• 한국지하수토양환경학회지:지하수토양환경
• /
• 제20권5호
• /
• pp.47-51
• /
• 2015

Biocatalytic degradation of total petroleum hydrocarbons (TPHs) in contaminated soil by hemoglobin and hydrogen peroxide is an effective soil remediation method. This study used a laboratory soil reactor experiment to evaluate the effectiveness of a nonspecific biocatalytic reaction with hemoglobin and H₂O₂ for treating TPH-contaminated soil. We also quantified changes in the soil microbial community using real-time PCR analysis during the experimental treatment. The results show that the measured rate constant for the reaction with added hemoglobin was 0.051/day, about 3.5 times higher than the constant for the reaction with only H₂O₂ (0.014/day). After four weeks of treatment, 76% of the initial soil TPH concentration was removed with hemoglobin and hydrogen peroxide treatment. The removal of initial soil TPH concentration was 26% when only hydrogen peroxide was used. The soil microbial community, based on 16S rRNA gene copy number, was higher (7.1 × 10⁶ copy number/g of bacteria, and 7.4 × 10⁵ copy number/g of Archaea, respectively) in the hemoglobin catalyzed treatment. Our results show that TPH treatment in contaminated soil using hemoglobin catalyzed oxidation led to the enhanced removal effectiveness and was non-toxic to the native soil microbial community in the initial soil.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제16권3호
• /
• pp.28-37
• /
• 2011

A preliminary study for energy efficient soil heating and contaminant removal using microwave was conducted. Soils sampled from floodplain were heated with microwave oven, and soil heating property and energy efficiency were compared to those heated with electrical furnace. In addition the effects of water, soil organic matter, and contaminated diesel on soil heating with microwave were investigated. Even though the electrical power consumption of electrical furnace and microwave oven were similar, temperature of soil heated with microwave oven was significantly higher than that of soil heated with electrical furnace. The increase of soil moisture content delays the raise of soil temperature during heating it with microwave oven. However, the effects of total petroleum hydrocarbon (TPH) (<10%) in contaminated soil matrix and small amount of soil organic matter (<5%) on the increase of soil temperature by microwave were not significant. Further studies for contaminated soils with different texture using pilot scale microwave reactor are required for application of this technique in the field.

• 환경영향평가
• /
• 제14권4호
• /
• pp.147-155
• /
• 2005

This study was designed to investigate the effect of plant as a botanical air purification on the indoor pollution by formaldehyde. Three indoor plants such as Dracaena marhginata, Spathiphyllum and Dracaena reflexa, were placed in the artificially contaminated reactor under laboratory condition. Both plant and soil effects on removal of formaldehyde from contaminated indoor air were observed. Reductions in the formaldehyde levels appeared to have been associated with soil medium factors as well as plant factors. The effect of soil on formaldehyde reduction was high in the early stage of the experiment and the results suggest that sorption could be more important factor than microbial degradation in the initial dissipation of contaminants in the soil. It was suggested that the effect of plant on formaldehyde reduction might be related to the plant species, total leaf surface area of plant, degree of contribution of soil medium, and exposed concentration level. The results of this study showed that air purification using plants is an effective means of reduction on indoor formaldehyde level, though, utilization of soil media with high sorption capacity and/or supplementary purifying aids were also suggested when the source is continuous or exposed concentration level is high.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제20권6호
• /
• pp.85-94
• /
• 2015

RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) is the most important explosive contaminant, both in concentration and in frequency, at military shooting ranges in which green technologies such as phytoremediation or constructed wetlands are the best option for mitigation of explosive compounds discharge to the environment. A study was conducted with two identical lab-scale plug flow constructed wetlands planted with Amur silver grass to treat water artificially contaminated with 40 mg/L of toxic explosive compound, RDX. The reactor was inoculated with or without RDX degrading mixed culture to evaluate plant-microorganism interactions in RDX removal, transformation products distribution, and kinetic constants. RDX and its metabolites in water, plant, and sediment were analyzed by HPLC to determine mass balance and kinetic constants. After 30 days of operation, the reactor reached steady-state at which more than 99% of RDX was removed with or without the mixed culture inoculation. The major transformation product was TNX (Trinitroso-RDX) that comprised approximately 50% in the mass balance of both reactors. It was also the major compound in the plant root and shoot system. Acute toxicity analysis of the water samples showed more than 30% of toxicity reduction in the effluent than that of influent containing 40 mg/L of RDX. In the Amur silver grass mesocosm seeded with the mixed culture, the specific RDX removal rate, that is 1st order removal rate normalized to plant fresh weight, was estimated to be 0.84 kg⁻¹ day⁻¹ which is 16.7% higher than that in the planted only mesocosm. Therefore, the results of this study proved that Amur silver grass is an effective plant for RDX removal in constructed wetlands and the efficiency can be increased even more when applied with RDX degrading microbial consortia.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
• /
• pp.73-76
• /
• 2004

Rusted iron could retain activity to redox-sensitive pollutants in batch reactor. Flow-through columns packed with permeable reactive iron filings (Fe$^{0}$ ) between soil and sand layers were used to evaluate the applicability of bio-enhanced iron barriers to treat explosives-contaminated groundwater. One column was bioaugmented with municipal anaerobic sludge to evaluate the enhancement of biodegradation. Military contaminants (RDX, HMX, TNT, 2,4DNT, 2,6DNT), which coexist in soils at military sites, were completely removed in the bioaugmented Fe$^{0}$ layer after 8 months of operation. Overall, this research suggests that Fe$^{0}$ barriers can effectively clean up groundwater contaminated with military explosives, and that treatment efficiency can be enhanced by bioaugmentation.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 추계학술발표회
• /
• pp.144-147
• /
• 2003

In this study, the mass transfer behaviors of phenanthrene, anthracene, and pyrene in soil slurry reactor (SSR) using two-liquid phase (TLP) system were investigated. The mass transfer ratio and rate of PAH in the TLP system using light paraffine oil, which has the highest solubility of PAH, were influenced by the amount of light paraffine oil and mixing speed. When the amount of light paraffine oil decreased from 15 % to 2.5 % (v/v), the mass transfer ratio of anthracene decreased significantly compared with that of phenanthrene and pyrene. As mixing speed increased, the initial mass transfer rate of PAH within 1 day was enhanced. However, each final mass transfer ratio of three PAHs after 5 day was similar irrespective of mixing speed.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2003년도 추계학술발표회
• /
• pp.158-161
• /
• 2003

Removal of phenanthrene by electrokinetic method combined with Fenton-like process was studied in a model system. The scale of reactor was 100cm in length, 100cm in width, and 70cm in height. The distance between electrodes was 70cm. Indonesia kaoline was selected as a model soil. When constant voltage of 100 V was applied to this system, current decreased from 200 mA to 100 mA for 14 days. Total accumulated EOF was about 55,000 mL. The concentration of phenanthrene near anode was very low because direction of electroosmosis was from anode to cathode and hydrogen peroxide was supplied to anode reservoir. Phenanthrene concentration was increased as the location was far from anode because hydrogen peroxide was gradually decomposed and then the rate of hydroxyl radical production was decreased.

• 대한지하수환경학회지
• /
• 제4권3호
• /
• pp.116-121
• /
• 1997

정화 효율과 운영상의 문제점을 파악하였다. 반응조 유입수 및 방류수에 대하여 현장에서 pH 및 Eh(산화환원전위)를 측정하였고 Cd, Pb, As, Zn, Cu, Fe, Al 및 Mn 등을 실험실에서 분석 하였다. 반응조 방류수에 대한 수질분석 결과 우분 및 석회석이 섞인 볏짚 반응조의 Cu, Zn, Fe, Cd, Al, Mn및 Pb의 정화효율(최대)은 98%, 100%, 99%, 100%, 97%, 61% 및 100%였고 이때 반응조의 수질환경은 pH 6 그리고 Eh 값이 -300 mV부근의 환원환경이었다. 그러나 시간이 경과함에 따라 Eh 값은 상승하였고 Al을 제외한 금속성분의 정화효율도 낮아져 반응조의 혐기환경유지는 금속성분의 정화에 매우 중요하였다. 반응조 시설을 운영한 결과 배관내의 산화물 Scale 및 기질물질의 부피 변화는 광산배수의 흐름을 방해하는 요소로 나타났다.

• 상하수도학회지
• /
• 제13권4호
• /
• pp.45-53
• /
• 1999

The microbial organisms named "Pseudomonas sp. LK-14" were isolated from farm land and shallow river sediment, activated, augmented and identified; which were using 2,4-D (2,4-Dichlorophenoxyacetic acid) as a sole carbon source and energy source. 2,4-D removal efficiency of LK-14 with 2,4-D sole carbon source (reactor S) were higher than that of Activated Sludge with 2,4-D sole carbon source (reactor A). Dynamic bioligical reaction kinetic parameters (sole carbon source was 2,4-D) obtained from batch reactor experiments were ${\mu}_{max}$ $0.105hr^{-1}$, $K_{s,24D}$ 15.64mg/L, $K_{i,24D}$ $1.94h^{r-1}$, $Y_{24D}$ 0.39 for LK-14 and ${\mu}_{max}$ $0.008hr^{-1}$, $K_{s,24D}$ 26.95mg/L, $K_{i,24D}$ $1.75hr^{-1}$, $Y_{24D}$ 0.10 for Activated Sludge. Using these parameters, we could predict the behaviors of 2,4-D substrate utilized by LK-14 and Activated Sludge in batch reactors. The kinetic parameters are enable to predict the 2,4-D substrate and microbial population behavior entering into wastewater treatment plants by using unsteady states dynamic simulation modeling technique.

• Environmental Engineering Research
• /
• 제19권1호
• /
• pp.47-57
• /
• 2014

The aim of this paper was to study the effect of five different waste combinations (C/N 15, C/N 20, C/N 25, C/N 30, and control) of sewage sludge coupled with sawdust and cattle manure in a pilot scale rotary drum reactor, during 20 days of the composting process. Our results showed that C/N 30 possesses a higher temperature regime with higher % reduction in moisture content, total organic carbon, soluble biochemical oxygen demand and chemical oxygen demand; and higher % gain in total nitrogen and phosphorus at the end of the composting period implying the total amount of biodegradable organic material is stabilized. In addition, $CO_2$ evolution and oxygen uptake rate decreased during the process, reflecting the stable behavior of the final compost. A Solvita maturity index of 8 indicated that the compost was stable and ready for usage as a soil conditioner. The results indicated that composting can be an alternate technology for the management of sewage sludge disposal.