• Journal of Korean Society on Water Environment
• /
• v.22 no.3
• /
• pp.468-474
• /
• 2006

In the secondary settling tanks, three different types of settling phenomena occurs; i.e., zone settling for sludge thickening in the bottom part of settling tank, and discrete and flocculent settling for clarification in the upper part. In this paper, morphological parameters of the floc in sludge blanket layers along the length of a long rectangular tank were investigated. The plant used for this study had a serious bulking problem caused by Microthrix parvicella. Floc size decreased as the surface area of settling tank increases, which indicates that in the secondary settling tank where zone settling believed to be predominant, free or flocculent type of settling contributes to floc size distributions. Large floc particles deposit in the front zone of settling tank, but small and loose flocs mostly in the zone near its outlet. On the other hand, filament length contained in one gram of sludge blanket solid increases along the flow direction. Large flocs with less filaments settle faster, but small flocs having more filaments result in poor settling. These results support function of microorganism selection occurring in secondary settling tank. In addition, designing a long rectangluar settling tank with double hoppers might be one of the ways of bulking control, but this idea has to be verified with a further study.

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

• Journal of Animal Environmental Science
• /
• v.4 no.1
• /
• pp.21-28
• /
• 1998

This study was carried out to estimate the economic impacts on operation cost and curtail the bulking agent between two kinds of plants in swine farms. Bulking agents and Plants have a variety of roles in the fields of the composting for livestock manure and also represent an economic problem in terms of plant operation costs and compost production. Two farms which have rotary(size of reactor : 10${\times}$35${\times}$1.5m) or bucket(size of reactor : 10${\times}$68${\times}$2m) plants were used for 24 weeks for bucket conveyor system, which are composed of refilling rice hull as a bulking agent every 3 weeks till decreasing volume, for 4 weeks for rotary conveyor system, which has continuous compost production system without refilling rice hull, respectively. Composts was produced in 24 weeks in the bucket conveyor system, in 4 weeks in the rotary conveyor system, respectively. The results are as follows : 1. The tissue change of Rice hull at the composts of 45 days pursuant to composting steps was more crumbling in bucket conveyor system than in rotary conveyor system. 2. Microbial counts of the final composts for safety and quality showed that total bacteria counts was 1.01${\times}$108 cfu/g in bucket conveyor system, 2.82${\times}$108 cfu/g in rotary conveyor system, Salmonella was 0.3${\times}$102 cfu/g in bucket conveyor system, 7.6${\times}$102 cfu/g in rotary conveyor system, colifom bacteria was 0.5${\times}$106 cfu/g in bucket conveyor system, 1.5${\times}$106cfu/g in rotary conveyor system, fungi 1.24${\times}$106 cfu/g in bucket conveyor system, 0.01${\times}$106 cfu/g in rotary conveyor system, respectively. However, Any system used in this trial could not be met the regulation of A grade compost of EPA and USA. 3. C:N ratio according to the composting was more rapidly changed in bucket conveyor system with 64.5 of 5 days compost to 25.4 of final products than in rotary conveyor system with 26.7 of 5 days compost to 25.9 of final products. 4. Based on the mechanical characteristics of plants used in trial and compared with Rotary conveyor system, the Bucket conveyor system in which has 0.72 ㎥/㎥ of bulking agent capacity per slurry could be curtailed 1.78 ㎥of rice hull for disposal of waste, 1㎥. It was proper facilities to produce composts quantitative in Rotary conveyor system, and to treat waste quantitative and obtain good results in compost quality in Bucket conveyor system.

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

• Journal of the Korea Organic Resources Recycling Association
• /
• v.8 no.2
• /
• pp.140-145
• /
• 2000

This study was performed to investigate whether the earthworm cast could be reused as bulking agent in the whole processing of the food wastes using the earthworm. In addition, the growth conditions of microorganism lived upon earthworm lasts was investigated. Because the raw food wastes used in this experiment had low pH, and high moisture and organic matter contents, it was unsuitable to use as direct feeds to earthworm. However, when the food wastes were mixed with some earthworm cast, the mixtures were suitable to the feed condition and the growth environment of the earthworm. Therefore, it shows the possibility that the earthworm cast be reused as bulking agent for food wastes. In the microbiological investigation on earthworm cast, the bacteria showed most high density among the microbial species. And the microbial density showed higher under the mid-temperature than under high-temperature, and higher under the anaerobic than the aerobic condition. The drying methods of earthworm cast for the moisture adjusting, has no effect on microorganism growth whether natural or artificial drying. And the activity of enzyme presented more highly before the drying than after the drying.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.12 no.1
• /
• pp.58-66
• /
• 2004

The purpose of this study is to examine the possibility of reuse fermented foodwaste as a bulking agent in livestock waste and foodwaste composting. Aerobic composting device was added to the following sample : Foodwaste + Sawdust, Livestock feces+Sawdust, Foodwaste + Ferment, Livestock feces + Ferment. Temperature, pH, OM/N ratio, moisture, heavy metals, and microbes were measured in process of aerobic composting. The results of this study are following. 1. The composting period is determined in 16~24days, according to the change of temperature and OM/N ratio. 2. The salinity contents in compost of livestock waste and foodwaste ferment is about 0.5%, which can be solved the problems of salinity contents in foodwaste composting. 3. The proper ratio of livestock waste composting is 40% of cow feces to 60% of foodwaste ferment. 4. Processing expense of aerobic composting of foodwaste and sawdust is 40 won/kg composting expense of foodwaste and ferment is 30 won/kg. Fermented product composting can cut down the expense of bulking agent than others.

• Proceedings of the Korean Fiber Society Conference
• /
• 1993.06b
• /
• pp.408-412
• /
• 1993

• Korean Journal of Organic Agriculture
• /
• v.5 no.1
• /
• pp.111-124
• /
• 1996

Composting of animal residues with weeds and waste papers as bulking agents was tested. Coorperative form of work with farmers, students, cleaning women and members of citizens' movement was attempted. The responses of participants for composting, through it's laboriousness and dirtiness, were favorable with feeling of doing good for social services. The temperature of compost was raised up to 83 $^{\circ}C$. in spite of cold winter weather after turning. The pH, water content, total carbon, total nitrogen and C/N ratio showed the similarity to stability steps of other usual composts. The contents of heavy metals were low except Cu in comparison with standard levels. The uses of waste papers as a bulking agent for composting of animal residues, especially for organic farming, would need more diverse investigations.

• Journal of environmental and Sanitary engineering
• /
• v.15 no.3
• /
• pp.24-30
• /
• 2000

In this study, to determine the optimum fermentation process for the feed production of food wastes and estimate the practical value of fermented feed using kudzu creeper and sawdust as bulking agent. This study considered initial C/N ratio control as the fermentation process variables. The result are summarized as follows. Minimum water contents of byproducts in the fermentation feed production showed 39%(kudzu), 37%(sawdust) at the C/N ratio 25 and 45%(kudzu, sawdust) at the C/N ratio 35. Temperature variations in the fermentation feed production at the C/N ratio 25 indicated $68^{\circ}C$(kudzu), $70^{\circ}C$(sawdust). Optimum condition of fermentation process of water content, C/N ratio and permeability (porous structure of the mixture). For optimum fermentation gravitationally dewatered garbage, the proper mixing ratios of kudzu(moisture contents : 17.3%) and sawdust(moisture contents : 13.2%) were 41% and 39%, respectively. Major biological reaction in the aerobic fermentation feed production occurred during 12~24hrs.

• Clinical and Experimental Pediatrics
• /
• v.56 no.4
• /
• pp.145-150
• /
• 2013

Endoscopic treatment is a minimally invasive treatment for managing patients with vesicoureteral reflux (VUR). Although several bulking agents have been used for endoscopic treatment, dextranomer/hyaluronic acid is the only bulking agent currently approved by the U.S. Food and Drug Administration for treating VUR. Endoscopic treatment of VUR has gained great popularity owing to several obvious benefits, including short operative time, short hospital stay, minimal invasiveness, high efficacy, low complication rate, and reduced cost. Initially, the success rates of endoscopic treatment have been lower than that of open antireflux surgery. However, because injection techniques have been developed, a recent study showed higher success rates of endoscopic treatment than open surgery in the treatment of patients with intermediate- and high-grade VUR. Despite the controversy surrounding its effectiveness, endoscopic treatment is considered a valuable treatment option and viable alternative to long-term antibiotic prophylaxis.