Personal Research Database

Full Text: 2007\J Haz Mat144, 449.pdf

Abstract: Poly(glycidylmethacrylate-methylmethacrylate), p(GMA-MMA-EGDMA), magnetic beads were prepared via suspension polymerization in the presence of ferric ions. The epoxy groups of the beads were converted into amino groups via ring opening reaction of the ammonia and, the aminated magnetic beads were used for the removal of Hg(II) ions from aqueous solution in a batch experiment and in a magnetically stabilized fluidized bed reactor (MFB). The magnetic p(GMA-MMA-EGDMA) beads were characterized with scanning electron microscope (SEM), FT-IR and ESR spectrophotometers. The optimum removal of Hg(II) ions was observed at pH 5.5. The maximum adsorption capacity of Hg(II) ions by using the magnetic beads was 124.8±2.1 mg g⁻¹ beads. In the continuous MFB reactor, Hg(II) ions adsorption capacity of the magnetic beads decreased with an increase in the flow-rate. The maximum adsorption capacity of the magnetic beads in the MFB reactor was 139.4±1.4 mg g⁻¹. The results indicate that the magnetic beads are promising for use in MFB for removal of Hg(II) ions from aqueous solution and/or waste water treatment.

Keywords: Magnetic Beads, Hg(II) Ions, Removal, Adsorption, Kinetic

? Manna, B. and Ghosh, U.A. (2007), Adsorption of arsenic from aqueous solution on synthetic hydrous stannic oxide. Journal of Hazardous Materials, 144 (1-2), 522-531.

Full Text: 2007\J Haz Mat144, 522.pdf

Abstract: The hydrated stannic oxide (HSO) was synthesized and arsenic adsorption behaviour is reported. HSO is found to be amorphous, and stable thermally up to 700 °C. The adsorption of As(III) is much higher than As(V) in the drinking water pH (6.5–8.5) range. The time required for reaching equilibrium is 4.0 and 3.0 h, respectively for As(III) and As(V). The adsorption kinetic data obtained at pH 7.0 (±0.1) and temperature 27(±1) °C follow the pseudo-second-order kinetic model best (R² > 0.98). The analyzes of isotherm adsorption data by two parameter isotherm model equations show the order to obey: Langmuir > Freundlich > Temkin for As(III), and Langmuir > Temkin > Freundlich for As(V). The monolayer adsorption capacities (mg/g) obtained for As(III) and As(V) are 15.85 and 4.30, respectively. Excepting phosphate, other anions studied show no adverse effect on adsorption of As(III) onto HSO. A fixed bed HSO packed column (internal diameter 0.70 cm, bed height 3.7 cm and particle size 0.14–0.29 mm) generates 2400 and 450 BV of potable water (As < 0.01 mg/L), respectively, for As(III) and As(V) from arsenic spiked (1.0 mg/L) water samples at pH 7.0 (±0.1), which indicated that HSO can be used as an efficient scavenger for As(III) from the contaminated water.

Keywords: Adsorption, Adsorption Capacities, Adsorption Kinetic, Amorphous, Anions, Aqueous Solution, Arsenic, Arsenic Adsorption, As(III), As(V), Bangladesh, Coated Sand, Column, Contaminated Water, Drinking Water, Drinking-Water, Equations, Equilibrium, Ferric-Oxide, Fixed Bed, Fixed-Bed, Freundlich, Groundwater, Hydrous Stannic Oxide, Iron, Isotherm, Isotherm Adsorption, Isotherm Model, Kinetic, Kinetic Model, Kinetics, Langmuir, Model, Monolayer, Natural-Water, Order, Oxide, Packed Column, Particle, Particle Size, pH, Phosphate, Potable Water, Pseudo Second Order, Pseudo Second Order Kinetic, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Range, Removal, Size, Sorption, Synthetic, Temperature, Water

? Tuzen, M., Uluozlu, O.D. and Soylak, M. (2007), Cr(VI) and Cr(III) speciation on Bacillus sphaericus loaded diaion SP-850 resin. Journal of Hazardous Materials, 144 (1-2), 549-555.

Full Text: 2007\J Haz Mat144, 549.pdf

Abstract: A speciation procedure for Chromium(III) and chromium(VI) in the environmental samples has been established in the presented work. The procedure presented based on quantitative biosorption of Chromium(III) on Bacillus sphaericus loaded Diaion SP-850 at pH 5. The Cr(VI) recoveries at pH 5 were below 5% on the biosorbent. After reduction of Cr(VI) by concentrated H₂SO₄ and ethanol, the system was applied to the total chromium. Cr(VI) was calculated as the difference between the total chromium content and the Cr(III) content. Optimal analytical conditions including pH, amounts of biosorbent, etc. for Cr(III) recoveries were investigated. The influences of the some alkaline and earth alkaline ions and some transition metals on the recoveries were also investigated. The capacity of biosorbent for Chromium(III) was 6.95 mg g⁻¹. The detection limit (3 sigma) of the reagent blank for Chromium(III) was 0.50 μg L⁻¹. The procedure was successfully applied to the speciation of Chromium(III) and chromium(VI) in natural water samples (R.S.D. lower than 5%, recoveries greater than 95%).

Keywords: Bacillus sphaericus, Diaion SP-850, Biosorption, Speciation, Chromium, Atomic Absorption Spectrometry

? Cavaco, S.A., Fernandes, S., Quina, M.M. and Ferreira, L.M. (2007), Removal of chromium from electroplating industry effluents by ion exchange resins. Journal of Hazardous Materials, 144 (3), 634-638.

Full Text: 2007\J Haz Mat144, 634.pdf

Abstract: Effluent discharged from the chromium electroplating industry contains a large number of metals, including chromium, copper, nickel, zinc, manganese and lead. The ion exchange process is an alternative technique for application in the treatment of industrial wastewater containing heavy metals and indeed it has proven to be very promising in the removal and recovery of valuable species. The main objective of the present work is to evaluate the performance of commercial ion exchange resins for removing chromium trivalent from industrial effluents, and for this purpose two resins were tested: a chelating exchange resin (Diaion CR11) and a weak cationic resin (Amberlite IRC86). In order to evaluate the sorption capacity of the resins some equilibrium experiments were carried out, being the temperature and pH the main variables considered. The chromium solutions employed in the experiments were synthetic solutions and industrial effluents. In addition, a transient test was also performed as an attempt to understand the kinetic behaviour of the process. (c) 2007 Elsevier B.V. All rights reserved.

Keywords: Chromium Recovery, Ion Exchange, Equilibrium, Isotherms, Waste-Water, Aqueous-Solutions, Chelating Resins, Recovery, Cr(III)

? Haque, M.N., Morrison, G.M., Perrusquía, G., Gutierréz, M., Aguilera, A.F., Cano-Aguilera, I. and Gardea-Torresdey, J.L. (2007), Characteristics of arsenic adsorption to sorghum biomass. Journal of Hazardous Materials, 145 (1-2), 30-35.

Full Text: 2007\J Haz Mat145, 30.pdf

Abstract: The development of efficient and economic new adsorbent materials for the removal of arsenic from groundwater is a priority in regions where human health is directly affected by elevated arsenic concentrations. Adsorption of arsenic on sorghum biomass (SB) was investigated for the removal of arsenic from aqueous solutions. Potentiometric titrations and FTIR analysis evidenced two potential binding sites associated with carboxyl and hydroxyl groups. Batch experiments were carried out to determine the equilibrium time for arsenic adsorption to SB. The effect of pH on arsenic adsorption to SB was investigated for a pH range of 2.0–10.0. A strong influence of pH was demonstrated with a maximum removal of arsenic at pH 5.0. Freundlich and Langmuir isotherms were applied to equilibrium data. The Freundlich model fitted the equilibrium data and provided evidence for site heterogeneity at the binding surface. Column experiments were performed to obtain the breakthrough curves for both non-immobilized sorghum biomass and immobilized sorghum biomass.

Keywords: Sorghum Biomass, Adsorption, Binding Sites, pH, Equilibrium Isotherms

? Bishnoi, N.R., Kumar, R., Kumar, S. and Rani, S. (2007), Biosorption of Cr(III) from aqueous solution using algal biomass spirogyra spp. Journal of Hazardous Materials, 145 (1-2), 142-147.

Full Text: 2007\J Haz Mat145, 142.pdf

Abstract: In the present investigation, a fresh water green algae spirogyra spp. was used as an inexpensive and efficient biosorbent for Cr(III) removal from aqueous solution. The algal biomass was treated with 0.1 M NaOH, 0.2 M CaCl₂ and 5% HCHO. The biosorption efficiency was compared with untreated biomass. The effects of various physico-chemical parameters were studied, e.g. pH 3.0–6.0, initial metal ions concentration 20–150 mg L⁻¹, algal dose 1.0–3.0 g L⁻¹, and contact time 15–180 min, respectively. Biosorption of Cr(III) is highly pH dependent. Maximum 81.02% adsorption of Cr(III) was observed with 0.2 M CaCl₂ treated biomass at pH 5.0. Removal of Cr(III) was more than 70% in 45 min of contact time with different treated and untreated algal biomass at concentration 30 mg L⁻¹. Maximum metal uptake (Q_max) was observed as 30.21 mg g⁻¹ with 0.2 M CaCl₂ treated algal biomass indicate good biosorbents than other treated and untreated biomass. The high values of correlation coefficient (r² < 0.90) indicate equilibrium data of treated and untreated form of algal biomass well fitted in Freundlich than Langmuir isotherms model equations.

Keywords: Biosorption, Chromium(III), Spirogyra spp., Pretreatments, Isotherms

? Gammoun, A., Tahiri, S., Albizane, A., Azzi, M., Moros, J., Garrigues, S. and de la Guardia, M. (2007), Separation of motor oils, oily wastes and hydrocarbons from contaminated water by sorption on chrome shavings. Journal of Hazardous Materials, 145 (1-2), 148-153.

Full Text: 2007\J Haz Mat145, 148.pdf

Abstract: In this paper, the ability of chrome shavings to remove motor oils, oily wastes and hydrocarbons from water has been studied. To determine amount of hydrocarbons sorbed on tanned wastes, a FT-NIR methodology was used and a multivariate calibration based on partial least squares (PLS) was employed for data treatment. The light density, porous tanned waste granules float on the surface of water and remove hydrocarbons and oil films. Wastes fibers from tannery industry have high sorption capacity. These tanned solid wastes are capable of absorbing many times their weight in oil or hydrocarbons (6.5–7.6 g of oil and 6.3 g of hydrocarbons per gram of chrome shavings). The removal efficiency of the pollutants from water is complete. The sorption of pollutants is a quasi-instantaneous process.

Keywords: Tannery, Solid Wastes, Oils, Hydrocarbons, Sorption, FT-NIR Spectrometry

? Matheswaran, M. and Karunanithi, T. (2007), Adsorption of Chrysoidine R by using fly ash in batch process. Journal of Hazardous Materials, 145 (1-2), 154-161.

Full Text: 2007\J Haz Mat145, 154.pdf

Abstract: This investigation deals with effective utilization of fly ash as adsorbent for the removal of Chrysoidine R from the aqueous solution. The fly ash is a major byproduct generated in coal-based thermal power plants and has good potential for use as an adsorbent. A series of experiments were carried out in a batch adsorption technique to obtain the effect of process variables viz. contact time, pH (2, 4, 6 and 8) initial concentration of the dye (400, 600, 800 and 1000 mg L⁻¹), amount of the adsorbent (125, 250, 375 and 500 mg L⁻¹), and temperature (303, 313, 323 and 333 K) on adsorption. The concentration of dye was determined by spectrophotometer. The results showed that as the amount of the adsorbent was increased, the percentage of dye removal increased accordingly; higher adsorption percentage was observed at lower concentration of chrysoidine. The adsorption data were analyzed using Langmuir and Freundlich isotherms. The adsorption was found to obey pseudo-first order kinetics. An intra particle diffusion model was used to fit the experimental data. The thermodynamic parameters such as standard change in free energy, enthalpy and entropy of adsorption have been calculated. Adsorption of Chrysoidine R on fly ash was found to be an exothermic reaction.

Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Kinetics, Aqueous Solution, Aqueous-Solutions, Azo Dye, Basic-Dyes, Batch, Batch Adsorption, Batch Process, Chrysoidine R, Color Removal, Concentration, Data, Diffusion, Diffusion Model, Dye, Dye Removal, Energy, Enthalpy, Entropy, Equilibrium, Exothermic, Experimental, Experiments, Fly Ash, Freundlich, Investigation, Isotherms, Kinetics, L1, Langmuir, Langmuir and Freundlich Isotherms, Methylene-Blue, Model, Particle Diffusion, Particle Diffusion Model, pH, Plants, Potential, Power, Pseudo First Order, Pseudo-First Order, Pseudo-First-Order, Removal, Rights, Solution, Sorption, Standard, Temperature, Thermodynamic, Thermodynamic Parameters, Triphenylmethane Dyes, Utilization, Waste-Water

? Aksu, Z. and Balibek, E. (2007), Chromium(VI) biosorption by dried Rhizopus arrhizus: Effect of salt (NaCl) concentration on equilibrium and kinetic parameters. Journal of Hazardous Materials, 145 (1-2), 210-220.

Full Text: 2007\J Haz Mat145, 210.pdf

Abstract: Some industrial wastewaters contain high quantities of salts besides heavy metal ions. The presence of salt ions leads to high ionic strength, which may significantly affect the performance of the biosorption process so the effect of salts on the biosorption of heavy metal ions should be investigated. In this study the biosorption of chromium(VI) from saline solutions on dried Rhizopus arrhizus was studied as a function of pH, initial chromium(VI) and salt (NaCl) concentrations in a batch system. The biosorption capacity of R. arrhizus strongly depended on solution pH and maximum chromium(VI) sorption capacity of sorbent was obtained at pH 2.0 both in the absence and in the presence of increasing concentrations of salt. Chromium(VI)–salt biosorption studies were performed at this pH value. Equilibrium uptakes of chromium(VI) increased with increasing chromium(VI) concentration up to 250 mg l⁻¹ and decreased considerably by the presence of increasing concentrations of salt. At 100 mg l⁻¹, initial chromium(VI) concentration, dried R. arrhizus biosorbed 78.0 mg g⁻¹ of chromium(VI) in 72 h without salt medium. When salt concentration was raised to 50 g l⁻¹, this value dropped to 64.0 mg g⁻¹ of chromium(VI) at the same conditions resulting in 17.9% decrease of biosorption capacity. The equilibrium sorption data were analysed by using Freundlich, Langmuir, Redlich–Peterson and Langmuir–Freundlich (Sips), the two and three parameters adsorption models, using non-linear regression technique and isotherm constants were evaluated depending on salt concentration. The Langmuir–Freundlich (Sips) was the best suitable adsorption model for describing the biosorption of chromium(VI) individually and in salt-containing medium. Pseudo-first-order, pseudo-second-order and saturation type kinetic models described the biosorption kinetics accurately at all chromium(VI) concentrations in the absence and in the presence of changing concentrations of salt. Isotherm and saturation type kinetic constants varied due to the level of salt were expressed as a function of initial salt concentration.

Keywords: Adsorption, Adsorption Model, Adsorption Models, Affect, Aqueous-Solutions, Batch, Batch System, Biosorption, Biosorption Capacity, Biosorption Kinetics, Capacity, Chromium, Chromium(VI), Concentration, Concentrations, Constants, Cr(VI), Equilibrium, Equilibrium Sorption, Freundlich, Function, Fungal Biomass, Heavy Metal, Heavy Metal Ions, Heavy-Metal, Hexavalent Chromium, Industrial, Ionic Strength, Isotherm, Isotherm Constants, Isotherms, Kinetic, Kinetic Models, Kinetic Parameters, Kinetics, L(1), Langmuir, Langmuir-Freundlich, Metal, Metal Ions, Model, Models, Nacl, Non-Linear, Non-Linear Regression, Nonlinear, Nonlinear Regression, Parameters, Performance, pH, Process, Pseudo Second Order, Pseudo-Second-Order, R.Arrhizus, Reactive Dye, Redlich-Peterson, Regression, Removal, Rhizopus Arrhizus, Rice Bran, Salt, Salt Concentration, Saturation, Solution pH, Solutions, Sorbent, Sorption, Sorption Capacity, Strength, Tannery Effluent, VI, Waste-Water, Wastewaters

? Dolphen, R., Sakkayawong, N., Thiravetyan, P. and Nakbanpote, W. (2007), Adsorption of Reactive Red 141 from wastewater onto modified chitin. Journal of Hazardous Materials, 145 (1-2), 250-255.

Full Text: 2007\J Haz Mat145, 250.pdf

Abstract: This research involved the adsorption of synthetic reactive dye wastewater (SRDW) by chitin modified by sodium hypochlorite and original chitin in batch experiments. The comparison of maximum adsorption capacity used the Langmuir model to describe SRDW adsorption onto chitin and modified chitin under a system pH of 11.0. Maximum dye adsorption by chitin increased from 133 mg g⁻¹ to 167 mg g⁻¹ at temperatures of 30–60 °C, respectively. For modified chitin, the capacity decreased from 124 mg g⁻¹ to 59 mg g⁻¹ when the temperature increased from 30 °C to 60 °C, respectively. Both Na₂SO₄ and Na₂CO₃ increased in dye adsorption. The spectra of attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrometry confirmed the hydroxyl groups as functional groups of modified chitin, which affected the modification and the SRDW adsorption. The adsorbed dyes were eluted by distilled water and 1 M NaOH to confirm the dye adsorption mechanism. Total elution of modified chitin and chitin were 92.76% and 55.29%, respectively. Although modified chitin had a maximum adsorption capacity less than chitin, elution of the dye from modified chitin was easier than chitin. Therefore, modified chitin could be suitable in a column system for dye pre-concentration as well as wastewater minimisation. In addition, the column study showed that modified chitin could be used for more than four cycles of adsorption and elution by distilled water.

Keywords: Adsorption, Adsorption Capacity, Adsorption Mechanism, Atr-FTIR, Batch, Batch Experiments, Capacity, Chitin, Column, Column Study, Comparison, Dye, Dye Adsorption, Dye Wastewater, Dyes, Elution, Experiments, Functional Groups, Hypochlorite, Langmuir, Langmuir Model, Mechanism, Model, Modification, Modified, NaOH, pH, Pre-Concentration, Preconcentration, Reactive Dye, Research, Sodium, Sodium Hypochlorite, Spectrometry, Temperature, Wastewater, Water

? Dermou, E. and Vayenas, D.V. (2007), A kinetic study of biological Cr(VI) reduction in trickling filters with different filter media types. Journal of Hazardous Materials, 145 (1-2), 256-262.

Full Text: 2007\J Haz Mat145, 256.pdf

Abstract: Two pilot-scale trickling filters were used in order to estimate Cr(VI) reduction through biological mechanisms in biofilm reactors operated in SBR mode with recirculation using different filter media types, i.e. plastic media and calcitic gravel. The feed concentrations of Cr(VI) examined were about 5, 10, 20, 30, 50 and 100 mg/l, while the concentration of the organic carbon was constant at 400 mg/l, in order to avoid carbon limitations in the bulk liquid. Maximum reduction rates of 4.8 and 4.7 g Cr(VI)/d were observed for feed Cr(VI) concentration of about 5 mg Cr(VI)/l, for the filters with the plastic support material and the gravel media, respectively. The reduction rates were significantly affected by the feed Cr(VI) concentration in both bioreactors. A dual-enzyme kinetic model was used in order to describe Cr(VI) reduction by aerobically grown mixed cultures. Model predictions were found to correspond very closely to experimental quantitative observations of Cr(VI) reduction at both pilot-scale trickling filters used.

Keywords: Hexavalent Chromium, Biological Reduction, Trickling Filter, Plastic Media, Gravel, Dual-Enzyme Model

? Purkait, M.K., Maiti, A., Das Gupta, S. and De, S. (2007), Removal of Congo Red using activated carbon and its regeneration. Journal of Hazardous Materials, 145 (1-2), 287-295.

Full Text: 2007\J Haz Mat145, 287.pdf

Abstract: Activated carbon is used for the removal of colored toxic congo red dye. The effects of different operating conditions like, initial dye concentration, contact time, pH and temperature are studied for adsorption of congo red by a known amount of activated carbon (1.0 g/L) under stirred batch condition. The zero point of charge of the activated carbon is found about 6.6. About 90% dye is removed for initial concentration of 50 and 100 mg/L, it is about 80% at pH 7.0. Maximum adsorption (about 100%) of dye is observed at pH 2.0 for the concentration range studied here. Freundlich isotherm is found to fit the equilibrium data more adequately. Pseudo second order kinetic model explain successfully the kinetic data. The surfactant enhanced carbon regeneration (SECR) technique using both cationic and anionic surfactants is adopted for the regeneration of spent carbon by desorbing the dye. A kinetic model for dye desorption from the commercial activated carbon (CAC) is also proposed. Anionic surfactants show better performance than the cationic ones. Efficiency of dye desorption using surfactants is also compared with the desorption using pH change.

Keywords: Activated Carbon, Adsorption, Adsorption Isotherm, Anionic, Anionic Surfactant, Anionic Surfactants, Aqueous-Solutions, Batch, Behavior, Carbon, Carbon Regeneration, Cationic Surfactant, Charge, Coir Pith, Color Removal, Concentration, Condition, Congo Red, Contact Time, Desorption, Dye, Effects, Equilibrium, Equilibrium Data, Freundlich, Freundlich Isotherm, Isotherm, Kinetic, Kinetic Model, Model, N-Hexane, Operating Conditions, Order, Performance, pH, pH Change, Range, Regeneration, Removal, Second Order, Sorption, Spent Carbon, Surfactant, Surfactants, Temperature, Time, Toluene, Toxic, Waste, Zero Point of Charge

? Hou, M.F., Li, F.B., Liu, X.M., Wang, X.G. and Wan, H.F. (2007), The effect of substituent groups on the reductive degradation of azo dyes by zerovalent iron. Journal of Hazardous Materials, 145 (1-2), 305-314.

Full Text: 2007\J Haz Mat145, 305.pdf

Abstract: To investigate the effects of substituent groups on the reductive degradation of azo dyes by zerovalent iron, Orange I, Orange II and Methyl Orange were selected as the model azo dyes with different substituent groups. The results showed that Orange I, Orange II and Methyl Orange could be effectively reduced by Fe-0 and the degradation of Orange I and Orange II could be described by the first-order kinetic model, while the degradation of Methyl Orange could be described by the zeroth-order kinetic model. The initial degradation rate followed the order as Orange I > Orange II > Methyl Orange under the same experimental conditions owing to the substituent effects. The degradation kinetic constants of Orange I and Orange II increased with the increase in the Fe-0 dosage, and with the decrease in the initial pH value and their initial concentration, while that of Methyl Orange increased with the decrease in the initial pH value, and with the increase in the Fe-0 dosage and their initial concentration. The results of high-performance liquid chromatography (HPLC)-mass spectra (MS) showed that sulfanilic acid was the same intermediate, while the second intermediate was 1-amino-4-naphthol for Orange I, 1-amino-2-naphthol for Orange II, and p-dimethylaminoaniline for Methyl Orange. It was suggested that the larger conjugated pi system of naphthalene rings of Orange I and Orange II for the delocalization of the nonbonding electron pairs of substituents and nitrogen in the azo bond might be favorable for the degradation of Orange I and Orange II, compared with the structure of Methyl Orange. The higher degradation rate of Orange I might be ascribed to its effective electron delocalization and favorable position effects, compared with Orange II. It should be concluded that the reductive degradation of azo dyes by zerovalent iron strongly depends on the effect of substituent groups. (c) 2006 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Azo Dye, Azo Dyes, Decomposition, Degradation, Dyes, Experimental, First Order, First-Order Kinetic Model, Forms, Iron, Irradiation, Kinetic, Kinetic Model, Model, Naphthalene, Nitrogen, One-Electron Oxidation, Orange II, pH, Ph Value, Photocatalytic Degradation, Pollutants, Reductive Degradation, Substituent Effect, Surface, Zero-Valent Iron, Zerovalent Iron

? Han, R.P., Wang, Y., Zou, W.H., Wang, Y.F. and Shi, J. (2007), Comparison of linear and nonlinear analysis in estimating the Thomas model parameters for methylene blue adsorption onto natural zeolite in fixed-bed column. Journal of Hazardous Materials,