The Experts below are selected from a list of 2208 Experts worldwide ranked by ideXlab platform
Manuel Ariasestevez - One of the best experts on this subject based on the ideXlab platform.
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cr vi sorption desorption on Pine Sawdust and oak wood ash
International Journal of Environmental Research and Public Health, 2015Co-Authors: Avelino Nunezdelgado, M J Fernandezsanjurjo, Esperanza Alvarezrodriguez, Laura Cutillasbarreiro, Juancarlos Novoamunoz, Manuel AriasestevezAbstract:The objective of this work was to study Cr(VI) sorption/desorption on two by-products from the wood industry: Pine Sawdust and oak wood ash. The retention/release experiments were carried out using standard batch-type trials. In the sorption-phase experiments, Pine Sawdust showed 23% sorption when a concentration of 100 mg Cr(VI)L−1 was added, whereas sorption on oak wood ash was 17%. In the desorption-phase, chromium release was clearly higher from Pine Sawdust than from oak wood ash (98% and 66%, respectively). Sorption curves were well fitted to the Freundlich and Lineal models. In view of the results, both materials can be considered of very limited value to remove Cr from polluted soil and water, which can be of relevance regarding its appropriate use as biosorbents and recycled by-products.
Florence J. Williams - One of the best experts on this subject based on the ideXlab platform.
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separation of cellulose hemicellulose from lignin in white Pine Sawdust using boron trihalide reagents
Tetrahedron, 2019Co-Authors: Zain M H Kazmi, Abhoy Karmakar, Vladimir K. Michaelis, Florence J. WilliamsAbstract:Abstract A mild method for the separation of cellulose/hemicellulose from extractives free Sawdust is described. Sequential treatments with an equimolar mixture of BCl3 and BBr3 remove polysaccharide components from a white Pine Sawdust sample. Spectroscopic analyses, including solution and solid-state NMR spectroscopy, confirm a reduction in the amount of aliphatic sugars in solid samples and show that extracted components consist only of polymeric sugars and are free of aromatics. Staining with fluorescent and colorimetric dyes confirm that the Sawdust sample after boron trihalide treatment is primarily lignin, with no detectable polysaccharides.
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Separation of cellulose/hemicellulose from lignin in white Pine Sawdust using boron trihalide reagents
Tetrahedron, 2019Co-Authors: M. Zain H. Kazmi, Abhoy Karmakar, Vladimir K. Michaelis, Florence J. WilliamsAbstract:Abstract A mild method for the separation of cellulose/hemicellulose from extractives free Sawdust is described. Sequential treatments with an equimolar mixture of BCl3 and BBr3 remove polysaccharide components from a white Pine Sawdust sample. Spectroscopic analyses, including solution and solid-state NMR spectroscopy, confirm a reduction in the amount of aliphatic sugars in solid samples and show that extracted components consist only of polymeric sugars and are free of aromatics. Staining with fluorescent and colorimetric dyes confirm that the Sawdust sample after boron trihalide treatment is primarily lignin, with no detectable polysaccharides.
Avelino Nunezdelgado - One of the best experts on this subject based on the ideXlab platform.
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cr vi sorption desorption on Pine Sawdust and oak wood ash
International Journal of Environmental Research and Public Health, 2015Co-Authors: Avelino Nunezdelgado, M J Fernandezsanjurjo, Esperanza Alvarezrodriguez, Laura Cutillasbarreiro, Juancarlos Novoamunoz, Manuel AriasestevezAbstract:The objective of this work was to study Cr(VI) sorption/desorption on two by-products from the wood industry: Pine Sawdust and oak wood ash. The retention/release experiments were carried out using standard batch-type trials. In the sorption-phase experiments, Pine Sawdust showed 23% sorption when a concentration of 100 mg Cr(VI)L−1 was added, whereas sorption on oak wood ash was 17%. In the desorption-phase, chromium release was clearly higher from Pine Sawdust than from oak wood ash (98% and 66%, respectively). Sorption curves were well fitted to the Freundlich and Lineal models. In view of the results, both materials can be considered of very limited value to remove Cr from polluted soil and water, which can be of relevance regarding its appropriate use as biosorbents and recycled by-products.
Scott X. Chang - One of the best experts on this subject based on the ideXlab platform.
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Adsorption of ammonium in aqueous solutions by Pine Sawdust and wheat straw biochars
Environmental Science and Pollution Research, 2018Co-Authors: Hye In Yang, Anushka Upamali Rajapaksha, Yong Sik Ok, Anthony O. Anyia, Scott X. ChangAbstract:Ammonium (NH_4 ^+) is a common form of reactive nitrogen in wastewater, and its discharge to water bodies can lead to eutrophication. This study was conducted to understand NH_4 ^+ adsorption mechanisms of Pine Sawdust and wheat straw biochars in aqueous solutions and the factors affecting NH_4 ^+ removal. Biochars were produced by pyrolysing Pine Sawdust at 300 °C (PS300) and 550 °C (PS550) and wheat straw at 550 °C (WS550). Pseudo-second-order and Redlich-Peterson models best fitted the adsorption data. The PS300 showed the highest NH_4 ^+ adsorption capacity (5.38 mg g^−1), followed by PS550 (3.37 mg g^−1) and WS550 (2.08 mg g^−1). Higher H/C and O/C ratios of PS300 (0.78 and 0.32, respectively) indicated the greater presence of functional groups on the biochar’s surface as compared to PS550 (0.35 and 0.10, respectively) and WS550 (0.36 and 0.08, respectively), resulting in different NH_4 ^+ adsorption through electrostatic interactions. The dominant mechanism for NH_4 ^+ adsorption by the biochars was likely chemical bonding and electrostatic interaction of NH_4 ^+ with the surface functional groups. Lower pyrolysis temperature resulted in a higher NH_4 ^+ adsorption capacity by the Pine Sawdust biochar. At the same pyrolysis temperature (550 °C), the biochar made with Pine Sawdust as the feedstock had a higher NH_4 ^+ adsorption capacity than biochar made from wheat straw. We conclude that biochars can be efficient absorbents for NH_4 ^+ removal from wastewater, and the removal efficiency can be optimised by selecting different feedstocks or the pyrolysis condition for biochar production.
S. N. Khadzhiev - One of the best experts on this subject based on the ideXlab platform.
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Kinetics of thermolysis of vacuum tower bottoms mixed with Pine Sawdust
Petroleum Chemistry, 2016Co-Authors: D. A. Strizhakov, A. I. Yusevich, V. V. Yurachka, Kh. M. Kadiev, V. E. Agabekov, S. N. KhadzhievAbstract:Basic features of thermal degradation of mixtures of vacuum tower bottoms with Pine Sawdust have been studied by dynamic thermogravimetry. The kinetic parameters of the process have been determined using the integral model-free Ozawa–Flynn–Wall method. The enthalpies and ethropies of activation of the thermal degradation of the vacuum residue, the Sawdust, and their mixtures have been calculated on the basis of the transition state theory. It has been shown that Pine Sawdust and its degradation products have an activity to enhance the kinetic parameters and the rate of thermal degradation of vacuum tower bottoms. It has been found that the E value of thermolysis of the heavy petroleum residue substantially decreases with an increase in the proportion of Sawdust in the vacuuum resid to 225.0 kJ/mol for the mixture containing 18.0 wt % Pine Sawdust at a degree of conversion of the mixture of 0.8.
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Hydrothermal treatment of electron-beam irradiated Pine Sawdust in a mixture with vacuum tower bottoms
Petroleum Chemistry, 2013Co-Authors: D. A. Strizhakov, Kh. M. Kadiev, V. E. Agabekov, V. I. Korbut, S. N. KhadzhievAbstract:Hydrothermal processing of electron-beam irradiated Pine Sawdust in a mixture with vacuum tower bottoms (VTB) in an autoclave with continuous removal of the vapor phase at a hydrogen pressure of 7.0 MPa has been investigated. It has been found that as the Sawdust irradiation dose increases to 1.0 MGy, the degree of VTB conversion during the hydrothermal treatment of the mixture increases and the amount of the hydrocarbon fraction in the resulting liquid product grows to reach a yield of 38.0 wt %. At a temperature of 430°C, the conversion of biomass for two hours is 83–84 wt % and the yields of liquid and gaseous products are 49.0 and 35.0 wt %, respectively.