• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.56-62
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• 2001

The investigation was carried out to analyze the generation and the composition of landfill gas generated from inserted pipe wells into the underground by boring operation and also study the undecomposed waste characteristics by open-cut test at S. waste landfill site in Pusan city. Pilot test was conducted for stabilization. The experimental results from this study were summerized as follows. ; Since COD matter was easuer decomposed than COD matter for continuously biological stabilization in underground, it seemed that BOD and CO $D_{Mn}$ were in the range of 854~4,813mg/$\ell$ and 1,156~6,977mg/$\ell$ and their ratio were generally as high as 0.55~0.74. As C $H_4$ compositions of generated gas were measured in the range of 37.36~60.1%, we could know that C $H_4$ gas was actively generated. Organic matters by open-cut test averaged 13.4~16.6% at each landfill layer, and considering rate of combustible compositions(36.2~66.5%) for landfilling wastes, they have been actively decomposed. The measured and theoretical values of generated gas in waste landfill site were almost similar to C $H_4$ 50.0% and 53.4%, $CO_2$ 39.63% and 45.24%, and after 0.5$^{\circ}C$ with heavy depth and long landfill period. From the results of pilot test for stabilization, after 180 days organic matters were actively decomposed beyond 2.2 times in facultative aerobic lystimeter(B) to exsiting anaerobic lysimeter(A). Therefore, it seemed that landfill site was of benefical to the conversion of facultative aerobic for stabilization.

• Journal of Environmental Health Sciences
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• v.27 no.3
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• pp.21-26
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• 2001

This study was performed to define the physicochemical characteristics of food waste and food wastewater, and to find the effect of salinity variation experiment, the samples of 1, 2, 3 and 4 were prepared by the salinity of 1.0%, 1.5%, 2.0% and 2.5%, respectively. In experiment, aerobic composting reactors were operated by the model which was composed of half an hour's stirring and 2 hour's aeration per day, for 45 days. Seeds of vegetables of Chinese cabbage and red pepper were seeded at compost-free control, compost 1, 2, 3 and compost 4 for the sake of investigation of germination rate and growth rate of those. The followings are the conclusions that were derived from this study. 1. In food waste, the moisture content was 60%, organic compound content was 95%, total carbon was 47.5%, total nitrogen was 1.6%(therefore, C/N ratio was 30). The values of pH were 4.0 and 3.8 the values of salinity were 0.9% and 1.2%, and the values of conductivity were 7.8 mS/cm and 18.0 mS/cm, respectively. 2. In salinity experiment, the reduction rate of volume was increased(40%) when the salinity was decreased(1.0%). Also, the reduction rate of mass was increased(52%) when the salinity was decreased(1.0%). This fact denotes that salinity hinders the process of composting. 3. Germination rate and growth rate of Chinese cabbage are more excellent than those of red pepper(97.14%, 5.2:2.5 cm). 4. In Chinese cabbage, germination rate and growth rate at compost with the lowest salinity are more excellent than those at compost-free control(97:94%, 5.2:4.5 cm).

• Resources Recycling
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• v.15 no.1 s.69
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• pp.66-73
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• 2006

The effects of operation conditions, such as bed temperature, temperature rising rate, particle size, moisture content and so on, on thermo-chemical conversion of waste wood have been determined in a micro fixed bed gasifier. The samples were waste wood-chips such as pine, oak, acacia and ginkgo. The thinning timbers used as reactants in the experiments had $35wt\%$ moisture content, $0.5wt\%$ ash content and 4,550 kcal/kg heating value on a dry basis. A typical product distribution was a $40wt\%$ liquid, $20wt\%$ solid, and $40wt\%$ dry syngas. The syngas concentration was affected by operation conditions and average syngas concentration was $H_2:40vol\%,\;CO:30vol\%,\;CH_4:10vol\%$.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.2
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• pp.69-79
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• 1998

The purpose of this study is to suggest the design parameters, which are applied to the solid waste treatment and management systems in rural area. In order to drive out the parameters, the solid waste production and management systems in rural and urban areas had been surveyed and analyzed, respectively. The comparisons of the analyzed results are also introduced in the paper. The rural areas referred to the survey are grouped in accordance with the industrial activities in those areas. The conclusions of the study are as follows: 1) The solid waste volumes produced per day per capita in rural area are less than those of urban area. For example, the average volume produced in rural area in 1995 is 0.85kg, which is two thirds of those in Seoul area. 2) for the treatment, the country has depended mainly on landfill. On the other hand, the incineration treatment ratio has been in creasing in rural area. 3) The physical and chemical properties of the rural solid waste, according to the analysis, are similar to those of the urban areas, which means the living pattern in those two areas have a little difference.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.10
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• pp.574-579
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• 2016

This study assessed feasibility of making granular fertilizer with fly ash from a sewage sludge incinerator in Korea. Composition, characteristics, strength, and heavy metal contents of the granular fertilizers were investigated. Due to its high contents of phosphorus, fly ash from a sewage sludge incinerator could be used to make fertilizers. Granulation rates (2-4 mm granules) over 80% could be achieved as the fly ash contents were 15% or less of the fertilizer. Leaching tests of the fertilizers, based upon the Korean Standard Methods for Solid Wastes, showed the concentrations of heavy metals less than the risk limits. However, contents analysis of the fertilizers, based upon the Korean Standard Methods for Soils, experienced higher levels of heavy metals than the risk limits as the fly ash content exceeded 7% of the fertilizer. Thus, the fly ash needs to be added less than 7% of the fertilizer if there is no pretreatment to remove heavy metals.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.21-27
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• 2009

A study was carried out to find out the methodology of biological treatment for wastes and wastewater caused by an organophosporus insecticide, fenitrothion, using fenitrothion-degrading microorganism. A fenitrothion-degrading microorganism was isolated by using a selective nutrient broth (NB) medium including fenitrothion, and identified to Bacillus sphaericus NFol based on its morphological and biochemical characteristics. Further, investigation was processed to determine the optimal culture conditions degrading fenitrothion in NB medium by using the NFo1 strain. As results, the cultural conditions determined for temperature, initial pH and inoculum for the optimum growth of the strain and degradation of fenitrothion, which has a exact co-relationship between both of them, were $35^{\circ}C$, 7.5 and 1.5 at $OD_{660}$ value, respectively. In this conditions, fenitrothion could be degraded within 5 days over 90% at the high concentrations of fenitrothion, upto 200 mg/L.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.609-614
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• 2010

In the present study, bioethanol was produced using batch style reactor from food wastes which has organic characteristics. Pretreatment was required to reduce its particle size and produce fermentable sugar. Two different enzymes such as carbohydrase and gulcoamylase were tested for saccharification of food waste. The efficiency of carbohydrase saccharification (0.63 g/g-TS) has shown higher than glucoamylase saccharification(0.42 g/g-TS). Saccharomyces cerevisiae produced bioethanol via separate hydrolysis & fermentation (SHF) method and simultaneous saccharification fermentation (SSF) method. The production amount of bioethanol was 0.27 g/$L{\cdot}hr$ for SHF and 0.44 g/$L{\cdot}hr$ for SSF.

• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.254-264
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• 2010

To obtain an efficient natural lignocellulolytic complex enzyme, we screened an efficient lignocellulose-degrading composite microbial system (XDC-2) from composted agricultural and animal wastes amended soil following a long-term directed acclimation. Not only could the XDC-2 degrade natural lignocelluloses, but it could also secrete extracellular xylanase efficiently in liquid culture under static conditions at room temperature. The XDC-2 degraded rice straw by 60.3% after fermentation for 15 days. Hemicelluloses were decomposed effectively, whereas the extracellular xylanase activity was dominant with an activity of 8.357 U/ml on day 6 of the fermentation period. The extracellular crude enzyme noticeably hydrolyzed natural lignocelluloses. The optimum temperature and pH for the xylanase activity were $40^{\circ}C$ and 6.0. However, the xylanase was activated in a wide pH range of 3.0-10.0, and retained more than 80% of its activity at $25-35^{\circ}C$ and pH 5.0-8.0 after three days of incubation in liquid culture under static conditions. PCR-DGGE analysis of successive subcultures indicated that the XDC-2 was structurally stable over long-term restricted and directed cultivation. Analysis of the 168 rRNA gene clone library showed that the XDC-2 was mainly composed of mesophilic bacteria related to the genera Clostridium, Bacteroides, Alcaligenes, Pseudomonas, etc. Our results offer a new approach to exploring efficient lignocellulolytic enzymes by constructing a high-performance composite microbial system with synergistic complex enzymes.

• Korean Journal of Veterinary Service
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• v.15 no.2
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• pp.203-214
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• 1992

Livestock waste causes ground and surface water pollution, eutrophication of reservoir as well as adverse affects living environment of those who dwell nearby. In order to investigate the pollution load from livestock waste, physical and chemical characteristics of the waste were determinded in the survey of livestock farms. Once pollution load is obtained as a function of the origin units of livestock, the influence of livestock waste on the Daecheong reservoir was studied. 1. For Daecheong reservoir inflow area, the liverstock manure productions of beef cattle swine, dairy cattle and chicken were 1,135.6t/day, 480t/day, 241.3t/day, 48t/day respectively； Beef cattle was the mai or source of the pollution. Pollution loading productions due to the livestock waste around the were found to be 53.31t/day for BOD, 222.49t /day for COD, 261.99t/day for T-S, 9.64t/day for T-N, 6.54t/day for T-P 2. Bocheong stream turnd out to be the major contribution for pollution loading production to Daecheong reservoir with 10,748kg /day of BOD, 47,157kg /day of COD, 1,946kg /day of T-N, 1,271kg /day of T-p. 3. Actual pollution loadings from livestock wastes for the area of Daecheong reservoir were estimated as 1,997kg /day(BOD), 8,546kg /day(COD), 364kg /day(T-N), 243kg /day (T-P), respectively Therefore, advanced treatment for livestock waste is recommended for Daectleong reservoir inflow area to eliminate the nutrients which are major sources of eutrophication of the reservoir.

• Korean Journal of Microbiology
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• v.25 no.2
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• pp.122-128
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• 1987

Several bacterial isolates capable of degrading 4-chlorobiphenyl or 2,4,5-trichlorophenoxyacetic acid were isolated from industrial wastes by the agar plate method and studied for their biodegradabilities of the hydrocarbons and some biochemical characteristics. The isolates DJ-12, DJ-26 and TP-1 were identified as Pseudomonas spp. and they could not degrade 2,4-dichlorophenoxyacetic acid. The absorption spectra for 4-chlorobiphenyl and 2,4,5-trichlorophenoxyacetic acid showed the peaks at 253 and 292 nm, respectively. Biodegradability of the isolates was determined by decrease of the absorbance for the test hydrocarbons with a UV-scanning spectrophotometer. The plasmids of the isolates were studied to examine whether or not the hydrocarbon-degrading genes exist in the plasmids. Antibiotics resistance was also examined to search out a proper marker for the isolates in further experiments, such as curing test and genetic recombination.