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Liu S.W.,Key Laboratory of Ecological Geochemistry | Liu X.D.,Key Laboratory of Ecological Geochemistry | Fan X.L.,China University of Geosciences | Yuan X.,Key Laboratory of Ecological Geochemistry
Advanced Materials Research | Year: 2014

The ion-absorbed rare earth deposit occurred in the South of China is unique all over the world. Since the 1970s, rare earth in Longnan, South China has begun to be mined with leaching methods using oxalates and ammonium sulfate. Although this kind of methods is simple and economic, its presence in the environmental causes a growing environmental problems, especially changes in regional hydrochemical environment. In this paper typical ion-absorbed rare earth deposit-the Longnan rare earth mine, Jiangxi Provence, South China was selected as the study object, where the surface water and groundwater samples were collected. Analytic results show that the mining activities have affected the regional hydrochemical environment, which are expressed in the decreased pH(pH 3-4) the enrichment of REE and heavy metal Pb in water with the maximum of 44760.1 μgL-1and 1550 μgL-1 respectively, and the sulfate(214-1121 mgL-1) ammonium(33.7-268 mgL-1)and nitrate ions(90-468 mgL-1) far beyond the background value. The impaction of the mining area surface hydrochemical environment is severest, then around the mining area, and the main rivers and groundwater in the study area have not been affected yet. © (2014) Trans Tech Publications, Switzerland.


Liu S.,Key Laboratory of Ecological Geochemistry | Fan X.,China University of Geosciences | Tian M.,China University of Geosciences
WIT Transactions on Ecology and the Environment | Year: 2014

To probe the environment change of the Badain Jaran Desert during the Last Interglacial, the representative Barunbaoritaolegai outcrop in the southeast of the desert is selected as the research object. The geochemical characteristics of sediment and changed trend of climatic proxies CIA, ICV, silicon-aluminium ratios, silicon-aluminium-iron ratios and paleotemperature, support that the chemical weathering of the researched region is weak and sensitive to climate and environmental change. We believe that the study area has undergone roughly moderately dry weather during 106.4-99.6ka BP, cold wet weather during 99.6- 90.6ka BP and moderately dry weather during 90.6-67.2ka BP since the Last Interglacial. © 2013 WIT Press.


Fan X.,China University of Geosciences | Tian M.,China University of Geosciences | Liu S.,Key Laboratory of Ecological Geochemistry
WIT Transactions on Ecology and the Environment | Year: 2014

Badain Jaran Desert is China's third largest desert, where hundreds of large and small lakes have developed. To ascertain the paleoenvironmental evolution of the southeast edge of the desert, this paper selects the representative outcrop deposits as the research object. Some analytical methods, such as C-M diagram, frequency curves, accumulation probability curves and grain-size parameters to research the Barunbaoritaolegai profile in the southeast edge of the Badain Jaran Desert. Results show that profile BRGH may be a highland at a lakeside or an island in a lake. Frequency distribution curves mainly show unimodal normal distribution which reflects the dominated water sedimentation. There are also some coarse particles which have excellent sorting and roundness at the bottom of the mega-dune. These particles may be derived from sediments that are similar to sediments of the BRGH profile. Grain composition reflects that the southeast edge of the Badain Jaran Desert has undergone a roughly wet period during 106.4-99.6kaBP and a drought period during 99.6-67.3kaBP in the late Pleistocene. © 2013 WIT Press.


Jiang W.,China University of Geosciences | Jiang W.,Key Laboratory of Ecological Geochemistry | Jiang W.,Guangxi University | Yang Z.,China University of Geosciences | And 10 more authors.
Journal of Soils and Sediments | Year: 2015

Purpose: Molybdenum (Mo) is an essential element critical to biochemical processes in plants and animals. The effects of soil properties on the availability of Mo to rice were investigated. Materials and methods: A total of 56 paired samples of topsoil and rice were collected. Relevant parameters in soil and Mo in rice grains were measured, and the results were analyzed using statistical methods. Results and discussion: Descriptive statistics for Mo contents in soil and soil properties are presented. Mo adsorption can be predicted using the following soil chemical properties: pH, cation exchange capacity, soil organic carbon (SOC) content, inorganic carbon content, and iron oxide content. This study focused on soil pH, SOC, S, and Na2O because these parameters are the most important factors in controlling the levels of soil Mo in correlation analyses. SOC and available P were the best predictors of Mo availability. Conclusions: Among the soil properties in this study, soil pH is the most important factor restricting the supply of soil available Mo. The dominant factors that directly affected Mo availability were the levels of available P and SOC. Leaching and adsorption of Mo in soils were considered key processes that affected the levels of soil available Mo. Rice grown in the study area may pose potential Mo risks to food safety and human health, especially in rural areas. © 2015, Springer-Verlag Berlin Heidelberg.


Lv Y.,China University of Geosciences | Lv Y.,Key Laboratory of Ecological Geochemistry | Yu T.,China University of Geosciences | Yu T.,Key Laboratory of Ecological Geochemistry | And 7 more authors.
Science of the Total Environment | Year: 2014

Kaschin-Beck disease (KBD), an endemic osteoarthropathy, is distributed in the low-selenium (Se)-belt that stretches from northeast to southwest China. However, very few studies have investigated the relationship between low bioavailabitity of Se and KBD. The present study examined the behavior of Se and other elements in areas with varying levels of KBD prevalence using pedological and geochemical methods. Rhizosphere soil samples obtained from the KBD-stricken Aba area were classified into Ustic Isohumisols (J2), Udic Luvisols (L4), Stagnic Gleysols (I2), and Cryic Cambisols (M1) and the integrated constraints on selenium bioavailability in these soils were analyzed. We found that Se concentration in soil profiles from a typical KBD area ranged between 0.08μg·g-1 and 0.215μg·g-1, indicating absent and marginal bioavailability, respectively. This suggested that low Se bioavailability may be a feature that soils inherit from their Se-deficient parent materials. Moreover, the soil types examined showed different geochemical behaviors such as eluviation for soluble Se(VI), migration of Se(IV) for its adsorption on clay and sesquioxide, and extreme redox conditions. In conclusion, a higher level of Se bioavailability in environment might be related to a lower risk of KBD, and our results offer a foundation for scientific theory on ecological geochemistry and improve our understanding of KBD. © 2014 Elsevier B.V.


Liu S.,National Research Center for Geoanalysis | Liu S.,Key Laboratory of Ecological Geochemistry | Wang H.,China University of Geosciences | Song J.,China University of Geosciences | And 2 more authors.
Communications in Computer and Information Science | Year: 2013

Ion-absorbing Type Rare Earths Ore mining caused a series of environmental problems. The thesis focused on the study of the district for heavy rare earth in Longnan County, Jiangxi Province, South China. It examined characteristics of spatial-temporal variation for vegetation fraction (vf) in study area by 10 images of Landsat TM and ETM+ during 1988 to 2009. The results supported that: (1) there were spatial-temporal differences of vf in each mineral district and the areas for medium to high vf dominated in mineral districts, but low vf distributed on concentrated mining districts; (2) dynamic variation for vf differentiated in each mining area each stage, no change areas dominated in mineral districts, but negative change areas only distributed on concentrated mining districts; (3) the history of production, various technologies and preventive measures were the main factors caused spatial-temporal differences of vf in mineral districts. © Springer-Verlag Berlin Heidelberg 2013.


Yang Z.,China University of Geosciences | Yang Z.,Key Laboratory of Ecological Geochemistry | Yu T.,China University of Geosciences | Hou Q.,China University of Geosciences | And 6 more authors.
Journal of Geochemical Exploration | Year: 2014

The evaluation of land quality is fundamental for land use planning. The geochemical evaluation of land quality in China is a basic part of the Multi-purpose Regional Geochemical Survey Project, which classifies land quality based on soil nutrients (e.g., N, P, and K), harmful elements (e.g., As, Cd, Cr, Hg, and Pb), pH, and soil organic carbon content. This project also classifies land quality using indicators, such as air quality, irrigation water quality, and agricultural products safety, and accordingly evaluates land management. This study introduces the scale, unit, indicators, criteria, and grade classification of the evaluation system. Taking the geochemical evaluation of national land quality as an example, we introduce the results for soil nutrient, soil environment, and comprehensive geochemical classifications of land quality in the primary farming areas of China. The results indicate that the proportions of high quality and excellent soil are 47.5% and 38.1% of the total study area, respectively, which are widely distributed in the major grain-producing areas of China. These results can be widely applied for land use planning, improvement of land production potential, and for the prevention and control of endemic diseases. The geochemical evaluation of land quality in China is still in its infancy. Thus, the evaluation methods need further improvement. In addition, some problems arise in the integration of these methods with the existing agricultural land classification and grading systems in China. Many aspects of the current evaluation system, such as methods for obtaining and interpreting results, need to be improved to fully reflect the quality of cultivated land in China and to be in accordance with developed countries worldwide. © 2013 Elsevier B.V.


Yu T.,China University of Geosciences | Yang Z.,China University of Geosciences | Yang Z.,Key Laboratory of Ecological Geochemistry | Lv Y.,China University of Geosciences | And 6 more authors.
Journal of Geochemical Exploration | Year: 2014

Mianyang City, located in the Fujiang River Basin, Sichuan Province, is a Se-rich area of China. The distribution of Selenium (Se) in the Mianyang area was studied based on assay data obtained from soil, irrigation water, fertilizer, and rice (grain and stem) samples. The ratio between natural and anthropogenic sources in the area was derived by analyzing the concentrations and spatial distributions of multiple elements (such as Se, cadmium, arsenic, and mercury) in the soil. The controlling factors affecting Se concentration in the soil were also investigated. We established a geochemical model of the Se cycle among the different media (i.e., the atmosphere, water, soils, and plants). We then calculated the annual Se flux caused by various inputs' (such as precipitation, fertilization, and irrigation) and outputs' (such as infiltration, crop harvest, removal of straws from cropland, and volatilization) pathways in the topsoil. We discuss the contribution of different pathways to the Se cycle and provide evidence for exploring Se-rich land in the study area. © 2013 Elsevier B.V.


Liu S.W.,National Research Center for Geoanalysis | Liu S.W.,Key Laboratory of Ecological Geochemistry | Liu X.D.,National Research Center for Geoanalysis | Liu X.D.,Key Laboratory of Ecological Geochemistry | And 3 more authors.
Legislation, Technology and Practice of Mine Land Reclamation - Proceedings of the Beijing International Symposium Land Reclamation and Ecological Restoration, LRER 2014 | Year: 2015

The iron-absorbed rare earth deposit occurred in Jiangxi, Fujian Provence et al. in the south of China and is a unique kind of rare earth ores in the world. The Longnan rare earth mining districting in the south of Jiangxi Provence are the most representative iron-absorbed rare earth deposits of China, where the rare earth minerals have been extracted by methods of leaching mining with the oxalate or the ammonium sulfuricum since the 1970s. Environmental problems including the serious chemical land pollution in mining areas and the severe soil and water loss, caused by rare earth mining are increasingly acute. The absence of effective polluted land restoration technology makes the work of polluted land restoration little progress. Combining the geochemical engineering and the flexible structure engineering technologies for polluted land’s restoration in rare earth mining areas is a new attempt. The Zudong rare earth mining area is selected as study object for land restoration, where pH values in polluted soil will be adjusted by clay minerals and contents of the ammonia nitrogen and the sulfate radical will be decreased. All soil removed from other place adding restoration materials will be filled in ecological bags and assembled on the exposed land of rare earth mine in way of the flexible structure engineering for plant restoration. Combination of the geochemical engineering and the flexible structure engineering technologies is a new attempt for rare earth polluted land ecological restoration. © 2015 Taylor & Francis Group, London.

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