Personal Research Database

Full Text: 2006\J Haz Mat135, 328.pdf

Abstract: The removal efficiency of waste tea from nickel containing aqueous solutions was investigated. All experiments were conducted fixed-bed columns. Experiments were carried out as a function of liquid flow rate (5–20 mL/min), initial Ni(II) concentration (50–200 mg/L), bed height (10–30 cm), pH of feed solution (2.0–5.0) and particle size (0.15–0.25 to 1.0–3.0 mm) of adsorbent. The total adsorbed quantities, equilibrium uptakes and total removal percents of Ni(II) related to the effluent volumes were determined by evaluating the breakthrough curves obtained at different flow rates, different inlet Ni(II) concentrations, different pH value, different bed height and different particle size for waste tea. The longest breakthrough time and maximum of Ni(II) adsorption is obtained at pH 4.0. Decrease in the particle size from 1.0–3.0 to 0.15–0.25 mm resulted in significant increase in the treated volume, breakthrough time and bed capacity. The results show that the column performed well at lowest flow rate. Also, column bed capacity and exhaustion time increased with increasing bed height. When the initial Ni(II) concentration is increased from 50 to 200 mg/L, the corresponding adsorption bed capacity appears to increase from 7.31 to 11.17 mg/g. The bed depth service time (BDST) model and the Thomas model were used to analyze the experimental data and the model parameters were evaluated. Good agreement of the experimental breakthrough curves with the model predictions was observed.

Keywords: Fixed-Bed Adsorption, Waste Tea, Nickel, BDST Model, Thomas Model

? Özer, A., Akkaya, G. and Turabik, M. (2006), Biosorption of Acid Blue 290 (AB 290) and Acid Blue 324 (AB 324) dyes on Spirogyra rhizopus. Journal of Hazardous Materials, 135 (1-3), 355-364.

Full Text: 2006\J Haz Mat135, 355.pdf

Abstract: In this study, the biosorption of Acid Blue 290 and Acid Blue 324 on Spirogyra rhizopus, a green algae growing on fresh water, was studied with respect to initial pH, temperature, initial dye concentration and biosorbent concentration. The optimum initial pH and temperature values for AB 290 and AB 324 biosorption were found to be 2.0, 30 °C and 3.0, 25 °C, respectively. It was observed that the adsorbed AB 290 and AB 324 amounts increased with increasing the initial dye concentration up to 1500 and 750 mg/L, respectively. The Langmuir, Freundlich, Redlich-Peterson and Koble-Corrigan isotherm models were applied to the experimental equilibrium data and the isotherm constants were determined by using Polymath 4.1 software. The monolayer coverage capacities of S. rhizopus for AB 290 and AB 324 dyes were found as 1356.6 mg/g and 367.0 mg/g, respectively. The intraparticle diffusion model and the pseudo-second order kinetic model were applied to the experimental data in order to describe the removal mechanism of these acidic dyes by S. rhizopus. The pseudo-second order kinetic model described very well the biosorption kinetics of AB 290 and AB 324 dyes. Thermodynamic studies showed that the biosorption of AB 290 and AB 324 on S. rhizopus was exothermic in nature.

Keywords: Acid Blue 290, Acid Blue 324, Algae, Biosorbent, Biosorption, Biosorption Kinetics, Concentration, Coverage, Data, Diffusion, Diffusion Model, Dye, Dyes, Equilibrium, Exothermic, Experimental, Freundlich, Green Algae, Intraparticle Diffusion, Intraparticle Diffusion Model, Isotherm, Kinetic, Kinetic Model, Kinetics, Langmuir, Mechanism, Model, Models, Monolayer, pH, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second-Order, Redlich-Peterson, Removal, Software, Spirogyra Rhizopus, Temperature, Thermodynamic, Water

? Liu, Y.W., Chang, X.J., Guo, Y. and Meng, S.M. (2006), Biosorption and preconcentration of lead and cadmium on waste Chinese herb Pang Da Hai. Journal of Hazardous Materials, 135 (1-3), 389-394.

Full Text: 2006\J Haz Mat135, 389.pdf

Abstract: The biosorption behavior of the solid waste Chinese herb Pang Da Hai (seeds of Sterculia lychnophera Hance) was studied as a sorbent for trace lead and cadmium. The solid waste Chinese herb Pang Da Hai has good sorption and desorption properties for Pb and Cd. The sorbed waste Chinese herb Pang Da Hai was both easily eluted with 0.1 mol l⁻¹ HNO₃ and easily digested with concentrated HNO₃.The extent of adsorption depends on pH, metal concentration, substrate concentration and the presence of interfering ions. The adsorption capacities were found to be 27.1 and 17.5 mg g⁻¹ for Pb and Cd. The relative standard deviation of the metal uptake experiment was found to be less than 10% for Pb(II) and Cd(II) using 100 μg l⁻¹ of metal ions and 20 mg substrate. Based on above, an ecofriend and low cost method for Cd and Pb preconcentration and determination with flame atomic absorption spectrophotometry was developed. The method was validated by the analysis of a standard reference material (GBW 08301). The results agree with those quoted by manufactures. It was used for 90-fold preconcentration of Cd and Pb from tap water and river water samples followed by flame atomic absorption spectroscopic (FAAS) determination with satisfactory results.

Keywords: Biosorption, Preconcentration, Pang Da Hai, Lead, Cadmium, River Water

? Valix, M., Cheung, W.H. and Zhang, K. (2006), Role of heteroatoms in activated carbon for removal of hexavalent chromium from wastewaters. Journal of Hazardous Materials, 135 (1-3), 395-405.

Full Text: 2006\J Haz Mat135, 395.pdf

Abstract: Heteroatoms are elements including sulfur, nitrogen, oxygen and hydrogen which are found on the surface of activated carbons. This study investigated the surface modification arising from heteroatoms bonding to carbon aromatic rings within the activated carbon and their corresponding influence on the chromium adsorption process. Activated carbons were prepared from bagasse by physical. Chromium removal capacities of these activated carbons by adsorption and reduction were determined. Models which related the chromium adsorption and reduction capacities of activated carbons to carbon acidity and heteroatom site concentrations were established using multi-variable linear regression method. It was found the individual heteroatoms contributed separately to the basicity of the carbon which in turn determined the mechanism by which chromium was removed from solution. The surface areas of the carbons were also observed to influence the adsorption and reduction of chromium. These understandings provide the fundamental method of optimising chromium removal through suitable control of carbon surface chemistry and textural properties.

Keywords: Chromium Removal, Activated Carbon, Adsorption, Carbon Acidity, Heteroatoms

? Namasivayam, C. and Sangeetha, D. (2006), Recycling of agricultural solid waste, coir pith: Removal of anions, heavy metals, organics and dyes from water by adsorption onto ZnCl₂ activated coir pith carbon. Journal of Hazardous Materials, 135 (1-3), 449-452.

Full Text: 2006\J Haz Mat135, 449.pdf

Abstract: The abundant lignocellulosic agricultural waste, coir pith is used to develop ZnCl₂ activated carbon and applied to the removal of toxic anions, heavy metals, organic compounds and dyes from water. Sorption of inorganic anions such as nitrate, thiocyanate, selenite, chromium(VI), vanadium(V), sulfate, molybdate, phosphate and heavy metals such as nickel(II) and mercury(II) has been studied. Removal of organics such as resorcinol, 4-nitrophenol, catechol, bisphenol A, 2-aminophenol, quinol, O-cresol, phenol and 2-chlorophenol has also been investigated. Uptake of acidic dyes such as acid brilliant blue, acid violet, basic dyes such as methylene blue, rhodamine B, direct dyes such as direct red 12B, congo red and reactive dyes such as procion red, procion orange were also examined to assess the possible use of the adsorbent for the treatment of contaminated ground water. Favorable conditions for maximum removal of all adsorbates at the adsorbate concentration of 20 mg/L were used. Results show that ZnCl₂ activated coir pith carbon is effective for the removal of toxic pollutants from water.

Keywords: Adsorption, ZnCl₂ Activated Coir Pith Carbon, Inorganic Anions, Heavy Metals, Organics, Dyes

? Przepiórski, J. (2006), Enhanced adsorption of phenol from water by ammonia-treated activated carbon. Journal of Hazardous Materials, 135 (1-3), 4539-456.

Full Text: 2006\J Haz Mat135, 453.pdf

Abstract: Influence of treatment with gaseous ammonia on adsorption properties toward phenol from water was examined for commercially available CWZ-series activated carbons. The treatment was carried out at elevated temperatures ranged from 400 °C to 800 °C for 2 h. In comparison with untreated material, activated carbons modified with ammonia demonstrated enhanced adsorption of phenol from water. The enhancement depended on the treatment temperature and porous structure of studied activated carbons. Fourier transform infrared spectroscopy (FTIR) measurements confirmed presence of N-containing species in ammonia-treated activated carbons. Optimal conditions of the modification with ammonia were determined. Influence of the N-containing groups and porous structure of activated carbons on adsorption of phenol is discussed.

Keywords: Activated Carbon, Surface Treatment, Ammonia, Adsorption, Phenol

? Kumar, K.V. (2006), Comparative analysis of linear and non-linear method of estimating the sorption isotherm parameters for malachite green onto activated carbon. Journal of Hazardous Materials, 136 (2), 197-202.

Full Text: 2006\J Haz Mat136, 197.pdf

Abstract: The experimental equilibrium data of malachite green onto activated carbon were fitted to the Freundlich, Langmuir and Redlich–Peterson isotherms by linear and non-linear method. A comparison between linear and non-linear of estimating the isotherm parameters was discussed. The four different linearized form of Langmuir isotherm were also discussed. The results confirmed that the non-linear method as a better way to obtain isotherm parameters. The best fitting isotherm was Langmuir and Redlich–Peterson isotherm. Redlich–Peterson is a special case of Langmuir when the Redlich–Peterson isotherm constant g was unity.

Keywords: Activated Carbon, Adsorption, Analysis, Carbon, Comparison, Data, Equilibrium, Experimental, Freundlich, Isotherm, Isotherm Parameters, Isotherms, Langmuir, Langmuir Isotherm, Linear Method, Malachite Green, Non-Linear Method, Redlich-Peterson, Sorption, Sorption Isotherm

? Ray, A.B., Selvakumar, A. and Tafuri, A.N. (2006), Removal of selected pollutants from aqueous media by hardwood mulch. Journal of Hazardous Materials, 136 (2), 213-218.

Full Text: 2006\J Haz Mat136, 213.pdf

Abstract: Generic hardwood mulch, usually used for landscaping, was utilized to remove several selected pollutants (heavy metals and toxic organic compounds) typically found in urban stormwater (SW) runoff. The hardwood mulch sorbed all the selected pollutants from a spiked stormwater mixture, including copper (Cu²⁺), cadmium (Cd²⁺), chromium (Cr⁶⁺), lead (Pb²⁺), zinc (Zn²⁺), 1,3 dichlorobenzene (DCB), naphthalene (NP), fluoranthene (FA), butylbenzylphthalate (BBP), and benzo(a)pyrene (B[a]P). Masses of the pollutants sorbed depended upon the pollutant species, contact time, and initial concentration which varied from 20 to 100%. Sorption rates of the metals, in general, were more rapid than those of the organics; however, mass removals (percent) of the organics, in contrast to those of the metals, were independent of their initial concentrations. With the exception of Cd, percentages (weight) of the metals removed declined as their initial concentrations decreased. None of the sorbed pollutants desorbed to any significant extent upon extended washing with water. It is quite feasible that in the presence of mulch the uptake of these pollutants by the aquatic species will be reduced significantly.

Keywords: Hardwood Mulch, Heavy Metals, Toxic Organic Compounds, Sorption, Desorption, Stormwater Runoff

? Šćiban, M., Klašnja, M. and Škrbić, B. (2006), Modified softwood sawdust as adsorbent of heavy metal ions from water. Journal of Hazardous Materials, 136 (2), 266-271.

Full Text: 2006\J Haz Mat136, 266.pdf

Abstract: The sawdust of deciduous softwood–poplar, and coniferous softwood–fir, have been found to possess some adsorption capacities for heavy metal ions. Their adsorption capacities can be increased by previous treatment with a sodium hydroxide solution. Adsorption capacities of alkali modified adsorbents were higher than for unmodified ones from 2.5 to 5 times for copper ions, and about 15 times for zinc ions. Also, for modification can be used solution of sodium carbonate, but that alkaline solution is less efficient than sodium hydroxide solution. The 1% sodium hydroxide solution is suggested for modification of softwood sawdust. It was established that the ion exchange is not only adsorption mechanism, than microprecipitation of metal-hydroxide in the pore liquid was happened, too. At the same time, the leaching of organic matters from modified softwood sawdust were less than from unmodified ones for about 7% for poplar and 23% for fir.

Keywords: Adsorption, Copper, Zinc, Softwood Sawdust, Alkaline Treatment

? Ünlü, N. and Ersoz, M. (2006), Adsorption characteristics of heavy metal ions onto a low cost biopolymeric sorbent from aqueous solutions. Journal of Hazardous Materials, 136 (2), 272-280.

Full Text: 2006\J Haz Mat136, 272.pdf

Abstract: In this study, the adsorption conditions of Cu(II), Pb(II) and Cd(II) metal ions onto sporopollenin have been studied. The different variables effecting the sorption capacity such as pH of the solution, adsorption time, initial metal ion concentration and temperature have been investigated. Adsorption isotherms correlated well with the Freundlich type adsorption isotherm and adsorption capacities were found to be 0.0195, 0.0411 and 0.0146 mmol g⁻¹ for Cu(II), Pb(II) and Cd(II) metal ions, respectively. Experimental data were also evaluated to find out kinetic characteristics of the adsorption process. Adsorption processes for three target heavy metal ions were found to follow pseudo-second order type adsorption kinetics. Intraparticle diffusion was found to take part in adsorption processes but it could not be accepted as the primary rate-determining step. The mean free energies of adsorption (E) were found to be between 8 and 16 kJ mol⁻¹ for the metal ions studied and therefore adsorption mechanism for the adsorbent was explained as an ion-exchange process. But it was observed that chelating effect is also playing an important role in the adsorption of metal ions onto sporopollenin.

Thermodynamic parameters, ΔH°, ΔS° and ΔG° were also calculated from graphical interpretation of the experimental data. Standard heats of adsorption (ΔH°) were found to be endothermic and ΔS° values were calculated to be positive for the adsorption of Cu(II), Pb(II) and Cd(II) ions onto the adsorbent. Negative ΔG° values indicated that adsorption process for these three metal ions onto sporopollenin is spontaneous.

Keywords: Adsorbent, Adsorption, Adsorption Capacities, Adsorption Isotherm, Adsorption Isotherms, Adsorption Kinetics, Adsorption Mechanism, Aqueous Solutions, Cadmium, Capacity, Cd(II), Cd(II) Ions, Characteristics, Concentration, Copper, Cost, Cu(II), D-R Isotherm, Data, Diffusion, Endothermic, Experimental, Freundlich, Freundlich Isotherm, Heavy Metal, Heavy Metal Ions, Intraparticle Diffusion, Ion Exchange, Ion-Exchange, Ionexchange, Isotherm, Isotherms, Kinetic, Kinetics, Langmuir Isotherm, Lead, Mechanism, Metal, Metal Ions, Pb(II), pH, Primary, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second-Order, Role, Solution, Solutions, Sorbent, Sorption, Sorption Capacity, Sporopollenin, Temperature, Thermodynamic, Thermodynamic Parameters, Thermodynamics

? Lakshmipathiraj, P., Narasimhan, B.R.V., Prabhakar, S. and Raju, G.B. (2006), Adsorption of arsenate on synthetic goethite from aqueous solutions. Journal of Hazardous Materials, 136 (2), 281-287.

Full Text: 2006\J Haz Mat136, 281.pdf

Abstract: Goethite was synthesized from the oxidation of ferrous carbonate precipitated from the double decomposition of ferrous sulfate doped with sodium lauryl sulfate (an anionic surfactant) and sodium carbonate in aqueous medium. The specific surface area and pore volume of goethite were 103 m² g⁻¹ and 0.50 cm³ g⁻¹. Batch experiments were conducted to study the efficacy of removal of arsenic(V) using this goethite as adsorbent for solutions with 5–25 mg l⁻¹ of arsenic(V). The nature of adsorption was studied by zeta-potential measurements. The adsorption process followed by Langmuir isotherm and diffusion coefficient of arsenate was determined to be 3.84×10¹¹ cm² s⁻¹. The optimum pH of adsorption was found to be 5.0. The kinetics of adsorption was evaluated with 10 mg l⁻¹ and 20 mg l⁻¹ of As(V) solutions and activation energy of adsorption, as calculated from isoconversional method was in the range of 20 kJ mol⁻¹ to 43 kJ mol⁻¹. This suggests that the adsorption process is by diffusion at the initial phase and later through chemical control. FT-IR characterization of arsenic treated goethite indicated the presence of both As－O－Fe and As－O groups and supported the concept of surface complex formation.

Keywords: Goethite, Arsenate, Kinetics, Isoconversional Method, Langmuir Isotherm

? Fahim, N.F., Barsoum, B.N., Eid, A.E. and Khalil, M.S. (2006), Removal of Chromium(III) from tannery wastewater using activated carbon from sugar industrial waste. Journal of Hazardous Materials, 136 (2), 303-309.

Full Text: 2006\J Haz Mat136, 303.pdf

Abstract: Chromium is commonly found in huge quantities in tannery wastewaters. For this reason, the removal and recovery of the chromium content of tannery wastewaters is crucial for environmental protection and economic reasons. Removal and recovery of chromium were carried out by using low-cost potential adsorbents. For this purpose three types of activated carbon; C1, the waste generated from sugar industry as waste products and the others (C2, C3) are commercial granular activated carbon, were used. The adsorption process and extent of adsorption are dependent on the physical and chemical characteristics of the adsorbent, adsorbate and experimental condition. The effect of pH, particle size and different adsorbent on the adsorption isotherm of Cr(III) was studied in batch system. The sorption data fitted well with Langmuir adsorption model. The efficiencies of activated carbon for the removal of Cr(III) were found to be 98.86, 98.6 and 93 % for C1, C2 and C3, respectively. The order of selectivity is C1 > C2 > C3 for removal of Cr(III) from tannery wastewater. Carbon “C1” of the highest surface area (520.66 m²/g) and calcium content (333.3 mg/l) has the highest adsorptive capacity for removal of Cr(III). The results revealed that the trivalent chromium is significantly adsorbed on activated carbon collected from sugar industry as waste products and the method could be used economically as an efficient technique for removal of Cr(III) and purification of tannery wastewaters.

Keywords: Chromium(III), Activated Carbon, Adsorption Isotherm, Tannery Wastewaters

? Çabuk, A., Akar, T., Tunali, S. and Tabak, Ö. (2006), Biosorption characteristics of Bacillus sp. ATS-2 immobilized in silica gel for removal of Pb(II). Journal of Hazardous Materials, 136 (2), 317-323.

Full Text: 2006\J Haz Mat136, 317.pdf

Abstract: The bacterial strain Bacillus sp. ATS-2 isolated from Pb(II) polluted soil was immobilized with a silica matrix and Pb(II) biosorption properties of immobilized biosorbent were examined. Optimum biosorption conditions were investigated in the fixed bed column with the variation in the parameters of pH, bed lenght, flow rate and influent concentration. The Pb(II) biosorption equilibrium was attained within 60 min and the maximum biosorption yield for silica gel immobilized Bacillus sp. ATS-2 was determined as 91.73% at pH 4.0. The higher biosorption yields were observed at flow rates of 60 and 180 ml h⁻¹. The optimum bed length for the column was found as 10 cm. Data obtained from batch studies were evaluated by Freundlich, Langmuir and Dubinin–Radushkevich (D–R) isotherm models. The maximum monolayer capacity of Bacillus sp. ATS-2 for Pb(II) was 2.36×10⁻⁵ mol g⁻¹. The involvement of the functional groups on the surface of immobilized cells in biosorption process was also evaluated by FTIR spectral analysis.

Keywords: Bacillus, Biosorption, Immobilized Cells, Pb(II); Isotherm

? Gode, F. and Pehlivan, E. (2006), Removal of Chromium(III) from aqueous solutions using Lewatit S 100: The effect of pH, time, metal concentration and temperature. Journal of Hazardous Materials, 136 (2), 330-337.

Full Text: 2006\J Haz Mat136, 330.pdf

Abstract: The removal of the Cr(III) ion from aqueous solutions with the Lewatit S 100 ion-exchange resin is described; and the performance of this resin was compared with Chelex-100 resin. The effect of adsorbent dose, initial metal concentration, contact time, pH and temperature on the removal of Cr(III) was investigated. Lewatit S 100 shows a remarkable increase in sorption capacity for Cr(III). The Batch ion-exchange process was relatively fast; and it reached equilibrium after about 150 min of contact. The ion-exchange process, which is pH dependent show maximum removal of Cr(III) in the pH range 2.8–4.0 for an initial Cr(III) concentration of 1.0×10⁻³ M. The equilibrium constants were 36.67 at pH value 3.5 for Lewatit S 100 and 6.64 at pH value 4.5 for Chelex-100 resin. Both of the resins had high-bonding constants. The equilibrium related to their ion-exchange capacity and the amount of the ion exchange was obtained by using the plots of the Langmuir adsorption isotherm. It was observed that the maximum ion-exchange capacity of 0.39 mmol of Cr(III)/g for Lewatit S 100 and 0.29 mmol of Cr(III)/g for Chelex-100 was achieved at optimum pH values of 3.5 and 4.5, respectively. The thermodynamic equilibrium constant and the Gibbs free energy flow were calculated for each system. The ion exchange of Cr(III) on these cation-exchange resins followed first-order reversible kinetics. The intra-particle diffusion of Cr(III) on ion-exchange resin represented the rate-limiting step. The rise in temperature caused a slight increase in the value of the equilibrium constant (Kc) for the sorption of Cr(III) ion for both resins.

Keywords: Chromium(III), Lewatit Ion-Exchange Resin, ICP-AES, Adsorption Isotherms, Ion-Exchange Kinetics

? Hsieh, C.H., Lo, S.L., Kuan, W.H. and Chen, C.L. (2006), Adsorption of copper ions onto microwave stabilized heavy metal sludge. Journal of Hazardous Materials, 136 (2), 338-344.

Full Text: 2006\J Haz Mat136, 338.pdf

Abstract: Microwave stabilized heavy metal sludge was used as an adsorbent to remove the copper ions from aqueous solution. The adsorption characteristics of copper on the stabilized-sludge were studied by various models, such as Freundlich and Langmuir isotherm equation. Results show that the pH_zpc of stabilized-sludge was at 9.2–9.5. Moreover, the adsorption of copper ions onto the stabilized-sludge surface was mainly on account of the heterogeneous surface of the stabilized-sludge. In the dynamic study, the experimental data was fitted to the intraparticle diffusion model, pseudo-first order model and pseudo-second order model. However, the experimental data was only well correlated with pseudo-second order model with the correlation coefficient > 0.995.

Furthermore, both Freundlich and Langmuir isotherm equations were found to represent the measured adsorption data well. From the Langmuir equation, the adsorption capacity increased from 18 to 28 mg/g as the temperature rose from 15 to 55 °C, since this adsorption process was an endothermic reaction. After this adsorption process, copper ions can be concentrated on and in a small bead and recovery efficiently.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Aqueous Solution, Capacity, Characteristics, Copper, Correlation, Data, Diffusion, Diffusion Model, Dynamic, Endothermic, Experimental, Freundlich, Heavy Metal, Heavy Metal Sludge, Intraparticle Diffusion, Intraparticle Diffusion Model, Isotherm, Isotherm Equations, Langmuir, Langmuir Equation, Langmuir Isotherm, Metal, Microwave, Microwave-Stabilized Sludge, Model, Models, Pseudo First Order, Pseudo Second Order, Pseudo-First Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second Order Model, Pseudo-Second-Order, Recovery, Sludge, Small, Solution, Surface, Temperature

? Bayramoğlu, G., Çelik, G. and Arıca, M.Y. (2006), Studies on accumulation of uranium by fungus Lentinus sajor-caju. Journal of Hazardous Materials,