Personal Research Database



Yüklə 2,92 Mb.
səhifə222/252
tarix15.08.2018
ölçüsü2,92 Mb.
#62455
1   ...   218   219   220   221   222   223   224   225   ...   252
181 (1-3), 1066-1071.

Full Text: 2010\J Haz Mat181, 1066.pdf

Abstract: This study investigates the species of As and Pb (beudantite) residues present in the seriously contaminated agricultural rice soils of the Guandu Plain. Two pedons in the Guandu Plain agricultural soils, each pedon separated into five horizons (each of 20 cm) were collected for this study. Soil samples were packed into a column for leaching with simulated acid rains. Soil pH ranged from 5.1 to 7.1 with high base saturation. Soils can be classified as clay loam, mixed, thermic, Typic or Umbric Albaqualfs. The XRD analysis indicated the beudantite particles are present in clay fractions, showing high concentrations of As and Pb. This is because of 50-100 years ago irrigation water was introduced from Huang Gang Creek of hot springs containing high concentrations of As and Pb. Only low concentrations of As and Pb can be leached out with simulated acid rains (i.e., pHs 2 and 4), even through 40 pore volumes of leaching experiments. The sequential extraction experiments resulted in the high portions of As and Pb remaining in the amorphous. Fe and Al oxyhydroxides and residual fractions. Thus, the remediation of As and Pb in this agricultural rice paddy soils merits further study. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Agricultural Paddy Soils, Analysis, Arsenic, Beudantite, Clay, Hot Springs, Lead, Metals, pH, Pore, Remediation, Removal, Sequential Extraction, Sequential Extraction Procedure, Soil, Soils, Sorption, Transport, Water, XRD, Zinc

? Aldaba, D., Rigol, A. and Vidal, M. (2010), Diffusion experiments for estimating radiocesium and radiostrontium sorption in unsaturated soils from Spain: Comparison with batch sorption data. Journal of Hazardous Materials, 181 (1-3), 1072-1079.

Full Text: 2010\J Haz Mat181, 1072.pdf

Abstract: As sorption data obtained from batch tests are often used to estimate pollutant transport in unsaturated soils, comparison between sorption data obtained in the two conditions is required to ensure a correct risk assessment. With this aim, radiostrontium and radiocesium apparent diffusion coefficients (D-a) were quantified in nine unsaturated soils, and the derived distribution coefficients (K-d) were compared with K-d data from batch experiments. The D-a(Sr) and the D-a(Cs) ranged from 1.8 x 10(-11) to 1.5 x 10(-10) m(2) s(-1), and from 1.0 x 10(-13) to 5.9 x 10(-11) m(2) s(-1), respectively. The D-a(Sr) varied according to both soil packing parameters and properties governing Sr interaction. For Cs, the soil sorption properties explained the variation on D-a(Cs). The K-d values derived from D-a (from 0.014 to 1.8 L kg(-1) for Sr: from 0.55 to 942 L kg(-1) for Cs) were lower than from batch tests (from 1 to 97 L kg(-1) for Sr: from 10 to 14.600 L kg(-1) for Cs), thus indicating that batch data may not accurately describe radionuclide transport in unsaturated soils. However, the two sets of data correlated well, thus suggesting that radionuclide transport can be estimated from batch tests, which are faster than diffusion experiments. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Apparent Diffusion Coefficient, Batch, Batch Tests, Cesium, Clay, Compacted Bentonite, Diffusion, Distribution Coefficient, Distribution Coefficients, Pollutant Transport, Prairie Soil, Prediction, Radionuclide, Retardation Factor, Retention, Risk Assessment, Soil, Soils, Sorption, Spain, Strontium, Transport-Properties

? Nowicki, P., Wachowska, H. and Pietrzak, R. (2010), Active carbons prepared by chemical activation of plum stones and their application in removal of NO2. Journal of Hazardous Materials, 181 (1-3), 1088-1094.

Full Text: 2010\J Haz Mat181, 1088.pdf

Abstract: A technology of obtaining active carbon from plum stones by chemical activation with KOH is described. The effect of carbonisation temperature as well as activation procedure on the textural parameters, acid-base character of the surface and sorption properties of active carbons has been checked. The sorption properties of the activated carbons obtained were characterised by determination of nitrogen dioxide adsorption in dry and wet conditions. The final products were microporous activated carbons of well-developed surface area varying from 2174 to 3228 m(2)/g and pore volume from 1.09 to 1.61 cm(3)/g, showing different acid-base character of the surface. The results obtained in our study have proved that a suitable choice of the carbonisation and activation procedure for plum stones can produce activated carbons with high capacity of nitrogen dioxide, reaching to 67 and 42 mg NO2/g in dry and wet conditions, respectively. The results of our study have also shown that the adsorption ability of carbonaceous sorbents depends both on the method of preparation as well as on the textural parameters and acid-base properties of their surface. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorbents, Adsorption, Adsorption Ability, Bituminous Coal, Brown-Coal, Carbonaceous Adsorbents, Carbonisation, Chemical Activation, Hydrogen-Sulfide, Ions, Nitrogen, NO2 Adsorption, Reduction, Oxidation, Plum Stones, Pore, Porosity, Removal, Shell, Sorption, Technology

? Cruz-Olivares, J., Perez-Alonso, C., Barrera-Díaz, C., López, G. and Balderas-Hernández, P. (2010), Inside the removal of Lead(II) from aqueous solutions by De-Oiled Allspice Husk in batch and continuous processes. Journal of Hazardous Materials, 181 (1-3), 1095-1101.

Full Text: 2010\J Haz Mat181, 1095.pdf

Abstract: A new adsorbent material for removing lead ions from aqueous solutions has been investigated. The residue of the allspice extraction process (De-Oiled Allspice Husk) was used on the removal of Pb(II) from water solutions. The lead sorption capacity of De-Olied Allspice Husk (DOAH) was studied in batch and continuous processes. It was found that percentage removals of Pb(II) depend on the pH and the initial lead concentrations. The Pb(II) uptake process was maximum at pH 5 in a range concentrations of 5-25 mg L-1. The overall sorption process was well described by the pseudo-second-order kinetic model under conditions of pH 5 (0.1 g adsorbent per 100 mL of contaminated solution) 0.001 mass/volume ratio and 25 degrees C. The sorption capacity of Lead(II) onto DOAH in batch process was 5.00, 8.02, 11.59, 15.23 and 20.07 mg g-1, when the concentration solutions were 5,10, 15,20 and 25 mg L-1 respectively. These values are lower than obtained in continuous process, where lead was removed by 95% and the experimental results were appropriately fitted by the Yoon-Nelson model. X-ray photoelectron spectroscopy (XPS) provides information regarding the interactions between lead ions and the adsorbent surface indicating that the formation of 2 complexes depends on the functional groups associated. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorbent, Adsorption, Aqueous Solutions, Batch, Batch Process, Biosorption, Black Gram Husk, By-Products, Capacity, Complexes, Concentration, Experimental, Extraction, Fixed-Bed Column, Functional Groups, Fungal Biomass, Heavy Metals, Heavy-Metal Ions, Industrial Waste-Water, Information, Ions, Kinetic, Kinetic Model, L1, Lead, Lead(II), Model, Pb(II), pH, Pimento Dioica, Pinus-Sylvestris Sawdust, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Model, Removal, Rice Husk, Rights, Solution, Solutions, Sorption, Sorption Capacity, Sorption Process, Spectroscopy, Surface, Uptake, Water, X-Ray, X-Ray Photoelectron Spectroscopy, XPS

? Yuan, M.J., Tong, S.T., Zhao, S.Q. and Jia, C.Q. (2010), Adsorption of polycyclic aromatic hydrocarbons from water using petroleum coke-derived porous carbon. Journal of Hazardous Materials, 181 (1-3), 1115-1120.

Full Text: 2010\J Haz Mat181, 1115.pdf

Abstract: Porous carbons were prepared from petroleum coke by KOH chemical activation, characterized and used as adsorbents for uptaking a mixture of polycyclic aromatic hydrocarbons (PAHs): naphthalene, fluorene, phenanthrene, pyrene and fluoranthene from aqueous solutions. The specific surface area (SSA) of these carbons ranges from 562 to 1904 m(2)/g, while their point of zero charge (pH(PZC)) varies from 2.6 to 8.8. The equilibrium adsorption of PAHs on all four carbons follows the non-linear Freundlich equation well. For any given PAH in the group, the adsorption capacity parameter K-f, increases with the SSA and pH(PZC) of the carbons, confirming the roles of dispersive interactions. For any given carbon, the value of K-f follows the order of naphthalene > fluorene > phenanthrene > pyrene. This dependence of K-f on molecular size suggests a certain degree of molecular sieving behavior of these carbons toward large PAHs. Under the condition studied, the uptake process is likely controlled by diffusive transport processes. And, it is unlikely that the competitive adsorption played any important roles in determining equilibrium adsorption of the mixed PAHs. Overall, the petroleum coke-derived porous carbon is very effective in adsorbing these PAHs. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Capacity, Aqueous Solutions, Aqueous-Solutions, Equilibrium, Freundlich, Granular Activated Carbon, Intraparticle Diffusion, Mechanism, Naphthalene, Oil, Pahs, Phenanthrene, Pollutants, Polycyclic Aromatic Hydrocarbons, Porous Carbon, Removal, Sorption, Water

? Hasan, S.H., Ranjan, D. and Talat, M. (2010), Agro-industrial waste ‘wheat bran’ for the biosorptive remediation of selenium through continuous up-flow fixed-bed column. Journal of Hazardous Materials, 181 (1-3), 1134-1142.

Full Text: 2010\J Haz Mat181, 1134.pdf

Abstract: Present study deals with the utilization of an agro-industrial waste wheat bran for the remediation of selenium species, Se(IV) and Se(VI) by continuous up-flow fixed-bed column system. Laboratory-scale column tests were performed to determine potentiality of wheat bran at various bed height, flow rates and initial metal ion concentration and it was found to be very potential biosorbent as it showed good sorption capacities of 72.54 mu g/g and 62.51 mu/g for Se(IV) and Se(VI) respectively. Different models like Bed Depth Service Time (BDST), Thomas and Yoon-Nelson were applied to the experimental sorption data. The data showed very good fit to BDST model and sorption capacities (No) computed using BDST model were 26,664 mu g/L and 26,400 mu g/L for Se(IV) and Se(VI) respectively. Also Yoon-Nelson model was found to show good agreement with the experimental kinetic results as compared to the Thomas model. Wheat bran was amenable to efficient regeneration with 10% NaOH. The biosorbent retained most of its original uptake capacity over three cycles of use. The excellent reusability of the biosorbent could lead to development of a viable metal remediation technology. Life factor calculation revealed that biosorbent bed will have sufficient capacity to avoid breakthrough at time t = 0 up to 12.17 cycles for Se(IV) and 6.28 cycles for Se(VI) and bed would be completely exhausted after 56.89 cycles for Se(IV) and 18.73 cycles for Se(VI). (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Aqueous-Solution, Aspergillus-Niger Biomass, Batch, Biosorptive Remediation, Breakthrough, Cadmium, Column, Copper, Kinetic, Lead, Packed-Bed, Regeneration, Remediation, Removal, Selenium, Sorption, System, T, Technology, Thomas Model, Treated Rice Husk, Water, Wheat Bran

? Noubactep, C. (2010), Elemental metals for environmental remediation: Learning from cementation process. Journal of Hazardous Materials, 181 (1-3), 1170-1174.

Full Text: 2010\J Haz Mat181, 1170.pdf

Abstract: The further development of Fe-0-based remediation technology depends on the profound understanding of the mechanisms involved in the process of aqueous contaminant removal. The view that adsorption and co-precipitation are the fundamental contaminant removal mechanisms is currently facing a harsh scepticism. Results from electrochemical cementation are used to bring new insights in the process of contaminant removal in Fe-0/H2O systems. The common feature of hydrometallurgical cementation and metal-based remediation is the heterogeneous nature of the processes which inevitably occurs in the presence of a surface scale. The major difference between both processes is that the surface of remediation metals is covered by layers of own oxide(s) while the surface of the reducing metal in covered by porous layers of the cemented metal. The porous cemented metal is necessarily electronic conductive and favours further dissolution of the reducing metal. For the remediation metal, neither a porous layer nor a conductive layer could be warrant. Therefore, the continuation of the remediation process depends on the long-term porosity of oxide scales on the metal surfaces. These considerations rationalized the superiority of Fe-0 as remediation agent compared to thermodynamically more favourable Al-0 and Zn-0. The validity of the adsorption/co-precipitation concept is corroborated. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Bed Reactor, Carbon-Tetrachloride, Cementation, Co-Precipitation, Groundwater Remediation, Long-Term Performance, Mechanism, Permeable Reactive Barriers, Reductive Dehalogenation, Remediation, Removal, Surface Scale, Surfaces, Technology, Uranium Removal, Waste-Water, Zero-Valent Iron, Zerovalent Iron

? Xu, X., Gao, B.Y., Yue, Q.Y. and Zhong, Q.Q. (2010), Preparation and utilization of wheat straw bearing amine groups for the sorption of acid and reactive dyes from aqueous solutions. Journal of Hazardous Materials, 182 (1-3), 1-9.

Full Text: 2010\J Haz Mat182, 1.pdf

Abstract: Removal of Acid Red 73 (AR 73) and Reactive Red 24 (RR 24) onto modified wheat straw (MWS) from aqueous solutions was investigated. Sorption experiments were carried out as function of MWS dosage, contact time, initial concentration, pH and temperature. Characterizations of MWS were measured and a mass of amine groups were observed in the framework of MWS. The equilibrium sorption data were well represented by the Langmuir isotherm equation, and the calculated thermodynamic parameters indicated a spontaneous and endothermic nature for sorption process. It was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. More over, the high maximum sorption capacity (q(e) (max), 714.3 mg g-1 for AR 73 and 285.7 mg g-1 for RR 24) and low cost (1.24 US$ kg-1) of MWS provided strong evidence of the potential of MWS for the technological applications of anionic dyes removal from aqueous solutions. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Acid Red 73, Adsorbent, Adsorption, Adsorption Kinetics, Anionic Dyes, Aqueous Solutions, Azo Dyes, Capacity, Chitosan, Concentration, Cost, Data, Dyes, Endothermic, Equilibrium, Equilibrium Isotherm, Evidence, Exchange Resin, Experiments, Fly-Ash, Framework, Function, Isotherm, Kinetic, Kinetic Equation, Kinetics, Langmuir, Langmuir Isotherm, Low Cost, Modified, Modified Wheat Straw (MWS), Peanut Hull, pH, Potential, Preparation, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Kinetic Equation, Reactive Dyes, Removal, Rice-Husk, Rights, Solutions, Sorption, Sorption Capacity, Sorption Process, Straw, Temperature, Thermodynamic, Thermodynamic Parameters, Utilization

? Al Mardini, F. and Legube, B. (2010), Effect of the adsorbate (Bromacil) equilibrium concentration in water on its adsorption on powdered activated carbon. Part 3: Competition with natural organic matter. Journal of Hazardous Materials, 182 (1-3), 10-17.

Full Text: 2010\J Haz Mat182, 10.pdf

Abstract: This study (part 3) was carried out to investigate the effect of the natural organic matter (NOM) concentration on Bromacil (pesticide) adsorption on powdered activated carbon (PAC) in the same experimental conditions as in our previous studies (parts 1 and 2). Our previous findings showed that Bromacil adsorption in buffered pure water (pH 7.8) occurred at two types of site. In the presence of NOM (three kinds), we noted a significant reduction in Bromacil adsorption capacities due to the competitive effects exerted by NOM. Highly reactive sites (or pores) in PAC appeared to be blocked by NOM adsorption, as demonstrated by the application of a pseudo-single solute isotherm and of the simplified ideal adsorbed solution theory (lAST), regardless of the initial Bromacil and NOM concentrations. The competing effect of low-molecular weight NOM was found to be greater than the competing effect of high-molecular weight NOM. The pseudo-second order surface-reaction model fitted Bromacil adsorption particularly well, even in the presence of NOM. However, the adsorption-kinetic constant values were found to be independent of the aqueous equilibrium concentration of the target compound, contrary to that observed in pure water. The kinetic data thus confirmed that high reactivity PAC sites were blocked by NOM adsorption. A practical approach concluded this work. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption Capacities, Adsorption Kinetic, Application, Approach, Atrazine, Bromacil, Carbon, Competition, Competitive, Concentration, Data, Equilibrium, Experimental, Humic Substances, Isotherm, Kinetic, Model, Molecular-Weight, Natural, Natural Organic Matter, Nom, Organic, Organic Matter, PAC, Parameters, Pesticide, pH, Powdered Activated Carbon, Pseudo Second Order, Pseudo-Second Order, Pseudo-Second-Order, Reduction, Rights, Site, Solution, Surface Reaction, System, Theory, Verification, Water, Work

? Huguenot, D., Bois, P., Jezequel, K., Cornu, J.Y. and Lebeau, T. (2010), Selection of low cost materials for the sorption of copper and herbicides as single or mixed compounds in increasing complexity matrices. Journal of Hazardous Materials, 182 (1-3), 18-26.

Full Text: 2010\J Haz Mat182, 18.pdf

Abstract: Low cost materials (sugar beet pulp, corncob, corncob char, perlite, vermiculite, sand, sediment) have been tested for their ability to quickly sorb copper, glyphosate, diuron and 3,4-dichloroaniline (3,4-DCA) as single or mixed compounds. Tests have been performed in increasingly complex liquid matrices: ultra pure water (UPW), runoff water (RW) and sediment extract medium (SEM). Highest sorption levels in UPW are achieved with corncob char for Cu (93%), glyphosate (74%), diuron (98%) and 3,4-DCA (99%). Other ready-to-use adequate sorbents are sugar beet pulp for Cu and sand for glyphosate, diuron and 3,4-DCA. Sorption levels obtained in UPW are significantly altered in SEM as a result of its higher dissolved organic carbon concentration, tenuous changes being obtained with RW. Interactions between herbicides and Cu are pointed out: higher sorption level is observed for glyphosate in mixture with Cu, as it is observed with diuron and 3,4-DCA when mixed with all other pollutants. Langmuir model has been found to better fit the data for copper, whereas Freundlich one has been found more relevant for diuron and 3,4-DCA. Our results stress the need for studying adsorption in different matrices when searching for sorbents to be used in field conditions. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: 3,4-Dichloroaniline, Adsorption, Adsorption Isotherm, Aqueous-Solutions, Cadmium Ions, Complex, Compounds, Copper, Dissolved Organic-Matter, Diuron, Facilitated Transport, Freundlich, Glyphosate, Heavy-Metals, Herbicides, Langmuir, Langmuir Model, Metal-Ions, Modified Corncobs, Runoff, Sediment, Sediment Extract, SEM, Sorption, Sugar-Beet Pulp, Supported-Liquid-Membrane, Vineyard Soils, Water

? Katsou, E., Malamis, S. and Haralambous, K. (2010), Examination of zinc uptake in a combined system using sludge, minerals and ultrafiltration membranes. Journal of Hazardous Materials, 182 (1-3), 27-38.

Full Text: 2010\J Haz Mat182, 27.pdf

Abstract: This work investigates the feasibility of zinc removal from wastewater with the use of ultrafiltration (UF) membranes combined with natural minerals and sludge. Activated sludge obtained from a membrane bioreactor (MBR) was enriched with initial zinc concentration of 320 mg/L and specific concentrations of zeolite, bentonite and vermiculite. The mixture was agitated and placed inside a batch ultrafiltration unit where the filtration process took place. The effect of several parameters on zinc removal was investigated including the mineral type, quantity and grain size, the metal-mineral contact time and the associated kinetics, the pH value, the zinc initial concentration and sludge mixed liquor suspended solids (MISS) concentration. The ultrafiltration membranes without any mineral addition were able to remove 38-78% of zinc ions due to biosorption on sludge flocs. The addition of minerals increased the Zn(II) removal efficiencies reaching in some cases more than 90%. Bentonite was the most effective mineral in zinc removal followed by vermiculite. Alkaline pH values favoured zinc removal due to enhanced chemical precipitation. A three-stage adsorption process was identified where the boundary layer diffusion process was followed by a two-stage intraparticle diffusion process. Powder size vermiculite was more effective than granular vermiculite in zinc removal. Minerals also resulted in membrane fouling mitigation since the membrane permeability drop was reduced. The combined sludge-mineral-ultrafiltration system can be effectively employed for the treatment of industrial wastewater. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Activated Sludge, Activated-Sludge, Adsorption, Aqueous-Solutions, Batch, Bentonite, Bioreactor, Biosorption, Boundary Layer, Chemical, Concentration, Copper, Diffusion, Drinking-Water, Feasibility, Filtration, Flocs, Fouling, Heavy-Metal Ions, Industrial Wastewater, Intraparticle Diffusion, Ions, Kinetics, Mbr, Membrane, Minerals, Miss, Mitigation, Natural, Permeability, pH, pH Value, Precipitation, Removal, Rights, Size, Sludge, Sorption, Suspended Solids, Treatment, UF, Ultrafiltration, Ultrafiltration Membranes, Uptake, Value, Vermiculite, Waste-Water, Wastewater, Work, Zeolite, Zinc, Zinc Removal, Zn(II), Zn(II) Removal

? Chen, M.J., Zhang, F.S. and Zhu, J.X. (2010), Effective utilization of waste cathode ray tube glass-Crystalline silicotitanate synthesis. Journal of Hazardous Materials, 182 (1-3), 45-49.

Full Text: 2010\J Haz Mat182, 45.pdf

Abstract: A novel process for crystalline silicotitanate (CST) synthesis was developed using waste cathode ray tube (CRT) panel glass as silicon source. The key trait of the process was to extract most of the silicon out of the glass for CST preparation, but leave Ba and Sr in the residue which had the potential to be employed as raw material for metallic Ba and Sr metallurgy. In the synthesis process, waste CRT panel glass was firstly treated by supercritical water (SCW)-NaOH solution for Si extraction, then sol-gel and hydrothermal treatments were used for CST preparation. 80% of Si in the glass could be extracted into the solution, while Sr and Ba were enriched in the residue in the form of Sr2SiO4 and Ba2Si3O8, respectively. Sr and Ba contents in the residue were 2-3 times higher than those in the raw glass. SEM, XRD and TEM results indicated that CST was successfully synthesized. Ion exchanging experiments showed that the batch distribution coefficient of the synthesized CST to Cs+ was up to 1.2 x 10(4) mL/g at pH 0.26. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Batch, Cesium, Cs, Foam Glass, Ion-Exchange, Lead-Silicate Glass, Liquid Waste, Matrix Composites, Mechanical-Properties, Microporous Silicotitanate Sorbent, pH, Powder Technology, SEM, Sol-Gel, Supercritical Water, Synthesis, TEM, Utilizing Subcritical Water, Water, WEEE, XRD

? Ghauch, A., bou Assi, H. and Bdeir, S. (2010), Aqueous removal of diclofenac by plated elemental iron: Bimetallic systems. Journal of Hazardous Materials,


Yüklə 2,92 Mb.

Dostları ilə paylaş:
1   ...   218   219   220   221   222   223   224   225   ...   252




Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©genderi.org 2024
rəhbərliyinə müraciət

    Ana səhifə