Personal Research Database

Full Text: J\J Haz Mat119, 183.pdf

Abstract: The potential of using activated phosphate as a new adsorbent for the removal of Pb from aqueous solutions was investigated. The kinetic of lead adsorption and the adsorption process were compared for natural phosphate (NP) and activated phosphate (AP). The results indicate that equilibrium was established in about 1 h for NP and 3 h for AP. The effect of the pH was examined in the range 2–6. The maximum removal obtained is between two and three for NP and between three and four for AP. The maximum adsorption capacities at 25 °C are 155.04 and 115.34 mg/g for AP and NP, respectively. The effect of temperature has been carried out at 25, 35 and 45 °C. The data obtained from adsorption isotherms of lead at different temperatures fit to linear form of Langmuir adsorption equation. The thermodynamic parameters such as enthalpy (ΔH), free energy (ΔG) and entropy (ΔS) were calculated. They show that adsorption of lead on NP and AP is an endothermic process more effective at high temperatures. These results show that AP is a good adsorbent for heavy metals from aqueous solutions and could be used as a purifier for water and wastewater.

Keywords: Activated Phosphate, Sorption, Lead, Langmuir, Thermodynamic Parameters

Namane, A., Mekarzia, A., Benrachedi, K., Belhaneche-Bensemra, N. and Hellal, A. (2005), Determination of the adsorption capacity of activated carbon made from coffee grounds by chemical activation with ZnCl₂ and H₃PO₄. Journal of Hazardous Materials, 119 (1-3), 189-194.

Full Text: J\J Haz Mat119, 189.pdf

Abstract: In order to evaluate the adsorptive capacities of granular activated carbon produced from coffee grounds by chemical activation, the adsorption of different phenols and acid and basic dyes, has been carried out. The comparison with a commercial activated carbon has been made. Adsorption isotherms of phenols and dyes (acid and basic) onto produced and commercial granular activated carbons were experimentally determined by batch tests. Both Freundlich [1] and Langmuir [2] models are well suited to fit the adsorption isotherm data. As a result, the coffee grounds based activated carbon may be promising for phenol and dye removal from aqueous streams.

Keywords: Adsorption, Coffee Grounds, Wastewater Treatment, Dyes, Organic Pollutants

Bayramoğlu, G., Çelik, G., Yalçın, E., Yılmaz, M. and Arıca, M.Y. (2005), Modification of surface properties of Lentinus sajor-caju mycelia by physical and chemical methods: Evaluation of their Cr⁶⁺ removal efficiencies from aqueous medium. Journal of Hazardous Materials, 119 (1-3), 219-229.

Full Text: J\J Haz Mat119, 219.pdf

Abstract: The hexavalent chromium biosorption onto untreated and heat-, acid- and alkali-treated Lentinus sajor-caju mycelia were studied from aqueous solutions. The particles sizes of the fungal mycelia ranged from 100 to 200 μm. The effect of pH, temperature, biosorbent dose, initial concentration of chromium ions, contact time parameters were investigated in a batch system. Biosorption equilibrium was established in about 4 h. The surface charge density of the fungal preparations varied with pH, and the maximum absorption of chromium ions on the fungal preparations were obtained at pH 2.0. The biosorption of chromium ions by the tested fungal preparations increased as the initial concentration of chromium ions increased in the medium. The maximum biosorption capacities of the untreated and heat, HCl^- and NaOH-treated fungal biomass were 0.363, 0.613, 0.478 and 0.513 mmol Cr⁶⁺ per gram of dry biomass, respectively. The correlation regression coefficients and the Langmuir constant values show that the biosorption process can be well defined by Langmuir equation. The chromium adsorption data were analysed using the first- and the second-order kinetic models. The first-order equation is the most appropriate equation to predict the biosorption capacities of all the fungal preparations. In addition, the polarity and surface energy of the untreated and all the modified biomass film preparations were determined by contact angle measurement. All the tested fungal biomass preparations could be regenerated using 0.1 M NaOH solution.

Keywords: White-Rot Fungus, Lentinus Sajor-Caju, Biosorption, Cr⁶⁺, Chemical and Physical Treatment, Contact Angle, Surface Energy

Manchón-Vizuete, E., Macías-García, A., Gisbert, A.N., Fernández-González, C. and Gómez-Serrano, V. (2005), Adsorption of mercury by carbonaceous adsorbents prepared from rubber of tyre wastes. Journal of Hazardous Materials, 119 (1-3), 231-238.

Full Text: J\J Haz Mat119, 231.pdf

Abstract: Rubber from tyre wastes has been used to prepare carbonaceous adsorbents and the products obtained have been tested as adsorbents for mercury in aqueous solution. The adsorbents have been prepared by applying thermal, chemical and combined (thermal and chemical or vice versa) treatments. Tyre rubber has been: heated at 400 or 900 °C for 2 h in N₂, chemically-treated with H₂SO₄, HNO₃ or H₂SO₄/HNO₃ solution for 24 h, and in two successive steps first heated at 400 °C for 2 h in N₂ and then treated with a H₂SO₄/HNO₃ solution for 24 h, or vice versa. Resultant products have been characterised in terms of elementary composition and textural properties. The adsorption of mercury has been studied from kinetic and equilibrium standpoints. The treatments effected to tyre rubber decrease the carbon content and the hydrogen content. The oxygen content and the nitrogen content increase for the chemically-treated products. The heat treatment of tyre rubber results in a larger development of surface area, microporosity, and mesoporosity than the chemical treatments. These treatments, however, produce a great creation of macropores. In comparison to the starting rubber, the adsorption process of mercury is faster when the material is heated or treated with the H₂SO₄, HNO₃ or 1:3 H₂SO₄/HNO₃ solution. These adsorbents are either a non-porous solid or possess a high mesopore volume or a wide pore size distribution in the macropore range. The adsorption capacity is larger for products prepared by heat, chemical and combined treatments of the rubber. A common textural characteristic of these adsorbents is their better developed microporosity. The ability to adsorb mercury is higher for the heated products than for the chemically-treated ones. The maximum adsorption of mercury is 211 mg g⁻¹. The constant K_f of the Freundlich equation is as high as 108.9 mg g⁻¹.

Keywords: Tyre rubber, Carbonaceous adsorbents, Mercury, Adsorption

Vijayaraghavan, K., Palanivelu, K. and Velan, M. (2005), Crab shell-based biosorption technology for the treatment of nickel-bearing electroplating industrial effluents. Journal of Hazardous Materials, 119 (1-3), 251-254.

Full Text: J\J Haz Mat119, 251.pdf

Abstract: This paper discusses the possible application of a biosorption system with acid-washed crab shells in a packed bed up-flow column for the removal of nickel from electroplating industrial effluents. Between two nickel-bearing effluents, effluent-1 is characterized by considerable amount of light metals along with trace amounts of lead and copper. Effluent-2 is characterized by relatively low conductivity, total dissolved solids and total hardness compared to effluent-1. Crab shells exhibited uptakes of 15.08 and 20.04 mg Ni/g from effluent-1 and effluent-2, respectively. The crab shell bed was regenerated using 0.01 M EDTA (pH 9.8, aq. NH₃) and reused for seven sorption–desorption cycles. The EDTA elution provided elution efficiencies up to 99% in all the seven cycles. This, together with the data from regeneration efficiencies for seven cycles, provided evidence that the reusability of crab shell in the treatment of nickel-bearing electroplating industrial effluents is viable.

Keywords: Heavy Metal, Packed Column, Pollution, Regeneration, Waste Treatment

? Lin, S.H., Kao, H.C., Su, H.N. and Juang, R.S. (2005), Effect of formaldehyde on Cu(II) removal from synthetic complexed solutions by solvent extraction. Journal of Hazardous Materials, 120 (1-3), 1-7.

Full Text: J\J Haz Mat120, 1.pdf

Abstract: The effect of formaldehyde (HCHO) on the extraction of Cu(II) from an equimolar EDTA (ethylenediaminetetraacetic acid, H₄L) solution with Aliquat 336 in kerosene (a quaternary amine) was examined. Experiments were carried out at different initial concentrations of Cu(II) (1.57–5 mol/m³), solution pH (3.0–8.0), HCHO concentrations (0–3 vol.%), Aliquat 336 concentrations (80–400 mol/m³), and temperatures (15–35 °C). It was shown that the distribution ratios (D) of Cu(II), which exists in the form of complexed anions CuL²⁻, increased with increasing equilibrium pH (pH_eq), but reached a plateau at pH_eq > 4 for the system without HCHO and at pH_eq > 4.5 for the system with 1 vol.% HCHO. The D values increased with increasing HCHO concentration, likely due to the reduction of Cu(II) to Cu(I) by HCHO in solution. A semi-empirical two-parameter model was proposed to describe the extraction equilibrium, in which the non-ideality in organic phases was considered. The thermodynamic parameters were also evaluated and discussed.

Keywords: Solvent Extraction, Copper(II), EDTA, Aliquat 336, Formaldehyde, Equilibrium

? Nakajima, T., Xu, Y.H., Mori, Y., Kishita, M., Takanashi, H., Maeda, S. and Ohki, A. (2005), Combined use of photocatalyst and adsorbent for the removal of inorganic arsenic(III) and organoarsenic compounds from aqueous media. Journal of Hazardous Materials, 120 (1-3), 75-80.

Full Text: J\J Haz Mat120, 75.pdf

Abstract: A novel method for the removal of inorganic arsenic(III) (As(III)), monomethylarsonate (MMA), and dimethylarsinate (DMA) from aqueous media, was proposed and investigated. This method involves the combined use of TiO₂-photocatalyst and an adsorbent, which has a high ability of As(V) adsorption, under photo-irradiation. When an aqueous solution of As(III) was stirred and irradiated by sunlight or xenon lamp in the presence of TiO₂ suspension, the oxidation of As(III) into As(V) was effectively attained. By use of the same photocatalytic reaction, MMA and DMA were also degraded into As(V), while the total organic carbon (TOC) in the aqueous phase was decreased. When an aqueous solution of As(III) was stirred with a mixed suspension of TiO₂ and an adsorbent for As(V) (activated alumina) under sunlight irradiation, the arsenic removal reached 89% after 24 h. By use of the same photocatalyst–adsorbent system, 98% of MMA and 97% of DMA were removed. The mechanism of the removal of arsenic species by the photocatalyst–adsorbent system was discussed.

Keywords: Arsenite, Organoarsenic Compounds, Removal, Photocatalytic Reaction, Adsorbent

? Ho, Y.S. and Ofomaja, A.E. (2005), Effects of calcium competition on lead sorption by palm kernel fibre. Journal of Hazardous Materials, 120 (1-3), 157-162.

Full Text: J\J Haz Mat120, 157.pdf J\J Haz Mat-Ho4.pdf J\J Haz Mat-Ho3.pdf

Abstract: The kinetics of sorption of a mono-solute of lead ions and of a bi-solute of lead and calcium ions onto palm kernel fibre was investigated in a batch system. The experimental data were analysed based on an intraparticle diffusion equation and a pseudo-second-order mechanism, in both the mono- and bi-solute sorption systems, in order to predict the rate constant of sorption, the equilibrium capacity, and the initial sorption rate. The results indicate that the sorption mechanism is described by a pseudo-second-order equation. Intraparticle diffusion was significant in the lower-concentration systems. In addition, a modified intraparticle diffusion equation was applied to the sorption systems. (c) 2005 Elsevier B.V. All fights reserved.

Keywords: Adsorption, Batch, Batch System, Calcium, Capacity, Competition, Data, Diffusion, Equilibrium, Experimental, Intraparticle Diffusion, Kinetics, Lead, Mechanism, Modified, Palm Kernel Fibre, Pseudo Second Order, Pseudo-Second-Order, Rate Constant, Sorption, Sorption Mechanism, Systems

? Zhu, M.X., Li, Y.P., Xie, M. and Xin, H.Z. (2005), Sorption of an anionic dye by uncalcined and calcined layered double hydroxides: A case study. Journal of Hazardous Materials, 120 (1-3), 163-171.

Full Text: J\J Haz Mat120, 163.pdf

Abstract: Layered double hydroxides (LDHs) with a Mg/Al molar ratio of 2:1 were synthesized by using a co-precipitation method and their calcined products (CLDHs) were obtained by heating Mg/Al-LDHs at 500 °C. Sorption of a weak acid dye, Brilliant Blue R (BBR), by LDHs and CLDHs indicated equilibrium time required for BBR sorption by CLDHs was less than 12 h, regardless of initial concentration of BBR, whereas BBR sorption by LDHs was longer than 20 h. Sorption capacity of CLDHs was much larger than that of LDHs. Therefore, CLDHs could be used to remove anionic dyes of relatively high concentrations while LDHs may only be used to remove anionic dyes of low concentrations. Isotherms for BBR sorption by CLDHs and LDHs were well described using the Freundlich and Langmuir equations, respectively. When the initial pH of BBR solutions was lower than 8.0, the final pH of the solution after sorption was enhanced and stabilized at 10.6–10.8. The effect of initial pH (<8.0) on BBR removal was negligible, which would be environmentally important for precipitation/co-precipitation of co-existing metal cations. The effects of both Cl⁻ and SO₄²⁻ on BBR sorption by CLDHs were minimal; but the presence of CO₃²⁻ markedly reduced BBR removal. Thermal regeneration for re-use of LDHs and CLDHs after BBR sorption was feasible only within the first two cycles, after which the regenerated materials suffered from a large loss in their sorption capacities.

Keywords: Adsorption, Hydrotalcite, Dye Sorption, Calcined Layered Double Hydroxides, Decolorization

? Duman, O. and Ayranci, E. (2005), Structural and ionization effects on the adsorption behaviors of some anilinic compounds from aqueous solution onto high-area carbon-cloth. Journal of Hazardous Materials, 120 (1-3), 173-181.

Full Text: 2005\J Haz Mat120, 173.pdf

Abstract: The adsorption of anilinic compounds; aniline, p-toluidine, 1-napthylamine and sodium salt of diphenylamine-4-sulfonic acid from solutions in H2O, in 1 M H2SO4 or in 0.1 M NaOH onto activated carbon-cloth was studied by in situ UV spectroscopy. A specially designed adsorption cell was used for this purpose. The adsorption processes were found to follow first-order kinetics and the rate constants were determined. The pH at the point of zero charge of the carbon-cloth surface was measured as 7.4. The highest rates and extents of adsorption were observed from H2O solutions for aniline, p-toluidine and 1-napthylamine and from solution in 1 M H2SO4 for the sodium salt of diphenylamine-4-sulfonic acid. The adsorption behaviors of these four anilinic compounds in the three solutions (in H2O, in 0.1 M NaOH and in 1 M H2SO4) were explained in terms of electrostatic and dispersion interactions between carbon-cloth surface and the anilinic species. The adsorption isotherm data for the anilinic compounds were derived at 30 degrees C and treated according to Langmuir and Freundlich models. The Freundlich model was found to represent the experimental isotherm data better than Langmuir model. (c) 2005 Elsevier B.V All rights reserved.

Keywords: Activated Carbon, Activated Carbon Cloth, Activated Carbon-Cloth, Adsorption, Adsorption Isotherm, Aniline, Anilinic Compounds, Aqueous Solution, Aromatic-Amines, Desorption, Electrodes, Electrosorption, Equilibrium, Experimental, First Order, Freundlich, Freundlich Model, In Situ UV Spectroscopy, Ionization, Isotherm, Kinetics, Langmuir, Langmuir And Freundlich Models, Langmuir Model, Model, NaOH, pH, Pyridine, Removal, Salt, Temperature, UV Spectroscopy, UV-Spectroscopy, Waste-Water Purification

? Gulnaz, O., Saygideger, S. and Kusvuran, E. (2005), Study of Cu(II) biosorption by dried activated sludge: Effect of physico-chemical environment and kinetics study. Journal of Hazardous Materials, 120 (1-3), 193-200.

Full Text: J\J Haz Mat120, 193.pdf

Abstract: Biosorption is a recent technology used to remove heavy metal ions from aqueous solutions. The biosorption of copper ions from aqueous solution by dried activated sludge was investigated in batch systems. Effect of solution pH, initial metal concentration and particle size range were determined. The suitable pH and temperature for studied conditions were determined as 4.0 and 20 °C, respectively. The theoretical max biosorption capacity of activated sludge was 294 mg g⁻¹ at 20 °C for <0.063 mm particle size. The equilibrium data fitted very well to both Langmuir and Freundlich isotherm models. The pseudo first and second-order kinetic models were used to describe the kinetic data. The experimental data fitted to second-order kinetic model. The particle size and initial metal concentration were effected the biosorption capacity of dried activated sludge. An increase in the initial metal concentration increases of biosorption capacity, which also increases with decreasing particle size. Dried activated sludge has different functional groups according to the FT-IR results.

Keywords: Activated Sludge, Aqueous Solution, Aqueous Solutions, Batch, Biosorption, Biosorption Kinetic, Capacity, Concentration, Copper, Cu(II), Cu(II) Biosorption, Data, Dried Activated Sludge, Environment, Equilibrium, Experimental, First, Freundlich, Freundlich Isotherm, FT-IR, FTIR, Functional Groups, Heavy Metal, Heavy Metal Ions, Isotherm, Kinetic, Kinetic Model, Kinetic Models, Kinetics, Langmuir, Metal, Metal Ions, Model, Models, Particle Size, pH, Second Order, Second-Order, Size, Sludge, Solution, Solutions, Systems, Technology, Temperature

? Lin, Y.B., Fugetsu, B., Terui, N. and Tanaka, S. (2005), Removal of organic compounds by alginate gel beads with entrapped activated carbon. Journal of Hazardous Materials, 120 (1-3), 237-241.

Full Text: J\J Haz Mat120, 237.pdf

Abstract: The adsorption of alginate gel (AG) beads and AG with activated carbon entrapped (AG–AC) beads prepared using different types of metal ions were investigated by measuring the removal of several organic compounds with different charges and size. AG–AC beads prepared in a CaCl₂ solution adsorbed strongly positively charged compounds as well as electrically neutral and low molecular weight compounds such as p-chlorophenol. However, a high molecular weight humic acid was not adsorbed by AG–AC. The AG–AC selectively adsorbed p-chlorophenol from a humic acid solution. The adsorption capacity obtained from the adsorption isotherm of AC entrapped in AG was compared with that of AC. The AG–AC beads prepared in a solution of FeCl₃ were able to specifically adsorb negatively charged gallic acid. Thus, entrapping AC into AG resulted in the selective adsorption.

Keywords: Alginate Gel Beads Entrapping Activated Carbon, Removal of Organic Compounds, Adsorption Isotherm

? Prado, A.G.S., Miranda, B.S. and Zara, L.F. (2005), Adsorption and thermochemical data of divalent cations onto silica gel surface modified with humic acid at solid/liquid interface. Journal of Hazardous Materials, 120 (1-3), 243-247.

Full Text: J\J Haz Mat120, 243.pdf

Abstract: Humic acid immobilized onto silica gel surface was studied by the calorimetric titration of divalent cations in aqueous solution. The adsorption isotherms were obtained by the batchwise method and were fitted to a modified Langmuir equation. The maximum number of moles per gram of the material gave: 10.42±0.75, 13.16±0.58, 7.87±0.58 for copper, nickel and zinc, respectively. Gibbs free energies were negative for all systems and the adsorption interactions calorimetrically followed presented endothermic enthalpic values: 6.24±0.47, 6.75±0.74, 6.97±0.58 kJ mol⁻¹ for the same sequence of divalent cations. All liquid/solid interface adsorptions were entropically driven.

Keywords: Absorption Spectrometric Determination, Adsorption, Adsorption Isotherms, Bases, Copper, Enrichment, Exchange, Humic, Humic Acid, Humic Acids, Interactions, Interface, Isotherms, Metal Ions, Metal-Ion Collector, Modified, Nickel, Removal, Separation, Silica, Silica Gel, Surface, Titration, Zinc

? Machida, M., Aikawa, M. and Tatsumoto, H. (2005), Prediction of simultaneous adsorption of Cu(II) and Pb(II) onto activated carbon by conventional Langmuir type equations. Journal of Hazardous Materials, 120 (1-3), 271-275.

Full Text: J\J Haz Mat120, 271.pdf

Abstract: Removal of Cu(II) and Pb(II) by adsorption onto activated carbon was examined in single- and binary-component aqueous solutions representative of contaminated solutions containing heavy metals. Reversibility of adsorption of the heavy metals on the activated carbon was evaluated by desorption experiments. The number of the maximum adsorption sites and adsorption equilibrium constants of Cu(II) and Pb(II) were estimated by the results of single-component systems assuming the Langmuir adsorption model. The adsorption sites per gram of activated carbon resulted in similar values for Cu(II) and Pb(II) from the isotherms. The adsorption constant for Pb(II) was nearly 1.8 times greater than that of Cu(II). Rate constants of adsorption and desorption were also estimated from the kinetic analysis. Using the single set of common parameters obtained from the single-component systems, the experimental results for a binary-component system were quantitatively predicted. Competitive adsorption of Cu(II) and Pb(II) on the same adsorption sites was confirmed by both experimental and predicted results of adsorption in the binary mixture.

Keywords: Activated Carbon, Adsorption, Adsorption Constant, Adsorption Equilibrium, Analysis, Aqueous Solutions, Aqueous-Solutions, Binary Mixture, Biosorption, Carbon, Competitive Adsorption, Conventional, Copper(II), Cu(II), Desorption, Equilibrium, Experimental, Experiments, Heavy Metal, Heavy Metals, Heavy-Metals, Ions, Isotherms, Kinetic, Kinetic Analysis, Kinetics, Langmuir, Langmuir Model, Lead(II), Metals, Mixture, Model, Models, Pb(II), Rate Constants, Removal, Rights, Solutions, Systems, Values, Water

? Öztürk, N. and Bektaş, T.E. (2005), Reply to comment on “Nitrate removal from aqueous solution by adsorption onto various materials”, by Y.S. Ho. Journal of Hazardous Materials, 120 (1-3), 277.

Full Text: J\J Haz Mat120, 277.pdf

? Singh, K.K., Rastogi, R. and Hasan, S.H. (2005), Removal of cadmium from wastewater using agricultural waste ‘rice polish’. Journal of Hazardous Materials, 121 (1-3), 51-58.

Full Text: J\J Haz Mat121, 51.pdf

Abstract: A novel biosorbent rice polish has been successfully utilized for the removal of cadmium(II) from wastewater. The maximum removal of cadmium(II) was found to be 9.72 mg g⁻¹ at pH 8.6, initial Cd(II) concentration of 125 mg l⁻¹ and temperature of 20 °C. The effect of different parameters such as contact time, adsorbate concentration, pH of the medium and temperature were investigated. Dynamics of the sorption process were studied and the values of rate constant of adsorption, rate constant of intraparticle diffusion and mass transfer coefficient were calculated. Different thermodynamic parameters, viz., changes in standard free energy, enthalpy and entropy have also been evaluated and it has been found that the reaction was spontaneous and exothermic in nature. The applicability of Langmuir isotherm showed monolayer coverage of the adsorbate on the surface of adsorbents. A generalised empirical model was proposed for the kinetics at different initial concentrations. The data were subjected to multiple regression analysis and a model was developed to predict the removal of Cd(II) from wastewater.

Keywords: Adsorption, Rice Polish, Cadmium, Exothermic, Monolayer

? Bang, S., Korfiatis, G.P. and Meng, X.G. (2005), Removal of arsenic from water by zero-valent iron. Journal of Hazardous Materials,