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박지호 ( Ji-ho Park ),김원일 ( Won-ii Kim ) 한국산업융합학회 2005 한국산업융합학회 논문집 Vol.8 No.1
Titanium specially has high specific strength, excellent mechanical properties as fatigue strength and fracture ductility, good corrosion resistance, and therefore are broadly applied to the various fields. It is required the development for the skills of wire-cut electrical discharge machining(WEDM), but the WEDMed surface was found to be worst due to the attached components of wire. Therefore precision maching method like lapping is necessary for getting high quilty surface. Roughness of lapped surface, surface hardness to each process depth and improved method of surface shape were stuided experimentally, by changing of grain size of diamond lap material and lapping pressure with constant speed in lapping process.
고우리 ( Woo Ri Go ),김지영 ( Ji Young Kim ),류지혁 ( Ji Hyock Yoo ),이지호 ( Ji Ho Lee ),( Anitha Kunhikrishnan ),이정미 ( Jeong Mi Lee ),김계훈 ( Kye Hoon Kim ),김두호 ( Doo Ho Kim ),김원일 ( Won Ii Kim ) 한국환경농학회 2012 한국환경농학회지 Vol.31 No.3
본 연구에서는 돈분액비를 연용한 논토양 및 밭토양의 유해 중금속을 관리하는 방안을 마련하고자 전국적으로 액비를 장기 시용한 연차별 논토양 41점과 밭토양 54점을 채취하여 유해 중금속인 카드뮴, 구리, 니켈, 납, 아연, 비소의 함량을 조사하였다. 액비연용에 따른 년차별 변화에서 논토양 및 밭토양 중금속 전함량은 원소별로 일부 증가하는 경향은 보이나 연도별 축적 차이를 통계적으로 확인할 수 없었다. 그러나 액비연용에 따른 중금속 특히 구리 및 아연의 축적 여부는 이들이 식물영양에 필수 원소로 작용함을 고려하여 보다 장기적인 관점으로 계속 검토되어야 할 사항이다. 그러나 일부 밭토양에서 토양오염 우려기준을 초과하는 지점이 조사되어 액비 시용 전 토양 내 중금속 함량조사를 통해 시용 여부를 결정하여야 할 것이다. BACKGROUND: Increase of heavy metals in agricultural ecosystem has become a social issue nationwide as it is related to public health. This study was performed to find out the status and long-term trends with consecutive application with the commercial liquid pig manure in the agricultural fields. METHODS AND RESULTS: Heavy metals including arsenic, cadmium, copper, lead, nickel, and zinc were analyzed in the 41 samples of paddy fields and 54 samples of upland fields consecutively applied with commercial liquid pig manure for 0 to 16 years, Heavy metal accumulation were not increased statistically at the both paddy and upland fields as the consecutive application year of commercial liquid pig manure were increased. However, some of surveyed upland soils exceeded the criteria of cadmium, copper, and zinc designated by the Soil Environmental Conservation Act in Korea, CONCLUSION: Therefore, analysis of heavy metals, specially copper and zinc, in agricultural fields is absolutely necessary before liquid pig manure application to the fields, In addition, heavy metal accumulation in agricultural fields following to the long-term application of liquid pig manure will be monitored periodically considering with bioavailability of copper and zinc to the crops as an essential nutrients.
정구복 ( Goo Bok Jung ),권순익 ( Soon Ik Kwon ),홍성창 ( Sung Chang Hong ),김민경 ( Min Kyeong Kim ),채미진 ( Mi Jin Chae ),김원일 ( Won Ii Kim ),이종식 ( Jong Sik Lee ),강기경 ( Kee Kyung Kang ) 한국환경농학회 2012 한국환경농학회지 Vol.31 No.2
폐금속 광산에서 유출되는 광산배수로 인한 하류 수계의 환경오염 영향을 검토하기 위하여 삼보광산 하류 수계 내 하천수질, 퇴적토양 및 인근 논토양에 대한 중금속 오염도를 평가한 결과는 다음과 같다. 삼보광산 주변 광미댐 침출수의 Cd 평균 농도(0.018∼0.035 mg/L)는 우리나라 농업용수 수질기준(0.01 mg/L)을 초과하였고, 미량성분 중 Zn, Fe 및 Mn 함량도 FAO의 관개용수 최대 권고치(Zn 2.0, Fe 5.0, Mn0.2 mg/L)를 초과하였다. 광산 하류 논토양의 Pb, Zn 평균함량은 우리나라 농경지의 토양오염 우려기준(Pb200, Zn 300 mg/kg)을 초과하였고, 중금속 오염지수 평균치는 상리가 1.2로 내리지역 0.45보다 높게 나타났다. 광산 하류 수계 내 퇴적토의 Cd, Pb 및 Zn 함량은 우리나라 하천용지의 토양오염 우려기준 (Cd10, Pb400, Zn 600 mg/kg)을 초과하였다. 또한 퇴적토의 중금속 오염지수(PI)는 상리지역 0.98∼7.32, 내리지역 0.34∼5.27로 지점별 편차가 컸으며, 하류 1km 지점 합류지점(SN-1, SN-2)까지 오염된 것으로 나타났다. 퇴적토의 부화계수(EFc) 평균치는 Cd>Pb>Zn>As>Cu>Cr>Ni 순으로 지점간의 편차가 큰 것으로 나타났다. 퇴적토의 중금속별 지화학적농축계수(Igeo)는 지점별로 약간의 차이는 있으나 Zn>Cd>Pb>Cu>As>Cr>Ni 순으로 높았으며, 특히 Zn의 경우광산 침출수 영향을 받은 퇴적토에서 경보오염에서 위험오염 (Igeo3.1∼6.2) 상태로 심하게 오염된 것으로 나타났다. 결과적으로 삼보광산 하류 하천수질 및 퇴적토의 오염도 평가를 종합해 볼 때 광산 침출수의 영향이 하류 수계 1 km 이상 (SN-1, SN-2)까지 미치는 것을 확인할 수 있었다. BACKGROUND: Mine drainage from metal mining districts is a well-recognized source of environmental contamination. Oxidation of metal sulfides in mines, mine dumps and tailing impoundments produces acidic, metal-rich waters that can contaminate the local surface water and soil. METHODS AND RESULTS: This experiment was carried out to investigate the pollution assessment of heavy metal on the water quality of mine drainage, paddy soils and sediment in lower watershed affected by mine drainage of the Sambo mine. The average concentrations of dissolved Cd (0.018∼0.035 mg/L) in mine drainage discharged from the main waste rock dumps(WRD) was higher than the water quality standards (0.01 mg/L) for agricultural water in Korea. Also, the average concentrations of dissolved Zn, Fe and Mn were higher than those of recommended maximum concentrations (Zn 2.0, Fe 5.0, Mn0.2 mg/L) of trace metal in irrigation water proposed by FAO (1994). The average contents of Pb and Zn in paddy soils was higher than those of standard level for soil contamination (Pb200, Zn 300 mg/kg) in agricultural soil by Soil Environmental Conservation Act in Korea. Also, the concentrations of Cd, Pb and Zn in sediment were higher than those of standard level for soil contamination (Cd10, Pb400, Zn 600 mg/L) in waterway soil by Soil Environmental Conservation Act in Korea. The enrichment factor (EFc) of heavy metals in stream sediments were in the order as Cd>Pb>Zn>As>Cu>Cr>Ni. Also, the geoaccumulation index (Igeo) of heavy metals in stream sediments were in the order as Zn>Cd>Pb>Cu>As>Cr>Ni, specially, the geoaccumulation index (Igeo) of Zn (Igeo3.1∼6.2) were relatively higher than that of other metals in sediment. CONCLUSION(s): The results indicate that stream water and sediment were affected by mine drainage discharged from the Sambo mine at least to a distance of 1 km downstream (SN-1, SN-2) of the mine water discharge point.