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Migration and speciation transformation mechanisms of mercury in undercurrent zones of the Tongguan gold mining area, Shaanxi Loess Plateau and impact on the environment

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China Geology 2021年第2期4卷 311-328页

作者： Rui-ping Liu You-ning Xu Hui-chao Rui El-Wardany RM Ying Dong Xi’an Center of China Geological Survey Ministry of Natural ResourcesXi’an 710054China Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region Ministry of EducationXi’an 710054China Key Laboratory for Geo-hazards in Loess Area Ministry of Natural ResourcesXi’an 710054China Field Base of Scientific Observation of Shaanxi Tongguan Ministry of Natural ResourcesXi’an 710054China School of Earth Science and Land Resources Chang’an UniversityXi’an 710054China Al-Azhar University Assiut Branch 71524Egypt

In order to study the migration and transformation mechanism of Hg content and occurrence form in subsurface flow zone of gold mining area in Loess Plateau and its influence on water environment,the field in-situ infiltration test and laboratory test were carried out in three typical sections of river-side loess,alluvial and proluvial strata in Tongguan gold mining area of Shaanxi Province,and the following results were obtained:(1)The source of Hg in subsurface flow zone is mainly caused by mineral processing activities;(2)the subsurface flow zone in the study area is in alkaline environment,and the residual state,iron and manganese oxidation state,strong organic state and humic acid state of mercury in loess are equally divided in dry and oxidizing environment;mercury in river alluvial or diluvial strata is mainly concentrated in silt,tailings and clayey silt soil layer,and mercury has certain stability,and the form of mercury in loess is easier to transform than the other two media;(3)under the flooding condition,most of mercury is trapped in the silt layer in the undercurrent zone where the sand and silt layers alternate with each other and the river water and groundwater are disjointed,and the migration capacity of mercury is far less than that of loess layer and alluvial layer with close hydraulic connection;(4)infiltration at the flood level accelerates the migration of pollutants to the ground;(5)the soil in the undercurrent zone is overloaded and has seriously exceeded the *** the groundwater monitoring results are safe this time,relevant enterprises or departments should continue to pay attention to improving the gold extraction process,especially vigorously rectify the small workshops for illegal gold extraction and the substandard discharge of the three wastes,and intensify efforts to solve the geological environmental problems of mines left over from *** present,the occurrence form of mercury in the undercurrent zone is relatively s

关键词： Mercury speciation Hyporheic zones Constant surface water level flood level Surface-groundwater Hydraulic connection Tongguan gold mining areas Loess Plateau Shannxi Province

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NUMERICAL MODELING OF CHANNEL EQUILIBRIUM PROFILE AND ITS EFFECT ON flood CONTROL

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Journal of Hydrodynamics 2002年第1期14卷 93-99页

作者： Deng Jin-yun, Li Yi-tian (The key Laboratory of Water and Sediment Sciences of Ministry of E ducation, Wuhan University, Wuhan 430072, China) The key Laboratory of Water and Sediment Sciences of Ministry of Education Wuhan University Wuhan 430072 China

Based on the morphology of Luoshan-Hankou reach at the middle Yangtze River, the one-dimensional, unsteady flow and sediment transport numerical model was adopted to study the generalized cha nnel equilibrium profile. The variation of the longitudinal equilibrium profile, and the r elation with the condition of the inflow water and sediment from the upper reach were analyzed. Meanwhile, the numerical simulation results were compared with t he corresponding theoretical results. Finally, the equilibrium longitudinal slop e variations and its impact on flood control were analyzed after the sediment tr ansport process has changed.

关键词： longitudinal equilibrium profile in flow water and sediment slope flood level

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A STUDY ON THE EQUILIBRIUM PROFILE FOR THE LUOSHAN-HANKOU REACH IN THE MIDDLE YANGTZE RIVER

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International Journal of Sediment Research 2003年第2期18卷 107-114页

作者： Jinyun DENG ,Yitian LI Wuhan University Key Lab of Water and Sediment Sciences Ministry of Education 430072 Wuhan

Based on the morphology of the Luoshan-Hankou reach in the middle Yangtze River, the one dimensional (1-D), unsteady flow and sediment transport model was applied to study the river channel equilibrium profile. Meanwhile, a simple theoretical model relating the equilibrium profile and the incoming flow and sediment from the upper reach was developed. The numerical simulation results of the 1-D model were compared with the corresponding results of the theoretical model with reasonable agreement found between the two models. Finally, the equilibrium slope variations and their effects on flood control in response to the changes in the sediment transport process because of the Three Gorges Reservoir were analyzed using the 1-D model.

关键词： Equilibrium profile Incoming flow and sediment Slope flood level 1-D mathematical model

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堤防加固设计中的若干技术问题

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人民长江 2001年第S1期32卷 41-44页

作者： ZHANG Jia-fa Professor Yangtze River Scientific Research Institute Senior Engineer Yangtze River Scientific Research Institute

The dyke experiences very high flood level more and more frequently. The timely issued ' The Standard of Dyke Design' has played an important role in the design, measure fea sibility study and examination of dyke reinforcement. Safety appraisal is required before dyke rein forcement design. But, the conducted item is safety demonstration in the process of dyke reinforcement design at present. This paper suggests that at least 8 aspects should be considered in safety demo nstration. The effective water head is considered as the most important factor for dyke safety and reinfo rcement design. Seepage control measure design is an important part of dyke reinforcement design . Its correct train of thought is discussed in this paper. Some other factors for dyke reinforcement d esign are also pointed out.

关键词：堤防加固设计 control measure examination of flood level

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