Personal Research Database

Full Text: 2006\J Haz Mat137, 1796.pdf; 2006\J Haz Mat-Ho-1.pdf; 2006\J Haz Mat-Ho-2.pdf

Abstract: Palm kernel fibre is a common agricultural waste in West Africa and its use as an adsorbent for the removal of copper ions from aqueous solution has been studied. Batch kinetics studies were carried out based on the assumption of the pseudo-second-order kinetic model, which was developed to predict the rate constant of adsorption, the equilibrium adsorption capacity, and initial adsorption rate with the effect of initial copper concentration and reaction temperature. A comparison was made of the linear least-squares method and a trial-and-error non-linear method of the pseudo-second-order kinetic model for the adsorption of copper onto palm kernel fibre.

Keywords: Adsorbent, Adsorption, Adsorption Capacity, Adsorption Rate, Africa, Agricultural, Agricultural Waste, Aqueous Solution, Capacity, Comparison, Concentration, Copper, Copper Ion, Equilibrium, Kinetic, Kinetic Model, Kinetic Studies, Kinetics, Model, Non-Linear, Non-Linear Method, Palm Kernel Fibre, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Rate Constant, Removal, Solution, Sorption, Temperature, Waste

? Kondo, S., Takizawa, K., Takahashi, A. and Tokuhashi, K. (2006), Extended Le Chatelier’s formula for carbon dioxide dilution effect on flammability limits. Journal of Hazardous Materials, 138 (1), 1-8.

Full Text: 2006\J Haz Mat138, 1.pdf

Abstract: Carbon dioxide dilution effect on the flammability limits was measured for various flammable gases. The obtained values were analyzed using the extended Le Chatelier’s formula developed in a previous study. As a result, it has been found that the flammability limits of methane, propane, propylene, methyl formate, and 1,1-difluoroethane are adequately explained by the extended Le Chatelier’s formula using a common set of parameter values. Ethylene, dimethyl ether, and ammonia behave differently from these compounds. The present result is very consistent with what was obtained in the case of nitrogen dilution.

Keyword: Flammability Limits, Extended Le Chatelier’s Formula, Inert Gas Dilution Effect, Carbon Dioxide

? Doyurum, S. and Çelik, A. (2006), Pb(II) and Cd(II) removal from aqueous solutions by olive cake. Journal of Hazardous Materials, 138 (1), 22-28.

Full Text: 2006\J Haz Mat138, 22.pdf

Abstract: The removal of heavy metals from wastewater using olive cake as an adsorbent was investigated. The effect of the contact time, pH, temperature and concentration of adsorbate on adsorption performance of olive cake for Pb(II) and Cd(II) ions were examined by batch method. Adsorption of Pb(II) and Cd(II) in aqueous solution onto olive cake was studied in single component. After establishing the optimum conditions, elution of these ions from the adsorbent surface was also examined. The optimum sorption conditions were determined for two elements. Maximum desorption of the Pb(II) and Cd(II) ions were found to be 95.92 % and 53.97 % by 0.5 M HNO₃ and 0.2 M HCl, respectively. The morphological analysis of the olive cake was performed by scanning electron microscopy (SEM).

Keywords: Heavy Metal, Adsorption, Olive Cake, Lead, Cadmium

? Seki, Y., Seyhan, S. and Yurdakoc, M. (2006), Removal of boron from aqueous solution by adsorption on Al₂O₃ based materials using full factorial design. Journal of Hazardous Materials, 138 (1), 60-66.

Full Text: 2006\J Haz Mat138, 60.pdf

Abstract: This paper aims the adsorption of boron from aqueous solution onto Siral 30 and Pural using 2³ full factorial design. The effect of individual variables and their interactional effects for boron adsorption were also determined. From the statistical analysis, it is inferred that as pH and temperature increased boron adsorption from aqueous solution decreased. Siral 30 was found to be more efficient adsorbent than Pural. The unimportant factor affecting boron adsorption from aqueous solution was also verified by using Fisher adequacy test. At the 90 % confidence level, the type of adsorbent, temperature and type of adsorbent-temperature interaction was effective on boron adsorption from aqueous solution. The experimental results were fitted to the Langmuir, Freundlich and Dubinin-Radushkevich (DR) equations to find out adsorption capacities. In most cases, the results indicate that Freundlich and DR equations are well described with the sorption data. The adsorption capacity values of Siral 30 calculated from Freundlich and DR equation was greater than that of Pural. The nthermodynamic parameters were also estimated and the adsorption process was not spontaneous nature.

Keywords: Boron, Adsorption, Full Factorial Design, Pural, Siral 30

? Alok, M.A., Mittal, J., Kurup, L. and Singh, A.K. (2006), Process development for the removal and recovery of hazardous dye erythrosine from wastewater by waste materials - Bottom Ash and De-Oiled Soya as adsorbents. Journal of Hazardous Materials, 138 (1), 95-105.

Full Text: 2006\J Haz Mat138, 95.pdf

Abstract: Erythrosine is a water-soluble xanthene class of dye. It is widely used as colorant in foods, textiles, drugs and cosmetics. It is highly toxic, causes various types of allergies, thyroid activities, carcinogenicity, DNA damage behaviour, neurotoxicity and xenoestrogen nature in the humans and animals. The photochemical and biochemical degradation of the erythrosine is not recommended due to formation of toxic by-products. The present paper is an attempt to remove erythrosine from wastewater using adsorption over Bottom Ash-a power plant waste and De-Oiled Soya-an agricultural waste. Under the batch studies, effect of concentration of dye, temperature, pH of the solution, dosage of adsorbents, sieve size of adsorbents, etc., have been studied for the uptake of the dye over both adsorbents. The adsorption process verifies Langmuir and Freundlich adsorption isotherms in both the cases and based on the data different thermodynamic parameters have been evaluated. Batch studies also include kinetic measurements, rate constant study, mass transfer behaviour and establishment of mechanistic pathway for both the cases. For the bulk removal of the dye column operations have been carried out and breakthrough capacities of the Bottom Ash and De-Oiled Soya columns have been calculated. Attempts have also been made for the recovery of the adsorbed dye from exhausted columns by eluting dilute NaOH and more than 90% of the dye was recovered. (c) 2006 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbents, Adsorption, Adsorption Isotherms, Adsorption Process, Agricultural, Agricultural Waste, Animals, Aqueous-Solutions, Batch, Batch Studies, Behaviour, Bottom Ash, Breakthrough, Column, Column Operations, Concentration, Cosmetics, Damage, Data, De-Oiled Soya, Degradation, Development, Dna, Dna Damage, Drugs, Dye, Equilibrium Uptake, Erythrosine, Freundlich, Humans, Isotherms, Kinetic, Langmuir, Lifetime Toxicity Carcinogenicity, Malachite Green, Mass, Mass Transfer, Methylene-Blue, NaOH, Neurotoxicity, NOV, pH, Plant, Power, Power Plant, Rate Constant, Recovery, Red NO-3 Erythrosine, Removal, Rhodamine-B, Rights, Size, Solution, Sorption Dynamics, Temperature, Textiles, Thermodynamic, Thermodynamic Parameters, Toxic, Uptake, Waste, Waste Materials, Wastewater, Xanthene Dye

? Radhika, M. and Palanivelu, K. (2006), Adsorptive removal of chlorophenols from aqueous solution by low cost adsorbent: Kinetics and isotherm analysis. Journal of Hazardous Materials, 138 (1), 116-124.

Full Text: 2006\J Haz Mat138, 116.pdf

Abstract: Adsorptive removal of parachlorophenol (PCP) and 2,4,6-trichlorophenol (TCP) from aqueous solutions by activated carbon prepared from coconut shell was studied and compared with activated carbon of commercial grade (CAC). Various chemical agents in different concentrations were used (KOH, NaOH, CaCO₃, H₃PO₄ and ZnCl₂) for the preparation of coconut shell activated carbon. The coconut shell activated carbon (CSAC) prepared using KOH as chemical agent showed high surface area and best adsorption capacity and was chosen for further studies. Batch adsorption studies were conducted to evaluate the effect of various parameters such as pH, adsorbent dose, contact time and initial PCP and TCP concentration. Adsorption equilibrium reached earlier for CSAC than CAC for both PCP and TCP concentrations. Under optimized conditions the prepared activated carbon showed 99.9 % and 99.8 % removal efficiency for PCP and TCP respectively where as the commercially activated carbon had 97.7% and 95.5% removal for PCP and TCP respectively for a solution concentration of 50 mg/L. Adsorption followed pseudo-second order kinetics. The equilibrium adsorption data were analyzed by Langmuir, Freundlich, Redlich-peterson and Sips model using non-linear regression technique. Freundlich isotherms best fitted the data for adsorption equilibrium for both the compounds (PCP and TCP). Similarly, acidic pH was favorable for the adsorption of both PCP and TCP. Studies on pH effect and desorption revealed that chemisorption was involved in the adsorption process. The efficiency of the activated carbon prepared was also tested with real pulp and paper mill effluent. The removal efficiency using both the carbons were found highly satisfactory and was about 98.7% and 96.9% as phenol removal and 97.9% and 93.5 % as AOX using CSAC and CAC respectively.

Keywords: Activated Carbon, Adsorbent, Adsorbent Dose, Adsorption, Adsorption Capacity, Adsorption Equilibrium, Analysis, AOX, Aqueous Solution, Aqueous Solutions, Batch Adsorption, Capacity, Carbon, Chemical, Chemisorption, Chlorophenol Removal, Chlorophenols, Coconut Shell, Concentration, Cost, Data, Desorption, Efficiency, Equilibrium, Freundlich, Isotherm, Isotherms, Kinetics, KOH, Langmuir, Model, NaOH, Non-Linear Regression, pH, pH Effect, Phenol, Phenol Removal, Preparation, Pseudo Second Order, Pseudo Second Order Kinetics, Pseudo-Second-Order, Pseudo-Second-Order Kinetics, Redlich-Peterson, Regression, Removal, Removal Efficiency, Solution, Solutions, Surface, Surface Area, TCP, ZnCl₂

? Cestari, A.R., Vieira, E.F.S., Vieira, G.S. and de Almeida, L.E. (2006), The removal of anionic dyes from aqueous solutions in the presence of anionic surfactant using aminopropylsilica: A kinetic study. Journal of Hazardous Materials, 138 (1), 133-141.

Full Text: 2006\J Haz Mat138, 133.pdf

Abstract: In this study, the aminopropyl-silica (Sil-NH₂) was used to adsorb a yellow- and a red-dye from aqueous solutions at pH 4.0. New data concerning the influence of the anionic surfactant SDS on the adsorption data was obtained. All interactions occurred above the cmc values of the Sil-NH₂/anionic dyes aggregates. A rise of temperature accelerates the mass transfer of the red-dye into the Sil-NH₂ surface, while the yellow-dye adsorption decreased. The presence of SDS increased the adsorption quantities in relation to the temperature increasing. The exception is observed for the yellow-dye adsorption at 55C. So, it is suggested that the chemical structure of the dye, as well as the presence and position of its sulfonate groups are important factors that affect the anionic dye/SDS aggregations and the adsorption quantities. The solid-phase interactions of dyes data present good fittings to the Avrami kinetic model, where from two to four kinetic regions were found, taking into account the variations of the contact time and temperature. The presence of several values of Avrami constants, namely kAv and n, has been attributed to the occupation of both the surface and the internal adsorption sites of the aminopropyl-silica.

Keywords: Silica Gel, Dyes Adsorption, Anionic Surfactants, Kinetic Modelings

? Malkoc, E., Nuhoglu, Y. and Dundar, M. (2006), Adsorption of chromium(VI) on pomace: An olive oil industry waste: Batch and column studies. Journal of Hazardous Materials, 138 (1), 142-151.

Full Text: 2006\J Haz Mat138, 142.pdf

Abstract: The waste pomace of olive oil factory (WPOOF) was tested for its ability to remove chromium(VI) from aqueous solution by batch and column experiments. Various thermodynamic parameters, such as ΔG°, ΔH° and ΔS° have been calculated. The thermodynamics of chromium(VI) ion onto WPOOF system indicates spontaneous and endothermic nature of the process. The ability of WPOOF to adsorb chromium(VI) in a fixed bed column was investigated, as well. The effect of operating parameters such as flow rate and inlet metal ion concentration on the sorption characteristics of WPOOF was investigated. The longest breakthrough time and maximum of Cr(VI) adsorption is obtained at pH 2.0. The total adsorbed quantities, equilibrium uptakes and total removal percents of chromium(VI) related to the effluent volumes were determined by evaluating the breakthrough curves obtained at different flow rates and different inlet chromium(VI) concentrations for adsorbent. The data confirmed that the total amount of sorbed chromium(VI) and equilibrium chromium(VI) uptake decreased with increasing flow rate and increased with increasing inlet chromium(VI) concentration. The Adams–Bohart model were used to analyze the experimental data and the model parameters were evaluated.

Keywords: Adsorption, Pomace (Wastes Of Olive Oil Factory), Chromium, Fixed Bed Column, Adams–Bohart Model

? Aravindhan, R., Fathima, N.N., Rao, J.R. and Nair, B.U. (2006), Wet oxidation of acid brown dye by hydrogen peroxide using heterogeneous catalyst Mn-salen-Y zeolite: A potential catalyst. Journal of Hazardous Materials, 138 (1), 152-159.

Full Text: 2006\J Haz Mat138, 152.pdf

Abstract: Catalytic wet hydrogen peroxide oxidation of acid dye has been explored in this study. Manganese(III) complex of N,N’-ethylene bis(salicylidene-aminato) (salenH2) has been encapsulated in super cages of zeolite-Y by flexible ligand method. The catalyst has been characterized by FT-IR, XRD, TG, DTA and nitrogen adsorption studies. The effects of various parameters such as pH, catalyst and hydrogen peroxide concentration on the oxidation of dye were studied. The results indicate that after 20 min at 30C, 0.175 M H₂O₂ and 3 g, L catalyst, about 90% dye removal was obtained. These studies indicate that manganese-salen complex immobilized on zeolite framework can act as a good heterogeneous catalyst for removal of dye from wastewaters.

Keywords: Acid Dye, Adsorption, Catalyst, Catalytic, Concentration, Dye, Dye Removal, Flexible Ligand Method, Framework, FT-IR, FTIR, H₂O₂, Heterogeneous Catalysis, Heterogeneous Catalyst, Hydrogen, Hydrogen Peroxide, Immobilized, Ligand, Mn(III), Nitrogen, Oxidation, pH, Potential, Removal, Wastewaters, XRD, Zeolite

? Hamdaoui, O. (2006), Dynamic sorption of methylene blue by cedar sawdust and crushed brick in fixed bed columns. Journal of Hazardous Materials, 138 (2), 293-303.

Full Text: 2006\J Haz Mat138, 293.pdf

Abstract: The dynamic removal of methylene blue by cedar sawdust and crushed brick was studied in packed bed columns. The values of column parameters were predicted as a function of flow rate and bed height. On evaluating the breakthrough curves, the sorption isotherms of methylene blue onto cedar sawdust and crushed brick in 20 °C aqueous solution were experimentally determined in batch conditions. Both the Freundlich and the Langmuir models were found to fit the sorption isotherm data well, but the Langmuir model was better. A series of column tests using cedar sawdust and crushed brick as low-cost sorbents were performed to determine the breakthrough curves with varying bed heights and flow rates. To predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design, five kinetic models; Bohart and Adams, bed depth service time (BDST), Clark, Wolborska, and Yoon and Nelson models were applied to experimental data. All models were found suitable for describing the whole or a definite part of the dynamic behavior of the column with respect to flow rate and bed height, with the exception of Bohart and Adams model. The simulation of the whole breakthrough curve was effective with the Yoon and Nelson and the Clark models, but the breakthrough was best predicted by the Wolborska model.

Keywords: Methylene blue, Dynamic sorption, Fixed bed, Modeling, Cedar sawdust, Crushed brick

? Lu, C.S., Chung, Y.L. and Chang, K.F. (2006), Adsorption thermodynamic and kinetic studies of trihalomethanes on multiwalled carbon nanotubes. Journal of Hazardous Materials, 138 (2), 304-310.

Full Text: 2006\J Haz Mat138, 304.pdf

Abstract: Multiwalled carbon nanotubes (MWCNTs) were purified by mixed HNO₃/H₂SO₄ solution and were employed as adsorbents to study adsorption kinetics and thermodynamics of trihalomethanes (THMs) from chlorinated drinking water. The amount of THMs adsorbed onto CNTs decreased with a rise in temperature and high adsorption capacities were found at 5 and 15 °C. Under the same conditions, the purified CNTs possess two to three times more adsorption capacities of CHCl₃, which accounts for a major portion of THMs in the chlorinated drinking water, than the commercially available PAC suggesting that CNTs are efficient adsorbents. The thermodynamic analysis revealed that the adsorption of THMs onto CNTs is exothermic and spontaneous.

Keywords: Carbon Nanotubes, Adsorption, Trihalomethanes, Kinetics, Thermodynamics

? Şenel, S., Kara, A., Alsancak, G. and Denizli, A. (2006), Removal of phenol and chlorophenols from water with reusable dye-affinity hollow fibers. Journal of Hazardous Materials, 138 (2), 317-324.

Full Text: 2006\J Haz Mat138, 317.pdf

Abstract: Reactive Green HE 4BD carrying polyamide hollow fibers were investigated as dye-affinity adsorbents for removal of chlorophenols (i.e., phenol, o-chlorophenol, p-chlorophenol and 2,4,6-trichlorophenol). Adsorption rates of chlorophenols were very high. Equilibrium was achieved in about 30 min. The applicability of two kinetic models including pseudo-first order and pseudo-second order model was estimated on the basis of comparative analysis of the corresponding rate parameters, equilibrium capacity and correlation coefficients. Results suggest that chemisorption process could be the rate-limiting step in the adsorption process. The maximum adsorption values of chlorophenols onto the Reactive Green HE 4BD carrying hollow fibers were 145.9 μmol/g for phenol, 179.2 μmol/g for 2,4,6-trichlorophenol, 194.5 μmol/g for p-chlorophenol and 202.8 μmol/g for o-chlorophenol. The affinity order was as follows: o-chlorophenol > p-chlorophenol > 2,4,6-trichlorophenol > phenol. The adsorption capacity of chlorophenols decreased with increasing pH. Desorption of chlorophenols was achieved using methanol solution (30%, v/v). The Reactive Green HE 4BD-carrying hollow fibers are suitable for repeated use for more than 10 cycles without noticeable loss of adsorption capacity.

Keywords: Adsorbents, Adsorption, Adsorption Capacity, Analysis, Capacity, Chemisorption, Chlorophenol Removal, Chlorophenols, Correlation, Desorption, Equilibrium, Fibers, Hollow Fibers, Kinetic, Kinetic Models, Model, Models, pH, Phenol, Polyamide, Pseudo First Order, Pseudo Second Order, Pseudo-First Order, Pseudo-First Order and Pseudo-Second Order, Pseudo-First-Order, Pseudo-Second Order, Pseudo-Second Order Model, Pseudo-Second-Order, Rate Limiting Step, Rate-Limiting Step, Rates, Reactive Green HE 4BD, Removal, Solution, Water

? Won, S.W., Wu, G.P., Ma, H., Liu, Q., Yan, Y., Cui, L.Z., Liu, C.F. and Yun, Y.S. (2006), Adsorption performance and mechanism in binding of Reactive Red 4 by coke waste. Journal of Hazardous Materials, 138 (2), 370-377.

Full Text: 2006\J Haz Mat138, 370.pdf

Abstract: The protonated coke waste was used as a new type of adsorbent for the removal of Reactive Red 4. To identify the binding sites in the protonated coke waste, the waste was potentiometrically titrated. As a result, four types of functional groups were present in the waste, which was confirmed by FT-IR analysis. Among functional groups, primary amine groups (–NH₂) were likely the binding sites for anionic Reactive Red 4. It was also found that sulfonate, carboxyl and phosphonate groups played a role in electrostatic interference with the binding of dye molecules. The maximum adsorption capacities of the coke waste were 70.3±11.1 and 24.9±1.8 mg/g at pH 1 and 2, respectively. Kinetic study showed a pseudo-first-order rate of adsorption with respect to the solution. The uptake of Reactive Red 4 was not significantly affected by the high concentration of salts. These results of adsorption performance indicate the coke waste as a potentially economical adsorbent for dye removal.

Keywords: Adsorbent, Adsorption, Adsorption Capacities, Adsorption Performance, Analysis, Binding, Binding Sites, Concentration, Dye, Dye Removal, FT-IR, FTIR, FTIR Analysis, Functional Groups, Kinetic, Kinetic Study, Mechanism, Performance, pH, Potentiometric Titration, Primary, Protonated Coke Waste, Pseudo First Order, Pseudo-First-Order, Reactive Red 4, Removal, Role, Salts, Solution, Uptake, Waste

? Choi, S.B. and Yun, Y.S. (2006), Biosorption of cadmium by various types of dried sludge: An equilibrium study and investigation of mechanisms. Journal of Hazardous Materials, 138 (2), 378-383.

Full Text: 2006\J Haz Mat138, 378.pdf

Abstract: Batch equilibrium sorption experiments were used for screening for cost-effective four types of sludge, which were DWS (drinking water treatment plant sludge), LLS (landfill leachate sludge), ADSS (anaerobically digested sewage sludge), and SS (sewage sludge). SS removed cadmium most efficiently from aqueous solution (0.38 mmol/g), and showed the highest desorption efficiency (26.3%). Only the SS can be fitted by Langmuir isotherm model (r² = 0.996). The FT-IR spectra of SS and cadmium loaded SS indicated that carboxyl groups were major binding sites of cadmium binding sites. In kinetic experiment, it was found that the uptake of the metal by the SS was accompanied with proton release, indicating that the metal binding occurs via an ion exchange as well as by electrostatic interaction between carboxylate groups and cadmium ions. This sorbent may have a potential for use as high-value biosorbent of heavy metals and it deserves further investigations into the details of practical application, for example on the development of desorption methods and on sorption process optimization.

Keywords: Biosorption, Sludge, Cadmium, Binding Site, Binding Mechanism

? Pehlivan, E. and Arslan, G. (2006), Comparison of adsorption capacity of young brown coals and humic acids prepared from different coal mines in Anatolia. Journal of Hazardous Materials, 138 (2), 401-408.

Full Text: 2006\J Haz Mat138, 401.pdf

Abstract: Binding of Zn²⁺ and Cd²⁺ cations to relatively young brown coals YBC (lignite), humic acids (HAs) and commercial humic acid (CHA) were studied in aqueous media at pH 2.7-6 by polarographic method. This study was conducted to evaluate the removal of heavy metals in an aquatic system without prior treatment. The general principles of cation binding to YBC and humic materials are discussed. Sorption of heavy metal ions (Zn²⁺ and Cd²⁺) on samples of YBCs from three areas (Ilgin, Beysehir, and Ermenek) in the vicinity of the city of Konya in Anatolia (Turkey) were compared with sorption of these metal ions on HAs, prepared from these YBCs. The ability of both types of sorbent to remove metals from aqueoussolutions was studied as a function of pH and concentration of initial metal solutions. Sorption dependsstrongly on pH, the origin of the YBC and on the nature of the metal ion. Whereas for YBCs the mainligand groups seem to be carboxylate ions, this is not the case for the HA polymers, prepared from threeYBCs, which differ substantially from properties of commercial samples of “HA”. The process is veryefficient especially in the case of low concentrations of pollutants in water, where common methods areeither economically unfavorable or technically complicated. Of the two metal ions examined, Cd²⁺ was foundto form the most stable HA complexes, followed by Zn. Effective removal of metals was demonstrated at pH values of 5-5.7. The adsorption isotherm was measured at 25 °C, using adsorptive solutions at the optimum pH value to determine the adsorption capacity. An important aspect of the proposed method was that the removal was performed on several metals at a pH range in which a given metal undergoes an adsorption process making the method useful for wastewater treatment.

Keywords: Sorption, Young Brown Coals, Humic Acids, Polarography, Heavy Metal Ions (Zn²⁺, Cd²⁺)

? Tor, A. and Cengeloglu, Y. (2006), Removal of Congo red from aqueous solution by adsorption onto acid activated red mud. Journal of Hazardous Materials,