Sawdust

About: Sawdust is a research topic. Over the lifetime, 5526 publications have been published within this topic receiving 86499 citations. The topic is also known as: wood dust & hard wood dust.

Degradation of typical antibiotics during human feces aerobic composting under different temperatures

Abstract: Four typical antibiotics were added to human feces for aerobic composting using batch reactors with sawdust as the bulk matrix. Under three composting temperatures (room temperature, 35 ± 2 °C and 55 ± 2 °C), decreases in the extractable concentrations of antibiotics in the compost were monitored for 20 days. As a result, the removals of extractable tetracycline and chlortetracycline were found to be more temperature-dependent than the removals of sulfadiazine and ciprofloxacin. However, more than 90 % of all of the extractable antibiotics were removed at 55 ± 2 °C. Three specific experiments were further conducted to identify the possible actions for antibiotic removal, including self-degradation in aqueous solution, composting with a moist sterile sawdust matrix without adding feces and composting with human feces and moist sterile sawdust. As a result, it was found that the removal of tetracycline and chlortetracycline was mainly due to chemical degradation in water, whereas the removal of sulfadiazine was mainly attributed to adsorption onto sawdust particles. The microbial activity of compost varied with temperature to a certain extent, but the differences were insignificant among different antibiotics. Although microbial action is important for organic matter decomposition, its contribution to antibiotic degradation was small for the investigated antibiotics, except for ciprofloxacin, which was degraded by up to 20 % due to microbial action.

Compost and Crude Humic Substances Produced from Selected Wastes and Their Effects on Zea mays L. Nutrient Uptake and Growth

Abstract: Production of agriculture and timber commodities leads generation of enormous quantity of wastes. Improper disposal of these agroindustrial wastes pollutes the environment. This problem could be reduced by adding value to them. Therefore, a study was carried out to analyse and compare the nutrients content of RS, RH, SD, and EFB of composts and crude humic substances; furthermore, their effect on growth, dry matter production, and nutrient uptake for Zea mays L., and selected soil chemical properties were evaluated. Standard procedures were used to analyze humic acids (HA), crude fulvic acids (CFA), crude humin (CH), soil, dry matter production and nutrient uptake. Sawdust and RS compost matured at 42 and 47 days, respectively, while RH and EFB composts were less matured at 49th day of composting. Rice straw compost had higher ash, N, P, CEC, HA, K, and Fe contents with lower organic matter, total organic carbon, and C/N and C/P ratios. The HA of sawdust compost showed higher carbon, carboxylic, K, and Ca contents compared to those of RS, RH, and EFB. Crude FA of RS compost showed highest pH, total K, Ca, Mg, and Na contents. Crude humin from RS compost had higher contents of ash, N, P, and CEC. Rice straw was superior in compost, CFA, and CH, while sawdust compost was superior in HA. Application of sawdust compost significantly increased maize plants' diameter, height, dry matter production, N, P, and cations uptake. It also reduced N, P, and K based chemical fertilizer use by 90%. Application of CH and the composts evaluated in this study could be used as an alternative for chemical fertilizers in maize cultivation.

Development of fuel briquettes from biomass-lignite blends

Abstract: The research was to study the briquetting of lignite combined with biomass binders. The biomass binders were rice husk and sawdust treated with sodium hydroxide. The ratio of biomass binders and lignite was 50:50 wt./wt. Rice husk was treated with 3% wt/v sodium hydroxide at 80C with a heating time of 1.5-4.5 hours, while sawdust was treated with a series of sodium hydroxide solution with a concentration of 7-13 % wt/v at the same temperature. The influence of time for sawdust digestion was investigated by increasing the time from 1.5 to 2.0 and 2.5 hours. The briquettes were formed in the cylindrical mold and the hydraulic press was used in the experiments. The mechanical, physical and combustion tests were performed. The investigations indicated that mechanical and physical tests related to NaOH concentration and digestion time depending on biomass used. The experiments showed that the rice husk and sawdust treated with sodium hydroxide would yield the quality of biomass-lignite briquetting.

Changes of organic constituents of crop residues and poultry wastes during fermentation for biogas production.

Abstract: Rice straw, maize, and cotton stalks and poultry droppings, both as such and with either wheat straw litter or sawdust litter, were used as substrates for biogasification. Water slurry combinations, each containing a crop residue and a type of poultry wastes, were prepared to achieve a uniform C/N ratio 30∶1 (w/w) and a total solids content 10% (w/v). Biogas generated and its methane component, as well as changes brought about in the major organic constituents of the feedstocks, were monitored in laboratory biogas digesters for 90 days at 35°C. The maximum cumulative volumes of biogas and methane, were respectively 30 and 14 l/l with rice straw plus wheat straw poultry droppings. The minimum volumes were 15 l biogas/l with cotton stalks + sawdust poultry droppings and 8 l methane/l with rice straw + sawdust poultry droppings. Rice straw combinations gave the highest rates of volatile solids disappearance, short-chain fatty acid formation, and NH4 -N liberation. No consistent trend among the poultry wastes mixed with each crop residue was evident. Changes in water-soluble substances, protein, fats, hemicellulose, cellulose and lignin depended on the components of each feedstock mixture.