Personal Research Database

Full Text: W\Was Man22, 471.pdf

Abstract: This paper investigates the ability of peanut hulls and peanut hull pellets to adsorb copper from dilute aqueous metal ion solutions in batch and fixed bed systems, The kinetics of copper uptake onto the media have been investigated in batch systems and the influence of pH and particle size on the rate and extent of copper capture determined. The Langmuir and Freundlich isotherm theories were determined; the Langmuir model was found to best represent the equilibrium isotherm data. In normalized kinetic tests at least 75% of copper removal occurred within the first 20 min; 92% removal was effected within the first 50 min. The rate of uptake was optimum within the pH range 5-7.5 and media capacities remained relatively constant at a pH above 4.0. Bench-scale column studies were performed using peanut hull pellets. The overall capacity of pelletized peanut hulls was higher than for unmodified peanut hulls. Due to their demonstrated ability for Cu(II) uptake and favorable structural characteristics, pelletized peanut hulls could gain use as a low-cost, once-through biomass filter medium for copper-bearing waste streams. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Adsorption Capacity, Adsorption Isotherms, Heavy Metals, Low-Cost Adsorbents, Rption, Cadmium, Water, Equilibrium, Adsorbent, Removal, Metals, Peat, Ions

Rengaraj, S., Moon, S.H., Sivabalan, R., Arabindoo, B. and Murugesan, V. (2002), Agricultural solid waste for the removal of organics: Adsorption of phenol from water and wastewater by palm seed coat activated carbon. Waste Management, 22 (5), 543-548.

Full Text: W\Was Man22, 543.pdf

Abstract: Adsorption studies for phenol removal from aqueous solution on activated palm seed coat carbon (PSCC) were carried out under varying experimental conditions of contact time. phenol concentration, adsorbent dose and pH. Adsorption equilibrium was reached within 3 h for phenolic concentrations 10-60 mg l^-1. Kinetics of adsorption obeyed a first order rate equation. The percent removal remained constant over the pH range 4-9 for a phenolic concentration of 25 mg l^-1. The equilibrium data could be described well by the Freundlich isotherm equation. The adsorption of phenol on PSCC follows the film diffusion process. A comparative study with a commercial activated carbon showed that PSCC is two times more effective than commercial activated carbon. The studies showed that the palm seed coat carbon can be used as an efficient adsorbent material for the removal of phenolics from water and wastewater. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Activated Carbon, Palm Seed Coat, Adsorption, Phenol, Isotherm, Kinetics, Wastewater, Bagasse Fly-Ash, Sugar-Industry

Mohan, S.V., Rao, N.C., Prasad, K.K. and Karthikeyan, J. (2002), Treatment of simulated Reactive Yellow 22 (Azo) dye effluents using Spirogyra species. Waste Management, 22 (6), 575-582.

Full Text: W\Was Man22, 575.pdf

Abstract: The potential of commonly available green algae belonging to Spirogyra species was investigated as viable biomaterials for biological treatment of simulated synthetic azo dye (Reactive Yellow 22) effluents. The results obtained from the batch experiments revealed the ability of the algal species in removing the dye colour and was dependent both on the dye concentration and algal biomass. Maximum dye colour removal was observed on the third day for all the system conditions. Monitoring of ORP values helped to understand the overlying biochemical mechanism of algal–dye system. Based upon the results, the dye–algal treatment mechanism was attributed to biosorption (sorption of dye molecules over the surface of algal cells), bioconversion (diffusion of dye molecules into the algal cells and subsequent conversion) and biocoagulation (coagulation of dye molecules present in the aqueous phase onto the biopolymers released as metabolic intermediates during metabolic conversion of dye and subsequent settlement).

Lin, S.H. and Cheng, M.J. (2002), Adsorption of phenol and m-chlorophenol on organobentonites and repeated thermal regeneration. Waste Management, 22 (6), 595-603.

Full Text: W\Was Man22, 595.pdf

Abstract: Experimental investigations were conducted on the adsorption characteristics of phenol and m-chlorophenol by organobentonites. The organobentonites were prepared by modifying natural bentonite with various quaternary ammonium salts including tetramethylammonium bromide, hexadecyltrimethylammonium bromide, benzyl-triethylammonium bromide, tetraethylamnionium bromide and cetylpyridinium bromide. The adsorption characteristics of phenol and chlorophenol by these organobentonites were examined in detail. The empirical Freundlich isotherm was found to describe well the equilibrium adsorption data. Thermal regeneration of spent organobentonites was also investigated and operating conditions of 200degreesC and 2 h heating were found to yield very good results. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Organobentonite, Phenol, M-Chlorophenol, Adsorption, Regeneration, Organo-Clays, Exchanged Clays, Sorption, Water, Pollutants, Cosorption, Bentonite, Oxidation

? Annadurai, G. and Juang, R.S., Lee, D.J. (2002), Microbiological degradation of phenol using mixed liquors of Pseudomonas putida and activated sludge. Waste Management, 22 (7), 703-710.

Full Text: 2002\Was Man22, 703.pdf

Abstract: This work investigated the biodegradation potential of phenol using mixed liquors of Pseudomonas putida (ATCC 31800) and activated sludge. Experiments were made as a function of solution pH (6-10), temperature (30-36°C), nitrogen source (NH₄)₂SO₄ (0.5-0.8 g/l), and carbon source glucose (0.5-0.8 g/l). Response surface methodology by the Box-Behnken model was used to examine the role of four process factors on phenol degradation. It was shown that a second-order polynomial regression model could properly interpret the experimental data with an R-2-value of 0.9997 and an F-value of 3605.45, based on which the maximum degradation of phenol was estimated up to 80.1% within the range examined. Interactions between process parameters and each significance effect on phenol degradation were also discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Fly-Ash, Adsorption, Biosorption, Temperature

Galiatsatou, P., Metaxas, M., Arapoglou, D. and Kasselouri-Rigopoulou, V. (2002), Treatment of olive mill waste water with activated carbons from agricultural by-products. Waste Management, 22 (7), 803-812.

Full Text: W\Was Man22, 803.pdf

Abstract: A series of activated carbons prepared by a two-step steam activation of olive stone and solvent extracted olive pulp (SEOP) have been used in an attempt to investigate the total phenol removal and chemical oxygen demand (COD) decrease in olive mill waste water (OMWW). The temperature of carbonization and activation were kept constant at 850 and 800 degreesC, respectively. One of the carbons was prepared by a single-step process at 800 degreesC. Activated carbons have been characterized by adsorption of N₂ at 77 K and mercury porosimetry. Their iodine values were also determined. Surface oxides of activated carbons were determined using the Boehm’s method. The porosity development and the surface chemistry of carbons were correlated to increasing removal ability of organic molecules. Kinetics of adsorption was evaluated by applying the Lagegren model while adsorption isotherm data were fitted to Langmuir model. Mesoporosity seems to be the key factor for total phenol removal while micoporosity controls the adsorption of total organics as expressed by the COD decrease in OMWW. For carbons with similar structure, the adsorption of phenols or total organics might be affected by the presence of carbonyls. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Adsorption, Removal, Phenol

Rao, M., Parwate, A.V. and Bhole, A.G. (2002), Removal of Cr⁶⁺ and Ni²⁺ from aqueous solution using bagasse and fly ash. Waste Management, 22 (7), 821-830.

Full Text: W\Was Man22, 821.pdf

Abstract: Raw bagasse and fly ash, the waste generated in sugar mills and boilers respectively have been used as low-cost potential adsorbents. Raw bagasse was pretreated with 0.1N NaOH followed by 0.1N CH₃COOH before its application. These low-cost adsorbents were used for the removal of chromium and nickel from an aqueous solution. The kinetics of adsorption and extent of adsorption at equilibrium are dependent on the physical and chemical characteristics of the adsorbent, adsorbate and experimental system. The effect of hydrogen ion concentration, contact time, sorbent dose, initial concentrations of adsorbate and adsorbent and particle size on the uptake of chromium and nickel were studied in batch experiments. The Sorption data has been correlated with Langmuir, Freundlich and Bhattacharya and Venkobachar adsorption models. The efficiencies of adsorbent materials for the removal of Cr(VI) and Ni(II) were found to be between 56.2 and 96.2% and 83.6 and 100%, respectively. These results were obtained at the optimized conditions of pH, contact time, sorbent dose, sorbate concentration of 100 mg/l and with the variation of adsorbent particles size between 0.075 and 4.75 mm. The order of selectivity is powdered activated carbon>bagasse>fly ash for Cr(VI) removal and powdered activated carbon>fly ash>bagasse for Ni(II) removal.

? Lusvardi, G., Malavasi, G., Menabue, L. and Saladini, M. (2002), Removal of cadmium ion by means of synthetic hydroxyapatite. Waste Management, 22 (8), 853-857.

Full Text: 2002\Was Man22, 853.pdf

Abstract: The reaction behaviour of synthetic hydroxyapatite [Ca-10(PO4)(6)(OH)(2)] (HAP) toward cadmium ion was investigated for the Cd/Ca molar ratio in the range 1-0.005, by means of ions, pH measurements and XRD, SEM, IR techniques. The reaction behaviour between HAP and cadmium ion could be explained by a formation of an amorphous phase and/or a sorption mechanism. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Cadmium, IR, Mechanism, SEM, Sorption

? Pagnanelli, F., Toro, L. and Veglio, F. (2002), Olive mill solid residues as heavy metal sorbent material: A preliminary study. Waste Management, 22 (8), 901-907.

Full Text: 2002\Was Man22, 901.pdf

Abstract: Biosorption of heavy metals is an innovative and alternative technology to remove these pollutants from aqueous solutions using inactive and dead biomasses such as agricultural and industrial wastes, algae and bacteria. In this study olive mill solid residue was used as heavy metal adsorbent material for its wide availability as agricultural waste and also for its cellulosic matrix, rich of potential metal binding active sites. Preliminary studies concerned with the removal of different heavy metals (Hg, Pb, Cu, Zn and Cd), the effect of pre-treatments by water and n-hexane and the regeneration possibility. Olive mill solid residue resulted able to remove heavy metals from aqueous solutions with an affinity series reflecting the hydrolytic properties of the metallic ions, but also a particular affinity for copper. It can be supposed that biosorption phenomenon occur by a general ion exchange mechanism combined with a specific complexation reaction for copper ions. Water pre-treatment is sufficient to reduce COD release in the effluent according to the law limit, while n-hexane pre-treatment strongly reduces also the adsorption properties of this material. Experimental isotherms obtained under different operating conditions were fitted using a nonlinear regression method for the estimation of the Langmuir parameters. Moreover a simple Scatchard plot analysis was performed for a preliminary investigation of the active sites, showing the presence of two different site affinities depending on the metal concentration, according to the previous hypothesis of two kinds of uptake mechanisms for copper biosorption, Regeneration tests gave good results in terms of yield of regeneration and also concentration ratios. (C) 2002 Elsevier Science Ltd. All rights reserved.

Keywords: Adsorption, Adsorption Properties, Binding, Biosorption, Complexation, Copper, Heavy Metal, Heavy Metals, Ion Exchange, Isotherms, Mechanism, Mechanisms, Metal, Metals, pH, Pomace, Regeneration, Removal, Waste, Water

? Mohan, S.V., Sistla, S., Guru, R.K., Prasad, K.K., Kumar, C.S., Ramakrishna, S.V. and Sarma, P.N. (2003), Microbial degradation of pyridine using Pseudomonas sp and isolation of plasmid responsible for degradation. Waste Management, 23 (2), 167-171.

Full Text: 2003\Was Man23, 167.pdf

Abstract: Pseudomonas (PI2) capable of degrading pyridine was isolated from the mixed population of the activated sludge unit which was being used for treating complex effluents, the strain was characterized. Aerobic degradation of pyridine was studied with the isolated strain and the growth parameters were evaluated. Pyridine degradation was further conformed by chromatography (HPLC) analysis. The process parameters like biomass growth and dissolved oxygen consumption were monitored during pyridine degradation. In order to conform with the plasmid capability to degrade pyridine, the requisite plasmid was isolated and transferred to DH 5alpha Escherichia coli. The subsequent biodegradation studies revealed the ability of the transformed plasmid capability to degrade the pyridine. (C) 2003 Elsevier Science Ltd. All rights reserved.

Keywords: Derivatives, Quinoline

Raposo, C., Windmöller, C.C. and Júnior, W.A.D. (2003), Mercury speciation in fluorescent lamps by thermal release analysis. Waste Management, 23 (10), 879-886.

Full Text: W\Was Man23, 879.pdf

Abstract: In this work, mercury speciation in phosphorus powder matrices and soda lime glass waste from new and spent fluorescent lamp wastes has been studied by thermo-desorption/atomic absorption spectrometry (TDAAS), X-ray diffraction (XRD), cold vapor-atomic absorption (CV-AAS) and atomic emission spectrometry/inductively coupled plasma (ICP/AES). TDAAS results show the presence of oxidized forms of mercury, i.e., Hg¹⁺ and Hg²⁺, especially in wastes with high mercury concentration. Such forms are mobile, and therefore represent a potential hazard waste material. Glass TD profiles of spent fluorescent lamps suggested the presence of mercury strongly linked to the matrix, which desorbs only at high temperatures.

Gan, Q., Allen, S.J. and Matthews, R. (2004), Activation of waste MDF sawdust charcoal and its reactive dye adsorption characteristics. Waste Management, 24 (8), 841-848.

Full Text: W\Was Man24, 841.pdf

Abstract: This paper reports an experimental investigation of converting waste medium density fibreboard (MDF) sawdust into chars and activated carbon using chemical activation and thermal carbonisation processes. The MDF sawdust generated during the production of architectural mouldings was characterised and found to have unique properties in terms of fine particle size and high particle density. It also has a high content of urea formaldehyde resin used as a binder in the manufacturing of MDF board. Direct thermal carbonisation and chemical activation of the sawdust by metal impregnation and acid (phosphoric acid) treatment prior to pyrolysis treatment were carried out. The surface morphology of the raw dust, its chars and activated carbon were examined using scanning electron microscopy (SEM). Adsorptive properties and total pore volume of the materials were also analysed using the BET nitrogen adsorption method. Liquid adsorption of a reactive dye (Levafix Brilliant red E-4BA) by the derived sawdust carbon was investigated in batch isothermal adsorption process and the results compared to adsorption on to a commercial activated carbon (Filtrasorb F400). The MDF sawdust carbon exhibited in general a very low adsorption capacity towards the reactive dye, and physical characterisation of the carbon revealed that the conventional chemical activation and thermal carbonisation process were ineffective in developing a microporous structure in the dust particles. The small size of the powdery dust, the high particle density, and the presence of the urea formaldehyde resin all contributed to the difficulty of developing a proper porous structure during the thermal and chemical activation process. Finally, activation of the dust material in a consolidated form (cylindrical pellet) only achieved very limited improvement in the dye adsorption capacity. This original study, reporting some unexpected outcomes, may serve as a stepping-stone for future investigations of recycle and reuse of the waste MDF sawdust which is becoming an increasing environmental and cost liability. (C) 2004 Elsevier Ltd. All rights reserved.

Keywords: Water, Carbon

Ko, D.C.K., Mui, E.L.K., Lau, K.S.T. and McKay, G. (2004), Production of activated carbons from waste tire: Process design and economical analysis. Waste Management, 24 (9), 875-888.

Full Text: W\Was Man24, 875.pdf

Abstract: The process design and economic analysis of process plants to produce activated carbons from waste tires and coal have been performed. The potential range of products from each process has been considered, namely for waste tire - pyro-gas, active carbon, carbon black and pyro-oil; for coal - pyro-gas and active carbons. Sensitivity analyses have been carried out on the main process factors; these are product price, production capacity, total production cost, capital investment and the tipping fee. Net present values for the two plants at various discount factors have been determined and the internal rates of return have been determined as 27.4% and 18.9% for the waste tire plant and the coal plant, respectively. (C) 2004 Elsevier Ltd. All rights reserved.

Keywords: Tyre Pyrolysis Oil, Scrap Tires, Vacuum Pyrolysis, Automotive Tires, Spanish Coals, Bed Reactor, Temperature, Combustion, Rubber, Black

? Jang, M., Hong, S.M. and Park, J.K. (2005), Characterization and recovery of mercury from spent fluorescent lamps. Waste Management, 25 (1), 5-14.

Full Text: 2005\Was Man25, 5.pdf

Abstract: Fluorescent lamps rely on mercury as the source of ultraviolet radiation for the production of visible light. Partitioning of mercury among vapor phase, loose phosphor powders produced during breaking and washing steps, glass matrices, phosphor powders attached on the glass and aluminum end caps was examined from simulated laboratory lamp recycling tests for different types of spent and new fluorescent lamps. Mercury concentrations in lamp glasses taken from commercial lamp recyclers were also analyzed for comparison with the simulated results of spent and new lamps of different types. The mercury content of the glass from spent lamps was highly variable depending on the lamp type and manufacturer; the median values of the mercury concentration in glasses for spent 26- (T8) and 38-mm (T12) diameter fluorescent lamps were approximately 30 and 45 μg/g, respectively. The average mercury concentration of samples taken from recycler A was 29.6 μg/g, which was about 64% of median value measured from the spent T12 lamps. Over 94% of total mercury in lamps remained either as a component of phosphor powders attached inside the lamp or in glass matrices. New T12 lamps had a higher partitioning percentage of elemental mercury in the vapor phase (0.17%) than spent T12 lamps (0.04%), while spent lamps had higher partitioning percentages of mercury resided on end-caps and phosphor powders detached from the breaking and washing steps. The TCLP values of simulated all lamp-glasses and samples obtained from recyclers were higher than the limit of LDR standard (0.025 mg/L). After investigating acid treatment and high temperature treatment as mercury reclamation techniques, it was found that heating provided the most effective mercury capture. Although the initial mercury concentrations of individual sample were different, the mercury concentrations after 1 h exposure at 100 °C were below 4 μg/g for all samples (i.e., <1% remaining). Therefore, it is recommended that heating be used for recovering mercury from spent fluorescent lamps.

? Antizar-Ladislao, B., Lopez-Real, J. and Beck, A.J. (2005), Laboratory studies of the remediation of polycyclic aromatic hydrocarbon contaminated soil by in-vessel composting. Waste Management, 25 (3), 281-289.

Full Text: 2005\Was Man25, 281.pdf

Abstract: The biodegradation of 16 polycyclic aromatic hydrocarbons (PAHs), listed as priority pollutants by the USEPA, present in a coal-tar-contaminated soil from a former manufactured gas plant site was investigated using laboratory-scale in-vessel composting reactors to determine the suitability of this approach as a bioremediation technology. Preliminary investigations were conducted over 16 weeks to determine the optimum soil composting temperature (38, 55 and 70°C). Three tests were performed; firstly, soil was composted with green-waste, with a moisture content of 60%. Secondly, microbial activity was HgCl₂-inhibited in the soil green-waste mixture with a moisture content of 60%, to evaluate abiotic losses, while in the third experiment only soil was incubated at the three different temperatures. PAHs and microbial populations were monitored. PAHs were lost from all treatments with 38°C being the optimum temperature for both PAH removal and microbial activity. Calculated activation energy values (Ea) for total PAHs suggested that the main loss mechanism in the soil-green waste reactors was biological, whereas in the soil reactors it was chemical. Total PAH losses in the soil-green waste composting mixtures were by pseudo-first order kinetics at 38°C (k = 0.013 day^-1, R-2 = 0.95), 55°C (k = 0.010 day^-1, R-2 = 0.76) and at 70°C (k = 0.009 day, R-2 = 0.73). (c) 2005 Elsevier Ltd. All rights reserved.

Keywords: Activation, Activation Energy, Activity, Aromatic, Aromatic Hydrocarbon, Aromatic Hydrocarbons, Biodegradation, Bioremediation, Chemical, Composting, Contaminated Soil, Energy, Experiment, Hydrocarbon, Hydrocarbons, Investigations, Kinetics, Losses, Mechanism, Microbial, Microbial Activity, Mixture, Mixtures, Moisture, Moisture Content, Order, PAH, PAHS, Plant, Pollutants, Polycyclic Aromatic Hydrocarbon, Polycyclic Aromatic Hydrocarbons, Priority Pollutants, Pseudo-First Order, Remediation, Removal, Soil, Systems, Temperature, Temperatures, Tests, Waste

? Cartellieri, A., Thiesen, P.H. and Niemeyer, B. (2005), Development of a basic procedure to design sorption processes. Waste Management, 25 (9), 985-993.

Full Text: 2005\Was Man25, 985.pdf

Abstract: The intention of this work is to offer, within the shortest time, an appropriate sorption separation process for almost any odour problem. The development is based on the preparation and characterisation of new adsorbents, the strategy for the selection of the best adsorbent, the process engineering and the choice of a suitable regeneration procedure. In this context a new method for the characterisation of the adsorbents-the adsorption profile analysis-was developed. The classification of the adsorbents was carried out by means of a cluster analysis, which simplifies the selection of the most suitable adsorbent for a particular problem. The physical and chemical behaviour of silica-adsorbents could be tailored by silanisation of the surfaces. Methods for the determination of process engineering parameters were developed, established and used. Adsorption kinetics and isotherms were determined with a magnetic adsorption balance. In a laboratory-scale fixed bed adsorber, breakthrough curves of different support materials were investigated and compared. For the investigations of different regeneration procedures, four innovative methods were employed: microwave desorption, ultrasonic desorption, ultrasonic-water desorption and extraction with water. Of the four desorption methods examined, microwave desorption and ultrasonic-water desorption demonstrated the best results. (C) 2005 Published by Elsevier Ltd.

Keywords: Activated-Charcoal, Adsorption, Air, Charcoal Fixed-Beds, Classification, Desorption, Fixed-Bed, Isotherms, Kinetics, Regeneration, Silica-Surface, Sorption, Thermal Regeneration, Waste-Gas, Water

? Coleman, N.J., Brassington, D.S., Raza, A. and Mendham, A.P. (2006), Sorption of Co²⁺ and Sr²⁺ by waste-derived 11 Åtobermorite. Waste Management, 26 (3), 260-267.

Full Text: 2006\Was Man26, 260.pdf

Abstract: Newsprint recycling gives rise to significant volumes of waste sludge which can be de-watered and combusted for energy-recovery. The residual combustion ash, whose primary crystalline constituents are; gehlenite (Ca₂Al₂SiO₇), åkermanite (Ca₂MgSi₂O₇), β-dicalcium silicate (Ca₂SiO₄) and anorthite (CaAl₂Si₂O₈), is currently consigned to landfill disposal. It is demonstrated herein that a mixed product of Al-substituted 11 Åtobermorite (Ca₅Si₆O₁₈H₂·4H₂O) and katoite (Ca₃Al₂SiO₁₂H₈) can be synthesised from newsprint recycling combustion ash via a hydrothermal route. Batch sorption studies confirm that this mixed product is an effective sorbent for the exclusion of Co²⁺ and Sr²⁺ from acidic aqueous media. Kinetic sorption data are analysed in accordance with the pseudo-first- and pseudo-second-order models, and steady-state data is fitted to the Langmuir and Freundlich isotherms. The Langmuir and pseudo-second-order models are found to provide the most appropriate descriptions of the sorption processes. The maximum uptake capacities for Co²⁺ and Sr²⁺ at 20 °C are 10.47 and 1.52 mg g⁻¹, respectively, and the respective apparent pseudo-second-order rate constants are estimated to be 5.08×10⁻³ and 6.96×10⁻³ g mg⁻¹ min⁻¹.

Keywords: Heavy-Metals Removal, Calcium Silicates, Ions, Exchange, Substitution, Adsorption, Hydration, Cations, Phase, Ash

? Sarkar, M. and Acharya, P.K. (2006), Use of fly ash for the removal of phenol and its analogues from contaminated water. Waste Management, 26 (6), 559-570.

Full Text: 2006\Was Man26, 559.pdf

Abstract: This work attempts to elucidate the effects of different operational variables affecting the mechanistic function of fly ash for removal of some priority organic pollutants viz. phenol and its analogues. Thermodynamic parameters like free energy change, enthalpy and entropy of the process, as well as the sorption isotherms for phenols on fly ash, were measured and the most suitable isotherm was determined. Results of the study indicate that the extent of solute removal is determined by the initial solute concentration, molecular size and molecular arrangement of the solute. At the fixed set of experimental conditions, a model equation can be developed from which the percent removal corresponding to the load of the particular solute is determined. It is assumed that the mechanism of adsorption is governed by the surface characteristics of fly ash; pH has a vital role in influencing the solute removal as both the ionizing power (acidity, pK(a)) of the solutes and the zero point charge of fly ash (pH(zpc)) depend on the solution pH. Isotherm pattern and the free energy change indicate that the process is favorable, as well as spontaneous. The information gathered from the study will serve as a predictive modeling procedure for the analysis and design of the removal of organic pollutants and decontamination of water. The leaching experiment indicates that the retained solutes do not release from fly ash. The retained solutes can be recovered and utilized as industrial raw material. (c) 2006 Elsevier Ltd. All rights reserved.

Keywords: Activated Carbon, Adsorption, Aqueous-Solutions, Biodegradation, Chlorophenols, Degradation, Fly Ash, Hydrogen-Peroxide, Isotherm, Isotherms, Mechanism, Modeling, Priority Organic Pollutants, Removal, Solid-Phase Extraction, Solute, Sorption, Substituted Phenols, Water

? Ochs, M., Pointeau, I. and Giffaut, E. (2006), Caesium sorption by hydrated cement as a function of degradation state: Experiments and modelling. Waste Management, 26 (7), 725-732.

Full Text: 2006\Was Man26, 725.pdf

Abstract: To provide reliable K-d data for Cs required for the performance assessment of cement-based radioactive waste repositories, two complementary approaches were followed. First, Cs sorption was determined on a range of hydrated cement paste (HCP) and mortar samples of CEM I and CEM V for different degradation states and solution compositions, as well as on some single mineral phases. Second, a surface complexation-diffuse layer model previously developed by Pointeau et al. [Pointeau, L, Marmier, N., Fromage, F., Fedoroff, M., Giffaut, E.. 2001. Cs and Pb uptake by CSH phases of hydrated cement. Material Research Society Symposium Proceedings, 663, 105-113] for Cs sorption on synthetic CSH phases was simplified to facilitate its application to whole HCP and mortars or concrete, following re-assessment of the model parameters. All measurements were compared with model predictions. The sorption data obtained on the different solid phases as a function of conditions corroborate that CSH minerals are the main sorbing phase for Cs in HCP. The data also clearly show the important influence of pH and the dissolved concentration of Na, K and Ca on K-d. It is further suggested that a decrease of pH is concomitant with a decrease of the Ca/Si ratio and a corresponding increase in surface sites with high affinity for Cs and, thus, K-d. Elevated concentrations of cations able to compete with Cs for these sites lead to a decrease of K-d, on the other hand. The simplified model was applied to the sorption measurements performed within this study as well as to a variety of literature data, mainly K-d values for a variety of fresh HCP and mortar or concrete samples based on different samples of Ordinary Portland Cement as well as blended cements. The results show that the model can be applied reasonably well to a very large variety of conditions in terms of solid and solution compositions that cover a range of K-d values from 10^-4 to ca. 3.2 m³/kg. The large scatter typically observed for Cs sorption, especially on fresh HCP samples prepared from different formulations, can be explained quantitatively by the variable concentrations of Na and K in the respective solutions, which compete with Cs for fixation sites. On the other hand, the comparatively uniform conditions in degraded HCP typically render the prediction of K-d values less uncertain than in case of fresh HCP. (c) 2006 Published by Elsevier Ltd.

Keywords: Assessment, Carbonation, Degradation, Diffusion, Lead, Research, Solubility, Sorption

? Kumpiene, J., Lagerkvist, A. and Maurice, C. (2008), Stabilization of As, Cr, Cu, Pb and Zn in soil using amendments - A review. Waste Management, 28 (1), 215-225.

Full Text: 2008\Was Man28, 215.pdf

Abstract: The spread of contaminants in soil can be hindered by the soil stabilization technique. Contaminant immobilizing amendments decrease trace element leaching and their bioavailability by inducing various sorption processes: adsorption to mineral surfaces, formation of stable complexes with organic ligands, surface precipitation and ion exchange. Precipitation as salts and co-precipitation can also contribute to reducing contaminant mobility. The technique can be used in in situ and ex situ applications to reclaim and re-vegetate industrially devastated areas and mine-spoils, improve soil quality and reduce contaminant mobility by stabilizing agents and a beneficial use of industrial by-products. This study is an overview of data published during the last five years on the immobilization of one metalloid, As, and four heavy metals, Cr, Cu, Pb and Zn, in soils. The most extensively studied amendments for As immobilization are Fe containing materials. The immobilization of As occurs through adsorption on Fe oxides by replacing the surface hydroxyl groups with the As ions, as well as by the formation of amorphous Fe(III) arsenates and/or insoluble secondary oxidation minerals. Cr stabilization mainly deals with Cr reduction from its toxic and mobile hexavalent form Cr(VI) to stable in natural environments Cr(III). The reduction is accelerated in soil by the presence of organic matter and divalent iron. Clays, carbonates, phosphates and Fe oxides were the common amendments tested for Cu immobilization. The suggested mechanisms of Cu retention were precipitation of Cu carbonates and oxyhydroxides, ion exchange and formation of ternary cation-anion complexes on the surface of Fe and Al oxy-hydroxides. Most of the studies on Pb stabilization were performed using various phosphorus-containing amendments, which reduce the Pb mobility by ionic exchange and precipitation of pyromorphite-type minerals. Zn can be successfully immobilized in soil by phosphorus amendments and clays. (c) 2007 Elsevier Ltd. All rights reserved.

Keywords: Adsorption, Arsenic(III) Oxidation, Bioavailability, Chemical Immobilization, Fly-Ash, Groups, Heavy Metals, Heavy-Metal Immobilization, In-Situ Stabilization, Ion Exchange, Ligands, Mechanisms, Metals, Mine Spoil, Phosphates, Phosphorus, Precipitation, Sewage-Sludge, Sludge-Amended Soil, Smelter-Contaminated Soil, Soil Quality, Soils, Sorption, Stabilization, Surface Precipitation, X-Ray-Fluorescence

? Feller, C. and Bernoux, M. (2008), Historical advances in the study of global terrestrial soil organic carbon sequestration. Waste Management, 28 (4), 734-740.

Full Text: 2008\Was Man28, 734.pdf

Abstract: This paper serves two purposes: it provides a summarized scientific history of carbon sequestration in relation to the soil-plant system and gives a commentary on organic wastes and SOC sequestration.

The concept of soil organic carbon (SOC) sequestration has its roots in: (i) the experimental work of Lundegårdh, particularly his in situ measurements of CO₂ fluxes at the soil-plant interface (1924, 1927, 1930); (ii) the first estimates of SOC stocks at the global level made by Waksman [Waksman, S.A., 1938. Humus. Origin, Chemical Composition and Importance in Nature, second ed. revised. Williams and Wilkins, Baltimore, p. 526] and Rubey [Rubey, W.W., 1951. Geologic history of sea water. Bulletin of the Geological Society of America 62, 1111–1148]; (iii) the need for models dealing with soil organic matter (SOM) or SOC dynamics beginning with a conceptual SOM model by De Saussure (1780–1796) followed by the mathematical models of Jenny [Jenny, H., 1941. Factors of Soil Formation: a System of Quantitative Pedology. Dover Publications, New York, p. 288], Hénin and Dupuis [Hénin, S., Dupuis, M., 1945. Essai de bilan de la matière organique. Annales d’Agronomie 15, 17–29] and more recently the RothC [Jenkinson, D.S., Rayner, J.H., 1977. The turnover of soil organic matter in some of the Rothamsted classical experiments. Soil Science 123 (5), 298–305] and Century [Parton, W.J., Schimel, D.S., Cole, C.V., Ojima, D.S., 1987. Analysis of factors controlling soil organic matter levels in great plains grasslands. Soil Science Society of America Journal 51 (5), 1173–1179] models.

The establishment of a soil C sequestration balance is not straightforward and depends greatly on the origin and the composition of organic matter that is to be returned to the system. Wastes, which are important sources of organic carbon for soils, are taken as an example. For these organic materials the following factors have to be considered: the presence or absence of fossil C, the potential of direct and indirect emissions of non-CO₂ greenhouse gases (CH₄ and N₂O) following application and the agro-system which is being used as a comparative reference.

? Rao, M.M., Rao, G.P.C., Seshaiah, K., Choudary, N.V. and Wang, M.C. (2008), Activated carbon from Ceiba pentandra hulls, an agricultural waste, as an adsorbent in the removal of lead and zinc from aqueous solutions. Waste Management, 28 (5), 849-858.

Full Text: 2008\Was Man28, 849.pdf

Abstract: The ability of low-cost activated carbon prepared from Ceiba pentandra hulls, an agricultural waste material, for the removal of lead and zinc from aqueous Solutions has been investigated. In the batch tests experimental parameters were studied, including solution pH, contact time, adsorbent dose and initial metal ions concentration. The adsorbent exhibited good sorption potential at pH 6.0. Maximum removal of lead (99.5%) and of zinc (99.1%) with 10 g/l of sorbent was observed at 50 mg/L sorbate concentration. Removals of about 60-70% occurred in 10 min, and equilibrium was attained at around 50 min for both metals. The functional groups (C=O, S=O,-OH) present on the carbon surface were responsible for the adsorption of metal ions. The adsorption parameters were analysed using both the Freundlich and Langmuir models. The data are better fitted by the Freundlich isotherm as compared to Langnmir model, and the adsorption capacities for lead and zinc were 25.5 and 24.1 mg/g, respectively. Kinetics of adsorption obeyed a second order rate equation and the rate constant was found to be 2.7110² and 2.0810² g/mg/min for lead and zinc, respectively. The desorption studies were carried out using dilute HCl, and the effect of HCl concentration on desorption was studied. Maximum desorptions of 85% for lead and 78% for zinc were attained with 0.15 M HCl. (C) 2007 Elsevier Ltd. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorbent Dose, Adsorption, Aqueous Solutions, Cadmium, Carbon, Cu(II), Desorption, Equilibrium, Experimental, Freundlich, Freundlich Isotherm, Heavy-Metals, Isotherm, Kinetics, Langmuir, Lead, Metal, Metal Ions, Metals, Model, Models, Pb(II), pH, Potential, Removal, Rights, Solution, Sorption, Sugarcane Bagasse Pith, Tree Fern, Zinc

? Qian, Q.R., Machida, M. and Tatsumoto, H. (2008), Textural and surface chemical characteristics of activated carbons prepared from cattle manure compost. Waste Management, 28 (6), 1064-1071.

Full Text: 2008\Was Man28, 1064.pdf

Abstract: Two activated carbons (ACs) prepared from cattle manure compost (CMC) by ZnCl₂ activation were selected and out-gassed in a helium flow at various temperatures for 2 h. The pore structure and surface chemical properties of the two selected ACs and their out-gassing treated ACs were characterized using N₂ adsorption-desorption, elements analysis, SEM and Boehm titration. A basic dye, methylene blue (MB), was chosen as an adsorbate to investigate the adsorption capacity for organic contaminant onto the activated carbons. It was found that the out-gassing treatment at 400°C had little effect on the textural characteristics of the carbons but significantly changed the surface chemical properties such as surface functional groups concentration, pH and pH(PZC). The CMC-based activated carbons exhibited excellent performance for MB adsorption due to their high surface area, large mesopore volume and high nitrogen content. The kinetics of MB adsorption onto the activated carbons followed a pseudo-second-order equation, and the equilibrium data agreed well with the Langmuir model under the experimental conditions. The highest adsorption rate constant of k(ad) and the largest adsorption capacity of q(m) were found be 1.4410^-4 g/mg min and 519 mg/g, respectively. The results suggested that the CMC-based activated carbons were effective adsorbents for the removal of methylene blue from aqueous solution. (C) 2007 Elsevier Ltd. All rights reserved.

Keywords: Activated Carbons, Activation, Adsorbents, Adsorption, Adsorption Performance, Analysis, Aqueous Solution, Aqueous-Solution, Basic Dye, Capacity, Compost, Dye, Dye Methylene-Blue, Equilibrium, Experimental, Kinetics, Langmuir, Langmuir Model, Mesopore, Methylene Blue, Model, pH, Removal, Rights, Sawdust, SEM, Sludge, Solution, Structure, Surface Area, Treatment, Waste-Water

? Chaspoul, F.R., Le Droguene, M.F., Barban, G., Rose, J.C. and Gallice, P.M. (2008), A role for adsorption in lead leachability from MSWI bottom ASH. Waste Management, 28 (8), 1324-1330.

Full Text: 2008\Was Man28, 1324.pdf

Abstract: Owing to its high porosity and large surface area, bottom ash from municipal solid waste incineration (MSWI) has been previously suggested as an adsorbent for removing heavy metals from wastewater. However, since lead leachability is not clearly understood, this study reports the behavior of lead for leaching from MSWI bottom ash, classified as NH, W and H. Leaching kinetics show a sorption/desorption mechanism producing equilibrium in the leachates. Adsorption experiments reveal a similarly high saturation coverage for NH, W and H bottom ash, demonstrating a considerable adsorption capacity. Adsorption mainly reflects an ion exchange mechanism. Successive leaching experiments prove that at least two species of lead can be stripped from bottom ash: one is Pb(OH)₄^2- and the second, dentified by XAS, is a lead complex sorbed on the surface of Fe colloid or FeOOH polymers. (C) 2007 Elsevier Ltd. All rights reserved.

Keywords: Adsorption, Adsorption Capacity, Capacity, Complex, Coverage, Equilibrium, Extraction, Fly Ashes, Heavy Metals, Heavy-Metals, Incineration, Ion Exchange, Isotherms, Kinetics, Leachability, Lead, Mechanism, Metals, Municipal, Soils, Sorption, Speciation, Species, Surface, Surface Area, Waste Incineration Residues, Wastewater

? Chen, Q.Y., Tyrer, M., Hills, C.D., Yang, X.M. and Carey, P. (2009), Immobilisation of heavy metal in cement-based solidification/stabilisation: A review. Waste Management, 29 (1), 390-403.

Full Text: 2009\Was Man29, 390.pdf

Abstract: Heavy metal-bearing waste usually needs solidification/stabilization (s/s) prior to landfill to lower the leaching rate. Cement is the most adaptable binder currently available for the immobilisation of heavy metals. The selection of cements and operating parameters depends upon an understanding of chemistry of the system. This paper discusses interactions of heavy metals and cement phases in the solidification/stabilisation process. It provides a clarification of heavy metal effects on cement hydration. According to the decomposition rate of minerals, heavy metals accelerate the hydration of tricalcium silicate (C3S) and Portland cement, although they retard the precipitation of portlandite due to the reduction of pH resulted from hydrolyses of heavy metal ions. The chemical mechanism relevant to the accelerating effect of heavy metals is considered to be H+ attacks on cement phases and the precipitation of calcium heavy metal double hydroxides, which consumes calcium ions and then promotes the decomposition Of C3S. In this work, molecular models of calcium silicate hydrate gel are presented based on the examination of Si-29 solid-state magic angle spinning/nuclear magnetic resonance (MAS/NMR). This paper also reviews immobilisation mechanisms of heavy metals in hydrated cement matrices, focusing on the sorption, precipitation and chemical incorporation of cement hydration products. It is concluded that further research oil the phase development during cement hydration in the presence of heavy metals and thermodynamic modelling is needed to improve effectiveness of cement-based s/s and extend this waste management technique. (C) 2008 Elsevier Ltd. All rights reserved.

Keywords: Accelerated Carbonation, C-S-H, Calcium Silicate Hydrate, CaO-SiO₂-H₂O System, Decomposition, Electron-Microscopy, Heavy Metal, Heavy Metals, Main Clinker Phases, Mechanism, Mechanisms, Metal, Metal Ions, Metals, Part Ii, Portland-Cement, Research, Solidified Waste Forms, Sorption, Thermodynamic, Tricalcium Silicate

? Lou, Z.Y., Chai, X.L., Niu, D.J., Ou, Y.Y. and Zhao, Y.C. (2009), Size-fractionation and characterization of landfill leachate and the improvement of Cu²⁺ adsorption capacity in soil and aged refuse. Waste Management, 29 (1), 143-152.

Full Text: 2009\Was Man29, 143.pdf

Abstract: Leachate was collected from all anaerobic lagoon at Shanghai Laogang refuse landfill, the largest landfill in China, and the sample was separated into six fractions using micro-filtration membranes, followed by ultra-filtration membranes. Several parameters of the samples were measured, including chemical oxygen demand (COD), total organic carbon (TOC), total solids (TS), pH, total phosphate (TP), total nitrogen (TN), fixed solids (FS), NH₄⁺, orthophosphate, color, turbidity, and conductivity. These parameters Were then quantitatively correlated with the molecular weight cutoff of the membrane used. Organic matter in the dissolved fraction (MW < 1 kDa) predominated in the leachate, accounting for 65%) of TOC. Thermal infrared spectroscopy was used to characterize the filter residues. Asymmetric and symmetric stretching of methyl and methylene groups, and of functional groups containing nitrogen and oxygen atoms. were observed. In addition, the ability of two different samples to adsorb heavy metals was tested. Cu²⁺ was chosen its the representative heavy metal in this Study, and the samples were soil; aged refuse, which had spent 8 years in it conventional sanitary landfill: and samples of soil and aged refuse treated for 48 h with leachate in the ratio of 5 g of sample per 50 nil Of, leachate. Cu²⁺ uptake by the raw soil was similar to 4.60 g/g, while uptake by the leachate-contacted soil and leachate-contacted aged refuse were 5.66 and 5.11 g/g. respectively. These results show that the organic matter in the leachate enhanced the capacity of aqueous solutions to adsorb Cu²⁺. (C) 2008 Elsevier Ltd. All rights reserved.

Keywords: Adsorption, Adsorption Capacity, Capacity, Carbon, China, Cu²⁺, Groups, Heavy Metal, Heavy Metals, Heavy-Metals, Membrane, Membranes, Metal, Metals, Nitrogen, Phosphate, Sorption, Spectroscopy, Ultrafiltration, Water

? Cossu, R. (2009), Story of a success which must go on. Waste Management, 29 (4), 1235-1236.

Full Text: 2009\Was Man29, 1235.pdf

? Lin, C., Hong, Y.J. and Hu, A.H. (2010), Using a composite material containing waste tire powder and polypropylene fiber cut end to recover spilled oil. Waste Management, 30 (2), 263-267.

Full Text: 2010\Was Man30, 263.pdf

Abstract: The superior oil absorption capacity of recycled polypropylene (PP) fiber and waste tire powder were used to recover spilled engine oil. We used ASTM F726-99 method to evaluate oil adsorbing capability of PP fiber and found it to have a large, rapid oil sorption capacity. However, its lack of elasticity dramatically limited that capacity after repeated use. Tire powder, which absorbs less oil more slowly, is more elastic than PP fiber and can be used repeatedly up to a hundred times without losing its oil adsorption capability. We combined PP fiber and tire powder to develop a composite material capable of recovering greater amounts of oil than any of its components. This composite can be use repeatedly for at least 100 times. Thus, the material cost for recovering 1 ton of spilled oil is about USD $0.03, making it very competitive on the market. (C) 2009 Elsevier Ltd. All rights reserved.

Keywords: Absorption, Adsorption, Capacity, Composite, Impact, Oil Sorption, Pyrolysis, Recycled Rubber, Sorption, Taiwan

? Fu, H.Z., Ho, Y.S., Sui, Y.M. and Li, Z.S. (2010), A bibliometric analysis of solid waste research during the period 1993–2008. Waste Management, 30 (12), 2410-2417.

Full Text: 2010\Was Man30, 2410.pdf; 2010\Was Man-Fu.pdf; 2010\Was Man-Fu1.pdf

Abstract: This study is a bibliometric analysis of solid waste research to evaluate the current trends, using the literature in the Science Citation Index (SCI) database from 1993 to 2008. Analyzed aspects included document type, language, and publication output as well as distribution of journals, subject category, countries, institutes, title-words, author keywords, and ‘Keywords Plus’. An evaluating indicator, h-index, was applied to characterize the solid waste publications. The trend of publication outputs during 1993-2008 coincided with a power and an exponential model. Based on the exponential model during 2001-2008, the number of articles on solid waste in 2013 is predicted to be twice that in 2008. The most common subject category is environmental science and the most productive journal is Waste Management. The USA with most publications and China with the highest growth rate were compared. Finally, author keywords, words in title, and ‘Keywords Plus’ were analyzed to provide research emphasis. The results showed that mainstream research was centered on the following methods: recycling, landfilling, composting and waste-to-energy. Heavy metals, fly ash and sewage sludge were considered recent research hotspots. (C) 2010 Elsevier Ltd. All rights reserved.

Keywords: Analysis, Author, Bibliometric, Bibliometric Analysis, China, Citation, Database, Diskette, Fly Ash, Growth, Growth Rate, h Index, h-Index, Heavy Metals, Index, Journal, Journals, Language, Li, Literature, Management, Metals, Model, Output, Plus, Publication, Publications, Recycling, Research, Research Hotspots, SCI, Science, Science Citation Index, Sciences, Sediment, Sewage Sludge, Trend, Trends, USA, Waste, Water

? Lu, W.S. and Yuan, H.P. (2011), A framework for understanding waste management studies in construction. Waste Management, 31 (6), 1252-1260.

Full Text: 2011\Was Man31, 1252.pdf

Abstract: During the past decades, construction and demolition (C&D) waste issues have received increasing attention from both practitioners and researchers around the world. A plethora of research relating to C&D waste management (WM) has been published in scholarly journals. However, a comprehensive understanding of the C&D WM research is somehow absent in spite of its proliferation. The aim of this paper is to develop a framework that helps readers understand the C&D WM research as archived in selected journals. Papers under the topic of C&D WM are retrieved based on a set of rigorous procedures. The information of these papers is then analyzed with the assistance of the Qualitative Social Research (QSR) software package NVivo. A framework for understanding C&D WM research is created based on the analytic results. By following the framework, a bibliometric analysis of research in C&D WM is presented, followed by an in-depth literature analysis. It is found that C&D generation, reduction, and recycling are the three major topics in the discipline of C&D WM. Future research is recommended to (a) investigate C&D waste issues in wider scopes including design, maintenance and demolition, (b) develop a unified measurement for waste generation so that WM performance can be compared across various economies, and (c) enhance effectiveness of WM approaches (e.g. waste charging scheme) based on new WM concepts (e.g. Extended Producer Responsibility). In addition to the above research findings, the approach for producing the research framework can be useful references for other studies which attempt to understand the research of a given discipline. (C) 2011 Elsevier Ltd. All rights reserved.

Keywords: Bibliometric, Bibliometric Analysis, Concrete, Demolition Waste, Design, Generation, Hong-Kong, Industry, Information, Journals, Literature, Literature Analysis, Malaysia, Measurement, Minimization, Papers, Research