Hydrogeochemical characteristics of acid mine drainage and water pollution at Makum Coalfield,India   总被引：1，自引：0，他引：1  

Sk. Md. Equeenuddin  S. Tripathy  P.K. Sahoo  M.K. Panigrahi 《Journal of Geochemical Exploration》2010

Acid mine drainage (AMD) is one of the severe environmental problems that coal mines are facing. Generation of AMD in the northeastern part of India due to the coal mining activities has long been reported. However detailed geochemical characterization of AMD and its impact on water quality of various creeks, river and groundwater in the area has never been reported. Coal and coal measure rocks in the study area show finely disseminated pyrite crystals. Secondary solid phases, resulted due to oxidation of pyrite, occur on the surface of coal, and are mainly consisting of hydrated sulphate complexes of Fe and Mg (copiapite group of minerals). The direct mine discharges are highly acidic (up to pH 2.3) to alkaline (up to pH 7.6) in nature with high concentration of SO₄²⁻. Acidic discharges are highly enriched with Fe, Al, Mn, Ni, Pb and Cd, while Cr, Cu, Zn and Co are below their maximum permissible limit in most mine discharges. Creeks that carrying the direct mine discharges are highly contaminated; whereas major rivers are not much impacted by AMD. Ground water close to the collieries and AMD affected creeks are highly contaminated by Mn, Fe and Pb. Through geochemical modeling, it is inferred that jarosite is stable at pH less than 2.5, schwertmannite at pH less than 4.5, ferrihydrite above 5.8 and goethite is stable over wide range of pH, from highly acidic to alkaline condition.  相似文献   

Spatiotemporal pattern of the dynamics in area,production, and yield of Aus rice in Bangladesh and its response to droughts from 1980 to 2018     

KHONDAKAR Arifuzzaman  DONG Jinwei  LI Zhichao  DENG Xiangzheng  SINGHA Mrinal  RAHMAN Md.Mizanur  JIN Zhenong  WANG Shaoqiang  ZHEN Lin  XIAO Xiangming 《地理学报(英文版)》2022,32(10):2069-2084

Bangladesh is one of the most vulnerable countries to natural disasters such as droughts in the world. The pre-monsoon Aus rice in Bangladesh depends on rainfall and is threatened by increasing droughts. However, limited information on the changes in Aus rice as well as droughts hamper our understanding of the country’s agricultural resilience and adaption to droughts. Here, we collected all the official statistical data of Aus rice at the district level from 1980 to 2018, and examined the inter...  相似文献