• Journal of Environmental Science International
• /
• v.18 no.2
• /
• pp.205-213
• /
• 2009

A laboratory experiment was conducted to investigate nitrogen removal from plating wastewater by a soil reactor. A combination of soil, waste oyster shell and activated sludge were used as a loading media in a soil reactor. The addition of 20% waste oyster shell and activated sludge to the soil accelerated nitrification (88.6% ${NH_4}^{+}-N$ removal efficiency) and denitrification (84.3% ${NO_3}^{-}-N$ removal) in the soil reactor, respectively. In continuous removal, the influent ${NH_4}^{+}-N$ was mostly converted to nitrate nitrogen in the nitrification soil reactor and only a small amount of ${NH_4}^{+}-N$ was found in the effluent. When methanol was added as a carbon source to the denitrification soil reactor, the average removal efficiency of ${NO_3}^{-}-N$ significantly increased. The ${NO_3}^{-}-N$ removal by methanol addition in the denitrification soil reactor was mainly due to denitrification. The phosphorus was removed by the waste oyster shell media in the nitrification soil reactor. Moreover, the phosphorus removal in the denitrification soil reactor was achieved by synthesis of bacteria and the denitrification under anaerobic conditions. The approximate number of nitrifiers and denitrifiers was $3.3{\times}10^5\;MPN/g$ soil at a depth of $1{\sim}10\;cm$ and $3.3{\times}10^6\;MPN/g$ soil at a depth of $10{\sim}20\;cm$, respectively, in the soil reactor mixed with a waste oyster shell media and activated sludge.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2000.11a
• /
• pp.315-319
• /
• 2000

400ppm의 pentachlorophenol(PCP) 오염토양을 5$m\ell$ scintillation vial의 multi reactor와 1L 크기의 one reactor를 써서 Hydrogen peroxide와 Hemoglobin 촉매반응에 의해 PCP 분해정도를 조사하였다. 대부분 초기에 반응이 빠르게 진행되므로 time scale을 8시간 이내와 한달여기간동안 살펴보았다. 8시간동안의 PCP 분해정도는 일차함수로 동력학 계수가 -0.0233으로 나타났고, 이때 제거효율은 60.8%이고 one reactor의 경우 30일동안 80%의 제거효율을 보였다. PCP 회수율은 multi reactor의 경우 96.5($\pm$6.7)이고 one reactor(fan scale)의 경우 90.1%였다.

• Journal of Soil and Groundwater Environment
• /
• v.8 no.2
• /
• pp.78-86
• /
• 2003

• Journal of the Korea Organic Resources Recycling Association
• /
• v.8 no.4
• /
• pp.160-167
• /
• 2000

This study was performed to evaluate efficiency of soil microbial inoculator for active composting of food waste. In addition the number of microorganisms in roil microbial inoculator and the effect of seeding in the process of composting were investigated. food waste samples collected from a refectory were analyzed for physical-chemical properties. The samples were adjusted to moisture content of 65% by saw dust and seeded with soil microbial inoculator of 10% by the weight in case of reactor B. The number of microorganisms, aerobic bacteria, actinomyces, yeast, and fungi in soil microbial inoculator were over $2.98{\times}10^9/g$, $3.93{\times}10^7/g$, $1.21{\times} 10^5/g$, and $5.79{\times}10^7/g$, respectively. During the process of composting, the highest temperatures were $63.4^{\circ}C$ at reactor A(unseeded control)after 10 days and $66.8^{\circ}C$ at reactor B(seeded compost) after 4 days. The pH values of reactor A and B rapidly increased after 3 days and after first few days during composting period, respectively. The highest $CO_2$ concentrations were 6.1%(after 10 days) and 10.8%(afer 4 days) in reactor A and B, respectively. The degradation rates of organic matter(rd) between reactor A and B increased by 17.1% and 64.5%, respectively Consequently, the effects of Inoculation on comporting parameter such as temperature increasing, pH change, chemical properties, and the degradation rates of organic matter(rd) were higher in seeded compost than in unseeded control.

• Journal of Korean Society on Water Environment
• /
• v.20 no.3
• /
• pp.215-222
• /
• 2004

The sewages produced from small villages, rural community, drinking water reservation area and park which doesn't have sewage piping system can be caused a serious water pollution at the restricted areas. The objective of this research was to suggest an economical and effective sewage treatment method by investigating the removal of the organics, nitrogen, and phosphorus in the multi-soil-layering reactor. Soil, natural zeolite, and iron slag were used as a supporting media of multi-soil-layering in this research. The purpose of natural zeolite addition was to maintain the consistent ammonium exchange capacity by providing a sequential environment, and that of iron slag addition was to remove phosphorus by adsorption. Continuous experiment of lab-scale single-soil-layering (S-1), multi-soil-layering (S-2), and mixed-soil-layering (S-3) methods were studied to compare and optimize three different types of the reactors. The organic removal efficiencies showed more than 90% in all three reactors. While S-1 and S-3 reactors showed about T-N removal of 31%, 45%, respectively, the average T-N removal efficiency of the S-2 reactor represented an 87%. In conclusion, that results suggest that the multi-soil-layering reactor could be effectively utilized as a plant for treatment of small village sewage.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2000.05a
• /
• pp.92-95
• /
• 2000

A mixed bacterial culture capable of mineralizing methyl tort-butyl ether (MTBE), other fuel oxygenates ethers, tertiary carbon alcohols, benzene and toluene was used to inoculate batch reactor and sequence batch reactor (SBR) to treat gasoline contaminated ground water containing about 60 mg/L MTBE, 5 mg/L benzene, 5 mg/L toluene, and low concentrations of several other aromatic and aliphatic hydrocarbons. Respirometery studies showed that MTBE degrading mixed culture could treat MTBE contaminated ground water with addition of nitrogen and phosphate. SBR was operated to demonstrate the feasibility of using suspended growth activated system for the treatment of ground water and to confirm that the respirometry derived kinetics and stoichiometric coefficients were useful for predicting reactor performance. Theoretical performance of the reactor was predicted using mathematical models calibrated with biokinetic parameters derived from respirometry studies.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1996.11a
• /
• pp.97-101
• /
• 1996

산림부산물인 수피에 의한 카드뮴 이온의 선택적 흡착 현상을 이용하여 인공폐수로부터 카드뮴이온의 제거를 시도하였다. 카드뮴 이온 선택성이 우수한 소나무와 상수리 나무의 수피를 이용한 효율적인 연속식 대량 수처리 시스템의 개발을 위한 기초 실험으로 카드뮴 이온흡착 등온선을 조사하였고, batch stirred reactor, airlift reactor, packed bed column 등 여러 접촉시스템에서의 카드뮴 이온의 제거 효율을 검토하였다. 카드뮴 흡착등온선은 두 수피 모두 Langmuir 형식으로 나타났으며 소나무 수피의 최대흡착용량은 약 7 mg/g, 상수리나무 수피의 경우에는 약 8 mg/g 정도로 나타났다. Batch stirred reactor를 이용한 시스템에서 초기농도 13 ppm의 카드뮴용액 100 $m\ell$ 을 수피 10 g 과 접촉시킨 결과 30분 이내에 95% 이상 제거되는 효율성을 보여주었다. Airlift reactor를 이용한 시스템에서는 수피 30 g 을 포기농도 10 ppm 카드뮴 용액 1 liter와 접촉시킨 결과 15분 이내에 93 % 이상 제거되었으며 4 cycle 반복 운전에서도 거의 같은 성능을 유지하였고 그 이상의 cycle에서는 점점 성능이 떨어짐을 보여주었다. Packed bed column을 이용한 시스템에서는 20 g의 수피를 충전시켰을 경우 초기농도 20 ppm에서 effluent 2.5 liter 까지는 95% 정도의 제거효율을 보여주었다.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.982-984
• /
• 2008

Generally, the soil around railroad is contaminated by the leakage of oil during its maintenance or the operation of rolling stock. Because the railroad soil is located under ballast and is hardened with the designated strength due to safety, the characteristics of the polluted site are different. In this study, the phenomena of oil diffusion in the railroad site was investigated using 2-D reactor. The used oil was lubricant. As a result, the maximum diffusion depth of lubricant was about 9.5 cm due to its high viscosity and the hardened soil. The lubricant was diffused by gravity more than by horizontal migration. In the future, these results can be applied to develop a remediation method for the contaminated railroad soil.

• Journal of Life Science
• /
• v.24 no.5
• /
• pp.543-548
• /
• 2014

Aquifer recharge and recovery is a technology used to ensure a stable supply of clean water. During the process, river water is injected into a soil aquifer and stored. The stored water is then recovered and used to produce drinking water. It is important to understand quality improvement of the injected water while it is stored in the aquifer. In the present study, a lab-scale column reactor containing saturated-zone soil was employed to mimic an aquifer. The reactor was used to investigate microbial removal of nitrate that is a major inorganic contaminant detected in the Nakdong River. The reactor was introduced with river water that contained nitrate at concentrations (5.07, 6.81, 8.27, and 11.07 mg $NO_3{^-}/l$) detected downstream of the Nakdong River in the past 2 years. The nitrate concentrations decreased during the introduced water is retained in the reactor. Effluent from the reactor contained 1.49 mg $NO_3{^-}/l$ or less and had an average pH of 7.98 regardless of the nitrate concentrations of the influent. However abiotic control reactor showed similar nitrate-concentrations in its influent and effluent. Considering the result of abiotic control, the decreased nitrate concentration observed in the test column suggested that microorganisms in saturated-zone soil removed nitrate in the river water introduced into the reactor. Results of this study will be used to better understand microbial improvement of water quality in aquifer recharge and recovery technology.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.16 no.3
• /
• pp.35-42
• /
• 2012

We propose a probabilistic method to evaluate the uniform hazard spectra (UHS) of the soil of nuclear power plant(NPP) sites corresponding to that of a bedrock site. To do this, amplification factors on the surface of soil sites were estimated through site response analysis while considering the uncertainty in the earthquake ground motion and soil deposit characteristics. The amplification factors were calculated by regression analysis with spectral acceleration because these two factors are mostly correlated. The proposed method was applied to the evaluation of UHS for the KNGR (Korean Next Generation Reactor) and the APR1400 (Advanced Power Reactor 1400) nuclear power plant sites of B1, B4, C1 and C3. The most dominant frequency range with respect to the annual frequency of earthquakes was evaluated from the UHS analysis. It can be expected that the proposed method will improve the results of integrated risk assessments of NPPs rationally. We expect also that the proposed method will be applied to the evaluation of the UHS and of many other kinds of soil sites.