) to Cr(III) reaction, whose reaction rate is assumed to be proportional to the Cr(VI) concentration in solution and (II) adsorption and desorption of Cr(VI) and formed Cr(III) assuming that all the processes follow Langmuir type kinetics. The proposed model fits successfully the kinetic data obtained at different temperatures and describes the kinetics profile of total, hexavalent and trivalent chromium. The proposed model would be helpful for researchers in the field of Cr(VI) biosorption to design and predict the performance of sorption processes. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Biomaterials, Biosorption, Chromate, Chromium, Cr(III) Sorption, Cr(VI) Reduction, Desorption, Elsevier, Grape Stalks, Hexavalent Chromium, Iron, Kinetic, Kinetics, Kinetics Model, Mechanism, Mechanisms, Modeling, pH, Reduction, Removal, Researchers, Sorbents, Sorption, Stirred Batch Reactor

? Gou, M., Qu, Y.Y., Zhou, J.T., Ma, F. and Tan, L. (2009), Azo dye decolorization by a new fungal isolate, Penicillium sp QQ and fungal-bacterial cocultures. Journal of Hazardous Materials, 170 (1), 314-319.

Full Text: 2009\J Haz Mat170, 314.pdf

Abstract: A new azo, dyes-decolorizing fungi strain QQ was isolated from activated sludge. It was identified as Penicillium sp. based on 26S rRNA gene sequence analysis. The study indicated that strain QQ could aerobically decolorize Reactive Brilliant Red X-3B by the way of bioadsorption. and nutrient-poor medium was more beneficial for adsorption. Decolorization rate was inversely proportional to the size of mycelial pellets. The optimum pH was observed at 4 or 5 for X-3B decolorization. There was still 70% color removal when salinity increased to 6%. By contrast with aerobic decolorization, the degradation of azo dyes occurred under anaerobic conditions, and some azo dyes could be absolutely decolorized. Furthermore, the decolorization of azo dyes by fungal-bacterial cocultures was investigated. The results demonstrated that strain QQ and Sphingomonas xenophaga QYY cocultures performed better than any single strain did. Weak acidity conditions and the presence of small amount of surfactant could enhance the ability of consortium to decolorize azo dyes. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Azo Dye, Azo Dyes, Azoreductase, Biosorption, Cocultures, Decolorization, Degradation, Dye, Dyes, Elsevier, Mycelial Pellets, Penicillium, Penicillium sp., pH, Removal, Sludge, Strain, Surfactant

? Jiang, M.Q., Wang, Q.P., Jin, X.Y. and Chen, Z.L. (2009), Removal of Pb(II) from aqueous solution using modified and unmodified kaolinite clay. Journal of Hazardous Materials, 170 (1), 332-339.

Full Text: 2009\J Haz Mat170, 332.pdf

Abstract: Modified kaolinite clay with 25% (w/w) aluminium sulphate and unmodified kaolin were investigated as adsorbents to remove Pb(II) from aqueous solution. The results show that amount of Pb(II) adsorbed onto modified kaolin (20 mg/g) was more than 4.5-fold than that adsorbed onto unmodified kaolin (4.2 mg/g) under the optimized condition. In addition, the linear Langmuir and Freundlich models were used to describe equilibrium isotherm. It is observed that the data from both adsorbents fitted well to the Langmuir isotherm. The kinetic adsorption of modified and unmodified kaolinite clay fitted well to the pseudo-second-order model. Furthermore, both modified and unmodified kaolinite clay were characterized by X-ray diffraction, Fourier transform infrared (FT-IR) and scanning electron microscope (SEM). Finally, both modified and unmodified kaolinite clay were used to remove metal ions from real wastewater, and results show that higher amount of Pb(II) (the concentration reduced from 178 to 27.5 mg/L) and other metal ions were removed by modified kaolinite clay compared with using unmodified adsorbent (the concentration reduced from 178 to 168 mg/L). (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorbents, Adsorption, Adsorption, Aluminium, Aqueous Solution, Cadmium Ions, Cd²⁺, Clay, Concentration, Cu(II), Cu²⁺, Data, Equilibrium, Equilibrium Isotherm, Freundlich, FT-IR, FTIR, Heavy-Metals, Ions, Isotherm, Kaolin, Kaolinite, Kaolinite Clay, Kinetic, Kinetic Adsorption, Kinetics, Langmuir, Langmuir Isotherm, Lead, Metal, Metal Ions, Model, Models, Modified, Modified Kaolin, Montmorillonite, Pb(II), Pb²⁺, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Removal, Rights, SEM, Solution, Thermodynamics, Wastewater, Water, X-Ray, X-Ray Diffraction

? Ahmad, A., Rafatullah, M., Sulaiman, O., Ibrahim, M.H. and Hashim, R. (2009), Scavenging behaviour of meranti sawdust in the removal of methylene blue from aqueous solution. Journal of Hazardous Materials, 170 (1), 357-365.

Full Text: 2009\J Haz Mat170, 357.pdf

Abstract: Meranti (Philippine mahogany) sawdust, an inexpensive material, showed strong scavenging behaviour through adsorption for the removal of methylene blue (MB) from aqueous solution. Batch studies were performed to evaluate and optimize the effects of various parameters such as contact time, pH, initial dye concentrations and adsorbent dosage. Langmuir, Freundlich and Temkin isotherms were used to analyze the equilibrium data at different temperatures. The experimental data fitted well with the Langmuir adsorption isotherm, indicating thereby the mono layer adsorption of the dye. The monolayer sorption capacity of meranti sawdust for MB was found to be 120.48, 117.64,149.25 and 158.73 mg/g at 30,40,50 and 60ºC, respectively. Thermodynamic calculations showed that the MB adsorption process is endothermic and spontaneous in nature. Kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model. The results indicated that the meranti sawdust could be an alternative material in place of more costly adsorbents used for dye removal. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorbent Dosage, Adsorbents, Adsorption, Adsorption Isotherm, Agricultural Waste, Alternative, Aqueous Solution, Basic Dye, Behaviour, Capacity, Cationic Dye, Data, Dye, Dye Removal, Endothermic, Equilibrium, Experimental, Fly-Ash, Freundlich, Isotherm, Isotherms, Kinetic, Kinetic Model, Kinetic Studies, Langmuir, Langmuir Adsorption Isotherm, Low-Cost Adsorbent, Malachite Green, Mb, Meranti Sawdust, Methylene Blue, Model, Monolayer, pH, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Reactive Dye, Removal, Response-Surface Methodology, Rights, Sawdust, Solution, Sorption, Sorption Capacity, Thermodynamic, Wood Sawdust

? Weng, C.H., Lin, Y.T. and Tzeng, T.W. (2009), Removal of methylene blue from aqueous solution by adsorption onto pineapple leaf powder. Journal of Hazardous Materials, 170 (1), 417-424.

Full Text: 2009\J Haz Mat170, 417.pdf

Abstract: The ability of an unconventional bio-adsorbent, pineapple leaf powder (PLP) for the adsorption of methylene blue (MB) from aqueous solution was studied. It was observed that intra-particle diffusion was involved in the adsorption process and that the kinetic data fitted well with a pseudo-second-order equation. Fitting parameters revealed that the rate of adsorption increased with decrease in dye concentration and decrease in ionic strength while the mixing speed did not have a significant effect on adsorption. The adsorption was favorable at higher pH and lower temperature, and the equilibrium data were well fitted by the Langmuir isotherm. The maximum adsorption capacity varied from 4.68×10^-4 to 9.28×10^-4 Mol/g when pH increases from 3.5 to 9.5. Thermodynamic parameters suggest that the adsorption is a typical physical process, spontaneous, and exothermic in nature. The results revealed that this agricultural waste has potential to be used as an economical adsorbent for the removal of methylene blue from aqueous solution. (C) 2009 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Agricultural, Agricultural Waste, Aqueous Solution, Capacity, Carbon, Cationic Dye, Chemical-Modification, Concentration, Data, Diffusion, Dye, Dye Adsorption, Equilibrium, Exothermic, Fly-Ash, Intra Particle Diffusion, Intra-Particle Diffusion, Intraparticle Diffusion, Ionic Strength, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Isotherm, Low-Cost Adsorbents, Mb, Methylene Blue, Mixing, pH, Physical, Pineapple Leaf, Potential, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Equation, Removal, Rights, Solution, Spent Activated Clay, Strength, Temperature, Thermodynamic, Thermodynamic Parameters, Waste, Waste-Water

? Liang, S., Guo, X.Y., Feng, N.C. and Tian, Q.H. (2009), Application of orange peel xanthate for the adsorption of Pb²⁺ from aqueous solutions. Journal of Hazardous Materials,