• The Korean Journal of Mycology
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• v.41 no.2
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• pp.85-90
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• 2013

This study investigated the internal and external morphological characteristics of decomposition and browning of oak sawdust medium for ground bed cultivation of Lentinula edodes. Within fifty days after L. edodes inoculation, surface hyphae on the bed browned. In 110 days, the fungal hyphae occupied and decomposed wood fibers, vessels and parenchymatous cells from the inside as white profuse hyphal mass was amorphously dissolving the saw dust particles from the outer surface. Most of the white hyphal bed surface became cleanly brown, however, some colony surface became blackened and slimy with contaminating bacteria, hyphae and spores. The brown layer was ca. 0.34 mm thick with highly dense and white hyphal mass beneath, whereas the blackened layer was ca. 1.17 mm thick with shrunken hyphae and less decomposed sawdust particles beneath. The surface hardness of the brown surface was ca. $0.73kgf/cm^2$, soft and resilient, while that of the blackened was ca. $0.91kgf/cm^2$, hard and nonresilient. By 150 days Lentinula edodes mushrooms fruited only on the brown surface and not on the blackened medium.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.335-340
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• 2010

This study was conducted to select organic materials (OM) and nitrogen sources in composting of waste mushroom bed from Agaricus bisporus. We examined physio-chemical properties of the organic materials and the mixture ratio for preparing the wasted mushroom bed (M) compost. The carbon content of sawdust was higher than those of rice straw (R) as OM source and the nitrogen content was high in the order of fowl manure (F)>> pig manure (P)> cow manure (C). The compost was prepared to maintain the criteria of above 25% organic matter and then the change of their ingredients was estimated during the process of fermentation. The temperature of waste mushroom bed+pig manure+rice straw (MRP) treatment was varied fast throughout fermentation, on the other hand the temperature of waste mushroom bed+pig manure+sawdust (MSP) treatment was steadily elevated to the middle of composting. The pH of the compost was somewhat high to pH 8.5~9.0 at the early stage, but decreased to 7.5 at the end stage of composting. The content of OM after fermentation was decreased to the level of 19~21% in rice straw, but the sawdust treatment maintained 25~27% organic matter. The waste mushroom bed+fowl manure+rice straw (MRF) treatment, which contains 26.2% organic matter and 0.68% nitrogen, was the highest among them. The volume of compost was reduced to 50% by using rice straw as organic matter, but reduced to 30% by using the sawdust. The contents of heavy metal in the compost were suitable within the legal criteria. The number of microorganisms were higher in the rice straw than those in the sawdust. It was high in the order of fowl manure> pig manure> cow manure. The major groups consisted of aerobic bacteria, gram negative bacteria and Bacillus sp. and their populations after fermentation were increased to $1{\times}10^1{\sim}1{\times}10^2\;cfu\;g^{-1}$ rather than those before fermentation. Therefore we concluded that the waste mushroom bed+fowl manure+sawdust (MSF 3:9:1 v/v/v) treatment was suitable combination for high organic matter and nitrogen source, and the periods of composting were 50~60 days.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.77-82
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• 2012

Sterilization of oak sawdust at $65^{\circ}C$ for Lentinula edodes bed cultivation can be efficient in sterilization facility cost, but its effect on the mushroom production is uncertain due to high contamination probability. The effective conditions for L. edodes hyphal growth in the low temperature sterilized oak sawdust were investigated with combinations of three sterilization temperatures ($65^{\circ}C$, $100^{\circ}C$ and $121^{\circ}C$) and four cultivation temperatures ($15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$). L. edodes inoculation density effect was also tested with 1 cm, 2 cm, and 4 cm distance in the sawdust (4%, 11% and 25% inoculation rate by surface area). L. edodes hyphal growth in the sawdust sterilized at $65^{\circ}C$ was as much as at those $100^{\circ}C$ and $121^{\circ}C$ when the fungus cultured below $25^{\circ}C$, but it was greatly reduced when cultured at $30^{\circ}C$. And the sawdust medium with 1cm distance inoculation density was fully occupied with L. edodes hyphae, but those with 2~4cm distance inoculation were contaminated by 4~33%. Therefore, we conclude that low temperature sterilized oak sawdust needs to be cultured under $25^{\circ}C$ after sufficient inoculation by 25% for successful bed cultivation of L. edodes.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.4
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• pp.439-445
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• 2008

Sawdust is considered one of the cheapest and abundantly available adsorbents, and it is not necessary to regenerate. The spent sawdust can be incinerated or reused as a fuel. The sawdust adsorption can be applied to the removal of color and metal cations from the wastewater. The aim of this study was to evaluate the adsorptive capacities of sawdust with respect to color, COD, SS, turbidity, metal cation from textile wastewater. Langmuir, Freundlich, BET and Sips adsorption isotherm were obtained for the sawdust adsorption of Fe(III). The effects of particle size and amount of sawdust on the adsorption of Fe(III) were also studied. COD, SS, color, turbidity and Fe(III) removal efficiencies were examined at the continuous fixed-bed adsorption test. It was showed the removal efficiencies of SS 50.0%, Fe(III) 25.0%, turbidity 79.4%, color 48.6% and COD 50.9%. In addition, the changes of surface structure between before and after adsorption were investigated through SEM analysis. It is confirmed that the waste sawdust can be successfully used as an adsorbent for wastewater treatment.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.146-153
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• 1997

An experimental study was performed of natural-convection downward smolder spread across a sawdust bed peripherally enclosed with an insulating container, to examine the effect of the open- ing condition at the top end on downward smolder spread. Experiments were conducted by using relatively coarse sawdust and 25-cm-long cylindrical container The variations of temperature profiles along the bed axis with time were determined far different opening conditions and were com-pared with those in smolder spread from open top to open bottom. It was shown that the smolder zone initiated from open top toward closed bottom penetrates the bed with keeping high peak temperature like the case of open top to open bottom spread, although mean spread rate is smaller. This indicates that the downward smolder zone can be sustained stably if sufficient air or oxygen Is supplied from the back of it by natural convection even if upward draft entering from the bottom of the bed is absent. When the top end was partially closed by mounting a cover after stable smolder spread had begun from open top toward open bottom, the temperature at the peak decreased more than 200 K and the smolder zone became to spread with thickening residue. In this case, the shape of temperature profiles continuously changed or decayed until end-effect at the open bottom end enhanced the reaction. The temperature at the shrunk peak, free from the end-effect, was almost identical with the temperature at the exothermic oxidative-degradation zone in smolder spread from open top to open bottom. from these results, it can be inferred for natural-convection downward smolder spread that the oxidation reaction of the char is very sensitive to the oxygen supply by natural convection in the space above the smolder zone, and that the top end opening condition strongly alters the completeness of reactions, structure, and behavior of the smolder zone.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.256-259
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• 2008

The gasification of biomass, sawdust, was carried out in order to investigate gasification characteristics. The experiment was performed using a down-draft fixed bed gasifier to surpass tar components generation in the gasification process. In the experiments, we investigated synthetic gas composition by varying reaction temperature, steam/carbon ratio, and excess ratio (ER), respectively. Higher reaction temperature, $700^{\circ}C$ to $900^{\circ}C$, could obtain higher $H_2$ yield. However, we could not obtain any meaning data by varying S/C ratio. Using $O_2$-LNG burner in the top of the gasifier may surpass water-gas shift reaction by increasing $CO_2$ concentration from the LNG-$O_2$ combustion reaction.

• Journal of Animal Environmental Science
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• v.13 no.1
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• pp.13-20
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• 2007

Sawdust biofiltration is an emerging bio-technology for control of ammonia emissions including compost odors from composting of biological wastes. Although sawdust is widely used as a medium for bulking agent in composting system and for microbial attachment in biofiltration systems, the performance of agitated bed composting and sawdust biofiltration are not well established. A pilot-scale composting of hog manure amended with sawdust and sawdust biofiltration systems for practical operation were investigated using aerated and agitated rectangular reactor with compost turner and sawdust biofilter operated under controlled conditions, each with a working capacity of approximately $40m^3\;and\;4.5m^3$ respectively. These were used to investigate the effect of compost temperature, seed germination rate and the C/N ratio of the compost on ammonia emissions, compost maturity and sawdust biofiltration performance. Temperature profiles showed that the material in three runs had been reached to temperature of 55 to $65^{\circ}C$ and above. The ammonia concentration in the exhaust gas of the sawdust biofilter media was below the maximum average value as 45 ppm. Seed germination rate levels of final compost was maintained from 70 to 93% and EC values of the finished compost varied between 2.8 and 4.8 ds/m, providing adequate conditions for plant growth.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.205-213
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• 2021

The present study aimed to determine the effect of co-pyrolysis of sawdust biomass and scrap tyre waste employing different blending ratios of sawdust to waste tyre such as 100:0, 75:25, 50:50, 25:75, and 0:100. The thermochemical characterization of feedstocks was carried out by employing the proximate, ultimate analysis, and thermogravimetric (TGA) analyses, calorific values, and scanning electron microscope coupled with energy dispersive x-ray analysis (SEM-EDX) to select the blending ratio having better bioenergy potential amongst the studied ratios. The blending ratio of 25:75 (sawdust to waste tyre) was selected for the co-pyrolysis study in a fixed-bed pyrolysis reactor system based on its solid biofuels properties such as heating value (30.18 MJ/kg), and carbon (71.81 wt%) and volatile matter (63.82 wt%) contents. The pyrolysis temperatures were varied as 500, 600 and 700 ℃ while the other parameters such as heating rate and nitrogen flowrate were maintained at 30 ℃/min and 0.5 L/min respectively. The bio-oil yields as 31.9, 47.1 and 61.2 wt%, bio-char yields as 34.5, 34.2 and 31.4 wt% and gaseous product yields as 33.6, 18.60 and 7.3 wt% at the pyrolysis temperatures of 500, 600 and 700 ℃ respectively were obtained. The blends of sawdust and waste tyres showed the improved energy characteristics which could provide the solution for the beneficial management of sawdust and scrape tyre wastes via co-pyrolysis processing.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.221-230
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• 2015

Ground bed cultivation method for shiitake mushroom (Phogo; Lentinula edodes) has been advanced to use the oak-sawdust composted by microorganisms. This method has some advantages in saving the labors and improving productivity. The aim of this study is to analyze microbial community in oak sawdust and to provide the information for efficient cultivation of shiitake mushroom. In process of composting, the proportions of thermophiles increased from 10% to 80%. This results show the microbial community succession from mesophilic bacteria to thermophilic bacteria. T-RFLP analysis and nucleotide sequencing of 16S rRNA gene demonstrated that the change of dominant bacteria coupled with shifts in each stages. The family of Enterobacteriaceae as a mesophilic bacteria were dominant (100%) in oak sawdust sample, but Amycolatopsis (49.0%) and Saccharopolyspora (26.5%) as a thermophilic Actinomycetes were dominant in the last day of composting. In hyphal growth stage, Leuconostoc (psychrophilic bacteria) was dominant (75.0%). The composting process of sawdust is very important for growth of mushroom mycelium. Therefore, there is need for the further study for the Amycolatopsis as thermophilic Actinomycetes.

• Journal of Animal Environmental Science
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• v.3 no.1
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• pp.13-18
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• 1997

This study was conducted to investigate the physicochemical changes during the aerobic composting of swine manure mixed with bulking agent, sawdust(v/v, 1:1), in a full-scale composting plant using rectangular escalator-aginated bed composting system. Physical and chemical properties were analyzed on the samples which were collected at 5, 15, and 25 day of composting, curing and final step. The results of this study were summarized as follows; 1. Moisture and K2O content, and pH of final step were higher than those of 5th day of composting (p＜0.05). 2. Ammonium nitrogen, total organic corbon and organic matter content, and electrical conductivity(EC) were significantly decreased (p＜0.05) but nitrate nitrogen, ash and P2O5 content increased(p＜0.05) throughout the aerobic composting process. 3. Total organic carbon per total nitrogen(C/N) and total organic matter per total nitrogen(OM/N) ratio were significantly decreased throughout the aerobic composting process(p＜0.05). 4. Physical and chemical properties of swine manure were varied by aerobic fermentation using rectangular escalor-aginated bed composting system.