Personal Research Database

Full Text: J\J Haz Mat96, 65.pdf

Abstract: Remediation of sites contaminated by chlorinated organic compounds is a significant priority in the environmental field. Subsequently, the addition of cosolvent solutions for in situ flushing of contaminated source zones has been successfully field tested. However, the treatment of effluent fluids in such cleanup efforts is an often overlooked component of this technology implementation. The purpose of this research was to evaluate the effectiveness of zero-valent iron (Fe⁰) in treating perchloroethylene (PCE) in an aqueous solution, and how the presence of a cosolvent (ethanol) and modification of the iron surface altered dechlorination. The modified iron surfaces included in this study were nickel-plated iron, acid-treated iron, and untreated iron surfaces. PCE dechlorination in the presence of each of the iron surfaces displayed pseudo first-order kinetics. The highest degradation rate of PCE occurred on the nickel-plated iron surface, 5.83×10^-3 h^-1, followed by the acid-treated iron, 4.92×10^-3 h^-1, and the untreated iron, 3.34×10^-3 h^-1. Dechlorination on each of the surfaces decreased with increasing cosolvent fractions. It was shown that as cosolvent fractions increased, PCE adsorption decreased and resulted in a concomitant decrease in PCE degradation rates.

Keywords: Zero-Valent Iron, PCE, Cosolvents, Adsorption, Dechlorination

Smith, J.A., Bartelt-Hunt, S.L. and Burns, S.E. (2003), Sorption and permeability of gasoline hydrocarbons in organobentonite porous media. Journal of Hazardous Materials, 96 (1), 91-97.

Full Text: J\J Haz Mat96, 91.pdf

Abstract: We investigate the use of organobentonites as liners for underground gasoline storage tanks to reduce the risk of subsurface contamination. A series of permeability measurements were conducted on two types of organobentonites: benzyltriethylammonium-bentonite (BTEA-bentonite) and hexadecyltrimethylammonium-bentonite (HDTMA-bentonite). Both water and commercial unleaded gasoline were used as the permeant liquids. Results of these measurements indicate that the intrinsic permeability of the organobentonite decreases by one to two orders of magnitude when the permeant liquid is changed from water to gasoline. Results of batch sorption measurements reveal that benzene sorption to both organobentonites from water is greater than benzene sorption to conventional bentonite. The magnitude of benzene sorption is related to the loading of the organic quaternary ammonium cation on the clay. As the HDTMA cation loading increases from 25% of cation exchange capacity (CEC) to 120% of CEC, benzene sorption increases. However, as the BTEA cation loading increases from 40 to 120% of CEC, benzene sorption decreases. Collectively, these results suggest that organobentonites can be used effectively to reduce hydrocarbon migration rates beneath leaking underground gasoline storage tanks, and that the optimal organic cation loading with respect to pollutant sorption may be less than 50% of cation exchange capacity for some organobentonite-solute combinations. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Benzene, Underground Storage Tank, Organoclay, Hexadecyltrimethylammonium, Benzyltriethylammonium, Adsorption, Partition, Ground Water, Alkylammonium-Montmorillonites, Tetrachloromethane Sorption, Clay, Water, Bentonite, Liners

Hasar, H. (2003), Adsorption of nickel(II) from aqueous solution onto activated carbon prepared from almond husk. Journal of Hazardous Materials, 97 (1-3), 49-57.

Full Text: J\J Haz Mat97, 49.pdf

Abstract: Activated carbon was prepared from almond husk by activating without (MAC-I) and with (MAC-II) H₂SO₄ at different temperatures. The ability of the activated carbon to remove nickel(II) ions from aqueous solutions by adsorption has been investigated under several conditions such as pH, carbonisation temperature of husk, initial concentration of metal ions, contact time, and adsorbent concentration. Optimal conditions were pH 5.0, the carbonisation temperature of 700 °C, 50 min of contact time and adsorbent concentration of 5 g/l. The results indicate that the effective uptake of Ni(II) ions was obtained by activating the carbon, prepared from almond husk at 700 °C, through the addition of H₂SO₄. The removal of Ni(II) were found to be 97.8% at initial concentration of 25 mg/l and the adsorbent concentration of 5 g/l. When the adsorbent concentration was increased up to 40 g/l, the adsorption density decreased from 4.89 to 0.616 mg/g for MAC-II. In the isotherm studies, the experimental adsorption data fitted reasonably well the Langmuir isotherm for both MAC-I and MAC-II.

Keywords: Nickel(II) Uptake, Activated Carbon, Almond Husk, Adsorption Isotherm

? Metaxas, M., Kasselouri-Rigopoulou, V., Galiatsatou, P., Konstantopoulou, C. and Oikonomou, D. (2003), Thorium removal by different adsorbents. Journal of Hazardous Materials, 97 (1-3), 71-82.

Full Text: 2003\J Haz Mat97, 71.pdf

Abstract: The removal of radiotoxic Th⁴⁺ from aqueous solutions has been explored using two different groups of adsorptive materials (e.g. two activated carbons and four zeolites-two natural and two synthetic). The activated carbons were prepared from solvent extracted olive pulp (SEOP) and olive stone (OS) by a two-step physical activation method with steam. They were characterized by N-2 at 77 K adsorption, Hg porosimetry and by determination of their iodine number. All carbons prepared are of the H-type (e.g. contain mainly basic surface oxides) confirmed by the results of the Boehm’s method. The natural zeolites, clinoptilolite (NaCLI) and mordenite (NaMOR), were pretreated with Na⁺ before the adsorption experiments, while the synthetic ones, NaX and NaA, were provided in their commercial sodium form. The natural zeolites, NaCLI and NaMOR, utilized 11.5 and 38.6% of the theoretical ion-exchange capacity, based on Al content, respectively, while NaX and NaA utilized 41.5 and 45.9%, respectively. The activated carbons showed better removal capability than NaCLI. NaMOR, showed comparable results to the carbon originated from OS, but lower removal capability than the carbon originated from SEOP The synthetic zeolites showed the highest removal ability for thorium ions due to their increased ion-exchange capacity because of their cleaner and larger framework channels and their higher number of ion-exchange sites. The carbons adsorption capacity mainly depends on the content and nature of functional surface groups. The adsorption data were fitted to Langmuir and Freundlich models. The former achieved best fits and was further applied to obtain the respective Langmuir constant and maximum adsorption capacity for each system. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Ability, Achieved, Activated Carbon, Activated Carbon, Activated Carbons, Activation, Activation Method, Adsorbents, Adsorption, Adsorption Capacity, Aqueous Solutions, Aqueous-Solutions, Capacity, Carbon, Clinoptilolite, Experiments, Freundlich, Iodine Number, Ion Exchange, Ion-Exchange, Ions, Langmuir, Langmuir Isotherm, Models, Natural, Natural Zeolites, NaX, Oxides, Physical Activation, Removal, Rights, Surface, Thorium, Thorium Adsorption, Zeolites

Genç, Ö., Soysal, L., Bayramoğlu, G., Arıca. M.Y. and Bektaş, S. (2003), Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes for heavy metal removal. Journal of Hazardous Materials, 97 (1-3), 111-125.

Full Text: J\J Haz Mat97, 111.pdf

Abstract: The effective removal of toxic heavy metals from environmental samples still remains a major topic of present research. Metal-chelating membranes are very promising materials as adsorbents when compared with conventional beads because they are not compressible, and they eliminate internal diffusion limitations. The purpose of this study was to evaluate the performance of a novel adsorbent, Procion Green H-4G immobilized poly(hydroxyethylmethacrylate (HEMA)/chitosan) composite membranes, for the removal of three toxic heavy metal ions, namely, Cd(II), Pb(II) and Hg(II) from aquatic systems. The Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes were characterized by elemental analysis, scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy. The immobilized amount of the Procion Green H-4G was calculated as 0.018±0.003 mol/cm² from the nitrogen and sulphur stoichiometry. The adsorption capacity of Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) composite membranes for selected heavy metal ions from aqueous media containing different amounts of these ions (30-400 mg/l) and at different pH values (2.0-6.0) was investigated. The amount of Cd(II), Pb(II) and Hg(II) adsorbed onto the membranes measured at equilibrium, increased with time during the first 45 min and then remained unchanged toward the equilibrium adsorption. The maximum amounts of heavy metal ions adsorbed were 43.60±1.74, 68.81±2.75 and 48.22±1.92 mg/g for Cd(II), Pb(II) and Hg(II), respectively. The heavy metal ion adsorption on the pHEMA/chitosan membranes (carrying no dye) were relatively low, 6.31±0.13 mg/g for Cd(II), 18.73±0.37 mg/g for Pb(II) and 18.82±0.38 mg/g for Hg(II). Competitive adsorption of the metal ions was also studied. When the metal ions competed with each other, the adsorbed amounts were 12.74±0.38 mg Cd(II)/g, 28.80±0.86 mg Pb(II)/g and 18.41±0.54 mg Hg(II)/g. Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) membranes can be regenerated by washing with a solution of nitric acid (0.01 M). The percent desorption achieved was as high as 95%. These novel membranes are suitable for repeated use for more than five adsorption/desorption cycles without any considerable loss in adsorption capacity. Adsorption equilibria were well described by Langmuir equation. It can be concluded that Procion Green H-4G immobilized poly(hydroxyethylmethacrylate/chitosan) membranes may effectively be used for the removal of Cd(II), Pb(II) and Hg(II) ions from aqueous solutions. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Phema/Chitosan Membranes, Procion Green H-4G, Heavy Metal Adsorption, Chelating Resin, Cadmium Ions, Adsorption, Microspheres, Acid, Chromatography, Bioseparations, Polymers, Fiber

? Duenas, J.F., Aloñso, J.R., Rey, A.F. and Ferrer, A.S. (2003), Characterisation of phosphorous forms in wastewater treatment plants. Journal of Hazardous Materials, 97 (1-3), 193-205.

Full Text: 2003\J Haz Mat97, 205.pdf

Abstract: The removal of different forms of phosphorous (namely total phosphorous, soluble phosphorous, particulate phosphorous and total phosphate) has been studied in two municipal wastewater treatment plants (WWTP) with different characteristics, but without any specific implemented strategy for phosphorous removal. The results obtained for the different forms of phosphorous can be summarised as follows: (1) complete removal of particulate phosphorous is achieved in either primary or secondary clarifiers; (2) total phosphorous concentration in the effluent is mostly soluble phosphorous and this is mainly phosphate; (3) a small amount of soluble phosphorous is removed by biomass growth and/or biosorption; (4) both WWTPs presented a high-buffered behaviour in response to high inlet loading of phosphorous, showing a constant pattern at the outlet of the WWTP; (5) removal of total phosphorous was approximately 60-70% for both WWTPs; and (6) recirculation streams such as supernatant from centrifuge sludge dehydration operation can have a significant contribution to the inlet amount of phosphorous. The results presented in this paper provide a basis to develop prospects for phosphorous removal, which may be adapted to the particular configurations of the WWTP studied. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Achieved, Behaviour, Biological Nitrogen, Biomass, Biosorption, Clarifier, Configurations, Effluent, Growth, Municipal Wastewater, Phosphate, Phosphate Removal, Phosphorous Forms, Phosphorous Removal, Prospects, Recirculation, Removal, Rights, Secondary, Sludge, Treatment, Wastewater, Wastewater Treatment, Wastewater Treatment Plant, Wastewater Treatment Plants, Water Treatment

de la Rosa, G., Peralta-Videa, J.R. and Gardea-Torresdey, J.L. (2003), Utilization of ICP/OES for the determination of trace metal binding to different humic fractions. Journal of Hazardous Materials, 97 (1-3), 207-218.

Full Text: J\J Haz Mat97, 207.pdf

Abstract: In this study, the use of inductively coupled plasma/optical emission spectrometry (ICP/OES) to determine multi-metal binding to three biomasses, Sphagnum peat moss, humin and humic acids is reported. All the investigations were performed under part per billion (ppb) concentrations. Batch pH profile experiments were performed using multi-metal solutions of Cd(II), Cu(II), Pb(II), Ni(II), Cr(III) and Cr(VI). The results showed that at pH 2 and 3, the metal affinity of the three biomasses exposed to the multi-metal solution that included Cr(M) presented the following order: Cu(II), Pb(II) > Ni(II) > Cr(III) > Cd(II). On the other hand, when Cr(VI) was in the heavy metal mixture, Sphagnum peat moss and humin showed the following affinity: Cu(II), Pb(II) > Ni(II) > Cr(VI) > Cd(II); however, the affinity of the humic acids was: Cu(II) > Pb(II), Cr(VI) > Ni(II) > Cd(II). The results demonstrated that pH values of 4 and 5 were the most favorable for the heavy metal binding process. At pH 5, all the metals, except for Cr(VI), were bound between 90 and 100% to the three biomasses. However, the binding capacity of humic acids decreased at pH 6 in the presence of Cr(VI). The results showed that the ICP/OES permits the determination of heavy metal binding to organic matter at ppb concentration. These results will be very useful in understanding the role of humic substances in the fate and transport of heavy metals, and thus could provide information to develop new methodologies for the removal of low concentrations of toxic heavy metals from contaminated waters. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: ICP/OES, Humic Substances, Trace Metal Binding, Metal Affinity, Batch Experiments, Medicago-Sativa Alfalfa, Heavy-Metals, Absorption Spectroscopy, Poly(Acrylic Acid), Waste-Water, Ion Binding, Adsorption, Moss, Removal, Chromium

Notes: highly cited

Babel, S. and Kurniawan, T.A. (2003), Low-cost adsorbents for heavy metals uptake from contaminated water: A review. Journal of Hazardous Materials, 97 (1-3), 219-243.

Full Text: J\J Haz Mat97, 219.pdf

Abstract: In this article, the technical feasibility of various low-cost adsorbents for heavy metal removal from contaminated water has been reviewed. Instead of using commercial activated carbon, researchers have worked on inexpensive materials, such as chitosan, zeolites, and other adsorbents, which have high adsorption capacity and are locally available. The results of their removal performance are compared to that of activated carbon and are presented in this study. It is evident from our literature survey of about 100 papers that low-cost adsorbents have demonstrated outstanding removal capabilities for certain metal ions as compared to activated carbon. Adsorbents that stand out for high-adsorption capacities are chitosan (815, 273, 250 mg/g of Hg²⁺, Cr⁶⁺, and Cd²⁺, respectively), zeolites (175 and 137 mg/g of Pb²⁺ and Cd²⁺, respectively), waste slurry (1030, 560, 540 mg/g of Pb²⁺, Hg²⁺, and Cr⁶⁺, respectively), and lignin (1865 mg/g of Pb²⁺). These adsorbents are suitable for inorganic effluent treatment containing the metal ions mentioned previously. It is important to note that the adsorption capacities of the adsorbents presented in this paper vary, depending on the characteristics of the individual adsorbent, the extent of chemical modifications, and the concentration of adsorbate. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Low-Cost Adsorbents, Activated Carbon, Heavy Metal Removal, Contaminated Water, Wastewater Treatment, Granular Activated Carbon, Oxide-Coated Sand, Aqueous-Solutions, Hexavalent Chromium, Fly-Ash, Ion-Exchange, Mixed Adsorbents, Waste-Water, China-Clay, Red Mud

? Chrysikopoulos, C.V., Hsuan, P.Y., Fyrillas, M.M. and Lee, K.Y. (2003), Mass transfer coefficient and concentration boundary layer thickness for a dissolving NAPL pool in porous media. Journal of Hazardous Materials, 97 (1-3), 245-255.

Full Text: 2003\J Haz Mat97, 245.pdf

Abstract: Analytical expressions for the time invariant, average mass transfer coefficient and the concentration boundary layer thickness applicable to dissolving single-component nonaqueous phase liquid (NAPL) pools in two-dimensional, saturated, homogeneous and isotropic porous formations are derived. Good agreement between predicted and experimentally determined time invariant average mass transfer coefficients is observed. (C) 2002 Elsevier Science B.V. All rights reserved.

Keywords: Agreement, Analytical Solutions, Aquifers, Concentration Boundary Layer, Contaminant Transport, Contaminant Transport, Dense Chlorinated Solvents, Dissolution, DNAPL, Expressions, Groundwater, Mass Transfer, Mass Transfer Coefficient, Media, NAPL Pool Dissolution, Nonaqueous Phase Liquid, Rights, Sorption, Subsurface Formations, Transfer, Trichloroethylene

? Huang, Z.H., Kang, F.Y., Liang, K.M. and Hao, J.M. (2003), Breakthrough of methyethylketone and benzene vapors in activated carbon fiber beds. Journal of Hazardous Materials, 98 (1-3), 107-115.

Full Text: 2003\J Haz Mat98, 107.pdf

Abstract: The breakthrough of low concentration methyethylketone (MEK) and benzene vapors in beds packed with rayon-based activated carbon fiber (ACF) with different surface areas was investigated. The breakthrough characteristics depend on the properties of the ACF and the vapors, as well as on the adsorption conditions. The results of dynamic adsorption in an ACF bed were consistent with those of equilibrium adsorption by gravimetric methods. The breakthrough adsorption indicates that ACF, with an appropriate surface area, could be utilized in controlling volatile organic compounds (VOCs) in indoor air. (C) 2002 Elsevier Science B.V All rights reserved.

Keywords: ACF, Activated Carbon, Activated Carbon Fiber, Adsorption, Air Purification, Benzene, Breakthrough, Carbon, Cloth, Dynamic, Dynamic Adsorption, Equilibrium, Fitting, Gas Streams, Methods, Methyethylketone, Organic Compounds, Phase, Rights, Surface, VOCs, Volatile Organic Compounds, Volatile Organic-Compounds

? Santhosh, G., Venkatachalam, S., Ninam, K.N., Sadhana, R., Alwan, S., Abarna, V. and Joseph, M.A. (2003), Adsorption of ammonium dinitramide (ADN) from aqueous solutions - 1. Adsorption on powdered activated charcoal. Journal of Hazardous Materials, 98 (1-3), 117-126.

Full Text: 2003\J Haz Mat98, 117.pdf

Abstract: Investigations on the adsorption of ammonium dinitramide (NH₄N(NO₂)₂) (ADN) from aqueous solutions on powdered activated charcoal (PAC) were carried out in order to find out an effective and easier method of separating ADN from aqueous solutions. The effectiveness of PAC in the selective adsorption of ADN from aqueous solutions of ADN (ADN-F) and ADN in presence of sulfate (SO₄^2-) and nitrate (NO₃^-) ions (ADN-PS) was examined and compared using batch and column methods. The adsorption process follows both Langmuir and Freundlich adsorption isotherms and the isotherm parameters for the models were detemined. The observed data favor the formation of monolayer adsorption. The adsorption capacities were found to be 63.3, 119, 105.3 and 82 mg of ADN per g of PAC for ADN-F (batch), ADN-PS (batch), ADN-F (column) and ADN-PS (column), respectively. Break-through curves for ADN-F and ADN-PS were obtained for the optimization of separation of ADN from aqueous solutions. Elution curves were generated for the desorption of ADN from PAC using hot water as eluent. (C) 2002 Elsevier Science B.V All rights reserved.

Keywords: Acid, Activated Charcoal, Adsorption, Adsorption Capacities, Adsorption Isotherms, Adsorption Process, Ammonium, Ammonium Dinitramide (ADN), Aqueous Solutions, Batch, Column, Desorption, Effectiveness, Freundlich, Ions, Isotherm, Isotherms, Langmuir, Langmuir and Freundlich Isotherms, Methods, Models, Monolayer, Nitrate, Optimization, PAC, Powdered Activated Charcoal, Presence, Process, Rights, Separation, Sulfate, Water

? Kim, J.Y., Shim, S.B. and Shim, J.K. (2003), Effect of amphiphilic polyurethane nanoparticles on sorption-desorption of phenanthrene in aquifer material. Journal of Hazardous Materials, 98 (1-3), 145-160.

Full Text: 2003\J Haz Mat98, 145.pdf

Abstract: Micelle-like amphiphilic nano-sized polyurethane (APU) nanoparticles were synthesized via chemical cross-linking reaction of nano-aggregates of urethane acrylate nonionomer (UAN) chain and were tested for extraction efficiency of sorbed phenanthrene from aquifer material. Even though the solubilizing performance and interfacial activity of APU nanoparticles were inferior to that of Triton X-100, in the low concentration region, APU nanoparticles could effectively reduce phenanthrene sorption on the aquifer material and extracted sorbed phenanthrene from the aquifer material, whereas Triton X-100 could not extract sorbed phenanthrene and rather increased phenanthrene sorption onto the aquifer materials. At higher concentrations, APU nanoparticles and Triton X-100 had almost the same soil washing effectiveness. This interesting result is mainly due to a lower degree of sorption of APU nanoparticles onto the aquifer material. The sorption of APU nanoparticles onto aquifer sand is largely hindered by their chemically cross-linked nature, resulting in better soil-washing performance of APU nanoparticles than Triton X-100. (C) 2003 Elsevier Science B.V All rights reserved.

Keywords: Amphiphilic, Amphiphilic Polymer, Contaminants, Cross-Linked, Crosslinked, Crosslinking, Desorption, Effectiveness, Efficiency, Extraction, Nanoparticles, Nonionic Surfactant, Performance, Phenanthrene, Polycyclic Aromatic-Hydrocarbons, Polyurethane, Region, Rights, Sand, Soil, Soil Washing, Solubilization, Sorption, Sorption-Desorption, Subsurface Remediation, Transport, Triton X-100, Washing, Water

? Pandey, A.K., Pandey, S.D., Misra, V. and Devi, S. (2003), Role of humic acid entrapped calcium alginate beads in removal of heavy metals. Journal of Hazardous Materials, 98 (1-3), 177-181.

Full Text: 2003\J Haz Mat98, 177.pdf

Abstract: Most of the available techniques for removal of heavy metals from solution such as leachates from waste sites are very expensive. The technique described in this paper is designed to study the removal of humic acid by alginate beads and the subsequent binding of the metals within the beads thus decreasing the leachability of heavy metals from a hazardous waste site. The entry of 500 mg/l humic acid into 3% calcium alginate beads in 24 h showed a distinct fluorescence as compared to the fluorescence shown by the entry of 100 and 250 mg/l of humic acid into alginate beads. Further, on treatment of calcium alginate beads containing 500 mg/l humic acid with metals such as Cu, Mn, Zn, Cr and Fe, quenching of fluorescence was noticed, which was maximum with Cu and minimum with Fe. (C) 2003 Elsevier Science B.V All rights reserved.

Keywords: Acid, Alginate, Alginate Beads, Beads, Biosorption, Ca-Alginate, Calcium, Calcium Alginate Beads, Cu, Disposal, Fluorescence Intensity, Quenching, Gel Beads, Hazardous Waste, Heavy Metals, Humic Acid, Leachates, Metal Removal, Metals, Removal, Rights, Technique, Treatment, Zn

Notes: highly cited

Özacar, M. and Şengil, İ.A. (2003), Adsorption of reactive dyes on calcined alunite from aqueous solutions. Journal of Hazardous Materials,