Personal Research Database

Full Text: 2006\J Haz Mat137, 218.pdf

Abstract: The adsorption of phosphate onto alunite in a batch adsorber has been studied. Four kinetic models including pseudo first- and second-order equation, intraparticle diffusion equation and the Elovich equation were selected to follow the adsorption process. Kinetic parameters, rate constants, equilibrium adsorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. It was shown that the adsorption of phosphate onto alunite could be described by the pseudo second-order equation. Adsorption of phosphate onto alunite followed the Langmuir isotherm. A model has been used for the design of a two-stage batch adsorber based on pseudo second-order adsorption kinetics. The model has been optimized with respect to operating time in order to minimize total operating time to achieve a specified amount of phosphate removal using a fixed mass of adsorbent. The results of two-stage batch adsorber design studies showed that the required times for specified amounts of phosphate removal significantly decreased. It is particularly suitable for low-cost adsorbents/adsorption systems when minimising operating time is a major operational and design criterion, such as, for highly congested industrial sites in which significant volume of effluent need to be treated in the minimum amount of time.

Keywords: Adsorbent, Adsorption, Adsorption Capacities, Adsorption Kinetics, Alunite, Batch, Batch Adsorber Design, Correlation, Design, Diffusion, Elovich, Elovich Equation, Equilibrium, First, Intraparticle Diffusion, Isotherm, Kinetic, Kinetic Model, Kinetic Models, Kinetic Parameters, Kinetics, Langmuir, Langmuir Isotherm, Minimum, Model, Models, Operating Time Optimization, Optimization, Phosphate, Phosphate Removal, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Rate Constants, Removal, Second Order, Second-Order, Second-Order Equation, Systems, Two-Stage Batch Adsorber, Volume

? Inbaraj, B.S., Chiu, C.P., Ho, G.H., Yang, J. and Chen, B.H. (2006), Removal of cationic dyes from aqueous solution using an anionic poly-γ-glutamic acid-based adsorbent. Journal of Hazardous Materials, 137 (1), 226-234.

Full Text: 2006\J Haz Mat137, 226.pdf

Abstract: Natural polymeric materials are gaining interest for application as adsorbents in wastewater treatment due to their biodegradable and non-toxic nature. In this study, a biopolymer, poly-γ-glutamic acid (γ-PGA) derived from bacterial sources (Bacillus species) was evaluated for its efficiency in removing basic dyes from aqueous solution. Sorption studies under batch mode were conducted using C.I. Basic blue 9 (BB9) and C.I. Basic green 4 (BG4) as test dyes. Equilibrium process conformed well with the Redlich-Peterson isotherm equation and the monolayer sorption capacity obtained from the Langmuir model was 352.76 and 293.32 mg/g for BB9 and BG4 dyes, respectively. The kinetic studies of dye sorption on γ-PGA gave high coefficients of determination (>0.98) for a pseudo second-order equation. An ion-exchange model, which assumes adsorption as a chemical phenomenon, was also found to fit the kinetic data precisely. The dye sorption largely depended on the initial pH of the solution with maximum uptake occurring at pH above 5. About 98% of the dye adsorbed on γ-PGA could be recovered at pH 1, which facilitates the reuse of spent γ-PGA.

Keywords: Adsorbent, Adsorbents, Adsorption, Application, Aqueous Solution, Bacillus, Basic Blue 9, Basic Dyes, Basic Green 4, Batch, Batch Mode, Capacity, Cationic Dyes, Chemical, Chemisorption, Data, Dye, Dyes, Efficiency, Equilibrium, Ion Exchange, Ion-Exchange, Ionexchange, Isotherm, Isotherms, Kinetic, Kinetic Studies, Kinetics, Langmuir, Langmuir Model, Mode, Model, Monolayer, pH, Poly-[Gamma]-Glutamic Acid, Polymeric, Pseudo Second Order, Pseudo Second-Order, Pseudo-Second-Order, Redlich-Peterson, Removal, Reuse, Second Order, Second-Order, Second-Order Equation, Solution, Sorption, Sorption Capacity, Sources, Species, Treatment, Uptake, Wastewater, Wastewater Treatment

? Lodeiro, P., Herrero, R. and Sastre de Vicente, M.E. (2006), The use of protonated Sargassum muticum as biosorbent for cadmium removal in a fixed-bed column. Journal of Hazardous Materials, 137 (1), 244-253.

Full Text: 2006\J Haz Mat137, 244.pdf

Abstract: The protonated Sargassum muticum seaweed was studied as a possible biosorbent for cadmium removal in a fixed-bed column. The experiments were conducted in order to determine the effect of flow rate (0.42, 5, 10 and 20 mL min⁻¹) and bed height (0.6 and 15.3 cm for the lowest flow rate or 7.4, 13 and 16.6 cm for the others) on breakthrough curves behaviour. The determined breakthrough and exhaustion times increased with the diminution in flow rate and with the increase in bed height. The maximum cadmium uptake capacity, obtained from the area below adsorbed cadmium concentration versus time curves, was found to remain practically constant with bed depth and flow rate. The bed depth service time (BDST) model was applied to analyse experimental data, determining the characteristic process parameters. The optimal lowest sorbent usage rate was evaluated at 2 min contact time and the minimum bed height values necessaries to prevent the effluent solution concentration from exceeding 0.02 mg L⁻¹ at zero time were 5.3, 6.9 and 7.5 cm for flow rates of 5, 10 and 20 mL min⁻¹, respectively. Several empirical models proposed in the literature (Bohart–Adams, Yan, Belter and Chu models) were investigated in order to obtain the best fit of column data, describing in a simple manner the breakthrough curves. A correlation between model parameters and the variables implied in the process was attempted.

Keywords: Sargassum Muticum, Fixed-Bed Column, Cadmium, Biosorption, Modelling

? da Fonseca, M.G., de Oliveira, M.M. and Arakaki, L.N.H. (2006), Removal of cadmium, zinc, manganese and chromium cations from aqueous solution by a clay mineral. Journal of Hazardous Materials, 137 (1), 288-292.

Full Text: 2006\J Haz Mat137, 288.pdf

Abstract: Vermiculite, a 2:1 clay mineral, was applied as adsorbent for removal of cadmium, zinc, manganese, and chromium from aqueous solutions. Parameters such as time of reaction, effect of pH and cation concentration were investigated. All isotherms were L type of the Gilles classification, except zinc (type S). The adsorbent showed good sorption potential for these cations. The experimental data was analyzed by Langmuir isotherm model showing reasonable adjustment. The quantity of adsorbed cations was 0.50, 0.52, 0.60, and 0.48 mmol g⁻¹ of Cd²⁺, Mn²⁺, Zn²⁺, and Cr³⁺, respectively.

Keywords: Adsorption, Clay Mineral, Cadmium, Chromium, Manganese, Zinc

? Ekmekyapar, F., Aslan, A., Bayhan, Y.K. and Cakici, A. (2006), Biosorption of copper(II) by nonliving lichen biomass of Cladonia rangiformis hoffm. Journal of Hazardous Materials, 137 (1), 293-298.

Full Text: 2006\J Haz Mat137, 293.pdf

Abstract: Biosorption of heavy metals can be an effective process for the removal of heavy metal ions from aqueous solutions. In this study, the adsorption properties of lichen biomass of Cladonia rangiformis hoffm. for copper(II) were investigated by using batch adsorption techniques. The effects of initial metal ion concentration, initial pH, biosorbent concentration, stirring speed and contact time on biosorption efficiency were studied. In the experiments the optimum pH value was found out 5.0 which was the native pH value of solution. The experimental adsorption data were fitted to the Langmuir adsorption model. The highest metal uptake was calculated from Langmuir isotherm and found to be 7.6923 mg Cu(II)/g inactivated lichen at 15 °C. The results indicated that the biomass of C. rangiformis is a suitable biosorbent for removing Cu(II) from aqueous solutions.

Keywords: Biosorption, Copper, Heavy Metal, Wastewater Treatment, Lichen, Cladonia Rangiformis

? Mishra, T. and Tiwari, S.K. (2006), Studies on sorption properties of zeolite derived from Indian fly ash. Journal of Hazardous Materials, 137 (1), 299-303.

Full Text: 2006\J Haz Mat137, 299.pdf

Abstract: Indian fly ash has been completely converted to crystalline porous 13X zeolite by NaOH fusion at 600 °C followed by hydrothermal treatment at 105°C for 20 h. Obtained materials were characterized by XRD, SEM and surface area measurement. Prepared material was used for the sorption study of different metal ions (Cu²⁺, Co²⁺ and Ni²⁺) at different pH, temperature. Thermodynamic data (ΔS, ΔH and ΔG) corresponding to different metal ion uptake were evaluated from Langmuir equation. In all the experiment sorption capacity of prepared zeolite was found to be quite high than that of fly ash at acidic pH. However, the uptake selectivity order for both the materials is Cu²⁺ > Co²⁺ > Ni²⁺.

Keywords: Fly Ash, Zeolite 13X, Sorption, Metal Ions, Langmuir Equation

? Osmanlioglu, A.E. (2006), Treatment of radioactive liquid waste by sorption on natural zeolite in Turkey. Journal of Hazardous Materials, 137 (1), 332-335.

Full Text: 2006\J Haz Mat137, 332.pdf

Abstract: Liquid radioactive waste has been generated from the use of radioactive materials in industrial applications, research and medicine in Turkey. Natural zeolites (clinoptilolite) have been studied for the removal of several key radionuclides (¹³⁷Cs, ⁶⁰Co, ⁹⁰Sr and ^110mAg) from liquid radioactive waste. The aim of the present study is to investigate effectiveness of zeolite treatment on decontamination factor (DF) in a combined process (chemical precipitation and adsorption) at the laboratory tests and scale up to the waste treatment plant. In this study, sorption and precipitation techniques were adapted to decontamination of liquid low level waste (LLW). Effective decontamination was achieved when sorbents are used during the chemical precipitation. Natural zeolite samples were taken from different zeolite formations in Turkey. Comparison of the ion-exchange properties of zeolite minerals from different formations shows that Gordes clinoptilolite was the most suitable natural sorbent for radionuclides under dynamic treatment conditions and as an additive for chemical precipitation process. Clinoptilolite were shown to have a high selectivity for ¹³⁷Cs and ^110mAg as sorbent. In the absence of potassium ions, native clinoptilolite removed ⁶⁰Co and ⁹⁰Sr very effectively from the liquid waste. In the end of this liquid waste treatment, decontamination factor was provided as 430 by using 0.5 mm clinoptilolite at 30 °C.

Keywords: Radioactive Waste, Sorption, Zeolite, Clinoptilolite

? Wu, C.H., Chang, H.W. and Chern, J.M. (2006), Basic dye decomposition kinetics in a photocatalytic slurry reactor. Journal of Hazardous Materials, 137 (1), 336-343.

Full Text: 2006\J Haz Mat137, 336.pdf

Abstract: Wastewater effluent from textile plants using various dyes is one of the major water pollutants to the environment. Traditional chemical, physical and biological processes for treating textile dye wastewaters have disadvantages such as high cost, energy waste and generating secondary pollution during the treatment process. The photocatalytic process using TiO₂ semiconductor particles under UV light illumination has been shown to be potentially advantageous and applicable in the treatment of wastewater pollutants. In this study, the dye decomposition kinetics by nano-size TiO₂ suspension at natural solution pH was experimentally studied by varying the agitation speed (50-200 rpm), TiO₂ suspension concentration (0.25-1.71 g/L), initial dye concentration (10-50 ppm), temperature (10-50 0C), and UV power intensity (0-96 W). The experimental results show the agitation speed, varying from 50 to 200 rpm, has a slight influence on the dye decomposition rate and the pH history; the dye decomposition rate increases with the TiO₂ suspension concentration up to 0.98 g/L, then decrease with increasing TiO₂ suspension concentration; the initial dye decomposition rate increases with the initial dye concentration up to a certain value depending upon the temperature, then decreases with increasing initial dye concentration; the dye decomposition rate increases with the UV power intensity up to 64 W to reach a plateau. Kinetic models have been developed to fit the experimental kinetic data well.

Keywords: Photocatalysis, Slurry Reactor, Dye Decomposition, Kinetics, Kinetic Model

? Hoda, N., Bayram, E. and Ayranci, E. (2006), Kinetic and equilibrium studies on the removal of acid dyes from aqueous solutions by adsorption onto activated carbon cloth. Journal of Hazardous Materials, 137 (1), 344-351.

Full Text: 2006\J Haz Mat137, 344.pdf

Abstract: Removal of acid dyes Acid Blue 45, Acid Blue 92, Acid Blue 120 and Acid Blue 129 from aqueous solutions by adsorption onto high area activated carbon cloth (ACC) was investigated. Kinetics of adsorption was followed by in situ UV-spectroscopy and the data were treated according to pseudo-first-order, pseudo-second-order and intraparticle diffusion models. It was found that the adsorption process of these dyes onto ACC follows the pseudo-second-order model. Adsorption isotherms were derived at 25 °C on the basis of batch analysis. Isotherm data were treated according to Langmuir and Freundlich models. The fits of experimental data to these equations were examined.

Keywords: Acid Dyes, Activated Carbon, Activated Carbon Cloth, Adsorption, Adsorption Isotherm, Adsorption Isotherms, Adsorption Kinetics, Analysis, Aqueous Solutions, Batch, Carbon, Data, Diffusion, Dyes, Equilibrium, Equilibrium Studies, Experimental, Freundlich, In Situ, In Situ UV Spectroscopy, Intraparticle Diffusion, Isotherm, Isotherms, Kinetic, Kinetics, Langmuir, Model, Models, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Model, Removal, Solutions, Water Treatment

? Kadirova, Z., Kameshima, Y., Nakajima, A. and Okada, K. (2006), Preparation and sorption properties of porous materials from refuse paper and plastic fuel (RPF). Journal of Hazardous Materials, 137 (1), 352-358.

Full Text: 2006\J Haz Mat137, 352.pdf

Abstract: Porous materials consisting of activated carbon and amorphous CaO–Al₂O₃–SiO₂ (CAS) compound were prepared from refuse paper and plastic fuel (RPF), (a mixture of old paper and plastic) by carbonizing and/or activating treatments. Samples formed by chemical activation using K₂CO₃ showed a high specific surface area (S_BET) of 1330 m²/g but a lower ash content due to being washed after activation. By contrast, samples prepared by physical activation using steam showed rather lower S_BET (510 m²/g) due to higher ash contents. The physically activated samples showed much higher uptake properties for Ni²⁺ (a representative heavy metal) and phosphate ions (a representative of a harmful oxyanion) than the chemically activated samples because of the higher content of amorphous CAS in the former samples. By contrast, the chemically activated samples showed higher uptake for methylene blue (MB, a representative organic material) than the physically activated samples because of the higher activated carbon content of higher surface area. Although differences in the sorption properties for Ni²⁺, phosphate ion and MB were found between the physically and chemically activated samples, both samples show excellent multiple sorption properties for cation–anion combinations and inorganic–organic sorbents.

Keywords: RPF, Activation, Porous Material, Multiple Sorption, Activated Carbon, CaO–Al₂O₃–SiO₂

? Yu, L.L. and Zhong, Q. (2006), Preparation of adsorbents made from sewage sludges for adsorption of organic materials from wastewater. Journal of Hazardous Materials, 137 (1), 359-366.

Full Text: 2006\J Haz Mat137, 359.pdf

Abstract: The carbon-bearing adsorbents were prepared from biochemical and surplus sludges by physical activation and chemical activation. The results indicated that the adsorbents made by way of chemical activation were better, with the optimum activator being complex of ZnCl₂ and H₂SO₄. Moreover, the optimum preparation conditions were concentration of two activators 5mol/L (the ratio of ZnCl₂ and H₂SO₄ was 2:1), at the activating temperature of 550 C, in the proportion of solid to liquid 1:2.5, in a period of 2 h. Contrasting the active carbon, the carbon-bearing adsorbents were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS), scanning electron microscope (SEM), BET and BJH. By application of those adsorbents to treatment of wastewater of urban, the treatment effect of the carbon-bearing adsorbents were better than the active carbon. On the condition that the concentration was 0.5%, the COD, P and chromaticity color removal rates of carbon-bearing adsorbent made from the biochemical sludge of sewage were higher, which were 79.1, 98.3 and 87.5% respectively, and the dynamic adsorption capacity was 47.8mg/g.

Keywords: Sewage Sludge, Carbon-Bearing Adsorbents, Characterization, Wastewater Treatment

? Kumar, Y.P., King, P. and Prasad, V.S.R.K. (2006), Removal of copper from aqueous solution using Ulva fasciata sp.: A marine green algae. Journal of Hazardous Materials, 137 (1), 367-373.

Full Text: 2006\J Haz Mat137, 367.pdf

Abstract: Batch adsorption experiments were carried out for the removal of copper from its aqueous solution using Ulva fasciata sp. a marine green algae as adsorbent. The adsorption of Cu(II) by Ulva fasciata sp. was investigated as a function of pH, contact time, initial Cu(II) and adsorbent concentrations and adsorbent size. About 0.1 g of Ulva fasciata sp. was found to be enough to remove 95% of 20 mg/L copper from 30 mL aqueous solution in 20 minutes. The optimum pH value was found to be 5. The dynamic data fitted to the pseudo-second order kinetic model. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were determined. The experimental adsorption data were fitted to the Langmuir adsorption model. The maximum adsorption capacity was 26.88 mg/g. The applicability of Lagergren kinetic model was also investigated.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Algae, Aqueous Solution, Batch Adsorption, Capacity, Copper, Cu(II), Data, Dynamic, Equilibrium, Equilibrium Studies, Experimental, Experiments, Freundlich, Function, Green Algae, Isotherm, Isotherms, Kinetic, Kinetic Model, Kinetic Studies, Langmuir, Marine Algae, Model, Models, pH, pH Value, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second-Order, Removal, Size, Solution, Ulva Fasciata sp., Value

? Li, Y.Z., Liu, C.J., Luan, Z.K., Peng, X.J., Zhu, C.L., Chen, Z.Y., Zhang, Z.G., Fan, J.H. and Jia, Z.P. (2006), Phosphate removal from aqueous solutions using raw and activated red mud and fly ash. Journal of Hazardous Materials, 137 (1), 374-383.

Full Text: 2006\J Haz Mat137, 374.pdf

Abstract: The effect of acidification and heat treatment of raw red mud (RM) and fly ash (FA) on the sorption of phosphate was studied in parallel experiments. The result shows that a higher efficiency of phosphate removal was acquired by the activated samples than by the raw ones. The sample prepared by using the RM stirred with 0.25 M HCl for 2 h (RM0.25), as well as another sample prepared by heating the RM at 700 °C for 2 h (RM700), registered the maximum removal of phosphate (99% removal of phosphate). This occurred when they were used in the phosphate sorption studies conducted at pH 7.0 and 25 °C with the initial PO₄^3– concentration of 155 mg P/l. The FA samples treated in the same way described above can achieve 7.0, 8.2 mg P/l phosphate removal for FA0.25 and FA700 respectively, corresponding to 45.2% and 52.9% removal. The activated materials performed higher phosphate removal over broader pH range compared with the raw ones. The influences of various factors, such as initial pH and initial phosphate concentration on the sorption capacity were also studied in batch equilibration technique. Solution pH significantly influenced the sorption. Each sample achieved the maximal removal of phosphate at pH 7. The amount of phosphate removal increased with the solute concentration. The Freundlich and Langmuir models were used to simulate the sorption equilibrium. The results indicate that the Langmuir model has a better correlation with the experimental data than the Freundlich model.

Keywords: Red Mud, Fly Ash, Phosphate, Sorption, Wastewater

? Han, R.P., Zou, W.H., Zhang, Z.P., Shi, J. and Yang, J.J. (2006), Removal of copper(II) and lead(II) from aqueous solution by manganese oxide coated sand. I. Characterization and kinetic study. Journal of Hazardous Materials, 137 (1), 384-395.

Full Text: 2006\J Haz Mat137, 384.pdf

Abstract: The adsorption equilibrium of MOCS and the Cu(II) and Pb(II) ions removal capacity by MOCS in single-(non competitive) and binary-(competitive) component sorption systems from aqueous solutions were investigated. The equilibrium data were analyzed using the Langmuir, Freundlich, Temkin and Redlich-Peterson isotherms. The characteristic parameters for each isotherm were determined. The Langmuir and Redlich-Peterson isotherms provided the best correlation for both Cu(II) and Pb(II) onto MOCS. From the Langmuir isotherms, maximum adsorption capacities of the MOCS towards Cu(II) and Pb(II) are determined at different temperature. The maximum adsorption capacity of Cu(II) and Pb(II) per gram MOCS in single component sorption systems were from 5.91 and 7.71 µmol to 7.56 and 9.22 µmol for the temperature range of 288 to 318 K, respectively. The order of affinity based on a weight uptake by MOCS was as follows: Pb(II) > Cu(II). The same behavior was observed during competitive adsorption that is in the case of adsorption from their binary solution. The thermodynamic parameters (∆G0, ∆H0, and ∆S0) for Cu(II) and Pb(II) sorption on the MOCS were also determined from the temperature dependence. This competitive adsorption showed that the uptake of each metal was considerably reduced with an increasing concentration of the other, the adsorption of Cu(II) being more strongly influenced by Pb(II) than vice versa due to the higher affinity of MOCS for the latter.

Keywords: Activation, Activation Energy, Adsorbent, Adsorbent Dose, Adsorption, Adsorption Behavior, Adsorption Kinetic, Adsorption Mechanism, Analyses, Analysis, Aqueous Solution, Behavior, Bet, Characterization, Chemical, Chemisorption, Choice, Chromium, Copper(II), Cu(II), Data, Diffusion, Diffusion Model, Efficiency, Elovich Equation, Energy, Experiments, Filter Media, Function, Infiltration, Intraparticle Diffusion, Intraparticle Diffusion Model, Ionic Strength, Iron, Kinetic, Kinetic Model, Kinetic Models, Kinetic Study, Lead(II), Manganese, Manganese Oxide, Manganese Oxide Coated, Manganese Oxide Coated Sand (MOCS), Mechanism, Media, Metal, Metal Adsorption, Metals, Model, Models, Oxide, Pb(II), Pb²⁺, pH, pH-Dependent, Physical, Preparation, Pseudo First Order, Pseudo Second Order, Pseudo-First-Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Pseudo-Second-Order Model, Removal, Removal Efficiency, Rights, Sand, SEM, Solution, Sorption, Spectroscopy, Strength, Surface, Temperature, Uptake, Value, Water, X-Ray, X-Ray Diffraction, XPS, XRD, Zinc

? Baghel, A., Singh, B., Pandey, P., Dhaked, R.K., Gupta, A.K., Ganeshan, K. and Sekhar, K (2006), Adsorptive removal of water poisons from contaminated water by adsorbents. Journal of Hazardous Materials,