황철석과 토착미생물이 광미를 활용한 전기 생산에 미치는 영향

주원정,조은혜,남경필,Ju, Won Jung,Jho, Eun Hea,Nam, Kyoungphile 응용생태공학회 2015 Ecology and resilient infrastructure Vol.2 No.1

Acid mine drainage (AMD) producing mine tailings can be beneficially recycled to generate electricity by applying fuel cell technology. Pyrite-containing mine tailings and indigenous bacteria from abandoned mine areas were used to construct fuel cells to investigate the effect of pyrite contents and the presence of iron-oxidizing bacteria. The results showed an enhanced electrical performance with a higher content of pyrite in mine tailings. The inoculation of the indigenous bacteria also enhanced the current density by about three times, and the power density by about 10 times. Overall, this study shows that the combined use of the ecological function of indigenous bacteria from mine areas and mine-tailings in fuel cells does not only contribute to reducing harmful effects of mine tailings but also generate electricity.

생태학적 기능을 이용한 광미 활용 전기 생산: 철산화박테리아를 이용한 황철석 산화 속도 증진을 통한 전류 밀도 향상 가능성 평가

주원정,조은혜,남경필,Ju, Won Jung,Jho, Eun Hea,Nam, Kyoungphile 응용생태공학회 2014 Ecology and resilient infrastructure Vol.1 No.1

The research evaluates the possibility of generating electricity using pyrite containing mine tailings, which are the major cause of acid mine drainage (AMD), by applying iron oxidizing bacteria (in this case, Acidithiobacillus ferrooxidans) and chemical fuel cell technology. The changes in the aqueous $Fe^{2+}$ concentration, which can represent an ionized form of pyrite, with an initial concentration of 9,000 mg/L were investigated during the 20 d growth period. Both the $Fe^{2+}$ and total iron (i.e., total $Fe^{2+}$)concentrations with or without A. ferrooxidans were observed. The $Fe^{2+}$ concentration decreased to about 6,000 mg/L, in the abiotic condition, while it decreased to about 400 mg/L in the biotic condition. The results showed that the increased $Fe^{2+}$ oxidation in the presence of A. ferrooxidans (i.e., catalytic ability of A. ferrooxidans) can be applied to electricity generation using pyrite containing mine tailings. In the co-presence of A. ferrooxidans and pyrite containing mine tailings, $Fe^{2+}$ oxidation and hence electron production increases, which, in turn, improves current density. This study can be applied to utilize ecological functions of indigenous bacteria in mine areas to enhance electricity generation efficiency.

갈바닉 산화와 황철석 용해를 이용한 친환경 원위치 광미 무해화 기술

주원정,조은혜,남경필,Ju, Won Jung,Jho, Eun Hea,Nam, Kyoungphile 응용생태공학회 2016 Ecology and resilient infrastructure Vol.3 No.4

Mine tailings generated during mining activity often contain high concentrations of heavy metals, with pyrite-containing mine tailings in particular being a major cause of environmental problems in mining areas. Chemical cell technology, or fuel cell technology, can be applied to leach heavy metals in pyrite-containing mine tailings. As pyrite dissolves through spontaneous oxidation (i.e. galvanic oxidation) in the anode compartment of the cell, $Fe^{3+}$, sulfuric acid are generated. A decrease in pH due to the generation of sulfuric acid allows heavy metals to be leached from pyrite-containing mine tailings. In this study, pyrite was dissolved for 4 weeks at $23^{\circ}C$ in an acidic solution (pH 2) and in a galvanic reactor, which induces galvanic oxidation, and total Fe leached from pyrite and pH were compared in order to investigate if galvanic oxidation can facilitate pyrite oxidation. The change in the pyrite surface was analyzed using a scanning electron microscope (SEM). Comparing the total Fe leached from the pyrite, there were 2.9 times more dissolution of pyrite in the galvanic reactor than in the acidic solution, and thus pH was lower in the galvanic reactor than in the acidic solution. Through SEM analysis of the pyrite that reacted in the galvanic reactor, linear-shaped cracks were observed on the surface of the pyrite. The study results show that pyrite dissolution was facilitated through the galvanic oxidation in the galvanic reactor, and also implied that the galvanic oxidation can be one remediation option for pyrite-containing mine tailings.

농업환경에서 발생하는 미세플라스틱 필름의 Cd, Pb 흡착 특성

주원정(Won Jung Ju),안진성(Jinsung An),조은혜(Eun Hea Jho) 대한환경공학회 2021 대한환경공학회지 Vol.43 No.1

목적: 플라스틱은 편리성, 단열성으로 일상 및 여러 가지 산업분야에서 다양하게 활용되고 있고, 플라스틱의 사용량은 계속 증가하는 추세이다. 농업환경에서는 비닐하우스, 멀칭비닐 등의 형태로 플라스틱이 사용되고 있다. 사용 후 환경으로 유입된 플라스틱은 물리적, 화학적, 생물학적 작용으로 작은 단위로 분해된다. 이 중 입자 사이즈가 5 mm 이하인 플라스틱을 미세플라스틱이라 정의한다. 토양 중에 잔류하는 미세플라스틱은 표면적이 넓기 때문에 중금속을 포함한 다양한 오염물질을 흡착시켜 농경지 생태계에 영향을 줄 개연성이 있다. 본 연구에서는 농업환경에서 빈번하게 발생하는 미세플라스틱 필름의 납(Pb)과 카드뮴(Cd)의 흡착특성을 평가하고자 한다. 방법: 본 연구에서는 농업환경에서 빈번하게 발생하는 미세플라스틱 필름의 Pb와 Cd 흡착특성을 평가하고자 한다. PVC (polyvinyl chloride) 필름 한 가지와 PE (polyethylene) 필름 두 가지를 5 mm × 5 mm 이하로 잘라 미세플라스틱을 준비한 후, Pb 용액 또는 Cd 용액에 넣어 72시간 동안 흡착 실험을 수행하였다. 흡착실험결과를 Langmuir, Freundlich, Temkin 등온 흡착 모델에 적용하였다. 결과 및 토의 : 등온 흡착 실험 결과를 Langmuir, Freundlich, Temkin 모델을 이용해 도식화한 결과, 전반적으로 Langmuir 및 Freundlich 모델에 잘 맞는 경향(R² > 0.9)을 보였고, Temkin 모델은 상대적으로 잘 맞지 않는 경향을 보였다. 플라스틱 종류와 관계 없이, Pb에 대한 흡착친화도를 나타내는 Langmuir 상수(KL)의 값과 최대흡착에너지를 의미하는 Temkin 상수(AT)의 값이 Cd에 대한 값보다 더 높게 나왔고, 흡착강도와 관련 있는 Freundlich 상수(nF) 는 Pb > Cd > 1의 경향을 나타내었다. 이는 Cd보다 Pb의 PVC와 PE에 대한 흡착친화도가 크다는 것을 의미한다. 결론: 본 연구는 토양 중 잔류하는 미세플라스틱 필름이 Cd와 Pb 같은 중금속을 흡착하고, 따라서 토양환경 중 중금속의 거동에 유의한 영향을 미칠 수 있음을 시사한다. 또한 폐플라스틱의 환경 문제가 사회적 이슈로 대두되고 있는 요즘, 다양한 폐플라스틱으로부터 발생할 수 있는 미세플라스틱의 지중환경 중 관리의 필요성에 대한 합리적 근거를 제공하고, 따라서 토양 환경 내 미세플라스틱에 대한 추가 연구가 이루어질 필요가 있다. Objectives : Plastics are widely used in daily life and in various industrial fields due to their convenience and thermal insulation, and the use of plastics is continuing to increase. In agricultural environments, plastics are largely used for vinyl houses and mulching vinyl. Used plastics are degraded into small fragments through physical, chemical, and biological processes. Among these, plastics with a particle size of 5 mm or less are defined as microplastics. Since microplastics have a relatively large surface area, various pollutants including heavy metals can potentially be adsorbed and affect the agricultural ecosystem. The purpose of this study is to evaluate the Pb and Cd adsorption characteristics on microplastic films frequently generated in agricultural environments. Methods : The Pb and Cd adsorption characteristics on microplastic films were studied with 3 different plastic films. Microplastic samples were prepared by cutting PVC (polyvinyl chloride) and PE (polyethylene) films to have the sizes of < 5 mm × 5 mm. The prepared microplastic samples were placed in Pb or Cd solutions having a range of concentrations and shaken for 72 h for sorption tests. The experimental results were fitted to the Langmuir, Freundlich, and Temkin isothermal adsorption models. Results and Discussion : The isothermal adsorption test results obtained fitted well to the Langmuir and Freundlich models (R² > 0.9), but not the Temkin model. Regardless of the plastic type, the values of Langmuir constant (KL) and Temkin constant (AT) for Pb were larger than those for Cd, and the Freundlich constant (nF) showed a tendency of Pb > Cd > 1, indicating the greater Pb sorption strength or affinity than Cd on PVC and PE. Conclusions : This study shows that the microplastics in soil adsorb heavy metals like Cd and Pb affecting the heavy metal fate in the soil environment. With an increasing attention on the environmental problems due to plastic wastes, this study provides the basis for the need of management of soil environment. Therefore, further research on microplastics in soil environment is required.

지하수 내 난분해성 복합유기화합물 제거를 위한 Nano-ZnO/Laponite/PVA 복합체 제조

주원정(Ju, Won Jung),주진철(Joo, Jin Chul),안호상(Ahn, Ho Sang),윤영한(Yoon, Young Han),권재형(Kwon, Jae Hyung),안창혁(Ahn, Chang Hyuck) 대한토목학회 2012 대한토목학회 학술대회 Vol.2012 No.10

열처리 방식에 따른 ZnO-Laponite 지하수정화볼의 수중안정성 연구

안호상(Ahn, Hosang),주원정(Ju, Won jung),주진철(Joo, Jin Chul),윤영한(Yoon, Young Han),안창혁(Ahn, Chang Hyuk),권재형(Kwon, Jae Hyeong) 대한토목학회 2012 대한토목학회 학술대회 Vol.2012 No.10

실험실 조건에서 붕어마름의 수질개선 효과 분석

안창혁(Chang Hyuk Ahn),주진철(Jin Chul Joo),주원정(Won Jung Joo),안호상(Ho Sang Ahn),이새로미(Saero Mi Lee),오주현(Ju Hyun Oh),송호면(Ho Myeon Song) 大韓環境工學會 2013 대한환경공학회지 Vol.35 No.4

침수식물인 Ceratophyllum demersum (C. demersum)의 영양염류 제거 효율과 남조류 성장 억제 능력을 평가하기 위해 총6개의 반응조에서 9일간 회분식 실험을 실시하였다. 실험이 시작되고 약 84 hr 후 C. demersum는 pH, DO에 대한 안정적인 일주기 경향을 보였다. 영양염류인 NH₃+, NO₃-, PO₄3-를 대상으로 저감률을 검토한 결과 실험초기부터 9일간 지속적인 감소를 보였고 특히 24 hr 이내에서 빠른 감소를 나타내었다. C. demersum의 단위면적당 생체량과 영양염류 제거율 사이에 높은 상관관계(r2 ≥ 0.96, p < 0.001)가 도출되었으며, 피복도가 높을수록 오염물 저감 효율이 큰 것으로 나타났다. 하지만 높은 밀도의 반응조에서는 C. demersum의 활성화 차이가 있었으며, 그럼에도 불구하고 수질정화 효과가 나타난 것은 침수식물에 존재하는 부착조류나 미생물의 영향이 큰 것으로 여겨진다. Microcystis aeruginosa (M. aeruginosa)는 C. demersum의 생장밀도 2,500 g fw/m2 (피복도 100%) 조건에서 성장률 0.31 /day를 보였으나 대조구는 0.47 /day을 나타내었다. 세포수 비교에서는 실험구보다 대조구가 약 1.7배 높게 나타나 C. demersum의 남조류 성장 억제 능력을 시사하였다. To evaluate the ability of the submerged plant, Ceratophyllum demersum`s (C. demersum) to remove nutrients and to inhibit growth of cyanobacteria, a total of 6 mesocosms were conducted in a batch reactor for 9 days. From the 84 hr of the experiment, C. demersum was stabilized and showed daily cycle trends according to changes in pH and DO levels. The concentration Analysis of Water Quality Improvement of Ceratophyllum demersum under Laboratory Condition-by Nutrients Removal Efficiency of nutrients, NH₃+, NO₃- and PO₄3 continuously decreased until 9 days of the experiment, with the rapid decrease in nutrient concentration for the first 24 hours. High correlation coefficient (r2 ≥ 0.96, p < 0.001) between the amount of C. demersum`s biomass per unit area and the nutrients removal level were derived, and greater C. demersum`s biomass per unit area showed higher removal efficiency of nutrients. However, there were differences in the C. demersum`s activity level between batch reactors with higher and similar density of the C. demersum, but nonetheless water purification effect appears to have a significant influence due to attached algae and microorganisms. The growth rate of harmful cyanobacteria, Microcystis aeruginosa (M. aeruginosa) with C. demersum`s density of 2,500 g fw/m2 (100% of cover degree) was 0.31 /day, compared to the growth rate of 0.47 /day for the control group (0% of cover degree). In terms of number of cells, the control group had 1.7 times higher number of cells than the experimental group, proving that C. demersum has the ability to inhibit the growth of harmful cyanobacteria.

미세플라스틱의 중금속 흡착 능력 연구

조은혜(Eun Hea Jho),김수현(Su Hyun Kim),전어진(Eo Jin Jeon),안세인(?Se In Ahn),문영진(Young Jin Mun),조찬희(Chan Hee Cho),김영홍(Yeonghong Kim),주원정(Won Jung Ju) 대한환경공학회 2020 대한환경공학회 학술발표논문집 Vol.2020 No.11