• Korean Journal of Environmental Agriculture
• /
• v.17 no.4
• /
• pp.301-305
• /
• 1998

This study was conducted to evaluate the liquid composting efficiency using pig manure in different condition such as simple storage type reactor, continuous aeration reactor, anaerobic reactor and anaerobic agitation reactor. Continuous aeration reactor was the most efficiency method to BOD and malodors removal than other methods. While nitrogen loss in continuous aeration reactor was 47% of initial concentration, which was the higher amount than any other digestion methods. The digestion efficiency between anaerobic reactor and anaerobic agitation reactor were similar, but E. coli and malodor removal efficiency were a little higher in the anaerobic agitation reactor. Simple storage type reactor which was conventional digestion method in rural area gave lower efficiency than aerobic and anaerobic digestion methods in view of BOD, E. coli and malodor removal. The liquid composting efficiency which were evaluated by various indicators like pH, BOD, E, coli, malodor and nitrogen loss was high in the order of anaerobic agitation reactor>continuous aeration reactor>anaerobic reactor>simple storage type reactor.

• KSBB Journal
• /
• v.11 no.5
• /
• pp.593-599
• /
• 1996

The strain which produces agar degrading enzyme was isolated from chiton(Liolophura japonica). The strain was identified as Cytophaga sp. through its morphological, physiological, and biological characteristics. For the production of agar degrading enzyme, 0.3% nutrient broth, 0.2% yeast extract and 0.5% agar was used as nitrogen and carbon source, respectively. The optimal initial pH, NaCl and temperature for the agar degrading activity of Cytophaga sp. were 7.0, 2.0% and $30{\pm}2^{\circ}C$, respectively. Agar degrading activity of enzyme obtained from Cytophaga sp. was increased until the incubation of 96hrs, but after 96hrs, the activity was decreased.

• Journal of Korea Soil Environment Society
• /
• v.5 no.1
• /
• pp.85-96
• /
• 2000

The purpose of this study was to Investigate the effect of environmental conditions on the degradation of total petroleum hydrocarbons(TPH) in soil. The soil used for this study was sandy loam. Target contaminant, diesel oil, was spiked at 10.000mgTPH/kg dry soil. Moisture content was controlled to 50%, 70%, and 90% of field capacity of the soil. Temperature was controlled to $5^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$, and $30^{\circ}C$. The active degradation of TPH was observed at the moisture contents of 50% and 70% of field capacity, and temperature of $10^{\circ}C$ to $30^{\circ}C$. Degradation rate of n-alkanes was about two times greater than that of TPH. Volatilization loss of TPH was about 2% of initial concentration. Biocide control and no aeration experiments indicated that removal of TPH was primarily occurred by biodegradation under aerobic condition.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.12
• /
• pp.1345-1352
• /
• 2007

To predict the effects of nutrient releasing on the water quality of Namyang Reservoir, nutrient releasing rates from sediments in oxic and anoxic conditions were estimated in a small microcosm. Organics and nitrogens were not released. The releasing pattern of inorganic phosphate and total phosphorus was depend on the oxygen concentration. The releasing rate of inorganic phosphate and total phosphorus in oxic condition was $1.01\sim2.48$ and $2.14\sim3.54$ mg-P/$m^2$/day, respectively. It was high in the upstream sediments indicating the particles containing easily degradable organic compounds are flowed into the area. Because the depth of Namyang Reservoir at the downstream adjacent to the Dam is $7\sim14$ m, the condition of most area of sediment surface will be oxic. Based on these results, the appropriate counterplans are required to reduce phosphorus release in oxic conditions to control water pollution.

• Journal of Food Hygiene and Safety
• /
• v.22 no.1
• /
• pp.57-62
• /
• 2007

Microbiological, pH, and sensory evaluations on pork tender-loins treated with potassium sorbate (PS) during storage at $4^{\circ}C$ were assessed. Treatments of 0.5-2.0% PS for 10 min effectively (P < 0.05) inhibited the growth of aerobic plate counts (APC) and gram-negative bacterial counts (GNC) compared to those of controls for 9 days at $4^{\circ}C$, respectively. Results of this investigation demonstrate that antimicrobial activity on APC and GNC in all treatments enhanced by increasing concentrations of PS during storage at $4^{\circ}C$. pH values of pork tender-loins treated with PS gradually increased by storage of 6 days at $4^{\circ}C$. Sensory data showed that 0.5-1.0% PS treatments were quite close in odor and appearance compared to fresh controls. Results indicated that pork tender-loins treated with 1.0% PS for 10 min could extend shelf-life to 9 days during refrigerated storage at $4^{\circ}C$ without adversely affecting sensory quality.

• Proceedings of the Korean Journal of Food and Nutrition Conference
• /
• 2003.07a
• /
• pp.80-80
• /
• 2003

가열살균 처리시의 온도값을 이용하여 다양한 미생물들의 가열살균 효과를 D값, z값 등의 미생물 내열성 특성치와 kinetic 모델 및 수식을 이용하여 살균치 계산을 컴퓨터를 이용하여 수행함으로써 target 미생물의 살균정도를 예측하고자, Excel과 Visual Basic을 연동하여 작성된 시스템으로 Excel을 기본으로 사용한 프로그램을 개발하였다. 가열살균 target 미생물을 선택하고자 야채식품을 기반으로 하는 식품에서의 미생물을 검토하여, 내열성인 가장 큰 호기성 포자형성균인 Bacillus spp. 계통이 산을 형성하여 맛 등의 품질을 저하시켜 변패를 유발하며, 위생적인 면에서 포자수를 줄이거나 사멸할 필요가 있어서 선택하였다. 병원성 균 중에서 D121.1이 0.0065분, z값이 7.8$^{\circ}C$인 Bacillus cereus와 부패현상 관련 균 중에서 D121.1이 0.5분, z값이 12$^{\circ}C$인 Bacillus subtilis를 대상으로 해서 개발되었으며, 필요시에는 D값과 z값을 직접 대입하므로서, 여러 가지 미생물에 대해서도 적용이 가능하게 하였다.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1997.10a
• /
• pp.133-134
• /
• 1997

1. 서론 : 제지산업은 용수 다소비용 산업으로, 생산하는 제품 톤당 약 40톤으로 폐수가 배출되고 있으며 공정내로 재활용하는 폐수량을 고려한다면 그 사용량은 더욱 클 것이다. 이와 같은 다량의 용수 사용으로 인하여 제지 공장의 폐수를 제조공정에서 재활용하는 방법이나 배출량을 감소시키는 방안들이 법률적이나 경제적인 측면에서 연구되고 있는 실정이다. 본 연구에서는 기존의 응집, 침전공정을 대신하고 여재를 이용힌 물리적 여과와 활성높은 미생물이 여재 표면에 부착되어 수중 유기물질을 생물학적으로 분해 제거하는 이중의 효과를 거둘 수 있는 호기성 생물막 공정을 도입하고 그 처리수의 유기물 및 용존 무기물을 Membrane 공정으로 제거함으로써 제지공업폐수를 재활용하여 용수기준까지 처리하 System의 개발을 그 목적으로 하였다.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.8 no.2
• /
• pp.124-129
• /
• 2000

The purpose of this study is to estimate the degradation rate and process efficiency of the composting according to the salinity concentration. The samples of food waste for this study were collected in Pocheon-Gun, Kyungki-Do. The collected samples were adjusted to the optimum range of moisture content, pH and C/N ratio. After that, adding the saline, the samples with 3 different salinity concentrations(1%, 5% and 10%) were made. Then each sample was fed into the reactor with temperature controller. During the aerobic composting process, the change of the physical and chemical properties of the sample as temperature, pH, C/N ratio and $CO_2$ and $O_2$ concentration in the reactor were measured. From the experiment of this study, the result are following. The highest temperatures are $59^{\circ}C$ at RUN 1(1% salinity conc.), $49^{\circ}C$ at RUN 2(5% salinity conc.) and $45^{\circ}C$ at RUN 3(10% salinity conc.). The change of $CO_2$ production and $O_2$ consumption have the positive correlation with the change of the temperature. $CO_2$ production and $O_2$ consumption are peaked at the low salinity concentration. During composting, Run 1, RUN 2 and RUN 3 are increased pH to 8.9, 8.6 and 7.2 and slowly decreased C/N ratio to 18.9, 19.1 and 22.1 and moisture content to 51.1%, 53.7% and 55.0%, respectively. It is supposed that increasing salinity concentration causes the retarding of the microbial degradation activities during the composting. And for the efficient composting, the salinity concentration in the sample hat to be maintained below 5%.

• Food Science and Preservation
• /
• v.13 no.2
• /
• pp.246-251
• /
• 2006

Organic compost is a useful fertilizer for organic farming. However, it poses a microbiological hazard to the farm produce because most of the compose are originated from excrementitious matters of domestic animals. Irradiation was performed to improve microbiological safety of organic compost and the effectiveness of gamma-irradiation for inactivating Salmonella typhimurium and E. coli was investigated. Total aerobic bacteria and coliform bacteria in 16 produce or commercial compose were ranged from $10^5\;to\;10^7\;CFU/mL\;and\;0\;to\;10^3\;CFU/mL$, respectively. All coliform bacteria in the composts were eliminated by irradiation at 5 kGy, while about $10^2\;CFU/mL$ of total aerobic bacteria survived up to 10 kGy of irradiation. In the inoculation test the test organisms (inoculated at $10^7\;CFU/mL$) were eliminated by irradiation at 3 kGy. $D_{10}$ values of inoculated Salmonella typhimurium and E. coli in the compost were $0.4{\pm}0.05\;and\;0.39{\pm}0.03kGy$. It was considered that $3{\sim}5kGy$ of gamma irradiation was effective for radicidation (radiation sterilization of pathogenic microbes) of organic fertilizer.

• Journal of Korean Society of Environmental Engineers
• /
• v.28 no.3
• /
• pp.276-285
• /
• 2006

When polluted stream water was treated with biological aerated filter(BAF) in pilot plant, all operation with 90, 60, 45 and 30 min of EBCT at fixed $0.1m^3air/m^2min$ of aeration showed 80% or higher treatment efficiency of particle materials(SS, turbidity and Chl.-a) and 85% or higher efficiency of ammonia nitrogen removal. It was thought that, in case of BOD, biological stability may sufficiently be assured with BAF because grade III or IV inflow water was changed to grade I for outflow water. In case of $COD_{Mn}$, about 60% of removal efficiency was found. When the mechanism of the result was investigated, about 30% of COD materials was produced by algae clogged in the reactor. There was almost no biological decomposition because specific substrate utilization rate of algogenic organic materials were $0.0245mg{\cdot}COD_{Mn}/mg{\cdot}VSS{\cdot}day$, thus partial backwashing(washing the media in 1 m upper of the reactor once a day) was required. It is thought that elevation of removal rate about 10% of $COD_{Mn}$ and 5.5% of $BOD_5$ could be obtained with partial backwashing resulting in assurance of biologically more stable raw water and that saving backwashing water may be significant.