Personal Research Database

Full Text: 2008\J Haz Mat154, 973.pdf

Abstract: The biosorption of lead(II), cadmium(II) and nickel(II) ions from aqueous solution by Spirulina platensis was studied as a function of time, concentration, temperature, repetitive reactivity, and ionic competition. The kinetic results obeyed well the pseudo second-order model. Freundlich, Dubinin Radushkevich and Temkin isotherm models were applied in describing the equilibrium partition of the ions. Freundlich isotherm was applied to describe the design of a single-stage batch sorption system. According to the thermodynamic parameters such as G, H and S calculated, the sorption process was endothermic and largely driven towards the products. Sorption activities in a three metal ion system were studied which indicated that there is a relative selectivity of the biosorbent towards Pb²⁺ ions. The measurements of the repetitive reusability of S. platensis indicated a large capacity towards the three metal ions. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Aqueous Solution, Batch, Biosorbent, Biosorption, Cadmium(II), Capacity, Competition, Concentration, Design, Endothermic, Equilibrium, Freundlich, Freundlich Isotherm, Function, Heavy Metal, Isotherm, Kinetic, Kinetic Studies, Lead(II), Metal, Metal Ions, Model, Models, Nickel(II), Pb²⁺, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Second Order, Second-Order, Second-Order Model, Solution, Sorption, Sorption Isotherm, Sorption Process, Spirulina Platensis, Temkin Isotherm, Temperature, Thermodynamic, Thermodynamic Parameters

? Biswas, B.K., Inoue, J.I., Inoue, K., Ghimire, K.N., Harada, H., Ohto, K. and Kawakita, H. (2008), Adsorptive removal of As(V) and As(III) from water by a Zr(IV)-loaded orange waste gel. Journal of Hazardous Materials, 154 (1-3), 1066-1074.

Full Text: 2008\J Haz Mat154, 1066.pdf

Abstract: Orange waste, produced during juicing has been loaded with zirconium(IV) so as to examine its adsorption behavior for both As(V) and As(III) from an aquatic environment. Immobilization of zirconium onto the orange waste creates a very good adsorbent for arsenic. Adsorption kinetics of As(V) at different concentrations are well described in terms of pseudo-second-order rate equation with respect to adsorption capacity and correlation coefficients. Arsenate was strongly adsorbed in the pH range from 2 to 6, while arsenite was strongly adsorbed between pH 9 and 10. Moreover, equimolar (0.27 mM) addition of other anionic species such as chloride, carbonate, and sulfate had no influence on the adsorption of arsenate and arsenite. The maximum adsorption capacity of the Zr(IV)-loaded SOW gel was evaluated as 88 mg/g and 130 mg/g for As(V) and As(III), respectively. Column adsorption tests suggested that complete removal of arsenic was achievable at up to 120 Bed Volumes (BV) for As(V) and 80 BV for As(III). Elution of both arsenate and arsenite was accomplished using I M NaOH without any leakage of the loaded zirconium. Thus this efficient and abundant bio-waste could be successfully employed for the remediation of an aquatic environment polluted with arsenic. (c) 2007 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Behavior, Adsorption Capacity, Adsorption Kinetics, Aquatic Environment, Arsenate, Arsenic, Arsenite, As(III), As(V), Behavior, Capacity, Carbonate, Chloride, Column, Correlation, Elution, Environment, Gel, Immobilization, Kinetics, Ligand Exchange, NaOH, Orange Waste, pH, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Rate, Remediation, Removal, Species, Sulfate, Waste, Water

? Garg, U., Kaur, M.P., Jawa, G.K., Sud, D. and Garg, V.K. (2008), Removal of cadmium(II) from aqueous solutions by adsorption on agricultural waste biomass. Journal of Hazardous Materials, 154 (1-3), 1149-1157.

Full Text: 2008\J Haz Mat154, 1149.pdf

Abstract: This paper reports the feasibility of using various agricultural residues viz. sugarcane bagasse (SCB), maize corncob (MCC) and Jatropha oil cake (JOC) for the removal of Cd(II) from aqueous solution under different experimental conditions. Effect of various process parameters, viz., initial metal ion concentration, pH, and adsorbent dose has been studied for the removal of cadmium. Batch experiments were carried out at various pH (2-7), adsorbent dose (250-2000 mg), Cd(II) concentration (5-500 mgl^-1) for a contact time of 60 min. The maximum cadmium removal capacity was shown by JOC (99.5%). The applicability of Langmuir and Freundlich isotherm suggests the formation of monolayer of Cd(II) ions onto the outer surface of the adsorbents. Maximum metal removal was observed at pH 6.0 with a contact time of 60 min at stirring speed of 250 rpm with an adsorbent dose of 20 g l^-1 of the test solution. The maximum adsorption of cadmium(II) metal ions was observed at pH 6 for all the adsorbents viz; 99.5%, 99% and 85% for JOC, MCC, and SCB, respectively. Order of Cd(II) removal by various biosorbents was JOC > MCC > SCB. JOC may be an alternative biosorbent for the removal of Cd(II) ions from the aqueous solution. Fr-IR spectra of the adsorbents (before use and after exhaustion) were recorded to explore number and position of the functional groups available for the binding of Cd(II) ions on to studied adsorbents. These results can be helpful in designing a batch mode system for the removal of cadmium from dilute wastewaters. (c) 2007 Elsevier B.V. All rights reserved.

Keywords: Wastewater, Sugarcane Bagasse (SCB), Jatropha Oil Cake (JOC), Maize Corncob (MCC), Adsorption, Activated Carbon, Heavy-Metals, Biosorption, Sorption, Water, Optimization, Microalgae, Kinetics, Cu(II), Nickel

? Selvam, P.P., Preethi, S., Basakaralingam, P., Thinakaran, N., Sivasamy, A. and Sivanesan, S. (2008), Removal of rhodamine B from aqueous solution by adsorption onto sodium montmorillonite. Journal of Hazardous Materials, 155 (1-2), 39-44.

Full Text: 2008\J Haz Mat155, 39.pdf

Abstract: The adsorption of rhodamine B dye was carried out using sodium montmorillonite clay. The effect of parameters such as pH, adsorbent dosage and initial dye concentration was studied. The Langmuir and Freundlich isotherm models were applied and the Langmuir model was found to best fit the equilibrium isotherm data. Langmuir adsorption capacity was found to be 42.19 mg/g. Kinetic data followed pseudo-second-order kinetics. Maximum color removal was observed at pH 7.0. The G value was found to be negative, the adsorption process was feasible. The results indicate that sodium montmorillonite clay can be used for the removal of basic dyes from aqueous solutions. (c) 2007 Elsevier B.v. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Adsorption Isotherms, Aqueous Solution, Aqueous Solutions, Basic Dyes, Capacity, Clay, Color Removal, Concentration, Data, Dye, Dyes, Equilibrium, Equilibrium Isotherm, Freundlich, Freundlich Isotherm, Isotherm, Kinetic, Kinetics, Langmuir, Langmuir Model, Model, Models, Montmorillonite, pH, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second-Order, Pseudo-Second-Order Kinetics, Removal, Rhodamine B, Rhodamine-B, Sodium, Sodium Montmorillonite, Solution, Solutions

? Weng, C.H., Sharma, Y.C. and Chu, S.H. (2008), Adsorption of Cr(VI) from aqueous solutions by spent activated clay. Journal of Hazardous Materials, 155 (1-2), 65-75.

Full Text: 2008\J Haz Mat155, 65.pdf

Abstract: Adsorption of Cr(VI) onto spent activated clay (SAC), a waste produced from an edible oil refinery company, was investigated for its beneficial use in wastewater treatment. After pressure steam treatment, SAC was used as an adsorbent. The adsorption kinetic data were analyzed and fitted well in a pseudo-first-order equation and the rate of removal was found to speed up with decreasing pH and increasing temperature. Activation energy for the adsorption process was found to be 4.01-5.47 kcal/K mol. The Langmuir adsorption isotherm was used to fit the equilibrium data and the effect of pH, temperature and ionic strength were studied. The maximum adsorption capacities for Cr(VI) ranged from 0.743 to 1.422 mg/g for temperature between 4 and 40C under a condition of pH 2.0. The studies conducted show the process of Cr(VI) removal to be spontaneous at high temperature and endothermic in nature. From the waste utilization and environment point of view, the work carried out is important and useful. Results obtained can serve as baseline data for designing a treatment process using this low-cost adsorbent for the treatment of wastewater rich in Cr(VI). (c) 2007 Elsevier B.V All rights reserved.

Keywords: Activated Clay, Adsorption, Chromium, Equilibrium, Kinetics, Low-Cost Adsorbents, Hexavalent Chromium, Waste-Water, Heavy-Metals, Removal, Carbon, Equilibrium, Ions, Nanoparticles, Sorption

? Atia, A.A., Donia, A.M. and Awed, H.A. (2008), Synthesis of magnetic chelating resins functionalized with tetraethylenepentamine for adsorption of molybdate anions from aqueous solutions. Journal of Hazardous Materials, 155 (1-2), 100-108.

Full Text: 2008\J Haz Mat155, 100.pdf

Abstract: Magnetic resins were synthesized through polymerization of glycidyl methacrylate (GMA) in the presence of divinylbenzene (DVB) or N,N’-methylenebisacrylamide (MBA) as hydrophobic or hydrophilic crosslinker, respectively and in presence of suspended magnetite particles. The resins containing (DVB or MBA) as crosslinker were immobilized with tetraethylenepentamine (TEP) to give the amino resins, GMA/DVB/TEP (R1-en) and GMA/MBA/TEP (R2-en), respectively. The uptake behavior of the two resins was studied towards molybdate anions and uptake capacities of 4.24 and 6.18 mmol/g [as (Mo(VI)] were obtained using (R1-en) and (R2-en). Kinetic studies showed that the adsorption followed the pseudo-second-order model pointing the influence of the textural properties of the resin on the rate of adsorption. Thermodynamic data indicated an endothermic adsorption process. The uptake of Mo(VI) and regeneration of the resins were also studied using the column method. Regeneration efficiency up to 90-96% was reached using ammonia buffer. © 2007.

Keywords: Adsorption, Ammonia, Aqueous Solutions, Behavior, Buffer, Column, Data, Efficiency, Endothermic, Glycidyl Methacrylate, Immobilized, Kinetic, Kinetic Studies, Kinetics, Magnetic, Magnetic Resins, Magnetite, Model, Molybdate, Particles, Polymerization, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Regeneration, Resin, Resins, Solutions, Synthesis, Thermodynamic, Thermodynamics, Uptake

? Issabayeva, G., Aroua, M.K. and Sulaiman, N.M. (2008), Continuous adsorption of lead ions in a column packed with palm shell activated carbon. Journal of Hazardous Materials, 155 (1-2), 109-113.

Full Text: 2008\J Haz Mat155, 109.pdf

Abstract: The continuous adsorption of lead ions from aqueous solution on commercial, granular, unpretreated palm shell activated carbon (PSAC) was studied. Effect of pH, flow rates and presence of complexing agents (malonic and boric acids) were examined. The breakthrough period was longer at pH 5 indicating higher adsorption capacity of lead ions at higher pH. Increase of the flow rate, expectedly, resulted in the faster saturation of the carbon bed. Presence of complexing agents did not improve adsorption uptake of lead ions. However, presence of malonic acid resulted in smoother pH stabilization of solution compared to single lead and lead with boric acid systems. The results on continuous adsorption of lead were applied to the model proposed by Wang et al. [Y.-H. Wang, S.-H. Lin, R.-S. Juang, Removal of heavy metals ions from aqueous solutions using various low-cost adsorbents, J. Hazard. Mater. B 102 (2003) 291-302]. The agreement between experimental and modelled breakthrough curves was satisfactory at both pHs. (c) 2007 Elsevier B.V All rights reserved.

Keywords: Acid, Activated Carbon, Adsorbents, Adsorption, Adsorption Capacity, Aqueous Solutions, Aqueous-Solutions, Boric Acid, Breakthrough, Breakthrough Curve, Capacity, Carbon, Copper, Effect of pH, Hazard, Heavy Metals, Lead, Lead Ions, Low Cost Adsorbents, Low-Cost Adsorbents, Malonic Acid, Metal-Ions, Metals, Model, Palm Shell, pH, Removal, Uptake, Zinc

? Sundaram, C.S., Viswanathan, N. and Meenakshi, S. (2008), Defluoridation chemistry of synthetic hydroxyapatite at nano scale: Equilibrium and kinetic studies. Journal of Hazardous Materials, 155 (1-2), 206-215.

Full Text: 2008\J Haz Mat155, 206.pdf

Abstract: This study describes the advantages of nano-hydroxyapatite (n-HAp), a cost effective sorbent for fluoride removal. n-HAp possesses a maximum defluoridation capacity [DC] of 1845 mg F-/kg which is comparable with that of activated alumina, a defluoridation agent commonly used in the indigenous defluoridation technology. A new mechanism of fluoride removal by n-HAp was proposed in which it is established that this material removes fluoride by both ion-exchange and adsorption process. The n-HAp and fluoride-sorbed n-HAp were characterized using XRD, FTIR and TEM studies. The fluoride sorption was reasonably explained with Langmuir, Freundlich and Redlich-Peterson isotherms. Thermodynamic parameters such as G, H, S and E-a were calculated in order to understand the nature of sorption process. The sorption process was found to be controlled by pseudo-second-order and pore diffusion models. Field studies were carried out with the fluoride containing water sample collected from a nearby fluoride endemic area in order to test the suitability of n-HAp material as a defluoridating agent at field condition. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activated Alumina, Adsorption, Adsorption Process, Alumina, Capacity, Chemistry, Cost, Cost-Effective, Defluoridation, Diffusion, Equilibrium, Field, Fluoride, Fluoride Removal, Freundlich, FTIR, Hydroxyapatite, Ion Exchange, Ion-Exchange, Ionexchange, Isotherms, Kinetic, Kinetic Studies, Langmuir, Mechanism, Models, N-Hap, Nano, Particle and Pore Diffusion, Pore Diffusion, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Redlich-Peterson, Removal, Scale, Sorbent, Sorption, Sorption Process, Technology, TEM, Thermodynamic, Thermodynamic Parameters, Water, XRD

? Guerra, D.L., Airoldi, C., Lemos, V.P. and Angélica, R.S. (2008), Adsorptive, thermodynamic and kinetic performances of Al/Ti and Al/Zr-pillared clays from the Brazilian Amazon region for zinc cation removal. Journal of Hazardous Materials, 155 (1-2), 230-242.

Full Text: 2008\J Haz Mat155, 230.pdf

Abstract: Smectite clay samples from the Amazon region, Brazil, were pillarized by intercalating the species obtained from the chemical reactions: (i) AlCl₃ center dot 6H₂O/NaOH, (II) titanium ethoxide in hydrochloric acid and (iii) direct use of ZrOCl₂ center dot 8H₂O solution. The natural matrices and the pillaring solutions were maintained under vigorous stirring at 298 K for 3 h and then subjected to calcination at temperatures of 723 and 873 K. Natural and pillared matrices were characterized by XRD, FTIR, TG-DTG and nitrogen adsorption-desorption isotherms. The resulting materials were used for zinc adsorption from aqueous solution at room temperature. The Langmuir, Freundlich and Temkin adsorption isotherm models have been applied to fit the experimental data and the Freundlich model is limited for higher concentrations. The pillaring process increases the thermal stability, the basal spacing of the natural clay sample (A(1)) from 1.55 to 2.06 nm and the surface area from 44.30 to 223.73 m² g^-1. Kinetic studies demonstrated an equilibrium time of 180 min for zinc adsorption on the pillared matrices. Pseudo-first-order, Lagergren pseudo-second-order and Elovich equations demonstrated a better agreement with second-order kinetics was obtained with K-2 = 4.17-10.4310^-3 g mg^-1 min^-1 for the A(1) sample. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Isotherm, Adsorption Isotherm Models, Amazon, Aqueous Solution, Brazil, Calcination, Cation, Chemical, Clay, Clays, Data, Elovich, Equilibrium, Experimental, Freundlich, Freundlich Model, FTIR, Isotherm, Isotherms, Kinetic, Kinetic Studies, Kinetics, Langmuir, Model, Models, Natural Clay, Nitrogen, Pillared Clay, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Removal, Room Temperature, Second Order, Second Order Kinetics, Second-Order, Second-Order Kinetics, Smectite, Solution, Solutions, Species, Stability, Surface, Surface Area, Temperature, Thermal Stability, Thermodynamic, Titanium, XRD, Zinc

? Rosa, S., Laranjeira, M.C.M., Riela, H.G. and Fávere, V.T. (2008), Cross-linked quaternary chitosan as an adsorbent for the removal of the reactive dye from aqueous solutions. Journal of Hazardous Materials, 155 (1-2), 253-260.

Full Text: 2008\J Haz Mat155, 253.pdf

Abstract: Adsorption of reactive orange 16 by quaternary chitosan salt (QCS) was used as a model to demonstrate the removal of reactive dyes from textile effluents. The polymer was characterized by infrared (IR), energy dispersive X-ray spectrometry (EDXS) analyses and amount of quaternary ammonium groups. The adsorption experiments were conducted at different pH values and initial dye concentrations. Adsorption was shown to be independent of solution pH. Three kinetic adsorption models were tested: pseudo-first-order, pseudo-second-order and intraparticle diffusion. The experimental data best fitted the pseudo-second-order model, which provided a constant velocity, k2, of 9.18×10^-4 g mg^-1 min^-1 for a 500 mg L^-1 solution and a value of k2, of 2.70×10^-5 g mg^-1 min^-1 for a 1000 mg L^-1 solution. The adsorption rate was dependent on dye concentration at the surface of the adsorbent for each time period and on the amount of dye adsorbed. The Langmuir isotherm model provided the best fit to the equilibrium data in the concentration range investigated and from the isotherm linear equation, the maximum adsorption capacity determined was 1060 mg of reactive dye per gram of adsorbent, corresponding to 75% occupation of the adsorption sites. The results obtained demonstrate that the adsorbent material could be utilized to remove dyes from textile effluents independent of the pH of the aqueous medium. © 2007 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Adsorption Rate, Ammonium, Analyses, Aqueous Medium, Aqueous Solutions, Capacity, Chitosan, Concentration, Cross-Linked, Data, Diffusion, Dye, Dyes, EDX, Effluents, Energy, Equilibrium, Experimental, Experiments, Intraparticle Diffusion, IR, Isotherm, Isotherm Model, Kinetic, Kinetic Adsorption, Langmuir, Langmuir Isotherm, Langmuir Isotherm Model, Model, Models, Occupation, pH, Polymer, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Quaternary Chitosan, Reactive Dye, Reactive Dyes, Removal, Salt, Solution, Solutions, Spectrometry, Surface, Textile Effluents, Value, X-Ray

? Lutfullah, Alam, M.N., Rahman, N. and Azmi, S.N.H. (2008), Optimized and validated spectrophotometric method for the determination of uranium(VI) via complexation with meloxicam. Journal of Hazardous Materials, 155 (1-2), 261-268.

Full Text: 2008\J Haz Mat155, 261.pdf

Abstract: An optimized and validated spectrophotometric method has been developed for the determination of uranyl ion in the presence of other metal ions. The method is based on the chelation of uranyl ion with meloxicam via [beta]-diketone moiety to produce a yellow colored complex, which absorbs maximally at 398 m. Beer’s law is obeyed in the concentration range of 5-60 g/mL with apparent molar absorptivity and Sandell’s sensitivity of 5.0210⁴ /mol/cm and 0.1 g/cm²/0.001 absorbance unit, respectively. The method has been successfully applied for the determination of uranyl ion in synthetic mixture and soil samples. Results of analysis were statistically compared with those obtained by Currah’s spectrophotometric method showing acceptable recovery and precision.

Keywords: Absorbance, Analysis, Chelation, Complexation, Concentration, Determination, Ions, Law, Meloxicam, Metal, Metal Ions, Precision, Recovery, Sensitivity, Soil, Spectrophotometry, Uranium(VI), Uranyl Nitrate Hexahydrate, Validation

? Tseng, R.L. and Wu, F.C. (2008), Inferring the favorable adsorption level and the concurrent multi-stage process with the Freundlich constant. Journal of Hazardous Materials, 155 (1-2), 277-287.

Full Text: 2008\J Haz Mat155, 277.pdf

Abstract: This paper proposes a method for inferring a favorable level for the adsorption isotherm curve with the Freundlich constant (1/n), explains that a favorable level is only a function of 1/n, and then, five favorable levels are classified according to 1/n value. The adsorbent consumption ratio of the concurrent multi-stage to single-stage system was deduced in order to investigate the relationship between favorable level and the most suitable number of stages. Activated carbon (TGBAC) was prepared from Taiwan Giant Bamboo with steam activation. The isotherm equilibrium of the adsorption of three phenols (phenol, 3-CP, and 4-CP), two dyes (MB and BB 69), and tannic acid on TGBAC was obtained. According to the Freundlich constant (1/n), the adsorption of MB was inferred in a strongly favorable zone. The favorable zone for BB69, phenol, 3-CP, and 4-CP was determined. The tannic acid, the pseudo-linear zone and their most suitable number of stages were also determined. The 1/n values and favorable levels summarized from more than a hundred sources/studies indicate that the favorable levels of the adsorption of dyes and phenols on TGBAC are excellent. This paper proposes a simple method for inferring the favorable level and the most suitable number of stages for the concurrent multi-stage adsorption system.

Keywords: Activated Carbon, Activation, Adsorbent, Adsorption, Adsorption Isotherm, Adsorption Process, Bamboo, Carbon, Consumption, Dyes, Equilibrium, Favorable Level, Freundlich, Freundlich Constant, Freundlich Equation, Function, Isotherm, MB, Multi-Stage, Phenol, Phenols, Steam Activation, Taiwan, Value

? Zhao, J.M., Li, Y.M., Zhang, C.J., Zeng, Q.L. and Zhou, Q. (2008), Sorption and degradation of bisphenol A by aerobic activated sludge. Journal of Hazardous Materials, 155 (1-2), 305-311.

Full Text: 2008\J Haz Mat155, 305.pdf

Abstract: Laboratory-scale batch experiments were conducted to investigate the sorption and degradation of bisphenol A (BPA) at mu g/L range in an aerobic activated sludge system. The sorption isotherms and thermodynamics indicated that the sorption of BPA on sludge was mainly a physical process in which partitioning played a dominating role. The values of sorption coefficient K-oc were between 621 and 736 L/kg in the temperature range of 10-30 degrees C. Both mixed liquor suspended solid (MLSS) and temperature influenced BPA sorption on sludge. The degradation of BPA by acclimated activated sludge could be described by first-order reaction equation with the first-order degradation rate constant of 0.80 h(-1) at 20 degrees C. The decrease of initial COD concentration and the increase of MLSS concentration and temperature enhanced BPA degradation rate. The removal of BPA in the activated sludge system was characterized by a quick sorption on the activated sludge and subsequent biodegradation. (C) 2007 Elsevier B.V. All rights reserved.

Keywords: Activated Sludge, Adsorption, Aerobic, Biodegradation, Biosorption, Bisphenol A, COD, Degradation, Endocrine Disrupting Chemicals, First Order, Isotherms, Municipal, Pharmaceuticals, Rate Constant, Removal, River Water, Sewage-Sludge, Sorption, Thermodynamics, Waste-Water

? Chen, Z., Ma, W. and Han, M. (2008), Biosorption of nickel and copper onto treated alga (Undaria pinnatifida): Application of isotherm and kinetic models. Journal of Hazardous Materials,