• Journal of Environmental Science International
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• v.27 no.2
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• pp.91-97
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• 2018

This study carried out first a component survey on the domestic waste shipped into a waste disposal facility in B city, and then heavy metal analysis of each component according to the SRF standards. Based on this, this study explored the problems with domestic waste and measures to improve them. The results are as follows. The result of the survey of physical components show that paper accounted for the largest proportion with 20.5 %~59.9 %, metals (including batteries) among incombustibles accounted for 0.0~8.3 %, other inorganic substances, glass and ceramics accounted for 0.0~43.7 % and 0.0 %~19.6 % respectively. However, the proportion of coated viny and plastics, which have high lead and cadmium content, was rather high with 2.9 %~30.9 %. This suggests the possibility that actual concentration of lead and cadmium within SRF is likely to be higher. Among the 15 components contained in the waste brought into the waste disposal facility, 10 components (food waste, textiles, vinyl, plastics, wood, rubber and leather, paper, metals, electronic substrates, and nail polish) were analyzed according to assay samples (approximately 0.1 g and 0.3 g). The result of analysis shows that the amount of Cd and Pb detected in coated vinyl for 0.109 g of assay sample was 98.6 mg/kg and 20.6 mg/kg respectively; 117.0 mg/kg and 29.0 mg/kg respectively for 0.313 g of assay sample. This is high contents exceeding the Cd standard. As for wooden component, the amount of Pb was 480.0 mg/kg for 0.3 g of assay sample. This suggests that there always exists the possibility of exceeding the exposure level of heavy metals (Cd and Pb) in SRF as long as coated wood and vinyl plastics with high contents of Pb and Cd are shipped into the waste disposal facility; and the local government and the residents need to work hard to improve the situation including development of the machine to sort electronic substrates and batteries for separate collection of the waste of coated vinyl and plastics within domestic waste.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.spc
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• pp.31-38
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• 2023

In this study, in order to develop a method to efficiently inject essential nutrients necessary for plant growth into wood chips, which are simply used as soil covering materials in the agriculture, landscaping and horticultural industries, the atmospheric pressure dipping method and the vacuum pressure impregnating method are used to improve the plant nutrients injectability and impregnation amount were comparatively analyzed. Nutrient ingredients and 8 major heavy metal contents of wood chips injected with nutrients were analyzed, and soil covering effects were examined by covering wood chips injected with nutrients on soil. Comparing the dipping method and the vacuum pressure impregnation method, it took about 48 hours or more to inject 1,500 g or more of the nutrient aqueous solution into 1 kg of wood chips in the dipping method, but the vacuum pressure impregnation method could be impregnated in about 5 minutes. Components of the impregnated nutrients were detected in proportion to the diluted concentration. As a result of covering the wood chips developed in this study on soil, they showed weakly acidic pH, and the heat insulation and moisturizing effects during the winter season were evaluated to be superior to those of uncovered soil. In the future, wood chips impregnated with nutrients are expected to contribute to the more efficient use of waste wood resources and the long-term supply of nutrients essential for plant growth, reducing excessive use of chemical fertilizers and reducing costs.

• Journal of the Korean Wood Science and Technology
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• v.34 no.5
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• pp.52-58
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• 2006

Coffee chaff for manufacturing of the 6 mm thick cement-bonded boards was obtained from a coffee processing industry at Omuo-Ekiti, in Ekiti State, Nigeria. Boards were produced with three levels of cement to coffee chaff ratio of 1.5:1, 2.5:1 and 3.5:1; and at three levels of mixing curing reagent of 2.0%, 2.5% and 3.0%. Three dimensional properties of thickness swelling (TS), water absorption (WA) and linear expansion (LE) were investigated after 48 hours immersion in water. The mean values obtained for TS, WA and LE ranged from 0.46% to 1.47%, from 11.52% to 24.00%, from 0.19% to 0.35%, respectively. The most dimensionally stable boards were produced at the highest mixing levels of curing reagent and cement to coffee chaff ratio of 3.0% and 3.5:1, respectively. The coffee chaff is suitable as raw material for the manufacture of cement-bonded composites and it would be able to stimulate and activate the use of other agro-byproducts for the manufacture of value-added panels.

• Journal of the Korean Wood Science and Technology
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• v.24 no.2
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• pp.15-19
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• 1996

To utilize the waste materials and develope wood adhesive from isolated bloods of slaughtered cow and pig and also to prevent water pollution, simple and rapid method of isolation and purification of plasma proteins from pig bloods with trichloroacetic acid(TCA) treatment was developed. Adding of TCA-precipitated blood powder to the phenol formaldehyde resin(PF) improved dry and wet strength of plywood and resulted in fast hot pressing times.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.1
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• pp.43-51
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• 1997

The various culture conditions of Trichoderma viride(ATCC 3454) and Phanerochaete chrysosporium(ATCC 26921) with glucose-pepton medium, Mandels medium, YMG medium for wood degradable enzyme were examined. Mycellium of the two species grew profusely on glucose-pepton medium. Maximum fungal growth was observed about 10days. But CMCase, Fpase, laccase activity in the culture medium with glucose-pepton was not detected. When grown in fermenter culture using Mandels medium, Trichoderma viride produced CMCase and Fpase. Its CMCase activity was 0.15 lU/ml and Fpase activity was 0.3 IU/ml within about 4-6days. Phanerochaete chrysosporium grown in a YMG medium gave the best enzyme activity when they were grown under stationary culture with an atmosphere of 100% oxygen. Levels of laccase activity of 3.0 mull were achieved in stationary culture under 100% oxygen. The enzyme condensation by ultrafiltration method caused a 2-fold(cellulase) and 6-fold(laccase) as compared to control activity.

• Journal of the Korean Wood Science and Technology
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• v.51 no.6
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• pp.481-492
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• 2023

The ecofriendly lifestyle has attracted considerable support for sustainable development. Natural dyes, as sustainable products, have become a research focus and development area for many scientists. Ecofriendly processing also supports circular sustainable development. This study effectively obtained tannins as a natural dye from merbau (Intsia bijuga) sawdust using water as an ecofriendly solvent. Merbau sawdust is an underutilized industrial waste. Temperature and solid-solvent ratio variations were performed to extract tannins from merbau sawdust. Temperature and solid-solvent ratio positively affected solution yield and tannin concentration. The optimal condition was identified using response surface methodology and experimental observations. A yield of 0.2217 g tannins/g merbau was obtained under the conditions of 333.15 K and 0.125 solid-solvent ratio. Extraction was controlled by convective mass transfer at the interface of solid particles.

• Hwankyungkyoyuk
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• v.2 no.1
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• pp.92-99
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• 1991

According to our secondary school curriculum for natural science and technical circles, there be used 353 of chemical reagents including 24 kinds of harmful and toxicant components. At present, most school are discharging their school laboratory waste water without any chemical and physical treatments. So as to solve the environmental problem for water pollution, this study tried to research a kind of adsorbant utilizing saw dust, wasted wood sources and designed the simple processing system using the adsorbent. This adsorbent was made by extracting lignin substances from raw saw dust under the solution of 0.5N-NaOH at the temperature of $100^{\circ}C$. Their metal removed rates was measured not only by processing of column and vessel. but also by comparing the standard solution and real waste water. The results were proved as more than 90(%) of the adsorptive efficiency on the average from Pb, Cd, Cu except Cr(VI)in case of the school experimental waste water soaked in vessels a long with 4g of the adsorbent for 24 hours. The new processing system enables to remove most harmful and toxicant metals by filtering, sedimenting and adsorbing at the low cost.

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.428-432
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• 2013

From the forest areas in Chungbuk, large amounts of wood wastes by pruning are generated, however most of them considered as by-products are not treated properly with no disposal options. In this work, among diverse wood wastes such as Quercus variabillis, Juniperus chinensis, Larix kaemoferi, and Pinus densiflora, Juniperus chinensis was found to be more effective biosorbent for the removal of lead ions than other wood wastes. Also, the enhancement of lead removal efficiency from the aqueous phase was investigated using Juniperus chinensis waste. It was observed that the optimal initial pH to increase the removal efficiency of 20 mg/L lead ions was 4.0 and the optimal dosage concentration with regard to the biosorbent for the enhanced removal of 50 mg/L lead ions was 0.6 g/100 mL. In addition, chemical treatment of Juniperus chinensis waste with sulfuric acid was required to improve the adsorption capacity for high lead concentrations (over 100 mg/L). When Juniperus chinensis waste was chemically treated with 6 M sulfuric acid, the adsorption quantities of lead ions were 180, 340, and 425 mg/g with regard to 200, 400, and 500 mg/L lead ions concentrations, respectively. These results indicate that the practical biosorbent technology developed in this study is a highly efficient method to treat the lead ion from an aqueous solution.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.258-267
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• 2017

In this study, pitch pine (Pinus rigida, PIR) and Mongolian oak (Quercus mongolica, QUM) pellets were fabricated with bark or/and drying waste liquor (DWL) of larch (Larix kaempferi, LAK) as an additive. Based on the results of fuel characteristics of the pellets, optimal conditions for producing the high-quality pellets were provided. In the analysis of chemical composition, bark contained holocelluose and lignin of 90% and over. DWL had 0.1% solid assumed to sugars which are generated from the oven-drying of LAK logs. QUM showed high ash content (2.2%) by containing of bark in the sawdust. Bark and DWL of LAK had high ash content of 4% and over. Calorific values of all specimens and additives were higher than that of the $1^{st}$-grade standard of wood pellets designated by NIFOS (18.0 MJ/kg). PIR and QUM pellets were fabricated with additive of 2 wt% based on the solid weight of oven-dried sawdust using a piston-type flat-die pelletizer, and thus ash content and calorific value of the pellets did not affect by the use of additive. Durability of the pellets increased with the use of additive. Durabilties of pellets, which were fabricated with bark as an additive and DWL as a controller of moisture content for sawdust, did not differ from those of pellets without additives and were lower than those of pellets either with bark or DWL. However, use of both bark and DWL for the production of wood pellets might be favorable because it can make a profit from the collection process of DWL. Based on the results of fuel characteristics of the pellets, QUM and PIR pellets were produced by a flat-die pelletizer. Moisture content (MC), bulk density and durability of the pellets improved with the use of additive. Particularly, sawdust MC of 10% and the addition of bark or DWL for PIR as well as sawdust MC of 12% and the addition of bark for QUM might be optimal conditions for the production of high-quality pellets. Except for the ash content of QUM pellets, other properties of PIR and QUM pellets exceeded the $1^{st}$-grade wood pellets standards of NIFOS.

• Journal of the Korean Wood Science and Technology
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• v.17 no.2
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• pp.13-19
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• 1989

Two different quartz types of gasification reactor were used for pyrolysis and gasification of sawdust, ricestraw, ricehusk and municipal wastes which contain only cellulosics., operating at 1 atmospheric and vacuum pressure respectively. Also a stainless steel autoclave gasification reactor was used which is possible to use up to 100 atmospheric pressures and $800^{\circ}C$ of reaction temperature to complete pyrolysis and gasification reaction. The catalysts used in this reaction w- ere $K_2CO_3$, $Na_2CO_3$, Ni and Ni-$K_2CO_3$ as CO-Catalyst. The product gas mixtures were identified to be CO, $CO_2$, $C_3H_3$, $CH_4$ and $CH_3CHO$ etc. by Gas Chromatography and Mass Spectrometry. The pressurized gasification reaction shows significant increase in terms of methane composition and yield of product gases, comparing with those from unpressurized gasification reactions. The total volume of product gas mixtures amounts to 1600-1800ml per1gof waste of waste lignocellulosics or municipal waste, and the metane content of the gas mixtures reached to 40%, when $800^{\circ}C$ of reaction temperature and 100 atmospheric pressures with Ni-$K_2CO_3$ as CO-catalyst in the pressurized gasification reaction were used. This results show that the product gas mixtures containing 40% of methane call be used for alternative enegy source.