분자생물학적 방법을 이용한 지열시스템 관정 및 주변지역 미생물종 모니터링

안창민,한지선,김창균,박유철,목종구,장범주,Ahn, Chang-Min,Han, Ji-Sun,Kim, Chang-Gyun,Park, Yu-Chul,Mok, Jong-Koo,Jang, Bum-Ju 한국지하수토양환경학회 2012 지하수토양환경 Vol.17 No.6

This study was conducted to monitor microbial species dynamics within the aquifer due to long term operation of geothermal heat pump system. The species were identified by molecular biological methods of 16S rDNA. Groundwater sample was collected from both open (S region) and closed geothermal recovery system (J region) along with the control. J measured and control as well as S measured found Ralstonia pickettii as dominant species at year 2010. In contrast, Rhodoferax ferrireducens was dominantly observed for the control of S. In 2011, Sediminibacterium sp. was universely identified as the dominant species regardless of the monitoring places and type of sample, i.e., measured or control. The difference in the dynamics between the measured and the control was not critically observed, but annual variation was more strikingly found. It reveals that possible environmental changes (e.g. ORP and DO) due to the operation of geothermal heat recovery system in aquifer could be more exceedingly preceded to differentiate annual variation of microbial species rather than positional differences.

생물학적 칼슘화에 의해 생성된 CaCO₃ 광물의 정량분석 방법 비교 평가

안창민,배영신,함종헌,천승규,김창균,Ahn, Chang-Min,Bae, Young-Shin,Ham, Jong-Heon,Cheon, Seung-Kyu,Kim, Chang-Gyun 한국지하수토양환경학회 2013 지하수토양환경 Vol.18 No.5

This study was performed to develop a method for quantitative analysis obtaining the amount of calcium carbonate minerals formed when Ca salts biomimetically reacted with carbon dioxide. There were two methods compared; 1) volumetric calcimeter method that determining the amount of released carbon dioxide after calcium carbonate minerals were acidified by 4N HCl and 2) Thermogravimetry-Differential Thermal Analysis (TG-DTA) adopting differential decomposition temperature breaking-up the structural link within calcium carbonate minerals. The comparisons were made by batch experiment (i.e., biocalcification process) along with control (i.e., nominal concentration of $CaCO_3$ prepared). For the control, TG-DTA took a minor root mean square deviation (RMSD) of 1.1~5.9 mg, whereas volumetric calcimeter exposed a greater RMSD of 28.3 mg. For the biocalcification, the amount of $CaCO_3$ was more precisely obtained for TG-DTA rather than that of volumetric calcimeter. It was decided that TG-DTA was more successfully used for quantitative analysis to observe the amount of calcium carbonate minerals derived from biocalcification.

매립지 복토용 슬러지 고화물내 이산화탄소 생광물화 고정균 분석 및 생광물화능 평가

안창민(Chang Min Ahn),배영신(Young Shin Bae),함종헌(Jong Heon Ham),천승규(Seung Kyu Chun),김창균(Chang Gyun Kim) 大韓環境工學會 2013 대한환경공학회지 Vol.35 No.8

본 연구에서는 실제 매립장에 매립되어 있는 슬러지 고화물을 대상으로 생광물화 미생물 종분석을 위한 기초 연구를 수행 하였고, 또한 분석된 미생물을 배양하여 일반적으로 알려진 생광물화균과의 대조 실험을 통해 토착 미생물의 carbonate 생성능을 기기분석을 통해 비교 평가하였다. 시료내 미생물 종분석을 16S rDNA 시퀀스 분석을 통해 수행해본 결과, 다양한 미생물종이 관찰되었으며, 특히 생광물화 기작에 관여한다고 알려진 호기성 토양 미생물의 한종인 Bacillus megaterium과 금속을 환원시켜 미네랄염 상태로 전환시키는 Alkaliphilus metalliredigens의 근연종을 확인 하였다. 복토재에서 분리 배양한 균주를 이용하여 실험을 수행한 결과, 생광물화 균주가 주입된 실험군에서 미생물이 주입되지 않은 대조군보다 이산화탄소의 감소량이 더 컸다. 이와 연계하여 반응후 열중량분석기(TG-DTA)를 이용하여 탄산염(carbonate minerals)을 정량한 결과, 미생물이 주입된 실험군에서 대조군에 비해 약 30% 정도 더 생성된 것을 확인 하였다. 이러한 실험 결과로 비춰 볼 때 열중량분석법(TG-DTA)은 이산화탄소의 생물학적 전환에 의해 생성된 탄산염물의 정략적 분석에 적합할 것으로 판단된다. 이를 종합해 보면 복토재로 현장 매립된 슬러지 고화물은 매립장에서 표면 발산되는 이산화탄소의 자연적인 탄산염 전환 매체로서 적용이 가능할 것으로 판단된다. This study was performed to determine whether biomineralization microbes were actively present underneath landfill cover soil producing biocalcification. From this, various types of microbes were observed. Among them, two species were dominantly found; Bacillus megaterium and Alkaliphilus metalliredigens that were known as biominerlization bacteria. With those microbes, CO₂ was more highly consumed than without bacteria. In response, the calcium carbonate mineral was produced at 30% (wt) greater than that of the control. At the same time, TG-DTA was successfully used for quantification of CO₂ consumed forming calcium carbonate minerals resulting from biocalcification. It was decided that the presence of solidified sewage sludge cake utilized as a cover soil in the landfill could efficiently contribute to possible media adaptably and naturally sequestering CO₂ producing from the landfill.

이산화탄소 생광물화 특성 및 슬러지 고화물 적용성 평가

민동희(Dong Hee Min),안창민(Chang Min Ahn),한지선(Ji Sun Han),윤순욱(Soon Uk Yoon),전은정(Eun Jeong Jeon),원종철(Jong Choul Won),천승규(Seung Kyu Chun),김창균(Chang Gyun Kim) 大韓環境工學會 2011 대한환경공학회지 Vol.33 No.11

본 연구는 이산화탄소의 생광물화에 관한 연구로 광물별 생광물화 특성을 알아보기 위하여 CaO, MgO, SiO₂ 수용액을 이용하여 bottle test를 진행하였으며, 슬러지 고화물을 이용하여 batch test를 진행하였다. 대상 미생물은 생광물화 관련 미생물 중 Bacillus Megaterium과 Bacillus pasteurii 종을 이용하여 실험을 진행하였다. 단일 수용액을 사용한 실험에서는 CaO, MgO, SiO₂에 대해 각각 1.1, 4.0, 0.3 mmol의 이산화탄소 가스가 감소되었다. 혼합 수용액을 사용한 실험에서는 Ca+Mg, Ca+Si, Mg+Si에 대해 각각 2.7, 1.8, 2.3 mmol의 이산화탄소가 감소되었다. 슬러지 고화물을 이용한 batch test의 경우, 슬러지 고화물의 양과 주입된 이산화탄소 가스의 농도에 따라 각각 다른 이산화탄소의 소모를 보였다. XRD 분석 결과, Ca 이온이 존재할 때CaCO₃ (Calcite)가 가장 잘 형성되었으며, SEM 분석 결과, 생광물화 반응 후 대상매체에 단립화된 결정이 더 많이 형성된 것을 확인할 수 있었다. 본 연구 결과 생광물화 기술이 이산화탄소를 저감하기 위한 기술로 활용될 수 있음을 알 수 있었다. This study was conducted to characterize CO₂ biomineralization on several minerals (i.e., CaO, MgO, SiO₂) by bottle test in an aqueous solution and solidified sludge using different aerobic bacterial strains like Bacillus megaterium and Bacillus pasteurii by batch test. These bacteria promote the formation of microenvironments that facilitate the precipitation of mineral phases that were unsaturated in the bulk solution. For one type of mineral solely amended, the CO₂ was reduced at the highest of 4.0 mmol for MgO while it was not that much lower for CaO and SiO₂ showing 1.1 and 0.3 mmol CO₂, respectively. For two types of minerals simultaneously amended, the CO₂ was reduced at the greater extent for both Ca+Mg and Mg+Si showing 2.7 and 2.3 mmol, respectively whereas it was less for Ca+Si at 1.8 mmol. For solidified sludge, the CO₂ reduction rate changed depending on the volume of solidified sludge placed in the medium and the input CO₂ concentration.. The reduction rate of CO₂ was increased with increasing the volume of solidified sludge. Results of XRD analysis indicate that CaCO₃ (Calcite) was dominantly formed among others (e.g., Aragonite, Dolomite). SEM analysis showed that the sample with Bacillus pasteurii, could more form minerals rather than control. As demonstrated in this study, CO₂ would be effectively sequestered in biomineralization process.

전기장 및 초음파에 의한 반송슬러지의 가용화에 따른 활성슬러지에서의 슬러지 감량화

윤순욱 ( Soou Uk Yoon ),안창민 ( Chang Min Ahn ),김창균 ( Chang Gyun Kim ) 한국물환경학회 2013 한국물환경학회지 Vol.29 No.3

This study was conducted to reduce excess sludge generation by recycling of return sludge to the aeration tank after solubilization by electric field charger and ultrasonifier. The return sludge was purposely broken-up to the ratio of SCODCr / TCODCr at 0.1, 0.2, and 0.3, which was tested along with control (i.e., untreated). Solubilized sludge was subsequently treated in a bench-scaled conventional activated sludge reactor. According to varying SCODCr / TCODCr ratios, TSS in the reactor was correspondingly increased from 129 to 219 mg/L and TCODCr was also from 257 to 335 mg/L. However, TSS in the effluent was nevertheless kept lower at below 30 mg/L and TCODCr was also unvaryingly below 40 mg/L. For SCODCr / TCODCr = 0.3, the amount of excess sludge produced was at the highest decreased up to as high as 78%.

생광물화를 통한 이산화탄소의 고화슬러지 고정

민동희 ( Dong Hee Min ),안창민 ( Chang Min Ahn ),한지선 ( Ji Sun Han ),윤순욱 ( Soon Uk Yoon ),김창균 ( Chang Gyun Kim ),전은정 ( Eun Jeong Jeon ),원종철 ( Jong Choul Won ),천승규 ( Seung Kyu Chun ) 한국물환경학회(구 한국수질보전학회) 2011 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2011 No.-

초음파와 전기장 처리에 의한 하수슬러지 탈수성 향상

모우종(Woo Jong Mo),한지선(Ji Sun Han),안창민(Chang Min Ahn),윤순욱(Soon Uk Yoon),석희정(Hee Jung Seok),김창균(Chang Gyun Kim) 大韓環境工學會 2013 대한환경공학회지 Vol.35 No.1

슬러지 처분비용은 하수처리장 운영에 있어서 중요한 경제적 요소이다. 더욱이, 2013년부터 유기성 폐기물의 해양투기가 금지되면서 대부분의 슬러지가 육상 처리 되어야 하기 때문에 슬러지의 발생량을 줄이는 것이 시급한 상황이다. 본 연구에서는, 초음파와 전기장 처리에 의한 하수슬러지의 탈수성 향상을 확인하고자 하였다. 슬러지는 pilot-scale의 전처리 장치로 초음파와 전기장 단독처리 그리고 초음파 및 전기장 병합처리 되었으며, 처리 후 lab-scale 필터프레스 장치로 탈수되었다. 실험한 초음파 에너지 밀도 범위는 225~1,200 kJ/L였고 전기장 처리장치는 4.5~24 kJ/L였다. 초음파 단독처리와 초음파 및 전기장 병합처리 된 슬러지의 탈수 cake 함수율은 에너지 밀도 1,200 kJ/L일 때, 처리하지 않은 슬러지보다 각각 10~12% 감소하였으며 이 때 슬러지 함수율은 65~66%였다. 초음파 및 전기장 병합처리가 초음파 단독처리보다 탈수된 슬러지 cake의 함수율을 낮추는데 효과적이었으나, 전기장 단독처리의 경우 에너지 밀도가 낮아 함수율의 변화는 거의 없었다. The sludge disposal is a major economic factor in the sewage treatment facility operation. Moreover, since the ocean dumping will be prohibited by Korean environmental law from 2013, sludge should be eliminated or sludge volumetric reduction should be performed urgently. In this study, improvement of the sewage sludge dewaterability was investigated by ultrasound and electric field treatment. Sludge was treated by a single or in combination of either the electric field or ultrasound on a pilot pretreatment facility, then it was dewatered by lab-scale filter press. The operating input energy of ultrasound device was varied from 225~1,200 kJ/L and electric field device was varied from 4.5~24 kJ/L. The water contents of dewatered sludge cake treated with ultrasound (1,200 kJ/L) and combination of ultrasound/electric field (1,224 kJ/L) were decreased 10~12% by comparing non treated sludge. At that time, water contents were 65~66%. The combination treatment of ultrasound/electric field was effective to reduce water content of dewatered sludge cake, however, water content was not changed by a single treatment of electric field because of low energy density.

메탄올탈수소효소 저해시 메탄산화에 의한 메탄올 전환생성 특성

유연선(Yeon Sun Yoo),한지선(Ji Sun Han),안창민(Chang Min Ahn),민동희(Dong Hee Min),모우종(Woo Jong Mo),윤순욱(Soon Uk Yoon),이종규(Jong Gyu Lee),이종연(Jong Yeon Lee),김창균(Chang Gyun Kim) 大韓環境工學會 2011 대한환경공학회지 Vol.33 No.9

본 연구에서는 메탄의 생물학적 메탄올 전환에 관한 연구를 수행하였다. 바이오가스 중의 메탄은 메탄산화균의 methane monooxygenase (MMO)의 생물학적 촉매반응에 의해 산화되었으며, 인산염, NaCl, NH₄Cl, EDTA와 같은 methanol dehydrogenase(MDH)의 활성 저해제를 이용하여 MDH의 활성도를 저해함으로써 메탄올의 전환이 이루어졌다. 메탄산화균은 35℃, pH 7, 인공 바이오가스(CH₄ 50%, CO₂ 50%) / Air의 부피비가 0.4인 조건에서 메탄 산화 정도가 0.56 mmol로 최대로 나타났다. 인산염40 mM, NaCl 50 mM, NH₄Cl 40 mM, EDTA 150 μm 이하일 때 저해제의 종류에 상관없이 메탄 산화율은 80% 이상을 달성하였다. 한편, 인산염 40 mM, NaCl 100 mM, NH₄Cl 40 mM, EDTA 50 μm 주입 시 각각 1.30, 0.67, 0.74, 1.30 mmol의 메탄이 산화되는 동시에 각각 0.71, 0.60, 0.66, 0.66 mmol의 메탄올이 최대로 생성되었다. 이때의 메탄올 전환율은 각각 54.7, 89.9, 89.6 및 47.8%였으며 최대 메탄올 생성 속도는 7.4 μmol/mg·h였다. 이로부터 대상 저해제로 MDH 활성도를 일반적으로 35% 저해 시에메탄올 생산량이 최대인 89.9%까지 나타남을 알 수 있었다. This study was conducted to biologically convert methane into methanol. Methane contained in biogas was bio-catalytically oxidized by methane monooxygenase (MMO) of methanotrophs, while methanol conversion was observed by inhibiting methanol dehydrogenase (MDH) using MDH activity inhibitors such as phosphate, NaCl, NH₄Cl, and EDTA. The degree of methane oxidation by methanotrophs was the most highly accomplished as 0.56 mmol for the condition at 35℃ and pH 7 under 0.4 (v/v%) of biogas (CH₄ 50%, CO₂ 50%) / Air ratio. By the inhibition of 40 mM of phosphate, 50 mM of NaCl, 40 mM of NH₄Cl and 150 μm of EDTA, methane oxidation rate could achieve more than 80% regardless of type of inhibitors. In the meantime, addition of 40 mM of phosphate, 100 mM of NaCl, 40 mM of NH₄Cl and 50 μm of EDTA each led to generating the highest amount of methanol, i.e, 0.71, 0.60, 0.66, and 0.66 mmol when 1.3, 0.67, 0.74, and 1.3 mmol of methane was each concurrently consumed. At that time, methanol conversion rate was 54.7, 89.9, 89.6, and 47.8% respectively, and maximum methanol production rate was 7.4 μmol/mg·h. From this, it was decided that the methanol production could be maximized as 89.9% when MDH activity was specifically inhibited into the typical level of 35% for the inhibitor of concern.

전기장과 초음파를 이용한 하수슬러지의 가용화 특성 연구

서장원(Jang Won Seo),한지선(Ji Sun Han),안창민(Chang Min Ahn),민동희(Dong Hee Min),유연선(Yeon Sun Yoo),윤순욱(Soon Uk Yoon),이종규(Jong Gyu Lee),이종연(Jong Yeon Lee),김창균(Chang Gyun Kim) 大韓環境工學會 2011 대한환경공학회지 Vol.33 No.9

초음파를 사용한 슬러지 가용화는 슬러지 부피 감소 및 혐기성 바이오가스 생산시의 소화효율 강화를 위해 그 이용이 증가하고 있다. 본 연구에서는 세 종류의 슬러지(G 하수처리장의 반송슬러지, 잉여슬러지와 혼합슬러지)를 대상으로 가장 효율적인 가용화를 위해 전기장단독처리와 초음파단독처리 및 전기장-초음파 복합처리를 연구하였다. 폐쇄된 회로로서, 평균 0.7 m3/h의 유량으로 200 L의 슬러지(이는 1시간당 3.5회 처리에 해당)를 24시간 동안 84회까지 연속적으로 가용화 공정을 통과시켰다. 전기장만 단독으로 적용하였을 때의 경우 슬러지 종류와 관계없이, 처리 전과 후에 어떤 sCOD/tCOD 변화도 발생하지 않았다. 그러나 초음파 단독 또는 복합된 공정을 이용한 경우 통과횟수에 따라 두 방법 모두 슬러지 가용화율이 증가하였고 복합된 경우 더 크게 증가하였다. 또한, 입자의 직경(0.9)과 직경(0.5)이 원 슬러지보다 감소하는 동시에 VSS/TSS는 2~6% 범위까지 감소 하였다. 잉여슬러지와 혼합슬러지에는 전기장 및 초음파 복합처리가 더 적합했던 것에 비해 반송슬러지는 초음파 처리가 더 가용화를 효과적으로 촉진하였다. 가장 효율적인 슬러지 파괴를 위해서는 슬러지 종류에 따라 가용화 공정이 선택적으로 적용되어져야 할 것으로 판단할 수 있었다. Sludge solubilization using sonification has been increasingly used for sludge volume reduction along with enhancing digestion efficiency during anaerobic biogas production. In this study, either electric field or ultrasonification or in combination with were investigated using three types of sludge (return, excess and mixed at G sewage treatment facility) for the most efficient solubilization. As a the closed loop, 200 L of sludge was continuously passing through the solubilization system at an average flow rate of 0.7 m3/h, which is equivalent to 3.5 times treated per hour for up to 84 times (24 h). Only implying electric field showed no variation for sCOD/tCOD before and after treatment on sludge solubilization regardless of types of sludge. However, employing the ultrasonic or combined system could both increasingly solubilize sludge with regard to the number of passing-through, which more enhanced by the combined. In addition, VSS/TSS was lowered to in the range of 2 and 6% while its particle size, diameter (0.9) and diameter (0.5) were more minimized than that of raw sludge. For return sludge, ultrasonification was more efficiently facilitated for solubilization, whereas electric field-ultrasonification was more preferably applied for excess and mixed sludge. It is concluded that depending on types of sludge, solubilization system must be selectively applied for the most efficient break-up of them.