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중금속(重金屬) 오염토양(汚染土壤)의 구산(枸酸) 침출(浸出)에 대한 pH의 영향(影響)
정경배,박홍기,류경근,박제현,최의규,Jung, Kyungbae,Park, Hongki,Yoo, Kyoungkeun,Park, Jay Hyun,Choi, Ui Kyu 한국자원리싸이클링학회 2013 資源 리싸이클링 Vol.22 No.5
구리, 아연 및 납 등의 중금속으로 오염된 사격장 토양으로부터 중금속 성분을 제거하기 위한 친환경적인 공정을 개발하기 위해 구연산용액을 이용하여 중금속 침출거동에 대한 pH의 영향을 조사하였다. 구연산 침출실험은 구연산과 구연산나트륨을 혼합하여 pH를 조절한 용액을 이용하여 시료입도 $75{\mu}m$이하, 반응온도 $50^{\circ}C$, 구연산 농도 1 몰, 광액농도 5%, 교반속도 100 rpm, 그리고 침출시간 1 시간의 조건에서 진행하였다. 침출반응 전후의 pH 변화는 미미하여 침출에 미치는 수소이온농도의 직접적인 영향은 크지 않은 것으로 판단되었다. 구리, 아연, 납의 제거율은 pH가 증가함에 따라 감소하였고, 열역학적인 계산결과, 이와 같은 침출거동은 중금속 이온이 구연산염 이온종과 착이온을 형성하는 반응과 중금속이온이 수산화이온과 결합하여 수산화물로 침전하는 반응에 의해 결정되는 것으로 분석되었다. The effect of pH on the citrate leaching behavior of heavy metal ion was investigated to develop an eco-friendly process for removing heavy metals from soil contaminated with copper, zinc, and lead. The leaching tests were performed using citrate solution with pH adjusted by mixing citric acid and sodium citrate under the following leaching conditions: particle size, under $75{\mu}m$; temperature, $50^{\circ}C$; citrate concentration, $1kmol/m^3$; pulp density, 5%; shaking speed, 100 rpm; leaching time, 1 hour. The difference of pH before and after the leaching test was not observed, and this result indicates the direct effect of hydrogen ion concentration on the leaching of metals was insignificant. The removal ratios of copper, zinc, and lead from the contaminated soil decreased with increasing pH. The thermodynamic calculation suggests that the leaching behaviors of metal ions were determined by two reactions; one is the reaction to form complex ions between heavy metal ions and citrate ion species, and the other is the reaction to form metal hydroxide between heavy metal ions and hydroxide ion.
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연속추출법을 이용한 사격장 오염토양 중 중금속의 화학적 형태 결정
문경혜,박홍기,유경근,김주엽,Moon, Gyeonghye,Park, Hongki,Yoo, Kyoungkeun,Manis Kumar, Jha,Richad Diaz, Alorro,Kim, Ju Yup 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.6
The soil sample obtained from shooting area contaminated with Pb, Cu, and Zn was investigated to determine the chemical forms of heavy metals with Tessier’s sequential extraction method, which is constituted of five fractions such as ‘exchangeable’, ‘bound to carbonate’, ‘bound to oxide’, ‘bound to organic matter’, and residual fractions. The amount of organic matter was measured by loss on ignition (LOI) and then the results of ‘bound to organic matter’ and LOI were compared. The sequential extraction results show that 4.7%-45% of Pb, 6.2%-25.9% of Cu and 3.9%-15.3% of Zn belong to the ‘bound to organic matter’ fraction, but LOI result shows that only 1.0%-2.8% of organic matter exists in the soil sample. In heavy medium separation tests, because Pb and Cu extracted in ‘bound to organic matter’ and residual fractions were removed, the heavy metals in the fractions would exist as heavier forms. These results suggest that the part of heavy metal extracted in ‘bound to organic matter’ fraction would result from the oxidation of metallic forms by hydrogen peroxide and nitric acid used in the fraction, and, consequently, that the ‘bound to organic matter’ fraction should be investigated in detail to determine the removal method and treatment capacity when the Tessier’s sequential extraction method is used to examine heavy metal contaminants resulted from elemental metal like bullets.
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문도현(Dohyun Moon),박홍기(Hongki Park),최은석(Eunseok Choi),김동구(Dong Goo Kim),김민정(Minjung Kim) 대한정형외과학회 2008 대한정형외과학회지 Vol.43 No.6
목적: 통증을 수반하는 성인의 후천성 편평족의 흔한 원인 질환인 후경골건 기능 장애는 동양인에서는 드문 질환으로 알려져 있다. 저자는 12예의 치료 경험이 있어 임상적 경험을 보고하고자 한다. 대상 및 방법: 2000년 3월부터 2007년 1월까지 후경골건 기능 장애로 진단된 12예의 임상 소견과 치료 결과를 분석하였으며 평균 추시기간은 32개월이다. 결과: 12예 중 8예가 여성, 평균 나이는 45세였으며, 체질량지수 분류상 과체중이 5예, 비만이 5예 있었다. 4예에서 과거 외상력이 있으며 4예는 기존의 유연성 편평족에서 진행하였다. 치료는 Johnson과 Strom의 임상단계에 따라 Ⅰ의 3예에서 건초 절제술을 시행하였고, 임상단계 Ⅱ에서는 장지굴근건 이행술, 종골 내측 전위 절골술을 시행하였고, 임상단계 Ⅰ, Ⅲ, Ⅳ의 각 1예에서 보존적 치료를 시행하였다. 술전 미국정형외과족부족관절학회의 후족부-족관절 수치는 평균 58점, 수술 후 90점이었으며, 보존적 치료군에서 최초 평균 38점에서 추시상 평균 57점으로 증가한 소견을 보였다. 결론: 한국에서도 통증을 수반하는 성인의 후천성 편평족의 감별진단에서 후경골건의 기능 장애를 고려해야 하고, 조기진단과 임상 평가에 의한 적절한 치료가 필요할 것으로 사료된다. Purpose: Posterior tibialis tendon dysfunction (PTTD) is one of the most common causes of acquired flatfoot deformity in western countries. But it was known that they were very rare in eastern countries. So we want to report the clinical features and outcomes of 12 patients with PTTD. Materials and Methods: We evaluated the results of 12 patients using clinical features and results from March 2000 to January 2007 and mean follow up periods is 32 months. Results: Average age was 45 years, 8 of 12 patients were female, 2 patient with hypertension and 1 with rheumatoid arthritis. 5 patients were overweighted and 5 patients were obese. 4 patients has a history of last trauma. 4 patients experienced progression of flatfoot. On behalf of Johnson and Strom classifications 6 cases were grade Ⅰ, 4 cases were grade Ⅱ, grade Ⅲ, and grade Ⅳ was 1 case, relatively. As a treatment we used tenosynovectomy for 3 cases of grade 1, additional FDL transfer was done for 2 cases of grade Ⅰ and 2 cases of grade Ⅱ. For other 2 patients of grade Ⅱ flexor digitorum longus transfer and Medial displacement calcaneal osteotomy was done. Pathologic findings of tendon showed degenerative tendinitis. Lastly conservative treatment group was 3 cases of grade Ⅰ, Ⅲ, Ⅳ each. Average preoperative and postoperative American Orthopedic Foot and Ankle Society's hindfoot/ankle scoreFAS score was 58 and 90. Initial and follow up AOFAS scores of the conservative group was 38 and 57, relatively. Conclusion: As a cause of acquired flatfoot in adult, PTTD is not a rare disease any more in Korea. To prevent the disability and progression of flatfoot, careful clinical evaluation and proper treatment is important.
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