Personal Research Database

180 (1-3), 683-692.

Full Text: 2010\J Haz Mat180, 683.pdf

Abstract: The compound N-[3-(trimethoxysilyl)propyl]diethylenetriamine (MPDET) was anchored onto Amazon kaolinite surface (KLT) by heterogeneous route. The modified and natural kaolinite clay samples were characterized by transmission electron microscopy (TEM), scanning electron microscopic (SEM). N-2 adsorption, powder X-ray diffraction, thermal analysis, ion exchange capacities, and nuclear magnetic nuclei of Si-29 and C-13. The well-defined peaks obtained in the C-13 NMR spectrum in the 5.0-62.1 ppm region confirmed the attachment of organic functional groups as pendant chains bonded into the porous clay. The adsorption of uranyl on natural (KLT) and modified (KLTMPDET) kaolinite clays was investigated as a function of the solution pH, metal concentration, temperature, and ionic strength. The ability of these materials to remove U(VI) from aqueous solution was followed by a series of adsorption isotherms adjusted to a Sips equation at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 8.37 x 10(-3) and 13.87 x 10(-3) mmol g(-1) for KLT and KLTMPDET at 298 K, respectively. The energetic effects (Delta H-int, Delta(int)G, and Delta S-int) caused by metal cations adsorption were determined through calorimetric titrations. (C) 2010 Published by Elsevier B.V.

Keywords: Adsorption, Adsorption Isotherms, Analysis, Aqueous-Solutions, Calorimetry, Clay, Europium(III), Hanford Site, Ion Exchange, Isotherms, Kaolinite, Mesoporous Materials, Montmorillonite, NMR, pH, Removal, SEM, Silica, Sorption, Surface Complexation, TEM, Thermodynamic, U(VI), Uranium, Uranyl, Uranyl Adsorption, X-Ray Diffraction

? Dorado, A.D., Lafuente, J., Gabriel, D. and Gamisans, X. (2010), The role of water in the performance of biofilters: Parameterization of pressure drop and sorption capacities for common packing materials. Journal of Hazardous Materials, 180 (1-3), 693-702.

Full Text: 2010\J Haz Mat180, 693.pdf

Abstract: The presence of water in a biofilter is critical in keeping microorganisms active and abating pollutants. In addition, the amount of water retained in a biofilter may drastically affect the physical properties of packing materials and packed beds. In this study, the influence of water on the pressure drop and sorption capacities of 10 different packing materials were experimentally studied and compared. Pressure drop was characterized as a function of dynamic hold-up, porosity and gas flow rate. Experimental data were fitted to a mathematical expression based on a modified Ergun correlation. Sorption capacities for toluene were determined for both wet and dry materials to obtain information about the nature of interactions between the contaminant, the packing materials and the aqueous phase. The experimental sorption capacities of materials were fitted to different isotherm models for gas adsorption in porous materials. The corresponding confidence interval was determined by the Fisher information matrix. The results quantified the dynamic hold-up effect resulting from the significant increase in the pressure drop throughout the bed, i.e. the financial cost of driving air, and the negative effect of this air on the total amount of hydrophobic pollutant that can be adsorbed by the supports. Furthermore, the results provided equations for ascertaining water presence and sorption capacities that could be widely used in the mathematical modeling of biofilters. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Ammonia Removal, Biofiltration, Biofiltration, Coconut Fiber, Degradation, Isotherm, Isotherm Models, Media, Microorganisms, Model Validation, Modeling, Packing Materials, Physical Properties, Pressure, Pressure Drop, Sorption, Toluene, Water, Water Influence

? Suksabye, P., Worasith, N., Thirayetyan, P., Nakajima, A. and Goodman, B.A. (2010), A reinvestigation of EXAFS and EPR spectroscopic measurements of chromium(VI) reduction by coir pith. Journal of Hazardous Materials, 180 (1-3), 759-763.

Full Text: 2010\J Haz Mat180, 759.pdf

Abstract: New measurements using extended X-ray absorption fine structure (EXAFS) and electron paramagnetic resonance (EPR) techniques are consistent with Cr in the Cr(III) oxidation state as the main product from the adsorption of Cr(VI) on coir pith. These confirm the previous X-ray measurements, but differ from the results of previous EPR studies, which indicated that Cr(V) was the main form of Cr. The reason for this discrepancy is the presence of a broad signal from Cr(III) in an unsymmetrical environment that was missed previously; the Cr(V) component is in fact only a minor reaction product. As a result of this problem with spectral acquisition and interpretation, some simple recommendations are presented for conducting EPR investigations on natural systems. (C) 2010 Published by Elsevier B.V.

Keywords: Adsorption, Aqueous-Solution, Binding, Biomass, Carbon, Chromium, Coir Pith, Cr(VI), EPR, EXAFS, Molybdate, Oxidation, Reduction, Removal, Water, XAS

? Gatica, J.M. and Vidal, H. (2010), Non-cordierite clay-based structured materials for environmental applications. Journal of Hazardous Materials, 181 (1-3), 9-18.

Full Text: 2010\J Haz Mat181, 9.pdf

Abstract: The applications of clay-based structured materials, excluding cordierites, for environmental protection are examined. In particular, their use in the abatement of some of the main hazardous species in polluted emissions such as nitrogen oxides, carbon monoxide, volatile organic compounds and heavy metals is discussed. A distinction is made between adsorption and catalytic processes. In addition, a general overview of the methods and general principles followed to prepare structured materials from clays is also given. Special attention is paid to those employed to obtain honeycomb monoliths and foams. (C) 2010 Elsevier BM. All rights reserved.

Keywords: Acid Activation, Adsorbents, Adsorption, Ammonia Decomposition, Behavior, Carbon Honeycomb Monoliths, Clay, Composites, Compounds, Environmental Applications, Heavy Metals, High-Temperature, Honeycomb Monoliths, Organic Compounds, Pillared Bentonites, Selective Catalytic-Reduction, Structured Catalysts, Supports

? Fierro, V., Muñiz, G., Basta, A.H., El-Saied, H. and Celzard, A. (2010), Rice straw as precursor of activated carbons: Activation with ortho-phosphoric acid. Journal of Hazardous Materials, 181 (1-3), 27-34.

Full Text: 2010\J Haz Mat181, 27.pdf

Abstract: Highly mesoporous activated carbons (ACs) with a mesopore fraction ranging from 42 to 73% were obtained by activation of rice straw (RS) with ortho-phosphoric acid (PA). Due to such a high mesoporosity, these ACs can be successfully used for pollutant removal in aqueous phase. The ACs were prepared at activation temperatures (T) ranging from 350 to 500 degrees C, using PA to RS weight ratios (R) from 0 to 1.6 and activation times from 0 to 2 h. They were characterised by nitrogen adsorption at -196 degrees C, SEM-EDX, and methylene blue adsorption. RS is a very heterogeneous material with a variable content of mineral matter: using the product of activated carbon yield multiplied by surface area (C x S-BET) as the performance criterion, the best AC was produced at T = 450 degrees C and R >= 1. These conditions lead to S-BET higher than 500 m(2) g(-1) and a C x S-BET around 270 m(2) g(-1). (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorption, Adsorption, Capacity, Chemical Activation, H₃PO₄, Impregnation, Kraft Lignin, Lead, Mesoporous, Methylene Blue, Porosity, Removal, Rice Straw, Shells, Weight, Wood

? Zein, R., Suhaili, R., Earnestly, F., Indrawati and Munaf, E. (2010), Removal of Pb(II), Cd(II) and Co(II) from aqueous solution using Garcinia mangostana L. fruit shell. Journal of Hazardous Materials, 181 (1-3), 52-56.

Full Text: 2010\J Haz Mat181, 52.pdf

Abstract: This study examines the possibility of using mangosteen shell to remove low concentrations of lead, zinc and cobalt (less than 100 mg/l) from aqueous solution. It was found that the biosorption capacities were significantly affected by solution pH, contact time and initial metal ions concentration. Un-extracted and extracted dyes of mangosteen shell were investigated. Moreover higher pH up to 5 favoring higher metal ion removal. Kinetic and isotherm experiments were carried out at the optimal pH: at pH 5.0 for lead and zinc, and at pH 4.0 for cobalt. The metal removal rates were rapid, with 90% of the total adsorption taking place within 60 min. Mangosteen shell showed the highest potential for the removal of toxic metals in aqueous solution. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Algal Biomass, Biosorption, Biosorption, Cadmium, Co(II), Contact Time, Copper, Dyes, FTIR, Green, Heavy-Metals, Ions, Isotherm, Kinetic, Lead, Mangosteen Shells, Metal Ions, Metal Removal, Nickel, Pb(II), pH, Removal, Toxic Metals, Waste, Xanthones, Zinc

? Zhu, M.X., Wang, Z., Xu, S.H. and Li, T. (2010), Decolorization of methylene blue by -MnO₂-coated montmorillonite complexes: Emphasizing redox reactivity of Mn-oxide coatings. Journal of Hazardous Materials, 181 (1-3), 57-64.

Full Text: 2010\J Haz Mat181, 57.pdf

Abstract: delta-MnO2 coatings on clay substrates tend to be poorer in crystallinity as compared with their discrete counterparts, which may be of environmental significance for adsorption and oxidation of contaminants. Discrete delta-MnO2 particles and three delta-MnO2-coated montmorillonite complexes with varying MnO2 loadings (4.8-34.9%) were synthesized, and oxidative decolorization of methylene blue (MB) by the synthetic materials was investigated in batch systems. Results showed that oxidative decolorization of MB increased with increasing loading of Mn-oxide coatings, whereas oxidation capacity of the coatings, on the basis of unit mass of MnO2, tended to decrease. Initial reaction rate of MB oxidation by both delta-MnO2 coatings and their discrete counterpart increased linearly with increasing Mn-oxide loadings, but the rate of the former was higher than that of the latter. An increase in humic acid concentration displayed a progressively enhanced promotive effect on MB decolorization, whereas the promotive effect was greatly suppressed at lower pH. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Antibacterial Agents, Aromatic-Amines, Batch, Birnessite, Clay, Decolorization, Delta-MnO₂ Coatings, Dissolution, Humic Acid, Iron, Kinetics, Manganese-Oxide, Methylene Blue, Montmorillonite, Oxidation, Oxidative Decolorization, Oxidative Transformation, pH, Reduction, Surfaces

? Medina, A., Gamero, P., Almanza, J.M., Vargas, A., Montoya, A., Vargas, G. and Izquierdo, M. (2010), Fly ash from a Mexican mineral coal. II. Source of W zeolite and its effectiveness in arsenic(V) adsorption. Journal of Hazardous Materials, 181 (1-3), 91-104.

Full Text: 2010\J Haz Mat181, 91.pdf

Abstract: Coal-fired plants in Coahuila (Mexico) produce highly reactive fly ash (MFA), which is used in a one-step process as a raw material in producing zeolite. We explored two routes in the synthesis of zeolite: (a) direct MFA zeolitization, which resulted in the formation of W zeolite with KOH and analcime with NaOH and (b) a MFA fusion route, which resulted in the formation of zeolite W or chabazite with KOH and zeolite X or P with NaOH. No residual crystalline phases were present. When LiOH was employed, ABW zeolite with quartz and mullite were obtained. For both zeolitization routes, the nature of the alkali (KOH, NaOH, LiOH), the alkali/MFA ratio (0.23-1.46), and the crystallization temperature and time (90-175 degrees C; 8-24 h) were evaluated. Additionally, the effect of temperature and time on MFA fusion was studied. W zeolite was obtained by both zeolitization methods. The direct route is preferred because it is a straightforward method using soft reaction conditions that results in a high yield of low cost zeolites with large crystal agglomerates. It was demonstrated that aluminum modified W zeolite has the ability to remove 99% of the arsenic(V) from an aqueous solution of Na2HAsO4 center dot 7H(2)O originally containing 740 ppb. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorbents, Adsorption, Arsenic Adsorption, As(V), Direct Method, Exposure, Faujasitic Zeolites, Fly Ash, Hdtma-Modified Zeolite, Merlinoite, Merlinoite, Mexican Fly Ash, Removal, Synthesis, Synthetic Zeolites, W Zeolite, Water, Zeolite

? Zheng, W., Guo, M.X., Chow, T., Bennett, D.N. and Rajagopalan, N. (2010), Sorption properties of greenwaste biochar for two triazine pesticides. Journal of Hazardous Materials, 181 (1-3), 121-126.

Full Text: 2010\J Haz Mat181, 121.pdf

Abstract: Biochar is a carbon-rich product generated from biomass through pyrolysis. This study evaluated the ability of an unmodified biochar to sorb two triazine pesticides - atrazine and simazine, and thereby explored potential environmental values of biochar on mitigating pesticide pollution in agricultural production and removing contaminants from wastewater. A greenwaste biochar was produced by heating waste biomass under the oxygen-limited condition at 450 degrees C. The effects of several experimental parameters, including biochar particle size, contact time, solid/solution ratio, and solution pH on the sorption of atrazine and simazine were comprehensively investigated. The biochar with small particle size needed less time to reach sorption equilibrium. The sorption affinity of the biochar for the two pesticides increased with decreasing solid/solution ratio. The sorbed amounts (C-s) of atrazine and simazine increased from 451 to 1158 mg/kg and 243 to 1066 mg/kg, respectively, when the solid/solution ratio decreased from 1:50 to 1:1000 (g/mL). The sorption of the biochar for both pesticides was favored by low pH. The sorption isotherms of atrazine and simazine on the biochar are nonlinear and follow a Freundlich model. When atrazine and simazine co-existed, a competitive sorption occurred between these two pesticides on the biochar, reflecting a decrease in sorption capacity (K-f) from 435 to 286 for atrazine and from 514 to 212 for simazine. Combined adsorption and partition mechanisms well depicted sorption of atrazine and simazine on carbonized and noncarbonized fractions of the biochar in the single-solute and co-solute systems. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Atrazine, Atrazine, Biochar, Bioenergy, Biomass, Carbon, Competitive Sorption, Competitive Sorption, Contact Time, Crop Residue Burns, Equilibrium, Freundlich, Isotherms, Particulate Matter, Pesticides, pH, Pollution, Production, Removal, Sequestration, Simazine, Soils, Sorption, Sorption Isotherms, Wastewater

? Perdigón-Melón, J.A., Carbajo, J.B., Petre, A.L., Rosal, R. and García-Calvo, E. (2010), Coagulation-Fenton coupled treatment for ecotoxicity reduction in highly polluted industrial wastewater. Journal of Hazardous Materials, 181 (1-3), 127-132.

Full Text: 2010\J Haz Mat181, 127.pdf

Abstract: A coupled coagulation-Fenton process was applied for the treatment of cosmetic industry effluents. In a first step. FeSO4 was used as coagulant and the non-precipitated Fe2+ remaining in dissolution was used as catalyst in the further Fenton process. In the coagulation process a huge decrease in total organic carbon (TOC) was achieved, but the high concentration of phenol derivatives was not diminished. The decrease in TOC in the coagulation step significantly reduces the amount of H2O2 required in the Fenton process for phenol depletion. The coupled process, using a H2O2 dose of only 2 g reduced TOC and total phenol to values lower than 40 and 0.10 mg l(-1), respectively. The short reaction period (less than 15 min) in TOC and phenol degradation bodes well for improving treatment in a continuous regime. The combination of both processes significantly reduced the ecotoxicity of raw effluent and markedly increased its biodegradability, thus allowing easier treatment by the conventional biological units in conventional sewage treatment plants (STPs). (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Anionic Surfactants, Carbon, Coagulation, Cork Processing Wastewaters, Cosmetic Industry Wastewater, Degradation, Ecotoxicity, Fenton’s Reagent, Industrial Wastewater, Ion-Exchange, Organic-Matter, Oxidation, Phenol, Removal, Systems, Total Phenol, Treatment, Wastewater

? Wei, Z.S. and Seo, Y. (2010), Trichloroethylene (TCE) adsorption using sustainable organic mulch. Journal of Hazardous Materials, 181 (1-3), 147-153.

Full Text: 2010\J Haz Mat181, 147.pdf

Abstract: Soluble substrates (electron donors) have been commonly injected into chlorinated solvent contaminated plume to stimulate reductive dechlorination. Recently, different types of organic mulches with economic advantages and sustainable benefits have received much attention as new supporting materials that can provide long term sources of electron donors for chlorinated solvent bioremediation in engineered biowall systems. However, sorption capacities of organic mulches for chlorinated solvents have not been studied yet. In this study, the physiochemical properties of organic mulches (pine, hardwood and cypress mulches) were measured and their adsorption capacity as a potential media was elucidated. Single, binary and quaternary isotherm tests were conducted with trichloroethylene (TCE), tetrachloroethylene (PCE), trans-dichloroethylene (trans-DCE) and cis-dichloroethylene (cis-DCE). Among the three tested mulches, pine mulch showed the highest sorption capacity for the majority of the tested chemicals in single isotherm test. In binary or quaternary isotherm tests, competition among chemicals appears to diminish the differences in Q., for tested mulches. However, pine mulch also showed higher adsorption capacity for most chemicals when compared to hardwood and cypress mulches in the two isotherm tests. Based upon physicochemical properties of the three mulches, higher sorption capacity of pine mulch over hardwood and cypress mulches appears to be attributed to a higher organic carbon content and the lower polarity. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Adsorption Capacity, Aspen Wood Fibers, Barrier, Bioremediation, Contaminants, Enhanced Sorption, Groundwater, Humic Substances, Hydrocarbons, Isotherm, Organic Mulch, Polarity, Removal, Soils, Sorption, Sustainability, TCE, Trichloroethylene

? Saha, R., Das, S., Banerjee, A., Sahana, A., Sudarsan, M., Slawin, A.M.Z., Li, Y. and Das, D. (2010), pH dependent separation of uranium by chelation chromatography using pyridine 2,6-dimethanol as a chelator: Single crystal X-ray structural confirmation of the chelated uranium complex. Journal of Hazardous Materials, 181 (1-3), 154-160.

Full Text: 2010\J Haz Mat181, 154.pdf

Abstract: A very effective sorbent material which exhibits exceptional capture of hexavalent uranium from other actinides and lanthanides at mu g g(-1) level, features pyridine 2,6-dimethanol immobilized onto alumina. The maximum sorption capacity for dioxouranium(VI) was found as 1.96 mmol g(-1) at pH 3.0. The adsorbed uranium complex was eluted completely by 0.05 mol L-1 (NH4)(2)CO3 solution and the concentration of hexavalent dioxouranium ion was monitored spectrophotometrically using Arsenazo III. The structure of the chelated uranium complex has been confirmed by single crystal X-ray structure analysis and Fourier transform infrared red (FTIR) spectroscopy. Thermo gravimetric analysis/differential thermo gravimetric analysis (TGA/DTG) of the chelated uranium complex was performed. The method is reproducible with a relative standard deviation (RSD) of 1.2% (N = 10) and the three sigma detection limits (N = 15) 1.2 mu g mL(-1) respectively. A pre-concentration factor, almost 500, for uranium was achieved. Interferences from Th4+, Mn2+, Ni2+ and Cu2+ ions were masked with ethylene diamine tetra acetic acid (di-sodium salt) (Na(2)EDTA) in the aqueous phase. The developed method has been tested for uranium recovery and estimation in some certified reference materials and environmental samples. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Analysis, Arsenazo Iii, Chelation, Column Preconcentration, Complex, Fourier Transform Infrared, FTIR, Geological-Materials, Infrared, Ni²⁺, pH, Plasma-Mass Spectrometry, Polymer, Preconcentration, Pyridine, Pyridine 2,6-Dimethanol, Resin, Silica-Gel, Single Crystal X-Ray Structure, Solid-Phase Extraction, Sorbent, Sorption, Spectrophotometric Determination, Spectrophotometry, Trace-Metals, Uranium Recovery, Water Samples

? Asuha, S., Zhou, X.G. and Zhao, S. (2010), Adsorption of methyl orange and Cr(VI) on mesoporous TiO₂ prepared by hydrothermal method. Journal of Hazardous Materials, 181 (1-3), 204-210.

Full Text: 2010\J Haz Mat181, 204.pdf

Abstract: Mesoporous TiO₂ was synthesized by a hydrothermal method using cetyltrimethyl ammonium bromide (CAB) as a structure-directing agent, and its adsorption abilities for the removal of methyl orange (MO) and Cr(VI) from waste waters were investigated. Transmission electron micrograph (TEM) observations together with nitrogen adsorption-desorption measurements show the formation of mesoporous TiO₂ with an average pore size of 5.2 nm and a surface area of 161.2 m(2)/g. The adsorption data for both MO and Cr(VI) fit well with either Langmuir or Freundlich adsorption model. The adsorption for MO is slightly influenced by pH of the solutions, while that for Cr(VI) is strongly dependent on solution pH. By an increase in solution pH from 3 to 12, the adsorbed percentage of MO decreases from ca. 87 to 78%; however, the adsorbed percentage of Cr(VI) decreases from ca. 45 to 0%. The maximum adsorption capacities of the mesoporous TiO₂ for MO and Cr(VI) are determined to be 454.5 and 33.9 mg/g, respectively, which suggests that the mesoporous TiO₂ is an excellent adsorbent for MO and Cr(VI). (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Adsorption, Capacity, Chromium, Cr(VI), Enhanced Photocatalytic Activity, Freundlich, Langmuir, Mesoporous, Mesoporous TiO₂, Metal-Oxides, Methyl Orange, pH, Pore, Removal, Surface, TEM, TiO₂, Waste, Water Treatment, Water-Treatment

? Nethaji, S., Sivasamy, A., Thennarasu, G. and Saravanan, S. (2010), Adsorption of Malachite Green dye onto activated carbon derived from Borassus aethiopum flower biomass. Journal of Hazardous Materials, 181 (1-3), 271-280.

Full Text: 2010\J Haz Mat181, 271.pdf

Abstract: In the present study, chemically prepared activated carbon derived from Borassus aethiopum flower was used as adsorbent. Batch adsorption studies were performed for the removal of Malachite Green (MG) from aqueous solutions by varying the parameters like initial solution pH, adsorbent dosage, initial MG concentration and temperature with three different particle sizes such as 100 m, 600 mu m and 1000 m. The zero point charge was 2.5 and the maximum adsorption occurred at the pH range from 6.0 to 8.0. Experimental data were analyzed by model equations such as Langmuir, Freundlich and Temkin isotherms and it was found that the Langmuir isotherm model best fitted the adsorption data. Thermodynamic parameters such as ΔG, ΔH and ΔS were also calculated for the adsorption processes. Adsorption rate constants were determined using pseudo first-order, pseudo second-order rate equations and also Elovich model and intraparticle diffusion models. The results clearly showed that the adsorption of MG onto PFAC followed pseudo second-order model and the adsorption was both by film diffusion and by intraparticle diffusion. (C) 2010 Elsevier B.V. All rights reserved.

Keywords: Activated Carbon, Adsorbent, Adsorbent Dosage, Adsorption, Adsorption Isotherms, Adsorption Rate, Aqueous Solutions, Aqueous-Solution, Batch Adsorption, Biomass, Carbon, Charge, Column Operations, Concentration, Data, Diffusion, Dye, Elovich, Elovich Model, Equilibrium, Film Diffusion, First Order, Fly-Ash, Freundlich, Industry Waste, Intraparticle Diffusion, Isotherm, Isotherm Model, Isotherms, Kinetics, Langmuir, Langmuir Isotherm, Langmuir Isotherm Model, Malachite Green, Methylene-Blue, Mg, Model, Models, Palm Flower Activated Carbon, pH, Process Design, Pseudo First Order, Pseudo First-Order, Pseudo Second Order, Pseudo Second-Order, Pseudo-First-Order, Pseudo-Second-Order, Rate Constants, Removal, Rhodamine-B, Rights, Second Order, Second-Order, Second-Order Model, Solution, Solutions, Temperature, Thermodynamic, Thermodynamic Parameters, Thermodynamics, Waste-Water, Zero Point Charge

? Cea, M., Jorquera, M., Rubilar, O., Langer, H., Tortella, G. and Diez, M.C. (2010), Bioremediation of soil contaminated with pentachlorophenol by Anthracophyllum discolor and its effect on soil microbial community. Journal of Hazardous Materials,