Showing papers on "Sawdust published in 2003"
TL;DR: In this paper, an acid dye, acid yellow 36, was used as the adsorbate for the removal of acid dyes from aqueous solution and the results showed that a pH value of 3 is favorable for the adsorption of acid dye.
926 citations
TL;DR: It is proposed that in batch or stirred tank reactors, both adsorbents can be an attractive option for dye adsorption.
763 citations
TL;DR: It can be concluded that the sawdust of P. sylvestris could be a good adsorbent for the metal ions coming from aqueous solutions and could also be used for purification of water before rejection into the natural environment.
677 citations
TL;DR: The experimental result inferred that chelation ion exchange is one of the major adsorption mechanisms for binding metal ions to the maple sawdust.
386 citations
TL;DR: In this article, the simulation of a wood waste (sawdust) gasifier using an equilibrium model based on minimization of the Gibbs free energy is presented, and sensitivity studies to verify the influence of the moisture sawdust content on the fuel gas composition and on its heating value are made.
288 citations
TL;DR: Rice straw appeared to be the best alternate substrate for growing oyster mushrooms based on the yield and BE of the substrates tested, and the yield was positively correlated to cellulose, lignin, fibre and fibre contents of the substrate.
Abstract: Eight lignocellulosic by-products were evaluated as substrates for cultivation of the oyster mushroom, Pleurotus ostreatus ( Jacq. ex. fr) Kummer. The yields of mushroom on the different substrates were 183.1, 151.8, 111.5, 87.8, 49.5, 23.3, 13.0 and 0.0 g for composted sawdust of Triplochiton scleroxylon, rice straw, banana leaves, maize stover, corn husk, rice husk, fresh sawdust, and elephant grass, respectively. The biological efficiency (BE) followed the same pattern and ranged from 61.0% for composted sawdust to 0.0% for elephant grass. The yield of mushroom was positively correlated to cellulose ( r(2) =0.6), lignin ( r(2) =0.7) and fibre ( r(2) =0.7) contents of the substrates. Based on the yield and BE of the substrates tested, rice straw appeared to be the best alternate substrate for growing oyster mushrooms.
233 citations
TL;DR: The three lignocellulosic substrates used for the production of cellulase enzyme gave their maximum enzyme activities at about the twelfth hour of cultivation, suggesting that the 12th hour is the optimum time when the enzyme may be harvested.
Abstract: Bagasse, corncob and sawdust were used as lignocellulosic substrates for the production of cellulase enzyme using Aspergillus flavus after ballmilling and pretreatment with caustic soda. From the fermentation studies, sawdust gave the best result with an enzyme activity value of 0.0743IU/ml while bagasse and corncob gave 0.0573IU/ml and 0.0502IU/ml respectively. The three lignocellulosics gave their maximum enzyme activities at about the twelfth hour of cultivation, suggesting that the 12th hour is the optimum time when the enzyme may be harvested.
(African Journal of Biotechnology: 2003 2(6): 150-152)
156 citations
TL;DR: In this paper, the authors show that cellulose powder and softwood sawdust were subjected to alkaline degradation under conditions representative of a cementitious environment for periods of 7 and 3 years, respectively.
Abstract: Cellulose powder and softwood sawdust were subjected to alkaline degradation under conditions representative of a cementitious environment for periods of 7 and 3 years, respectively. During the fir ...
122 citations
TL;DR: In this article, smokeless fuel briquettes have been prepared with low-rank coal and biomass, and they have been pyrolysed at 600°C with the aim to reduce both the volatile matter and the sulphur content, and to increase the high calorific value (HCV).
100 citations
TL;DR: The use of untreated sawdust as a filler in polyvinyl chloride (PVC) was examined in this paper, where the effects of sawdust content on structural and thermal changes, and rheological and mechanical properties being of main interest.
Abstract: The use of untreated sawdust as a filler in poly(vinyl chloride) (PVC) was examined—the effects of sawdust content on structural and thermal changes, and rheological and mechanical properties being of main interest. The results revealed that the torque and die entrance pressure drop values during mixing were independent of sawdust particles up to 23.1 wt%. The extrudate swell monotonically decreased up to 33.3 wt% sawdust content. Smooth wood-like texture with controllable size of the extrudate could be obtained at a sawdust content greater than 33.3 wt%. Tensile, impact, flexural and hardness properties of the PVC/sawdust composites considerably decreased with up to 16.7 wt% sawdust content before leveling off for higher sawdust loadings. The composites having sawdust higher than 16.7 wt% showed a benefit of cost savings. The decreases in the mechanical properties of PVC with sawdust are explained in association with the presence of moisture, interfacial defects between fibre and polymer, and fibre dispersions in the PVC matrix. Thermal degradations of PVC in PVC/sawdust composites were evidenced by a decrease in decomposition temperature and an increase in polyene sequences, which were caused by Cl cleavage due to strong hydrogen bonds of fibre–PVC molecules. The maximum of tanδ transition and the glass transition temperature were found to improve with sawdust content as a result of re-formation of hydrogen bonds between the macromolecules of the fibre and the polymer. The overall results in this work suggest that the properties of PVC/sawdust composites were strongly influenced by sawdust content up to 16.7 wt%. Beyond this value the effect of sawdust content on the properties was comparatively small. Copyright © 2003 Society of Chemical Industry
97 citations
TL;DR: EDTA extraction removes significant quantities of copper from CCA-treated wood, which could be important in the remediation of wood waste treated with the newest formulations of organometalic copper compounds and other water-borne wood preservatives containing copper.
TL;DR: In this paper, the organic composition of a paper mill sludge (PMS) mixture was investigated during composting to better understand the changes in main chemical components, such as lipids, sterols, lignin, N-compounds, and carbohydrates.
TL;DR: A wide variety of silicon carbide and oxide-based ecoceramics has been fabricated by infiltration of wood cellulose derived carbonaceous templates by molten silicon, refractory metal-silicon alloys, oxide sols, or gaseous silicon monoxide phases.
Abstract: Environmentally conscious ceramics (ecoceramics) are a new class of materials, produced using natural, renewable resources (wood) or wood wastes (wood chips or sawdust). A wide variety of silicon carbide and oxide-based ecoceramics has been fabricated by infiltration of wood cellulose derived carbonaceous templates by molten silicon, refractory metal–silicon alloys, oxide sols, or gaseous silicon monoxide phases. This technology provides a cost effective and eco-friendly route to advanced ceramic materials. Ecoceramics have tailorable properties and behave like ceramic materials manufactured by conventional approaches. Various by-products generated at different steps in this process are reusable and recyclable.
TL;DR: In this article, the weight-loss curve from TGA based on different reference samples and final product distribution as well as gas composition from the fixed-bed reactor was presented, showing that producer gas is a very important product, up to 60 wt%, and H2 and CO account for more than 60 vol%.
Abstract: Several types of biomass wastes were pyrolyzed with an atmospheric pressure TGA apparatus and a self-made fixed-bed reactor. The weight-loss curve from TGA based on different reference samples and final product distribution as well as gas composition from the fixed-bed reactor are presented here. TGA results indicate that biomass pyrolysis can be identified as 3 phases, i.e., moisture evaporation, main devolatilization, and continuous devolatilization; the reference sample has a slight influence on the weight loss of the biomass sample; different biomass samples can lead to the same tread of its weight-loss curve, but a different amount of weight loss. Fixed-bed pyrolysis results show that producer gas is a very important product, up to 60 wt%, and H2 and CO account for more than 60 vol%. The producer gas is hereby thought of as a high quality gas source, with a heating value of 13,000–14,000 kJ/Nm3 and a low tar concentration.
TL;DR: In this article, the results of a combined experimental and numerical investigation of the combustion reactivity of sawdust char in a drop tube furnace were presented, and the experimental results indicated that the bulk of the char oxidation reaction for sawdust occurred in Regime II where chemical reaction and pore diffusion rates are comparable.
Abstract: This article discusses the results of a combined experimental and numerical investigation of the combustion reactivity of sawdust char in a drop tube furnace. The work presented here was motivated by the lack of reliable data in the open literature on the combustion reactivity of woody biomass char. This study involved the experimental determination of the global kinetic parameters of sawdust-char oxidation and the subsequent application of these parameters in a computational fluid dynamics (CFD) code. The modified code was employed for mathematical modeling of the sawdust-char combustion in the drop tube furnace. The experiments were conducted at furnace temperatures of 1473 and 1673 K in a 10 mol% O 2 environment and 1473 K in air. Experimental results indicated that the bulk of the char oxidation reaction for sawdust occurred in Regime II where chemical reaction and pore diffusion rates are comparable. In addition, the sawdust char exhibited distinctive near-extinction combustion behavior at the early ...
TL;DR: Modification of sawdust by ultrasound increased lignin consumption and may be recommended for accelerating biodegradation of lignocellulose substrates.
Abstract: Lignin consumption and synthesis of lignolytic enzymes by the fungus Panus (Lentinus) tigrinuscultivated on solid phase (modified and unmodified birch and pine sawdusts) were studied. The fungus grew better on and consumed more readily the birch lignin than the pine wood. Peroxidase activity was higher in the case of pine sawdust; laccase and lignolytic activities, in the case of birth sawdust. Treatment with ammonia or sulfuric acid decreased lignin consumption by this fungus cultivated on either medium. Modification of sawdust by ultrasound increased lignin consumption and may be recommended for accelerating biodegradation of lignocellulose substrates.
TL;DR: In this article, smoke components from oxidative pyrolysis of softwood pellets from compressed sawdust and wood shavings were sampled on Tenax cartridges and assessed by gas chromatography and mass spectrometry.
TL;DR: In this paper, a mixture of softwood sawdust using a hydrolytic pretreatment and a subsequent soda-anthraquinone delignification/pulping stage was evaluated.
Abstract: Lignins were obtained from a mixture of softwood sawdust using a hydrolytic pretreatment and a subsequent soda-anthraquinone delignification/pulping stage. Their potential uses and the effect of the pretreatment conditions on the yield (% of recovered lignin from black liquors) and chemical composition of isolated lignins were evaluated. The severity factor used combined the temperature and time of the hydrolytic process in a single ordinate (Ro). The severity range was modified from log Ro = 2.6 to log Ro = 4.6 and the pulping conditions were constant throughout the experiments. The effect of the cooking time on the chemical composition of precipitated lignins was also studied between 135–170 min for original (non-pretreated) material. Yield, elemental analysis, molecular weight distribution, Fourier transform infrared spectra (FTIR), structure, and the methoxyl and aliphatic/aromatic alcohol content of the various lignins, were compared.
TL;DR: Findings reveal that sawdust may be suitable litter followed by rice husk, sugarcane bagasse and wheat straw in late-autumn in Bangladesh in respect of broiler growth performance.
Abstract: A total of 168 seven days-old Arbor Acres chicks were reared in late-autumn on 4 types of litters; sawdust, rice husk, sugarcane bagasse or wheat straw up to 49 days of age to compare the growth performance, evaluate the manureal value and Coccidial oocyst population in used litter. Sadust, rice husk, sugarcane bagasse and wheat straw did not differ statistically for live weight, feed consumption, feed conversion ratio and survivability (p>0.05). However, live weight and survivability tended to increase on sawdust. The highest moisture content of used litter was found in sugarcane bagasse followed by sawdust, rice husk and wheat straw (p<0.05). Rice husk contained the highest amount of of nitrogen, phosphurus and potassium followed by sawdust, sugarcane bagasse and wheat straw (p<0.01). Oocyst content of all treatment groups increased suddenly up to 5 weeks of age and thereafter suddenly declined up to 7 weeks of age. Litter materials did not differ at 35 and 42 days of age for oocyst content, but significantly differed at 49 days of age (p<0.01). So, the above findings reveal that sawdust may be suitable litter followed by rice husk, sugarcane bagasse and wheat straw in late-autumn in Bangladesh in respect of broiler growth performance. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 4 : 555-557)
Journal Article•
TL;DR: In this article, the emissions from sawdust of Norway spruce (Picea abies), dried at three temperature schedules (T = 140°C, T = 170°C and T = 200°C), were analyzed by a gas chromatograph with a mass spectrometric detector and a flame ionization detector.
Abstract: Emissions of volatile hydrocarbons are considered an environmental problem and a health problem. A wood-drying process is a source of volatile organic compound (VOC) emissions. Emissions of monoterpenes, as well as total VOCs, from a pilot-scale continuous spouted bed dryer have been investigated regarding the influence of the drying medium temperature and the final sawdust moisture content. The emissions from sawdust of Norway spruce (Picea abies), dried at three temperature schedules (T = 140°C, T = 170°C, and T = 200°C), was analyzed by a gas chromatograph with a mass spectrometric detector and a flame ionization detector. Emissions of terpenes and VOC per ovendry weight increased rapidly when the sawdust moisture content was reduced below 12 percent (wb). The concentration of VOCs in the drying medium, and the amount of emitted monoterpenes, increased with drying medium temperature. The composition of different monoterpenes in the drying medium was not influenced by the sawdust's final moisture content. The relative amount of less volatile monoterpenes increased with drying medium temperature.
TL;DR: In this paper, the authors investigated the carbonisation of a fir wood sample in an open pyrolysis system under a nitrogen atmosphere at temperatures ranging from 50 to 300°C to contribute to the knowledge of artificial coalification.
Journal Article•
TL;DR: In this article, the authors developed a method to establish the amount of emitted substances from dryers, and to determine the effect of drying medium temperature and end moisture content of the processed material on emissions of monoterpenes and other hydrocarbons.
Abstract: The central aim of this thesis is to support the efforts to counteract certain environmental problems caused by emissions of volatile organic compounds. The purpose of this work was (1) to develop a method to establish the amount of emitted substances from dryers, (2) to determine the effect of drying medium temperature and end moisture content of the processed material on emissions of monoterpenes and other hydrocarbons, (3) to examine the emissions of monoterpenes during production of pellets, and (4) to examine the natural emissions from forests with an eye to implications for modelling. The measurement method (1) resolves the difficulties caused by diffuse emissions, and also solves the problems associated with high moisture content of the drying medium. The basic idea is to use water vapour to determine the exhaust flow, while a dry ice trap is used both to preconcentrate emitted volatile organic compounds and to determine the moisture content of the drying medium. The method as used in this paper has an uncertainty of 13% using a 95% confidence interval. Emissions from a spouted bed (2) in continuous operation drying Norway spruce sawdust at temperatures of 140°C, 170°C or 200°C was analysed with FID and GC-MS. When the sawdust end moisture content was reduced below 10%wb, emissions of terpenes and volatile organic compounds per oven dry weight increased rapidly. Increased temperature of the drying medium increased the amounts of emitted monoterpenes when sawdust moisture content was below the fibre saturation point. Examination of sawdust and wood pellets from different pellets producers (3) revealed that most of the terpene emissions happened during the drying step, with rotary dryers causing higher emissions than steam dryers. Almost all of the volatile terpenes remaining in wood after drying were released during pelleting. When sawdust with higher moisture content was used in the pellets press, the terpene emissions were increased. Terpenes emitted naturally from vegetation can have an adverse environmental impact. Factors affecting terpene emissions from tree species in Sweden were reviewed (4). Models for prediction of terpene fluxes should include not only temperature but also light intensity, seasonal variation, and a base level of herbivory and insect predation. Prediction of high concentrations of ambient terpenes demand sufficient resolution to capture emission peaks e.g. those caused by bud break.
Patent•
16 Apr 2003
TL;DR: In this article, a sawdust collection apparatus for a compound miter saw includes a turntable and a saw dust collection assembly, which is rotatably mounted on a base.
Abstract: A sawdust collection apparatus for a compound miter saw includes a turntable and a sawdust collection assembly. The turntable is rotatably mounted on a base and has a cutting groove defined in the turntable and a sawdust guide communicating with the cutting groove. The sawdust collection assembly has a hollow sawdust duct with a sawdust channel communicating with the sawdust guide and a hollow sawdust entry duct with a sawdust entry port to receive sawdust and debris and a sawdust passage to communicate with the sawdust entry port. The sawdust channel is connected to a vacuum cleaner to efficiently pull sawdust and debris out of the miter saw through the sawdust channel and the sawdust passage.
TL;DR: In this article, the effects of chelating agents, such as ethylenediaminetetracetic acid (EDTA), nitrilotriacetic acid, and oxalic acid (OA), on the removal of copper, chromium, and arsenic from CCA-C treated wood chips and sawdust were evaluated.
Abstract: This study evaluates the effects of the common chelating agents, ethylenediaminetetracetic acid (EDTA), nitrilotriacetic acid (NTA), and oxalic acid (OA) on the removal of copper, chromium, and arsenic from CCA-C treated wood. In the study, the removal of the metal oxides from treated chips and sawdust by EDTA and NTA in conjunction with OA in dual extraction processes was investigated using batch-leaching experiments. Exposing CCA-C treated chips and sawdust to chelat extraction enhanced the removal of CCA-C components compared to extraction by deionized water. Grinding CCA-C treated wood chips into 40-mesh sawdust provided greater access to and removal of CCA-C components. Extraction with EDTA/OA and NTA/OA in dual extraction processes removed about 100% copper and arsenic and 90% chromium from CCA-C treated sawdust. However dual extraction of CCA-C treated chips resulted in about 80% copper and arsenic, and 70% chromium removal. In single extraction processes, EDTA and NTA removed significant amounts of copper from CCA-C treated chips and sawdust compared to other components.
TL;DR: The effects of competitive ion exchange, because of affinity differences between the metal ions for sawdust, resulting in the metals having the lower affinity being displaced by those having a higher one and to overshoot the 0.2 meq l−1 feed solution, are investigated.
Abstract: The adsorption‐desorption of copper ions and a mixture of five metal ions (cadmium, copper, nickel, lead and zinc) in aqueous solutions by a spruce sawdust column was reported. Different studies about the copper binding mechanism, the efficiency of some regenerating solutions for the copper desorption, the use of column for copper adsorption‐desorption by successive cycles as well as the adsorption‐desorption of a multi‐component solution were investigated. An ion exchange mechanism seemed to explain the removal of copper by the natural components of sawdust, i.e., calcium, magnesium and manganese accounting for 71, 13 and 5.5% respectively of the copper binding on sawdust. But, there was evidence variation in the contribution of these ions during the copper adsorption in the continuous flow process. Regeneration of the sawdust column was described by the efficiency sequence: H∗ > Ca2+ ≫ Na+, where protons were the most promising regenerating agents. Adsorption‐desorption cycles showed that coppe...
TL;DR: In this article, the physicochemical and rheological properties of cellulose-containing dispersions were investigated for aqueous dispersions and their physicomechanical properties of composites based on such systems.
Abstract: The form and sizes of the particles of cellulose-containing disperse systems obtained by dry grinding or dispersing in water a source material (wood pulp and sawdust), destructed by the thermocatalytic method, have been investigated. Their physicochemical and rheological (for aqueous dispersions) properties as well as the physicomechanical properties of composites based on such systems have been studied. By dry grinding, a powder of microcrystalline cellulose (MCC) (in the case of wood pulp) and technical powder (in the case of sawdust) containing particles of sizes from 3 to 20 μm were obtained. By dispersing in an aqueous medium the wood pulp destructed to the levelling-off degree of polymerization (LODP), MCC dispersions containing separate microcrystallites and their aggregates were obtained. In the case of their sufficiently high concentration (≥ 8%), MCC gels having rheological properties typical of liquid-crystalline polymers were formed. It is shown that the cellulose-containing disperse systems obtained may be useful in composites made with polymer materials for improving their strength properties.
TL;DR: In this paper, a study concerning alternative materials that might be used as wastewater filters was conducted for the utilization of wastewater from swine confinement in fertigation of agricultural crops, mainly in the case of localized irrigation.
Abstract: For the utilization of wastewater from swine confinement in fertigation of agricultural crops, mainly in the case of localized irrigation, it is necessary to remove the suspended solids and some of the dissolved ones. Since the use of conventional sand filters for wastewater is not possible there is a need for a study concerning alternative materials that might be used as wastewater filters. The following filtering materials were evaluated: rice husk, coffee husk, sugarcane bagasse, milled corncob, sawdust and fine charcoal. The filtration columns consisting of PVC tubes with 100 mm diameter and 600 mm length were filled with filtering material up to 500 mm height and compression of 12,490 N m-2. Evaluations were performed for the chemical and physical changes occurring in the material following its use as a filter in treatment with swine wastewater. The filtering materials showing a higher retention capacity for the pollutants were the sugarcane bagasse and sawdust.
TL;DR: In this paper, an improvement of decay resistance of wood with ethanolamine is described, and the treatment of the spruce wood samples with aqueous solutions of ethanolamine resulted in colour changes.
Abstract: Wood is the most abundant non-toxic, recycable and biodegradable natural material, valued as a construction material because of its appearance and its high strength at low density. On the other hand its biodegradability is an important drawback. Improvement of decay resistance of wood with ethanolamine is described in this paper. Ethanolamine chemically reacts with wood (Norway spruce sapwood) and does not evaporate from it. During this reaction, significant amounts of oxygen are consumed. Upgraded specimens show increased fungal activity and increased combustibility. The treatment of the spruce wood samples with aqueous solutions of ethanolamine resulted in colour changes.
TL;DR: Composted nitrogenous waste has the potential to produce excessive amounts of nitrous oxide (N2O), a potent greenhouse gas that also contributes to stratospheric ozone depletion, but in this laboratory study, sawdust was irrigated with varying amounts of landfill leachate with high NH4+-N content.