Personal Research Database

Full Text: 2008\J Haz Mat157, 503.pdf

Abstract: In the present study, nickel removal efficiency of sulphuric acid-treated Parthenium carbon (SWC) from simulated wastewater has been investigated. Batch mode adsorption experiments have been conducted by varying pH, nickel concentration, adsorbent dose and contact time. Ni(II) removal was pH-dependent and found to be maximum at pH 5.0. The maximum removal of Ni(II) was achieved within 4 h after the start of every experiment. The equilibrium adsorption data were fitted to Freundlich and Langmuir adsorption isotherm models to evaluate the model parameters. Both models represented the experimental data satisfactorily. The monolayer adsorption capacities of SWC as obtained from Langmuir isotherm was found to be 17.24 mg/g. The Lagergren first-order model was less applicable than pseudo-second-order reaction model. The adsorbent was also characterized including infrared spectroscopy and scanning electron microscopy. The FT-IR study indicated the presence of O-H, C-H, C = O and C-O groups in the adsorbent. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorbent Dose, Adsorption, Adsorption Capacities, Adsorption Isotherm, Adsorption Isotherm Models, Aqueous Solution, Carbon, Co, Concentration, Data, Efficiency, Electron Microscopy, Equilibrium, Experiment, Experimental, Experiments, First Order, First-Order Model, Freundlich, FT-IR, FTIR, Isotherm, Langmuir, Langmuir Adsorption Isotherm, Langmuir Isotherm, Mode, Model, Models, Monolayer, Ni(II), Nickel, Nickel Removal, Parthenium, Parthenium Weed, pH, pH-Dependent, Pseudo Second Order, Pseudo-Second-Order, Removal, Removal Efficiency, Scanning Electron Microscopy, SEM, Solution, Spectroscopy, Wastewater

? Arshad, M., Zafar, M.N., Younis, S. and Nadeem, R. (2008), The use of Neem biomass for the biosorption of zinc from aqueous solutions. Journal of Hazardous Materials, 157 (2-3), 534-540.

Full Text: 2008\J Haz Mat157, 534.pdf

Abstract: An adsorbent was developed from mature leaves and stem bark of the Neem (Azadirachta indica) tree for removing zinc from water. Adsorption was carried out in a batch process with several different concentrations of zinc by varying pH. The uptake of metal was very fast initially, but gradually slowed down indicating penetration into the interior of the adsorbent particles. The data showed that optimum pH for efficient biosorption of zinc by Neem leaves and stem bark was 4 and 5, respectively. The maximum adsorption capacity showed that the Neem biomass had a mass capacity for zinc (147.08 mg Zn/g for Neem leaves and 137.67 mg Zn/g Neem bark). The experimental results were analyzed in terms of Langmuir and Freundlich isotherms. The adsorption followed pseudo-second-order kinetic model. The thermodynamic assessment of the metal ion-Neem tree biomass system indicated the feasibility and spontaneous nature of the process and G values were evaluated as ranging from -26.84 to -32.75 (Neem leaves) kJ/mol and -26.04 to -29.50 (Neem bark) kJ/mol for zinc biosorption. Due to its outstanding zinc uptake capacity, the Neem tree was proved to be an excellent biomaterial for accumulating zinc from aqueous solutions. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Aqueous Solutions, Assessment, Azadirachta Indica, Batch, Batch Process, Biomass, Biosorption, Capacity, Data, Experimental, Feasibility, Freundlich, Gibbs Free Energy, Isotherms, Kinetic, Kinetic Model, Kinetics, Langmuir, Langmuir and Freundlich Isotherms, Metal, Model, Neem, Particles, pH, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Solutions, Thermodynamic, Uptake, Waste Water, Water, Zinc

? Anirudhan, T.S., Divya, L. and Ramachandran, M. (2008), Mercury(II) removal from aqueous solutions and wastewaters using a novel cation exchanger derived from coconut coir pith and its recovery. Journal of Hazardous Materials, 157 (2-3), 620-627.

Full Text: 2008\J Haz Mat157, 620.pdf

Abstract: A new adsorbent (PGCP-COOH) having carboxylate functional group at the chain end was synthesized by grafting poly (hydroxyethylmethacrylate) onto coconut coir pith, CP (a coir industry-based lignocellulosic residue), using potassium peroxydisulphate as an initiator and in the presence of N,N’-methylenebisacrylamide as a cross-linking agent. The adsorbent was characterized with the help of infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and potentiometric titrations. The ability of PGCP-COOH to remove Hg(II) from aqueous solutions was assessed using batch adsorption technique under kinetic and equilibrium conditions. Adsorbent exhibits very high adsorption potential for Hg(II) and more than 99.0% removal was achieved in the pH range 5.5-8.0. Adsorption process was found to follow first-order-reversible kinetics. An increase of ionic strength of the medium caused a decrease in metal removal, indicating the occurrence of outer-sphere surface complex mechanism. The equilibrium data were fitted well by the Freundlich isotherm model (R-2=0.99; chi(2) = 1.81). The removal efficiency was tested using chlor-alkali industry wastewater. Adsorption isotherm experiments were also conducted for comparison using a commercial carboxylate-functionalized ion exchanger, Ceralite IRC-50. Regeneration experiments were tried for four cycles and results indicate a capacity loss of <9.0%. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Isotherm, Batch Adsorption, Capacity, Carbons, Cation Exchanger, Coir Pith, Desorption, Equilibrium, Freundlich, Freundlich Isotherm, Functional, Graft Copolymerization, Hg(II), Industry, Ions, Isotherm, Kinetic, Kinetics, Lead(II), Mechanism, Mercury(II) Removal, Metal, Microscopy, Model, pH, Recovery, Regeneration, Removal, Strength, Surface-Chemistry, Toxic Metals, Waste-Water, Wastewater, X-Ray Diffraction

? Skodras, G., Diamantopoulou, Ir., Pantoleontos, G. and Sakellaropoulos, G.P. (2008), Kinetic studies of elemental mercury adsorption in activated carbon fixed bed reactor. Journal of Hazardous Materials, 158 (1), 1-13.

Full Text: 2008\J Haz Mat158, 1.pdf

Abstract: Activated carbons are Suitable materials for Hg-0 adsorption in fixed bed operation or in injection process. The fixed bed tests provide good indication of activated carbons effectiveness and set-vice lives, which depend on the rates of Hg-0 adsorption. In order to correlate fixed bed properties and operation conditions, with their adsorptive capacity and saturation time, Hg-0 adsorption tests were realized in a bench-scale unit, consisted of F400 activated carbon fixed bed reactor. Hg-0 adsorption tests were conducted at 50C, under 0.1 and 0.35 ng/cm³ Hg-0 initial concentrations and with carbon particle sizes ranging between 75-106 and 150-250 m. Based on the experimental breakthrough data, kinetic studies were performed to investigate the mechanism of adsorption and the rate controlling steps. Kinetic models evaluated include the Fick’s intraparticle diffusion equation, the pseudo-first order model, the pseudo-second order model and Elovich kinetic equation. The obtained experimental results revealed that the increase in particle size resulted in significant decrease of breakthrough time and mercury adsorptive capacity, due to the enhanced internal diffusion limitations and smaller external mass transfer coefficients. Additionally, higher initial mercury concentrations resulted in increased breakthrough time and mercury uptake. From the kinetic studies results it was observed that all the examined models describes efficiently Hg-0 breakthrough curves, from breakpoint up to equilibrium time. The most accurate prediction of the experimental data was achieved by second order model, indicating that the chemisorption rate seems to be the controlling step in the procedure. However, the successful attempt to describe mercury uptake with Fick’s diffusion model and the first order kinetic model, reveals that the adsorption mechanism Studied was complex and followed both surface adsorption and particle diffusion. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Activated Carbons, Adsorption, Adsorption Kinetics, Adsorption Mechanism, Breakthrough, Breakthrough Curves, Capacity, Carbon, Chemisorption, Data, Diffusion, Diffusion Model, Effectiveness, Elovich, Elovich Model, Equilibrium, Experimental, First, First Order, Fixed Bed, Indication, Internal Diffusion, Intraparticle Diffusion, Kinetic, Kinetic Model, Kinetic Models, Kinetic Studies, Langmuir Expression, Mass Transfer, Mechanism, Mechanism Of Adsorption, Mercury, Model, Models, Operation, Particle Diffusion, Particle Size, Prediction, Procedure, Pseudo First Order, Pseudo Second Order, Pseudo-First Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second Order Model, Pseudo-Second-Order, Rates, Saturation, Second Order, Second-Order, Service, Size, Surface, Uptake

? Ren, Y.M., Wei, X.Z. and Zhang, M.L. (2008), Adsorption character for removal Cu(II) by magnetic Cu(II) ion imprinted composite adsorbent. Journal of Hazardous Materials, 158 (1), 14-22.

Full Text: 2008\J Haz Mat158, 14.pdf

Abstract: A novel magnetic Cu(II) ion imprinted composite adsorbent (Cu(II)-MICA) was synthesized. characterized and applied for the selective removal Cu(II) from aqueous solution in the batch system. The adsorption-desorption and selectivity characteristics were investigated. The maximum adsorption occurred at pH 5-6. The equilibrium time was 6.0 h, and a pseudo-second-order model could best describe adsorption kinetics. The adsorption equilibrium data fit Langmuir isotherm equation well with a maximum adsorption capacity of 46.25 mg/g and Langmuir adsorption equilibrium constant of 0.0956 L/mg at 298 K. Thermodynamic parameters analysis predicted an exothermic nature of adsorption and a spontaneous and favourable process that could be mainly governed by physisorption mechanism. The relative selectivity coefficients of Cu(II)-MICA for Cu(II)/Zn(II) and Cu(II)/Ni(II) were 2.31, 2.66 times greater than the magnetic non-imprinted composite adsorbent (MNICA). Results suggested that Cu(II)-MICA was a material of efficient, low-cost, convenient separation under magnetic field and could be reused five times with about 14% regeneration loss. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Adsorption Equilibrium, Adsorption Kinetics, Analysis, Aqueous Solution, Batch, Batch System, Capacity, Characteristics, Composite, Cu(II), Cu(II) Ion, Cu(II) Ion Imprinted, Data, Equilibrium, Exothermic, Field, Heavy Metals, Isotherm, Kinetics, Langmuir, Langmuir Isotherm, Magnetic, Magnetic Adsorbent, Magnetic Field, Mechanism, Model, pH, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Regeneration, Removal, Selective Removal, Separation, Solution, Thermodynamic, Thermodynamic Parameters

? Huang, W.W., Wang, S.B., Zhu, Z.H., Li, L., Yao, X.D., Rudolph, V. and Haghseresht, F. (2008), Phosphate removal from wastewater using red mud. Journal of Hazardous Materials, 158 (1), 35-42.

Full Text: 2008\J Haz Mat158, 35.pdf

Abstract: Red mud, a waste residue of alumina refinery, has been used to develop effective adsorbents to remove phosphate from aqueous solution. Acid and acid-thermal treatments were employed to treat the raw red mud. The effects of different treatment methods, pH of Solution and operating temperature on adsorption have been examined in batch experiments. It was found that all activated red mud samples show higher surface area and total pore volume as well as higher adsorption capacity for phosphate removal. The red mud with HCI treatment shows the highest adsorpiion capacity among all the red mud samples. giving adsorption capacity of 0.58 mg P/g at pH 5.5 and 40 degrees C. The adsorption capacity of the red mud adsorbents decreases with increase of pH. At pH 2, the red mud with HCI treatment exhibits adsorption of 0.8 mg P/g while the adsorption can be lowered to 0.05 mg P/g at pH 10. However, the adsorption is improved at higher temperature by increasing 25% from 30 to 40 degrees C. The kinetic studies of phosphate adsorption onto red mud indicate that the adsorption mainly follows the parallel first-order kinetics due to the presence of wo acidic phosphorus species, H2PO4- and HPO42-. An analysis of the adsorption data indicates that the Freundlich isotherm provides a better fitting than the Langmuir model. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Acid Treatment, Acid-Heat Treatment, Adsorption, Aluminum-Industry Waste, Analysis, Aqueous-Solutions, Bauxite, Capacity, First Order, Fly-Ash, Freundlich, Freundlich Isotherm, HCI, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Model, Metals, Model, Ph, Phosphate, Phosphate Removal, Phosphorus, Phosphorus Removal, Raw, Red Mud, Removal, Treatment, Wastewater

? Zhao, M.F., Tang, Z.B. and Liu, P. (2008), Removal of methylene blue from aqueous solution with silica nano-sheets derived from vermiculite. Journal of Hazardous Materials, 158 (1), 43-51.

Full Text: 2008\J Haz Mat158, 43.pdf

Abstract: The adsorption kinetics of a cationic dye, methylene blue (MB), onto the silica nano-sheets derived from vermiculite via acid leaching was investigated in aqueous solution in a batch system with respect to contact time. initial dye concentration, pH, and temperature. Experimental results have shown that increasing initial dye concentration favors the adsorption while the acidic pH and temperature go against the adsorption. Experimental data related to the adsorption of MB on the silica nano-sheets Under different conditions were applied to the pseudo-first-order equation, the pseudo-second-order equation and the intraparticle diffusion equation, and the rate constants of first-order adsorption (k(1)). the rate constants of second-order adsorption (k(2)) and intraparticle diffusion rate constants (k(int)) were calculated, respectively. The experimental data fitted very well the pseudo-second-order kinetic model. The activation energy of system (E,,) was calculated as 3.42 kJ/mol. The thermodynamics parameters of activation such as Gibbs free energy, enthalpy, entropy were also evaluated and found that G. H, and S are 65.95 (71 63, 77.45) kJ/mol, 0.984 (0.776, 0.568) kJ/mol, and -0.222 (-0.223, -0.224) kJ/(K mol) at 20 (45, 70) C, respectively. The desorption of the dye on the silica nano-sheets using ethanol was also investigated primarily. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Activation, Activation Energy, Adsorption, Adsorption Kinetics, Aqueous Solution, Batch, Batch System, Cationic Dye, Concentration, Data, Desorption, Diffusion, Dye, Energy, Enthalpy, Entropy, Ethanol, Experimental, First Order, Gibbs Free Energy, Intraparticle Diffusion, Kinetic, Kinetic Model, Kinetics, Leaching, MB, Methylene Blue, Model, pH, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Rate Constants, Removal, Second Order, Second-Order, Silica, Silica Nano-Sheets, Solution, Temperature, Thermodynamics, Vermiculite

? Yin, H., He, B.Y., Peng, H., Ye, J.S., Yang, F. and Zhang, N. (2008), Removal of Cr(VI) and Ni(II) from aqueous solution by fused yeast: Study of cations release and biosorption mechanism. Journal of Hazardous Materials, 158 (2-3), 568-576.

Full Text: 2008\J Haz Mat158, 568.pdf

Abstract: Biosorption of Cr(VI) and Ni(II) by a fused yeast from Candida tropicalis and Candida lipolytica Under varying range of pH. initial metal concentration and reaction time was investigated. Net cation release and Cr removal reached 2.000 mmol/l and 81.37% when treating 20 mg/l Cr(VI) at pH 2 with 25 mg/l biomass for 30 min, while for Ni were 0.351 mmol/l and 64.60%. respectively. Trace metal elements such as Co, Col. Mn, Mo, Se and Zn played active role in biosorption as important ingredients of functional enzymes. Cr(VI) was reduced to less toxic Cr(III) and chelated with extracellular secretions, and further accumulated inside the cells. For Ni biosorption, however. largely a passive uptake process influenced by ion gradient led to lower adsorption capacity and cations release. Fourier transform infrared (FTIR) spectrum analysis indicated that amide and pyridine on cells were involved in binding With Cr, bill for Ni. bound-OH and nitro-compounds were the main related functional groups. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis confirmed that considerable amounts of metals precipitated on cell surface when dealing with high concentration metals. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Fused Yeast, Heavy Metal, Ion Transport, Biosorption Mechanism, Cadmium, Metals, Bioremoval, Reduction, Biomass, Sludge, Water, Ions

? Turabik, M. (2008), Adsorption of basic dyes from single and binary component systems onto bentonite: Simultaneous analysis of Basic Red 46 and Basic Yellow 28 by first order derivative spectrophotometric analysis method. Journal of Hazardous Materials, 158 (1), 52-64.

Full Text: 2008\J Haz Mat158, 52.pdf

Abstract: The present study deals with the simultaneous analysis and adsorption of Basic Yellow 28 and Basic Red 46 dyes in binary mixture onto bentonite. First order derivative spectrophotometric method was used for simultaneous analysis of BY28 and BR46 in binary mixtures. The adsorption experiments were carried out in a batch system. The mono- and multi-component Langmuir and Freundlich isotherm models were applied to experimental data and the isotherm constants were calculated for BY28 and BR46 dyes. The monolayer coverage capacities of bentonite for BY28 and BR46 dyes in single solution system were found as 256.4 mg/g and 333.3 mg/g, respectively. It was observed that the equilibrium uptake amounts of BY28 and BR46 dyes in binary mixture onto bentonite decreased considerably with increasing concentrations of the other dye resulting in their antagonistic effect. The adsorption equilibrium data fitted more adequately to mono-component Langmuir isotherm model than mono-component Freundlich isotherm model, while the extended Freundlich isotherm model adequately predicted the multi-component adsorption equilibrium data at moderate ranges of concentration. Thermodynamic parameters showed that adsorption of BR46 and BY28 was endothermic and spontaneous in nature. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Equilibrium, Analysis, Aqueous-Solution, Basic Dye, Basic Dyes, Basic Red, Basic Red 46, Bentonite, Binary Mixture, Biosorbent, Biosorption, Blue, Coverage, Derivative Spectrophotometry, Equilibrium, Experimental, First Order, Freundlich, Freundlich Isotherm, Isotherm, Isotherm Models, Isotherms, Kinetics, Langmuir, Langmuir Isotherm, Model, Rhizopus-Arrhizus, Sepiolite, Thermodynamic, Thermodynamic Parameters, Thermodynamics, Uptake

? Hameed, B.H., Mahmoud, D.K. and Ahmad, A.L. (2008), Equilibrium modeling and kinetic studies on the adsorption of basic dye by a low-cost adsorbent: Coconut (Cocos nucifera) bunch waste. Journal of Hazardous Materials, 158 (1), 65-72.

Full Text: 2008\J Haz Mat158, 65.pdf

Abstract: In this paper, the ability of coconut bunch waste (CBW), ail agricultural waste available in large quantity in Malaysia, to remove basic dye (methylene blue) from aqueous solution by adsorption was studied. Batch mode experiments were conducted at 30C to study the effects of pH and initial concentration of methylene blue (MB). Equilibrium adsorption isotherms and kinetics were investigated. The experimental data were analyzed by the Langmuir, Freundlich and Temkin models of adsorption. The adsorption isotherm data were fitted well to Langmuir isotherm and the monolayer adsorption capacity was found to be 70.92 mg/g, at 30C. The kinetic data obtained at different concentrations have been analyzed using a pseudo-first-order, pseudo-second-order equation and intraparticle diffusion equation. The experimental data fitted very well the pseudo-second-order kinetic model. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Adsorption Isotherm, Adsorption Isotherms, Agricultural, Agricultural Waste, Aqueous Solution, Basic Dye, Capacity, Coconut Bunch Waste, Cocos Nucifera, Concentration, Data, Diffusion, Dye, Equilibrium, Experimental, Experiments, Freundlich, Intraparticle Diffusion, Isotherm, Isotherms, Kinetic, Kinetic Model, Kinetic Studies, Kinetics, Langmuir, Langmuir Isotherm, Low Cost Adsorbent, Low-Cost Adsorbent, Malaysia, MB, Methylene Blue, Mode, Model, Modeling, Models, Monolayer, pH, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Solution, Waste

? El-Khaiary, M.I. (2008), Least-squares regression of adsorption equilibrium data: Comparing the options. Journal of Hazardous Materials, 158 (1), 73-87.

Full Text: 2008\J Haz Mat158, 73.pdf

Abstract: Experimental and simulated adsorption equilibrium data were analyzed by different methods of least-squares regression. The methods used were linear regression, nonlinear regression, and orthogonal distance regression. The results of the regression analysis of the experimental data showed that the different regression methods produced different estimates of the adsorption isotherm parameters, and consequently, different conclusions about the surface properties of the adsorbent and the mechanism of adsorption. A Langmuir-type simulated data set was calculated and several levels of random error were added to the data set. The results of regression analysis of the simulated data set showed that orthogonal distance regression gives the most accurate and efficient estimates of the isotherm parameters. Nonlinear regression and one form of the linearized Langmuir isotherm also gave accurate estimates, but only at low levels of random error.

Keywords: Adsorption, Isotherm, Least Squares, Regression, Orthogonal Distance Regression

? Kao, W.C., Huang, C.C. and Chang, J.S. (2008), Biosorption of nickel, chromium and zinc by MerP-expressing recombinant Escherichia coli. Journal of Hazardous Materials, 158 (1), 100-106.

Full Text: 2008\J Haz Mat158, 100.pdf

Abstract: Escherichia coli hosts able to over-express metal-binding proteins (MerP) originating from Gram-positive (Bacillus cereus RC607) and Gram-negative (Pseudomonas sp. K-62) bacterial strains were used to adsorb Ni²⁺ center dot Zn²⁺ and Cr³⁺ in aqueous solutions. The initial adsorption rate and adsorption capacity were determined to evaluate the performance of the biosorbents. With the expression of MerP protein, the metal adsorption capacity of the recombinant strains for Ni²⁺, Zn²⁺ and Cr³⁺ significantly improved. The cells carrying Gram-positive merP gene (GB) adsorbed Zn²⁺ and Cr³⁺ at a capacity of 22.3 and 0.98 mmol/g biomass, which is 121% and 72% higher, respectively, over that of the MerP-free host cells. Adsorption capacity of the cells carrying Gram-negative merP gene (GP) also increased 144% and 126% for Zn²⁺ and Cr³⁺, respectively. Both recombinant strains also exhibited 24% and 5% enhancement in adsorption of Ni²⁺ for GB and GP, respectively. The initial adsorption rate of the recombinant biosorbents was also higher than that of the MerP-free host, suggesting an increased metal-binding affinity with MerP expression. Severe cell damage on GB biosorbent was observed after Cr³⁺ adsorption, probably due to the metal toxicity effect on the cells. (C) 2008 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Capacity, Adsorption Rate, Alginic Acid, Aqueous Solutions, Aqueous-Solution, Bacillus, Bioaccumulation, Biomass, Biosorbent, Biosorption, Cadmium, Capacity, Cell-Surface Display, Chromium, Cr³⁺, Enhancement, Heavy-Metals, Initial Adsorption Rate, Mercury, MERP, Metal, Metal Adsorption, Metal Binding, Metal-Binding Proteins, Ni²⁺, Nickel, Performance, Pseudomonas, Removal, Rights, Toxicity, Waste-Water, Zinc, Zn²⁺

? Thinakaran, N., Panneerselvam, P., Baskaralingam, P., Elango, D. and Sivanesan, S. (2008), Equilibrium and kinetic studies on the removal of Acid Red 114 from aqueous solutions using activated carbons prepared from seed shells. Journal of Hazardous Materials,