• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.2
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• pp.45-57
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• 1998

The object of this experiment was to determine the optimum mixing ratio of paper mill sludge and sewage sludge with woodchips as a bulking agent. The bulking agent was mixed with the mixture of paper mill sludge and sewage sludge(2:1 by dried weight) at the rates of 0(W-0), 20(W-20), 33(W-33), and 50(W-50)% on volume basis, and then the mixtures were composted by forced aerated static pile. The changes of physicochemical properties of the mixtures were measured during the composting in order to evaluate the maturity of composts. The temperatures of W-30 and W-50 treatments increased rapidly as soon as the composting started, and reached $60^{\circ}C$ in the fifth day of composting. Reduction of hot water soluble C/N ratio of W-33 and W-50 treatments showed faster than that of W-0 and W-20 treatments at early stage of the composting. The contents of hot water soluble $NO_3{^-}-N$ showed little change in the early stage of the composting in all treatments, but increased rapidly after 20 days of the composting, and the contents of W-0 among all treatments were lower than the others. The G.I. values of W-50 treatment were over 80 before 20 days after starting the composting, those of W-0 treatment were over 80 after 30 days. As a result of evaluation of compost, W-33 and W-50 treatments were found very reasonable at the mixing ratio of a bulking agent. But it is very difficult to aerate compost pile for W-50 treatment than W-33 treatment due to intensified fluctuation of temperature. Considering cost, availability of a bulking agent, and productivity of compost, W-33 treatments more efficient than W-50 treatment.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.3
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• pp.127-135
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• 2001

Achieved to grasp possibility to use compost that make food waste and sawdust (bulking agent) by raw material in this research droopingly to bulking agent calamity. To be kept by aerobic experiment method to 4 composting device that air is supplied Food Waste + Sawdust, Livestock Feces + Sawdust, Food Waste + Compost, Livestock Feces + Compost free medical care and investigated composting sledding and temperature, pH, the moisture rate, heavy metals item etc. Judged that food waste of the moisture rate mix experiment result food waste input (food waste and sawdust composting done material mean) compost happened after resources anger as bulking agent food waste and Livestock Feces quantity is 72~77%, because axis dries to promote optimum composting progress appearing by 64~65%, thing which use need and was difficult to set salt 1% that is by-product compost standard when use compost as bulking agent of food waste but by dilution effect of Livestock Feces quantity using compost being expose that preservation is available by standard low because salt content density of done compost becomes found possibility that can solve salt content problem.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.805-810
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• 2002

Development of tenderizer using domestic fruits was studied. Kiwifruit was dried using various methods, and the quality of kiwifruit powder was observed during 12 week storage. Frozen kiwifruit was prepared in paste, dice, and whole flesh. After drying, paste-type kiwifruit showed 2.0 and 1.3 times higher proteolytic activity than dice and whole flesh kiwifruits, respectively. Nine hour of hot-air drying or 46 h of freeze-drying eliminated more than 90% of water from kiwifruit, during which discoloring of kiwifruit occurred. Freeze-dried powder showed 6.6 times higher yield and proteolytic activity, and resulted in almost no discolorization than those of air-dried powder. Addition of bulking agent affected the quality of hot air-dried kiwifruit powder, except color, resulting in $3.2{\sim}3.6$ times higher proteolytic activity than that without bulking agent, which is comparable to 60% of the initial freeze-dried powder content. Moisture content of kiwifruit powder with bulking agent sustained consistently during 12 week storage, whereas proteolytic activity decreased for the first 4 weeks. Freeze-drying is a preferable method to produce kiwifruit powder for tenderizer, although hot air-drying with bulking agent treatment is more economical.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.3
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• pp.71-82
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• 2012

Common bulking agents in composting system include woody materials such as sawdust and woodchips. These bulking agents are mainly used for the purpose of the proper control of C/N ratio and moisture content in the composting. The topic for the effect on air permeability of bulking agents has far received relatively little attention in the composting field. This study investigated the effect of bulk density, moisture content, air-filled porosity, particle size and air flow rate on air permeability of several mixture ratios of sawdust and woodchip bulking agent. Increasing the moisture contents, the air-filled porosity was decreased and the particle size was increased for all kinds of bulking agent mixtures. Especially, with the increasing of mixing ratio of woodchip, these effects were sharply magnified. The air permeability respond to air-filled porosity was very similar to that for moisture content which was anticipated the linear relationship between air-filled porosity and moisture content. Above the region of moisture content 0.25 or 0.43(d.b.)(20 or 30% w.b.), the pressure drop decreased even though air-filled pore spaces were filling with water. Especially, to the particle size of 5 mm the pressure drop was decreased exponentially, so the air permeability was dramatically improved. By the water had the role of binding of the small particles, the macropores less resistances to air flow were created in the matrix. The effect of particle size on air permeability was much stronger than that of air-filled porosity or moisture content. And it is needed the preparing of initial particle size above 5 mm for efficient composting.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.644-647
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• 2003

Materials currently used as an injectable bulking agent in the dermatologic and urologic fields revealed several drawbacks such as particles migration, inflammatory reaction, allergic reaction, rapid volume shrinkage, and necessity of a donor site. In this study, we have developed injectable biomaterial comprising poly (DL- lactide-co-glycolide)(PLGA) and hyaluronic acid gel to overcome these problems. PLGA is a biocompatible synthetic material and hyaluronic acid is a common substance found in living organisms. We examined the feasibility of injection through needle and tested biocompatibility in animal model. After transplantation, injected sites and distant organs were examined histologically to verify a new tissue formation, inflammation, and particles migrations. Injected volume was maintained approximately 80 percent for 2 months. Results demonstrated that the developed material was injectable through various gauges of needles and induced a new bulking tissue formation without serious inflammatory reaction.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.405-410
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• 1999

This study was performed to find the recycling performance and to provide design data during recycle solid composting system to reduce bulking agent cost, Dairy manure amended with rice hulls and recycled compost was composted in a laboratory -scale vessel by continuous aeration for 10 days. The temperature and ammonia emission variations according to the ratios of bulking agents during the primary aeration stage were surveyed. Also, the influence of fresh compost quality on the recycling performance were anlayzed. While recycled composting system were operatured. The temperature in compost was maintained in the range of 40∼60$^{\circ}C$ needed for biodegradation and death of pathogenic organisms, but the ammonia emission was different by the ratios of recycled compost. The ammonia emission increased due to the low C/N ratio(17.6), high pH value(8.1) of the recycled compost.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.121-128
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• 2007

To develop the composting system to reduce the use of bulking agent, continuous composting was performed with farmer scale facility, The plant comprises a horizontal pit reactor closed inside a greenhouse and equipped with a turning machine moving on rails. The pit was 9m wide and 50m long and the maximum height of loaded materials was $1.8m^2$. The materials remained in the reactor for 5 months. During the composting process, temperature and water content measured and water balance was evaluated. The reaction temperature of composting was changed $30{\sim}50^{\circ}C$ and high in the middle and low in under composting piles. The moisture contents of the compost were approximately 70% during the experiment. The amount of effluent was 10.6% and $3.16m^3$ of pig slurry per $1m^3$ of bulking agent was treated during continuous composting process. BOD and SS reduction of the effluent in continuous composting was 86.5% and 92.2%, respectively. Indoor relative humidity in night time was changed between 80 and 100%.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.4
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• pp.49-58
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• 2011

The maximum drying shrinkage velocity was proposed to verify bulk and stiffness improvement mechanism during drying according to papermaking parameters. It was based on the wet-web shrinkage behavior without the restraint of wet-web during drying, so intact drying impact could be measured. Bulking agent reduced the drying shrinkage and the maximum drying shrinkage velocity, so paper bulk increased and paper strength decreased. When adding cationic starch to stock with the bulking agent for strengthening, the bulk was increased further with additional decreasing of the drying shrinkage and the maximum drying shrinkage velocity. Paper strength also increased except tensile stiffness index with decreasing the drying shrinkage and the maximum drying shrinkage velocity. When using additional strength additives for strengthening of fiber interfaces extended by bulking agent and cationic starch, amphoteric strength additive increased paper stiffness without loss of paper bulk. It was considered that the added amphoteric strength additives were cross-linked to the stretched cationic starch and this cross-linking increased elasticity of fiber-polymer-fiber interfaces without changing the drying behavior. Paper bulk could be increased with decreasing the maximum drying shrinkage velocity. The drying shrinkage of paper also could be controlled by fiber-to-fiber bonding interfaces by the bulking agent. In this case, paper strength including stiffness was decreased by reducing fiber-to-fiber bonding but it could be improved by strengthening fiber-to-fiber interfaces with polymer complex without loss of bulk.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.183-188
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• 1998

Changes of chemical and physical properties of the butchery waste compost were assessed when the wastepaper was used as a bulking agent (BP). Temperature of compost, with frequent turnover, was increased up to $83^{\circ}C$ even during the winter. Canon exchange capacity of the compost was increased with composting time, but pH, water content, total carbon, total nitrogen, C/N ratio and salt concentration were decreased to the extents showing a convergency. Heavy metal contents of BP-192 were lower than the standard criteria. Germination rate of cucumber seed, when BP-34 and BP-96 composts were applied more than 15 g, was under 40%, but those of BP-143 and BP-192 were 100%, irrespective of the amounts of compost used. The C/N ratio of the matured compost was 8.6. Results indicated that wastepaper might be employed as a bulking agent for butchery wastes composting.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1032-1036
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• 2012

A bulking agent is an essential material for composting of high-moisture livestock manure such as pig slurry. Sawdust has been used as the most popular bulking agent but resources are limited in Korea. In this study, the feasibility of rice hull as a bulking agent was examined for composting of solid pig manure. The solid pig manure was mixed with 15% sawdust (PM+SD15), 15% rice hull (PM+RH15), 10% sawdust and 5% rice hull (PM+SD10+RH5), and 5% sawdust and 10% rice hull (PM+SD5+RH10) based on fresh weight. These mixtures were composted for 35 days. The average temperature of the composting file for 35 days was higher in PM+SD10+RH5 and PM+SD5+RH10 than in PM+SD15 and PM+RH15. The mass loss of PM+SD10+RH5 and PM+SD5+RH10 were 36.7 and 36.4%, respectively, which were higher than that of PM+SD15 and PM+RH15. After composting, organic matter content and organic matter/nitrogen ratio in all treatments met the official standards of commercial fertilizers. We concluded that rice hull may be a good bulking agent for pig manure composting when it is used in mixture with sawdust.