염산을 사용한 납 오염 토양의 토양 세척에 의한 정화

백기태,김도형,서창일,양중석,이재영,Baek, Ki-Tae,Kim, Do-Hyung,Seo, Chang-Il,Yang, Jung-Seok,Lee, Jae-Young 한국지하수토양환경학회 2007 지하수토양환경 Vol.12 No.3

납으로 오염된 실제 토양을 처리하기 위해 토양세척기술의 적용성을 평가하였다. 세척제로는 염산을 사용하였으며, 0.2 M 염산을 사용하여 고액비 1:3으로 하여 10분간 접촉하여 2회 세척하여준 결과 96%의 제거율을 보였다. 세척액과 토양의 접촉시간을 5분에서 120분까지 증가하였을 때, 제거효율은 69.3%에서 81.9%로 증가하였다. 입경별 토양세척 효율은 온도와 교반시간에 영향을 받았으며, 20분 이상 교반하여 준다면, 0.075 mm 이하, 0.075 mm-2.0 mm, 2.0-4.0 mm 의 입경별 토양에서는 모두 99%의 제거효율을 보였다. 이상의 결과는 본 연구에 사용된 납 오염 토양은 토양세척기술을 적용하여 효과적으로 처리할 수 있는 것을 의미한다. The feasibility of soil washing was investigated to remediate Pb-contaminated field soil. Hydrochloric acid was used as a washing agent. As mixing time increased from 5 min to 120 min, removal efficiency of Pb from contaminated soil increased from 69.3% to 81.9%. Two times washing with 0.2 M HCl showed 96% removal efficiency even at mixing time of 10 min. The Pb content in soil increased sharply as particle size of soil decreased, and removal efficiency was highly dependent on mixing time and temperature. Based on this result, acid washing technologies can be applied to remediate the Pb-contaminated soil used in this study.

투자 주체별 거래행태의 특징이 주식시장 수익률에 미치는 영향

백기태(Ki Tae Baek),민병길(Byoung kil Min),백지원(Ji Won Baek) 충남대학교 경영경제연구소 2021 경영경제연구 Vol.43 No.1

본 연구에서는 시장미시구조 이론 관점에서 국내 주식시장의 투자집단별 투자성과 차이의 원인을 분석한다. 개별 투자자들이 주가 수익률에 미치는 영향과 각 투자집단의 거래행위와의 관계에 대한 비교분석을 통해 투자집단별 성과의 차이를 살펴보기 위하여, 단일계좌 거래량 상위종목들에 대한 사건연구(Event study)와 고정효과 모형(Fixed effect model)의 추정방법을 사용하였다. 정보기반거래확률 모형을 고려하여 해당 사건을 일으킨 투자자를 정보기반거래자로 가정하였고 반대 거래자를 노이즈 트레이더로 보았는데, 사건연구 결과 개별 투자자 단위의 정보기반거래자는 개인과 기타법인에서 활발하였다. 그러나 투자자 집단의 순매수 금액을 분석한 결과 개인 투자자 집단은 대부분의 매수·매도사건에서 평균적으로 사건을 주도한 정보기반 거래자와 반대방향의 거래를 하는 것으로 나타났다. 또한 고정효과모형을 통해 이러한 거래패턴의 차이가 각 투자자 집단의 투자성과에도 통계적으로 유의미한 차이를 발생시킴을 확인하였다. 본 연구의 결과는, 일부 개인 투자자도 정보기반거래자가 될 수 있으나, 그보다 훨씬 더 많은 개인 투자자들이 노이즈 트레이더가 되고 있음을 보여주며, 이러한 거래 패턴 차이가 투자자 집단별 투자성과 차이, 특히 개인 투자자 집단의 투자성과가 저조한 원인으로 판단된다. Market microstructure explains short-term stock price movements related with the trading activities of strategic investors, trading volume, pending orders, market orders, etc., is useful for explaining the recent stock market, where algorithmic trading and high-frequency trading are gradually increasing. The purpose of this study is to analyze the causes of differences in investment performance in the domestic stock market by investor groups from the perspective of market microstructure theory. To do this, I analyzed the stocks with a large volume of transactions in a single account using Event Study and Fixed Effects Models. From the perspective of market microstructure theory, I assumed the trader who led the event is an information-based trader, and the counter trader is a noise trader. In the event study, I found out that some individual and other corporate investors led the event most actively in a single investor unit. And the impact of each event on CAAR did not differ significantly depending on the group classification the investor belongs to. However, in terms of the investor group, mainly the individual investor group trades a lot against the investors who led the event. Even if a single individual investor made a large sale, the net buying amount of the individual investor group increased. Finally, it was confirmed that this trend was statistically significant by a fixed effect model. In conclusion, some individual investors may become information-based traders, but far more individual investors become noise traders, which is only found in groups of individual investors. This is one of the main causes of the difference in investment performance by investor groups.

Cu, Pb, As 복합 중금속오염 토양의 전기동력학적 정화에서 전해질의 영향 평가

박근용,김도형,백기태,Park, Geun-Yong,Kim, Do-Hyung,Baek, Ki-Tae 한국지하수토양환경학회 2010 지하수토양환경 Vol.15 No.5

Electrokinetic technology was applied to remediate Cu, Pb and As-contaminated paddy soil. Removal of metal is highly dependent on the processing fluid during electrokinetic treatment. Tap water, NaOH, $HNO_3$, $Na_2EDTA$, and citric acid were evaluated as the processing fluids to enhance metal removal. Cu and Pb were transported toward cathode, however, it did not removed from soil section, while 56.6% of As was removed at a acidic condition. The strong acidic condition with nitric acid as a processing fluid enhanced the desoprtion of As from soil surface. However, longer operation time is needed to get the higher removal of Cu and Pb, and the acidification of soil after electrokinetic treatment should be solved.

토양세정 기술을 활용한 윤활유와 아연 복합오염 철도토양의 정화 연구

박성우,조정민,이재영,박준규,백기태,Park, Sung-Woo,Cho, Jung-Min,Lee, Jae-Young,Park, Joon-Kyu,Baek, Ki-Tae 한국지하수토양환경학회 2011 지하수토양환경 Vol.16 No.4

The feasibility study of soil flushing was investigated to remediate lubricant oil and zinc contaminated railway soil. In this study, mixed washing agents of surfactant and inorganic acid/base were used for the simultaneous removal. The mixed washing agent of non-ionic surfactant and HCl removed 15% of the lubricant oil and 40% of zinc, respectively. Alkaline-enhanced soil washing process increased the removal of lubricant oil up to 40%. This is because alkaline solution reduced the interfacial tension between water phase and lubricant oil phase due to the soap formation reaction. To simulate in-situ soil flushing for the remediation of railroad-related contamination, two dimensional soil flushing was carried out based on the results of batch soil washing. In the soil flushing, the removal efficiencies of lubricant oil and zinc were 34% and 16%, respectively. Even though the removal efficiency was low, the mixed washing agent can remove metal and lubricant oil simultaneously.

Zn와 Ni로 오염된 토양의 산을 이용한 전처리 및 산순환 동전기 정화의 타당성 연구

박성우,조정민,류병곤,김경조,백기태,양중석,Park, Sung-Woo,Cho, Jung-Min,Ryu, Byung-Gon,Kim, Kyung-Jo,Baek, Ki-Tae,Yang, Jung-Seok 한국지하수토양환경학회 2008 지하수토양환경 Vol.13 No.6

산순환 동전기적 정화기술의 아연과 니켈로 오염된 토양의 정화 타당성을 조사하였다. 1M HCl을 활용한 토양세척에서 아연과 니켈의 제거율은 각각 24%와 9%였으며, 산세척은 이 토양을 정화하기에 적합하지 않았다. 일반적인 동전기 정화 방법으로 28일 동안 운전한 결과, 아연과 니켈의 제거율은 산세척보다도 낮았다. 강산으로 음극을 순환시켜주어 토양 전체의 pH를 산성으로 조절한 실험에서 아연과 니켈의 제거는 비약적으로 증가하였다. 또한 강산으로 전처리한 토양에서는 그 제거율이 보다 많이 증가하였다. 이러한 실험결과를 근거로 볼 때 산순환 동전기 정화는 아연과 니켈로 오염된 토양을 정화하는데 매우 효과적인 것으로 판단된다. The feasibility of acid-enhanced electrokinetic remediation on zinc and nickel-contaminated soil was investigated in the laboratory. Simple extraction efficiency using 1M HCl was 24% for Zn and 9% for Ni, as a result, the acid washing is not effective to remove Zn and Ni from the soil. The effiencey of normal electrokinetic treatment during 28 days was less than simple soil washing. Catholyte circulation with a strong acid enhanced dramatically the removal of Zn and Ni and pretreatment of soil with acid increased more the removal. Based on the result, acid-enhanced electrokinetic remediation is effective to remove Zn and Ni from the contaminated soil.

염류집적 농경지 제염기술에 대한 경제성분석 - 작물생산량을 기준으로

김도형,최정희,김이열,남창모,백기태,Kim, Do-Hyung,Choi, Jeong-Hee,Kim, Lee-Yul,Nam, Chang-Mo,Baek, Ki-Tae 한국지하수토양환경학회 2012 지하수토양환경 Vol.17 No.5

In this study, economic analysis of five desalination technologies for saline agricultural land was carried out. The analysis was comprehensively evaluated by calculating changes in crop production and benefit/cost (B/C) ratio. The analysis of crop production was in the order of tomato > cucumber > a (musk) melon > watermelon > cabbage, and economical efficiency for desalination technology was in the order of soil exchange > soil addition > electrokinetics > under-drainage > subsoil reversal. In cost benefit analysis, B/C ratio was in the order of under-drainage > soil exchange > electrokinetics > soil addition > subsoil reversal, and all desalination technologies used in this study have the ratio higher than 1, which means economical efficiency was high. Based on the net production considering B/C ratio, the general economic analysis was exactly order from that of crop production analysis. As a result, economical efficiency of soil exchange was highest, and economical efficiency of soil addition and electrokinetic was relatively higher than others.

골프장의 잔디 토양에서 인산 비료의 이동성 평가를 위한 정보 구축

정근욱(Keun-Yook Chung),백기태(Ki-Tae Baek),고성환(Seong-Hwan Ko),노재관(Jae-Goan Noh),이경호(Kyung-Ho Lee),우선희(Sun-Hee Woo) 한국콘텐츠학회 2008 한국콘텐츠학회논문지 Vol.8 No.8

일반적으로, 골프장의 퍼팅그린(putting green)지역에서 사용되는 토양은 매우 낮은 CEC(양이온치환용량)와 알루미늄 및 철 수산화물의 코팅이 없는 모래로 이루어진 근권 혼합물로 구성되었다. 이러한 성질로 인해서, 토양에 의한 인산(Phosphorus, P)의 보유는 극히 제한될 수 밖에 없다. 새로운 상업용 인산비료는 골프장의 그린지역에서 적절한 인산의 유지에 도움을 줄 수 있다. 본 연구에서는 잔디 품종 Floradwarf bermudagrass (Cynodon dactylon L. PERS.)을 유리온실에서 재배하면서 상업용 인산비료의 이동성과 영양분 공급력을 평가하였다. 전체 12주의 실험기간 동안 격주로 인산의 농도를 측정하기 위해 절단된 잔디와 용출액(leachate)이 수집되었다. 깎여진 잔디는 48시간 동안 70oC에서 건조되었고 건물중량(dry matter)측정이 이루어졌다. 인산의 용출에 있어서 MKP(monopotassium phosphate)와 APP(ammonium polyphosphate)가 가장 많은 양의 인산을 용출시켰고 MAP(monoammonium phosphate)와 0-20-20(액체)이 그 다음으로 많은 양의 인산을 용출 시켰고, CSP(concentrated superphosphate)가 가장 적은 양의 인산을 용출 시켰다. 전체 12주 동안 용출된 인산의 양을 시간별로 분석해 본 결과에 따르면, 2주와 4주 동안 수집된 용출액속에 시비된 인산의 대부분이 용출되었다. 나머지 6주, 8주, 10주, 12주 동안에 용출된 인산의 양은 미미하였다. 용출된 인산의 양은 건조물이나 영양분 흡수와는 상관 관계가 없었다. 전체 인산의 회수율은 43%에서 93%의 범위에 있었다. 인산 비료의 본래의 용해성으로 인해, 인산 비료간의 흡수, 총 건물중량 및 용출에 있어서 차이점이 존재하는 것 같다. 그러므로, 라이시미터(lysimeter) 실험결과에 따르면 CSP, 0-20-20, 그리고 MAP가 골프장의 퍼팅 그린 지역에 사용될 수 있는 환경친화적인 인산 비료로 사료된다. This study was initiated to evaluate the Phosphorus(P) leaching potential in the putting green soils and P uptake by the turfgrass in the golf course using the P fertilizers. The turfgrass, Floradwarf bermudagrass(Cynodon dactylon L. PERS.) was planted and grown in the mixture of sand and peat moss in this lysimeter study. Five representative P fertilizers, such as, ammonium polyphosphate (APP), monopotassium phosphate (MKP), MAP(monoammonium phosphate), 0-20-20(liquid), and concentrated superphosphate(CSP, solid) were used in this study. Based on the total P quantity of leachate collected during the whole 12 weeks, MKP and APP are the first group of P fertilizers contributing to the leaching of P, then MAP and 0-20-20 are the second group of P fertilizers causing the P leaching. Finally, CSP is the third group of P fertilizer resulting in the P leaching. However, most of P applied and collected in the lysimeter were leached during the first period of two and four weeks, compared to that of P leached during the second period of six, eight, ten, and twelve weeks. Applications of MAP, APP and CSP, MKP and 0-20-20 in order produced the largest amount of total dry matter. However, APP, MKP and MAP, CSP and 0-20-20 in order showed the largest amount of P uptake. Therefore, based on the data of P leaching, dry matter production, and plant P uptake, it appears that CSP, 0-20-20, and MAP are the environmentally sound fertilizers recommended in the turfgrass putting green soil of golf course.

염류집적 농경지의 전기동력학적 정화

조성웅,김도형,양중석,정근욱,백기태,Jo, Sung-Ung,Kim, Do-Hyung,Yang, Jung-Seok,Chung, Keun-Yook,Baek, Ki-Tae 한국지하수토양환경학회 2012 지하수토양환경 Vol.17 No.4

The influence of operation time on electrokinetic restoration was investigated to remove salts from sulfate-accumulated greenhouse soil. Operation time is directly related to the process cost, therefore, we determined the relationship between operation time and removal of salts. Nitrate and sodium were removed almost completely within 2 weeks, chloride and calcium was removed in proportion to the operation time. Sulfate was accumulated at the center of anode and cathode. The soil electrical conductivity (EC), an indicator for soil salinity, showed similar shape with the residual sulfate after electrokinetic treatment. The soil EC was not changed after 2 weeks, however, the energy consumption increased with operation time. Based on the experimental results, most salts except sulfate were removed within 2 weeks, but sulfate was not removed during same time period. For the further removal of sulfate, longer operation time is in need.

질산염 및 황산염 집적 염류 토양의 전기역학적 개량

조정민,조성웅,김도형,양중석,백기태,Cho, Jung-Min,Jo, Sung-Ung,Kim, Do-Hyung,Yang, Jung-Seok,Baek, Ki-Tae 한국지하수토양환경학회 2011 지하수토양환경 Vol.16 No.5

The electrokinetic transport characteristics of salts were investigated using nitrate and sulfate accumulated saline greenhouse soil. Within 8 days, 95% of nitrate was removed from the soil, while sulfate removal was 19% for 8 days. The low removal of sulfate came from adsorption reaction on the soil particles or organic matter and precipitation with calcium. Divalent cations such as calcium and magnesium were transported toward cathode via electromigration, and most monovalent cation such as potassium was removed. The pattern of residual electrical conductivity was similar with that of sulfate. Based on the results, electrokinetic technique is effective to restore nitrate-accumulated saline soil, but is not effective to restore sulfate-accumulated soil.

윤활유 유래 철도 오염토양의 정화방법 연구

박성우,신민철,전칠성,백기태,이재영,Park, Sung-Woo,Shin, Min-Chul,Jeon, Chil-Sung,Baek, Ki-Tae,Lee, Jae-Young 한국지하수토양환경학회 2008 지하수토양환경 Vol.13 No.2

본 연구에서는 철도 윤활유 유래 오염토양을 정화하기 위해 토양세척방법, 화학적 산화법, 초음파 추출법의 타당성을 연구하였다. 세척제로는 tergitol이 사용되었으며, 세척실험은 보조용매인 iso-propyl alcohol을 사용하여 진행되었다. Tergitol이 디젤오염토양의 세척에는 효과적인 것으로 알려져 있으나, 윤활유 오염토양의 세척에는 효과적이지 못했다. iso-propyl alcohol을 보조용매로 사용한 경우 계면활성제의 토양 흡착을 증가시켜 오히려 세척효율이 감소하였다. 화학적 산화방법은 윤활유의 약 30% 정도만 제거할 수 있었다. 화학적 산화처리후 계면활성제에 의한 토양세척을 통해 약 16-17%의 추가적인 윤활유의 세척효과를 얻을 수 있었다. 초음파는 토양세척의 효과를 증가시키는 것으로 나타났다. 따라서 TPH 오염 철도 토양의 오염원에 따라 다른 방법을 적용하야 한다. In this study, the feasibility of soil washing, chemical oxidation and sonication was investigated to treat lubricantcontaminated railroad soil. Tergitol, a non-ionic surfactant, was used as a washing agent with or without iso-propyl acohol as a cosolvent. However, it was not effective to remove lubricant from soil even though tergitol was the most effective washing agent for diesel-contaminated soil. The cosolvent reduced the overall washing efficiency. Chemical oxidation removed 30% of lubricant from contaminated soil. Soil washing after chemical oxidation extracted additionally 16-17% of lubricant. Sonication enhanced-soil washing showed enhanced overall efficiency of soil washing. Lubricant-contaminated soil should be remediated by the other technology used for diesel-contaminated soil.