http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Zahra Derakhshan (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
-
Zahra Derakhshan Nejad,김정욱,정명채 한국지질과학협의회 2017 Geosciences Journal Vol.21 No.3
Arsenic (As) is a known carcinogen and is one of the most commonly reported contaminants in farmland soils around mining sites. This study aimed to investigate four different soil amendments (rice husk biochar (RHB), maple leaf biochar (MLB), red mud (R.M), and steel slag (S.S)) with respect to the stabilization of arsenic in soil combined with revegetation of two hyperaccumulators (Asteraceae (lettuce) and Brassicaceae (mustard green)). Soil amendments at different application rates (0.5%, 1%, and 2% w/w) and small particle sizes (<74 μm) were added to the soil. A different pattern was observed for stabilization of As in treated soils. A meaningful decline in As stabilization was observed with increasing application dosage of MLB, R.M, and S.S, while in case of RHB efficiency was increased. Generally, maximum stabilization efficiency of As was observed following the adding of RHB (2%), MLB (0.5%), R.M (0.5%), and S.S (0.5%), by 90%, 94%, 94%, and 89%, respectively, which was primarily attributed to amendmentsinduced specific surface area within the structure. For lettuce, As was strongly accumulated by leaves, while As, for mustard green, was extracted much more by its roots. Sequential extraction analysis confirmed high proportions of Fe and Mn oxides and organic fractions of As, before and after planting. Altogether, the establishment of a suitable plant cover on treated soil with amendments showed encouraging results for preventing the dispersion of As through runoff and percolation. Besides, this combined technique, which is aesthetically pleasant, increases biodiversity.
-
Zahra Derakhshan,Mohammad Hassan Ehrampoush,Amir Hossein Mahvi,Mansooreh Dehghani,Mohammad Faramarzian,Mohammad Taghi Ghaneian,Mehdi Mokhtari,Ali Asghar Ebrahimi,Hossein Fallah Zadeh 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.67 No.-
The present study examined a moving bed biofilm reactor (MBBR) bioreactor on a laboratory scale for simultaneous removal of atrazine, organic carbon, and nutrients from wastewater. The maximum removal efficiency of atrazine, chemical oxygen demand (COD), total phosphorus (TP) and total nitrogen (TN) were 83.57%, 90.36%, 90.74% and 87.93 respectively. Increasing salinity up to 40 g/L NaCl in influent flow could inhibit atrazine biodegradation process strongly in the MBBR reactor.Results showed that MBBR is so suitable process for efficiently biodegrading of atrazine and nitrogen removal process was based on the simultaneous nitrification-denitrification (SND) process.
-
다양한 차폐시스템을 이용한 광산폐기물의 자연방사능 차폐성능평가
전순원,정명채,Zahra Derakhshan Nejad,Edy Puteri Tiara Maulida,황인호,박제현,최홍일 한국자원공학회 2015 한국자원공학회지 Vol.52 No.2
The objective of this study is to evaluate covering system for natural radioactivity in mine wastes from the Boeun(jeil) mine underlain by the Okcheon black shale using various radiation shielding materials including bentonite, lime(pozzolan), steel slag, thickness of covering materials and particle size of the materials. Concentrations of uranium in the wastes were 174.8 mg/kg, and the average natural radioactivity of the wastes was 15.5 mSv/year. A large scaled in situ column system with 0.3 m3 in volume was adapted. In the column, a 80 kg of the mine waste and a 0.6 m thickness of various covering materials were filled. Among the shielding materials, a column shielded with bentonite reduced up to 80% of natural radioactivity. In addition, the radioactivities were decreased with increasing thickness of covering materials irrespective of particle size and compaction ratio of the materials. Therefore, natural radioactivity from mine waste can be controlled by covering system with over 0.6 m thickness of covering materials, particularly the efficiency of the covering system filled with mixture of gravels and covering materials will be enhanced. 이 연구의 목적은 옥천대 흑색 셰일이 분포하는 지역인 보은광산 주변 광산폐기물을 대상으로 벤토나이트, 소석회(포졸란공법), 제강슬래그 등의 차폐재, 복토재 두께 및 입자크기 등을 적용하여 자연방사능의 수준변화 특성을 평가하는 것이다. 채취한 광산폐기물(광물찌꺼기와 폐석 등)의 평균 우라늄함량은 174.8 mg/kg이었으며, 광산폐기물의 주변 자연방사능을 측정한 결과 연간 평균 15.5 mSv의 방사선량이 확인되었다. 차폐특성을평가하기 위하여 내부 부피가 0.3 m3인 대형 컬럼을 현장에 설치하고 광산폐기물 80 kg(0.3 m)을 충진한 후, 그 상부에 0.6 m 두께의 다양한 차폐재를 충진하였다. 차폐성능을 평가한 결과, 벤토나이트로 충진한 경우 초기자연방사능의 80% 이상을 저감할 수 있었다. 또한, 복토재는 입자의 크기 및 다짐 정도에 관계없이 충진 두께가증가될수록 차폐능이 증가되어 연간방사선량 기준과 근접한 수준까지 저감되었다. 따라서 경제성과 현장 적용성을 고려한다면 상기 차폐 두께를 최소 0.6 m 전후로 충진할 경우 적절한 자연방사능 차폐가 가능하며, 특히자갈과 함께 충진할 경우에는 차폐효율이 더욱 증가될 것으로 판단된다.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
