Personal Research Database

Full Text: 2005\J Haz Mat125, 231.pdf

Abstract: PCP-degrading anaerobic granular sludge could be formed in an upflow anaerobic sludge blanket (UASB) reactor that was seeded with anaerobic sludge acclimated to chlorophenol. When hydraulic retention time (HRT) was 20–22 h and PCP loading rate was 200–220 mg L⁻¹ d⁻¹, the wastewater containing170–180 mg L⁻¹ PCP could be treated effectively in UASB reactor, and PCP removal rate reached up to 99.5%. PCP adsorption and desorption by anaerobic granular sludge follow Freundlich isothermal equation and part of adsorption capacity was not reversible. and the isothermal equation could well describe the variation law of PCP adsorption and desorption by anaerobic granular sludge. The results indicated that the principal removal mechanism of PCP was biodegradation by anaerobic granular sludge, but not adsorption or volatilization.

Keywords: Pentachlorophenol, Bio-Degradation, Bio-Adsorption, Volatilization, Anaerobic Granular Sludge

? Özcan, A. and Özcan, A.S. (2005), Adsorption of Acid Red 57 from aqueous solutions onto surfactant-modified sepiolite. Journal of Hazardous Materials, 125 (1-3), 252-259.

Full Text: 2005\J Haz Mat125, 252.pdf

Abstract: The adsorption of Acid Red 57 (AR57) onto surfactant-modified sepiolite was investigated in aqueous solution in a batch system with respect to contact time, pH and temperature. The surface modification of surfactant-modified sepiolite was controlled using the FTIR technique. The pseudo-first-order, pseudo-second-order kinetic models and the intraparticle diffusion model were used to describe the kinetic data and the rate constants were evaluated. The experimental data fitted very well the pseudo-second-order kinetic model and also followed the intraparticle diffusion model up to 90 min, whereas diffusion is not only the rate controlling step. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were also determined. The Freundlich model agrees with experimental data well. The activation energy, change of free energy, enthalpy and entropy of adsorption were also evaluated for the adsorption of AR57 onto surfactant-modified sepiolite. The results indicate that surfactant-modified sepiolite could be employed as low-cost material for the removal of textile dyes from effluents.

Keywords: Acid Dye, Acid Dyes, Activation, Activation Energy, Adsorption, Aqueous Solution, Aqueous Solutions, Batch, Batch System, Bentonite, Cation-Exchange, Clay, Data, Diffusion, Diffusion Model, Dye Adsorption, Dyes, Effluents, Energy, Enthalpy, Entropy, Equilibrium, Equilibrium Isotherms, Experimental, Fly-Ash, Freundlich, Freundlich Model, FTIR, Intraparticle Diffusion, Intraparticle Diffusion Model, Isotherm, Isotherms, Kinetic, Kinetic Model, Kinetic Models, Kinetics, Langmuir, Low Cost, Low-Cost Material, Methylene-Blue, Model, Model-Calculations, Models, Modification, pH, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Rate Constants, Reactive Dye, Removal, Rights, Sepiolite, Solution, Solutions, Surface, Surface Modification, Surfactant, Temperature

? Han, R.P., Zhang, J.H., Zou, W.H., Shi, J. and Liu, H.M. (2005), Equilibrium biosorption isotherm for lead ion on chaff. Journal of Hazardous Materials, 125 (1-3), 266-271.

Full Text: 2005\J Haz Mat125, 271.pdf

Abstract: A new adsorbent system for removing lead ion from aqueous solutions has been investigated. This new adsorbent is cereal chaff, an agriculture product in middle-west region in China. Variables of the system include biosorption time, chaff dose and solution temperature. The experimental results were fitted to the Langmuir, Freundlich, Koble–Corrigan and Temkin model isotherms to obtain the characteristic parameters of each model. Both the Langmuir and Koble–Corrigan isotherms were found to best represent the measured biosorption data. According to the evaluation using the Langmuir equation, the maximum biosorption capacities of lead ion onto chaff was 12.5 mg g⁻¹ at 293 K. Using the thermodynamic equilibrium coefficients obtained at different temperatures, various thermodynamic parameters, such as ΔG⁰, ΔH⁰ and ΔS⁰, have been calculated. The thermodynamics of lead ion–chaff system indicates spontaneous and exothermic process. It was concluded that an increase in temperature result in a lower metal loading per unit weight of the chaff.

Keywords: Chaff, Biosorption, Lead, Equilibrium, Thermodynamic

? Hardin, A.M. and Admassu, W. (2005), Kinetics of heavy metal uptake by vegetation immobilized in a polysulfone or polycarbonate polymeric matrix. Journal of Hazardous Materials, 126 (1-3), 40-53.

Full Text: 2005\J Haz Mat126, 40.pdf

Abstract: The ability of four common vegetations – wood, grass, compost, and peat moss – to remove cadmium, chromium, and lead from dilute aqueous solutions is investigated. Dried ground vegetations are immobilized in polysulfone, and poly (bisphenyl A) carbonate to form spherical beads through a phase inversion process. The beads are contacted with a dilute aqueous solution containing metal ions of interest. The removal of metal ions from the solution is monitored over the course of the experiment and the first-order kinetics parameters estimated. The rates of removal as well as the equilibrium bead loadings are shown to be affected by both the choice of vegetation and the choice of polymer.

Keywords: Heavy Metal Adsorption, Immobilized Vegetation, Cadmium, Chromium, Lead

? Kumar, B.G.P., Miranda, L.R. and Velan, M. (2005), Adsorption of Bismark Brown dye on activated carbons prepared from rubberwood sawdust (Hevea brasiliensis) using different activation methods. Journal of Hazardous Materials, 126 (1-3), 63-70.

Full Text: 2005\J Haz Mat126, 63.pdf

Abstract: Hevea brasiliensis or rubberwood tree, as it is commonly known finds limited use once the latex has been tapped. The sawdust of this tree is chosen to ascertain it viability as a precursor for activation. The carbons thus obtained were characterized in terms of iodine, methylene blue number and surface area. The best carbon in each method was utilized to study the adsorption of Bismark Brown, a dye used in the leather industry. Adsorption equilibrium studies were carried out with the synthetic solutions of the dye, at room temperature (298 K). Equilibrium data are fitted with the Langmuir and the Freundlich isotherms models for the system. The effects of contact time, adsorbent dosage and initial dye concentrations on sorption capacity were carried out. Excellent adsorption capacities of 2000 and 1111 mg g⁻¹ were obtained for steam and chemical followed by steam-activated carbons, respectively. Pilot-plant experimental studies have been performed using packed-bed column with different feed concentrations, flow rates and bed heights, to evaluate sorption of Bismark Brown on steam-activated carbon. Bed depth service time (BDST) design model have been used to analyze the data.

Keywords: Activated Carbons, Activation, Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Capacities, Adsorption Equilibrium, Adsorption Isotherms, Bdst, Bismark Brown Dye, Capacity, Carbon, Chemical, Column, Data, Design, Dye, Equilibrium, Equilibrium Studies, Experimental, Feed, Flow, Freundlich, Isotherms, Langmuir, Latex, Methods, Methylene Blue, Model, Models, Packed Bed, Packed-Bed, Packed-Bed Column, Rates, Room Temperature, Rubberwood Sawdust, Sawdust, Service, Solutions, Sorption, Sorption Capacity, Surface, Surface Area, Temperature, Viability

? Wang, S.B. and Li, H.T. (2005), Dye adsorption on unburned carbon: Kinetics and equilibrium. Journal of Hazardous Materials, 126 (1-3), 71-77.

Full Text: 2005\J Haz Mat126, 71.pdf

Abstract: Unburned carbon in fly ash is an important by-product from coal combustion. In this investigation, unburned carbon has been separated from fly ash and been employed as a low cost adsorbent for a basic dye adsorption (Rhodamine B) in aqueous solution. Adsorption isotherm and kinetics of adsorption have been investigated using batch experiments. It is found that dye adsorption capacity depends on initial concentration, pH of solution, and temperature. The adsorption isotherm can be described by Langmuir model and the adsorption capacity of Rhodamine B at 30, 40, and 50°C can reach 9.7×10⁻⁵, 1.14×10⁻⁴, and 1.5×10⁻⁴ mol g⁻¹, respectively. The pseudo first- and second-order kinetic models have been employed to fit the dynamic adsorption. It is found that the dynamic adsorption follows the pseudo second-order model. Thermodynamic calculations indicate that the adsorption is endothermic reaction with ΔH° at 25 kJ mol⁻¹.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Adsorption Isotherm, Aqueous Solution, Basic Dye, Batch, Batch Experiments, Capacity, Carbon, Coal, Combustion, Concentration, Cost, Dye, Dye Adsorption, Dynamic, Endothermic, Equilibrium, Experiments, First, Fly Ash, Investigation, Isotherm, Kinetic, Kinetic Models, Kinetics, Kinetics of Adsorption, Langmuir, Langmuir Model, Low Cost Adsorbent, Model, Models, pH, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Rhodamine B, Second Order, Second-Order, Second-Order Model, Solution, Temperature, Thermodynamic, Unburned Carbon

? Dermou, E., Velissariou, A., Xenos, D. and Vayenas, D.V. (2005), Biological chromium(VI) reduction using a trickling filter. Journal of Hazardous Materials, 126 (1-3), 78-85.

Full Text: 2005\J Haz Mat126, 78.pdf

Abstract: A pilot-scale trickling filter was constructed and tested for biological chromium(VI) removal from industrial wastewater. Indigenous bacteria from industrial sludge were enriched and used as inoculum for the filter. Sodium acetate was used as carbon source and it was found to inhibit chromate reduction at high concentrations. Three different operating modes were used to investigate the optimal performance and efficiency of the filter, i.e. batch, continuous and SBR with recirculation. The latter one was found to achieve removal rates up to 530 g Cr(VI)/m² d, while aeration was taking place naturally without the use of any external mechanical means. The low operating cost combined with the high hexavalent chromium reduction rates indicates that this technology may offer a feasible solution to a very serious environmental problem.

Keywords: Chromate, Biological Removal, Trickling Filter, Sequencing Batch Reactor, Recirculation

? Wang, S.B. and Zhu, Z.H. (2005), Sonochemical treatment of fly ash for dye removal from wastewater. Journal of Hazardous Materials, 126 (1-3), 91-95.

Full Text: 2005\J Haz Mat126, 91.pdf

Abstract: Fly ash samples modified by NaOH solution and sonochemical treatment were tested for a basic dye (methylene blue) adsorption in aqueous solution. It is found that sonochemical treatment of fly ash can significantly increase the adsorption capacity depending on the concentration of NaOH and treatment time. The untreated FA and the sonochemically treated sample exhibits adsorption capacity at 6×10⁻⁶ mol/g and 1.2×10⁻⁵ mol/g at 30 °C, respectively. The adsorption tests show that solution pH and adsorption temperature also influence the adsorption behaviour. The adsorption isotherms can be fitted by Langmuir and Freudlich models, while the two-site Langmuir heterogeneous model will present the best result.

Keywords: Fly Ash, Basic Dyes, Wastewater, Adsorption, Ultrasonic Treatment

? Saygideger, S., Gulnaz, O., Istifli, E.S. and Yucel, N. (2005), Adsorption of Cd(II), Cu(II) and Ni(II) ions by Lemna minor L.: Effect of physicochemical environment. Journal of Hazardous Materials, 126 (1-3), 96-104.

Full Text: 2005\J Haz Mat126, 96.pdf

Abstract: The free floating macrophyte Lemna minor L. was harvested locally. Untreated, acid pretreated (H₂SO₄), alkali pretreated (NaOH) biomass were used for adsorption of copper, cadmium and nickel ions from aqueous solutions. The effect of initial pH, initial metal concentration and multi metal interaction were carried out in a batch system. The equilibrium adsorption was reached within 40–60 min. The Langmuir and Freundlich models were used for describing of adsorption isotherm data. The maximum adsorption capacities of alkali pretreated biomass were determined as 83, 69 and 59 mg g⁻¹ for the Cd(II), Cu(II) and Ni(II) ions, respectively. The pseudo first- and second-order intraparticle diffusion models were used to describe the adsorption kinetics. The experimental data fitted to pseudo second-order kinetic. Adsorption capacity decreased with acid pretreatment; however alkali pretreatment was not affected significantly adsorption capacity and adsorption capacity a little increased according to native biomass. The FT-IR results of Lemna biomass showed that biomass has different functional groups and these functional groups are able to react with metal ions in aqueous solution.

Keywords: Adsorption, Adsorption Capacities, Adsorption Capacity, Adsorption Isotherm, Adsorption Kinetics, Aqueous Solution, Aqueous Solutions, Batch, Batch System, Biomass, Biosorption, Cadmium, Capacity, Cd(II), Concentration, Copper, Cu(II), Data, Diffusion, Environment, Equilibrium, Experimental, First, Freundlich, FT-IR, FTIR, Functional Groups, Interaction, Intraparticle Diffusion, Isotherm, Kinetic, Kinetic Models, Kinetics, Langmuir, Lemna Minor, Lemna Minor l., Metal, Metal Ions, Metal-Interaction, Minor, Models, NaOH, Ni(II), Ni(II) Ions, Nickel, pH, Pretreatment, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Second Order, Second-Order, Solution, Solutions

? Yang, G.P., Zhao, X.K., Sun, X.J. and Lu, X.L. (2005), Oxidative degradation of diethyl phthalate by photochemically-enhanced Fenton reaction. Journal of Hazardous Materials, 126 (1-3), 112-118.

Full Text: 2005\J Haz Mat126, 112.pdf

Abstract: A kinetic investigation into the photo-degradation of aqueous diethyl phthalate by Fenton reagent was conducted in this study. The obtained results showed the enhancement of diethyl phthalate (DEP) decomposition by UV irradiation with the Fenton reaction. It was found that H₂O₂ concentration, Fe²⁺ concentration, and aqueous pH value were the three main factors that could significantly influence the degradation rates of DEP. The highest degradation percentage (75.8%) of DEP was observed within 120 min at pH 3 in the UV/H₂O₂/Fe²⁺ system, with original H₂O₂ and Fe²⁺ concentrations of 5.0010^-4 and 1.6710^-4 mol g^-1, respectively. The present study provides an effective approach to the treatment of wastewater containing DEP.

Keywords: Approach, Concentration, Decomposition, Degradation, Diethyl Phthalate (DEP), Fe(II), Fenton, Fenton Reagent, H₂O₂, Hydroxyl Radical, Investigation, Irradiation, Kinetic, pH, pH Value, Photodegradation, Phthalate, Rates, Treatment, UV, Value, Wastewater

? Özer, A., Akkaya, G. and Turabik, M. (2005), Biosorption of Acid Red 274 (AR 274) on Enteromorpha prolifera in a batch system. Journal of Hazardous Materials, 126 (1-3), 119-127.

Full Text: 2005\J Haz Mat126, 119.pdf

Abstract: The biosorption of Acid Red 274 (AR 274) dye on Enteromorpha prolifera, a green algae grown on Mersin costs of the Mediterranean, Turkey, was studied as a function of initial pH, temperature, initial dye and biosorbent concentration. The experiments were conducted in a batch manner. The Langmuir and Freundlich isotherms were used for modelling the biosorption equilibrium. At optimum temperature 30°C and initial pH 2.0–3.0, the Langmuir isotherm fits best to the experimental equilibrium data with a maximum monolayer coverage of 244 mg/g. The equilibrium AR 274 concentration of the exit stream of a single batch was also obtained by using the experimental equilibrium curve and operating line graphically. The pseudosecond-order kinetic model and Weber–Morris model were applied to the experimental data and it was found that both the surface adsorption as well as intraparticle diffusion contribute to the actual adsorption process. The biosorption process follows a pseudosecond-order kinetics and activation energy was determined as −4.85 kJ/mol. Thermodynamic studies showed that the biosorption of AR 274 on E. prolifera is exothermic and spontaneous in nature.

Keywords: Biosorption, Acid Red 274, Enteromorpha Prolifera, Kinetic Models, Isotherm Models

? Fernández, Y., Marañón, E., Castrillón, L. and Vázquez, I. (2005), Removal of Cd and Zn from inorganic industrial waste leachate by ion exchange. Journal of Hazardous Materials, 126 (1-3), 169-175.

Full Text: 2005\J Haz Mat126, 169.pdf

Abstract: This paper presents a study of the removal of Cd and Zn present in the leachate from an inorganic industrial waste landfill using cationic exchange resins (Amberlite 200, 252-C, IR-120, Duolite C-464), a chelating resin, Amberlite IRC 718, and an adsorbent resin, XAD-2. The chelating resin Amberlite IRC 718 presented the higher removal in batch experiments for both metals (93% for Zn and 50% for Cd). Five hundred ten bed volumes of leachate were treated in column experiments using this material, reducing the concentrations of Cd and Zn from 18 mg/dm³ to 0.1 and 1.0 mg/dm³, respectively. Regeneration of the saturated bed was achieved with 11 BV of 2 M HCl.

Keywords: Leachates, Landfill, Industrial Waste, Ion Exchange, Heavy Metal Removal

? Erdem, M., Altundoğan, H.S., Turan, M.D. and Tümen, F. (2005), Hexavalent chromium removal by ferrochromium slag. Journal of Hazardous Materials, 126 (1-3), 176-182.

Full Text: 2005\J Haz Mat126, 176.pdf

Abstract: The aim of this study is to demonstrate the potential of Cr(VI) generation during jigging operation applied for ferrochrome recovery from slag. The Cr(VI) concentrations of water contacted with ferrochromium slag (W/FS = 10) in a closed cycle after 50 batches were found as 0.61 mg/l. Also, reduction of Cr(VI) to Cr(III) and a subsequent precipitation of Cr(III) by using ferrochrome slag (FS) in a model solution has been aimed. The effects of amount of acid, contact time, FS dosage, initial Cr(VI) concentration and temperature on the Cr(VI) reduction have been studied through the batch runs. The amount of acid has been found to be the most effective parameter affecting the Cr(VI) reduction. A 10 g/l FS dosage and 3.5 ml/l H₂SO₄ (5 M) are sufficient to reduce all Cr(VI) in the model solution containing 10 mg/l Cr(VI) and for contact time of 60 min at 25 °C. In reduced solutions, precipitation of metal ions has been studied by using extra FS. A 60 g/l dosage of fresh FS can precipitate all Cr(III) and Fe ions in the reduced solution. Thus, it has been demonstrated that the treatment of jigging water stream to be generated in a ferrochrome plant containing Cr(VI) can be accomplished by using ferrochromium slag and sulphuric acid. Also, it has been determined that solid residues of the process are environmentally stable by applying TCLP test.

Keywords: Hexavalent Chromium, Reduction, Ferrochromium Slag, Heavy Metal Removal, TCLP

? Kim, G.Y., Lee, K.B., Cho, S.H., Shim, J. and Moon, S.H. (2005), Electroenzymatic degradation of azo dye using an immobilized peroxidase enzyme. Journal of Hazardous Materials, 126 (1-3), 183-188.

Full Text: 2005\J Haz Mat126, 183.pdf

Abstract: Azo dyes are largely resistant to biodegradation and persist in conventional wastewater treatment processes. Combining enzymatic catalysis and the electrochemical generation of hydrogen peroxide (H₂O₂), an electroenzymatic process was developed, which is a potential alternative to traditional processes. In this study, an electroenzymatic method that uses an immobilized horseradish peroxidase enzyme (HRP), was investigated to degrade orange H (azo dye) within a two-compartment packed-bed flow reactor. To evaluate the electroenzymatic degradation of orange II, electrolytic experiments were carried out with 0.42 U/mL HRP at -0.5 V. It was found that removal of orange H was partly due to its adsorption to the graphite felt. The overall application of the electroenzymatic led to a greater degradation rate than the use of electrolysis alone. Also the by-products formed were found to consist primarily of an aromatic amine, sulfanilic acid, and unknown compounds. (c) 2005 Elsevier B.V. All rights reserved.

Keywords: Azo Dye, Electroenzymatic Method, Horseradish Peroxidase, Hydrogen Peroxide, Zero-Valent Iron, Hydrogen-Peroxide, Horseradish-Peroxidase, Waste-Water, Orange-Ii, Phenol, Decolorization, Reduction, Kinetics, Removal

? Kumar, K.V. and Sivanesan, S. (2005), Prediction of optimum sorption isotherm: Comparison of linear and non-linear method. Journal of Hazardous Materials, 126 (1-3), 198-201.

Full Text: 2005\J Haz Mat126, 198.pdf

Abstract: Equilibrium parameters for Bismarck brown onto rice husk were estimated by linear least square and a trial and error non-linear method using Freundlich, Langmuir and Redlich–Peterson isotherms. A comparison between linear and non-linear method of estimating the isotherm parameters was reported. The best fitting isotherm was Langmuir isotherm and Redlich–Peterson isotherm equation. The results show that non-linear method could be a better way to obtain the parameters. Redlich–Peterson isotherm is a special case of Langmuir isotherm when the Redlich–Peterson isotherm constant g was unity.

Keywords: Sorption, Rice Husk, Bismarck Brown, Equilibrium, Linear Method, Non-Linear Method

? Akmil-Başar, Ç., Önal, Y., Kılıçer, T. and Eren, D. (2005), Adsorptions of high concentration malachite green by two activated carbons having different porous structures. Journal of Hazardous Materials, 127 (1-3), 73-80.

Full Text: 2005\J Haz Mat127, 73.pdf

Abstract: The adsorption of malachite green (MG) from aqueous solution by two different adsorbents (CZn5, PETNa8) were studied. Adsorbents were prepared from pine sawdust and polyethyleneterephatalate (PET) by chemical activation with ZnCl₂ and NaOH, respectively. The adsorption was carried out in a batch system as a function of dye concentration, pH and contact time. Both adsorbents were found to be very effective in removing the dye at high concentration with adsorption percentage in the order of CZn5 > PETNa8. The pH of dye solution in the range of 6–10, was found favorable for the removal of malachite green by using the two adsorbents at high concentrations. Equilibrium times were 120 and 90 min for CZN5 and PETNa8, respectively. Kinetics of removal MG was studied using Lagergren equation and diffusion phenomena was analyzed using Weber and Morris intraparticle diffusion plots. It was also showed that the adsorption isotherm followed Langmuir model.

Keywords: Activated Carbon, Activated Carbons, Activation, Adsorbents, Adsorption, Adsorption Isotherm, Aqueous Solution, Batch, Batch System, Chemical, Chemical Activation, Concentration, Diffusion, Dye, Equilibrium, Function, Intraparticle Diffusion, Isotherm, Kinetics, Lagergren Equation, Langmuir, Langmuir Model, Malachite Green, MG, Model, NaOH, PET, pH, Removal, Sawdust, Solution, ZnCl₂

? Öztürk, N. and Kavak, D. (2005), Adsorption of boron from aqueous solutions using fly ash: Batch and column studies. Journal of Hazardous Materials, 127 (1-3), 81-88.

Full Text: 2005\J Haz Mat127, 81.pdf

Abstract: In the present paper, boron removal from aqueous solutions by adsorption was investigated. Fly ash particle size used in adsorption experiments was between 250 and 400 μm. During the experimental part of this study, the effect of parameters such as pH, agitation time, initial boron concentration, temperature, adsorbent dosage and foreign ion on boron removal were observed. In addition, adsorption kinetics, adsorption isotherm studies and column studies were made. Maximum boron removal was obtained at pH 2 and 25 °C. Thermodynamic parameters such as change in free energy (ΔG°), enthalpy (ΔH°), entropy (ΔS°) were also determined. As a result of the kinetic studies, it was observed that the adsorption data conforms to the second degree kinetics model. In the isotherm studies, Langmuir and Freundlich isotherm models were applied and it was determined that the experimental data conformed to Langmuir isotherm model. Batch adsorbent capacity (q_o) was calculated as 20.9 mg/g. The capacity value for column study was obtained by graphical integration as 46.2 mg/g. The Thomas and the Yoon–Nelson models were applied to experimental data to predict the breakthrough curves and to determine the characteristics parameters of the column useful for process design.

Keywords: Boron Removal, Adsorption, Fly Ash, Batch Study, Column Study

? Hui, K.S., Chao, C.Y.H. and Kot, S.C. (2005), Removal of mixed heavy metal ions in wastewater by zeolite 4A and residual products from recycled coal fly ash. Journal of Hazardous Materials,