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Yu X.-P.,Jilin University | Song M.,Center for Hydrogeology and Environmental Geology Survey | Zhang W.-J.,Jilin University
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2015

Based on the hydrogeological conditions and the organic pollution characteristics in this study area, DRSIC model has been established to classify the vulnerability of groundwater. According to this vulnerability results and hazard load conditions, organic pollution risk assessment model have been built and verified by the groundwater organic contamination situation. The weighting of all models was calculated by AHP (analytic hierarchy process). The assessment results indicated that the levels of organic pollution risk along Xihe River and Yangshi to Yuhong Area was higher than the other areas. The assessment results are well reflected organic pollution status in this study area. ©, 2015, Chinese Society for Environmental Sciences. All right reserved.

Zhang L.,CAS Changchun Northeast Institute of Geography and Agroecology | Zhang L.,Jilin University | Lu W.,Jilin University | An Y.,Jilin University | And 2 more authors.
Fresenius Environmental Bulletin | Year: 2013

The purpose of this study is to identify the critical areas of Dongliao River watershed and evaluate the reduction effect of non-point source pollution by applying the best management practices (BMPs) using a physical process-based watershed scale model-SWAT (Soil and Water Assessment Tool). At first, the SWAT model's performance was tested for the watershed with observed data. Data from 2005 to 2007 was used for calibration while data from 2008 to 2009 was used for validation. The calibration and validation results indicated that the SWAT model was able to simulate well the stream-flow and nonpoint source pollutant loads, with coefficient of determination and Nash-Sutcliffe efficiency both about 0.7 for calibration and validation, respectively. Then, the model was used to identify the critical sub-basins and to assess the impacts of seven BMP scenarios including contour farming, conversation tillage, parallel terraces, filter strips, grassed waterways, grade stabilization structures, and residue management on river loads at the outlet. The results showed that among the seven BMPs simulated, filter strip had the best effects on the reduction of sediment. The reduction rate could reach 63.24%. The conversation tillage, parallel terrace, contour farming, filter strip and residue management all showed significant TN and TP load reduction, and the reduction rate could reach about 30% both for TN and TP loading. The grassed waterway had minimal benefit on TP and TN loads but had significant effect on sediment reduction. So, BMPs have significant effects on the reduction of non-point source pollutant loads and the improvement of water quality, and the results will provide a scientific basis for the protection and improvement of water quality in Dongliao River. © by PSP.

Yang G.,Wuhan University | Li Y.,Wuhan University | Ma X.,Center for Hydrogeology and Environmental Geology Survey | Dong J.,Wuhan University
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | Year: 2014

In order to understand the geochemical processes of key minerals in the supercritical CO2 -water-rock system, we establish a one-dimensional vertical model to study the effect of chlorite contents in cap rock of 3%, 9% and 15% on CO2 -water-rock interaction by numerical simulation software of TOUGHREACT based on the basic geological conditions of deep saline aquifer in Ordos basin, China. It is found that the mineral composition and permeability of the caprock change greatly after CO2 broke into the caprock. It is not favorable for CO2 storage when chlorite volume fraction is 3% because of the increasing permeability in 5 000 years. The permeability of caprock increases first and then decreases when chlorite volume fraction is 9% and 15%, resulting in self-sealing which facilitates the sequestration of CO2. The results show that the dissolution of chlorite provides Mg2+, Fe2+ and AlO2 - for precipitation of calcium montmorillonite, ankerite, dawsonite, and magnesite. The higher the chlorite content, the greater the amount of CO2 mineralization capture, and the more obvious the effect of caprock self-sealing with the maximum caprock permeability decrease of 10%. This study provides a theoretical basis for long-term geological storage of CO2 and its stability evaluation.

Wang L.,Water Resources University | Shen Z.,Water Resources University | Hu L.,Center for Hydrogeology and Environmental Geology Survey | Yu Q.,Water Resources University
Fluid Phase Equilibria | Year: 2014

Geological carbon storage (GCS) is recognized as an effective method for mitigating the greenhouse effect. Deep saline aquifers hold the highest potential capacity for CO2 storage. CO2 solubility in salty aqueous solutions under geological sequestration conditions plays a key role in GCS. However, most CO2 solubility studies focus mainly on single-salt solutions (NaCl and CaCl2), and extrapolation of these studies to aqueous solutions with mixed ions is unavailable. To fill the research gap, based on the collection of CO2 solubility data, a semi-empirical thermodynamic model is proposed in this paper to calculate CO2 solubility in aqueous solutions containing K+, Na+, Ca2+ and Mg2+ in the temperature and pressure ranges from 313K to 378K and from 50bar to 220bar. To describe the CO2-liquid phase equilibrium, the Peng-Robinson equation of state (PR EoS) and the Setschenov equation are applied. The former has been modified to improve its performance in the studied T-P range, and the latter shows excellent accuracy with only three optimized parameters. Before modeling was done, experimental studies were conducted. Brine sampling from five reservoirs potentially chosen for CO2 sequestration in the Erdos Basin was carried out using a monitoring well in the support of the Shenhua Group carbon capture and storage (CCS) site project. The chemical composition of the samples was determined, and experiments measuring CO2 solubility were carried out in synthetic brine with 64 valid data points reported. An analytical method with a simplified sampling technique was chosen. In the range studied, the average absolute deviation of CO2 solubility between the model and experimental results was 2.01%, and the maximum absolute deviation in this study was less than 4.79%. The proposed model and experimental data therefore possess broad adaptability to GCS with satisfactory accuracy. © 2014.

Xing A.,Shanghai JiaoTong University | Xu Q.,Chengdu University of Technology | Zhu Y.,Guizhou Institute of Geo Environment Monitoring | Zhu J.,Center for Hydrogeology and Environmental Geology Survey | Jiang Y.,Kyoto University
Landslides | Year: 2016

At about 8:30 p.m. on 27 August 2014, a catastrophic rock avalanche suddenly occurred in Fuquan, Yunnan, southwestern China. This landslide and related impulse water waves destroyed two villages and killed 23 persons. The impulse waves occurred after initiation of the landslide, caused by the main part of the slide mass rapidly plunging into a water-filled quarry below the source area. The wave, comprising muddy water and rock debris, impacted the opposite slope of the quarry on the western side of the runout path and washed away three homes in Xinwan village. Part of the displaced material traveled a horizontal distance of about 40 m from its source and destroyed the village of Xiaoba. To provide information for potential landslide hazard zonation in this area, a combined landslide–wave simulation was undertaken. A dynamic landslide analysis (DAN-W) model is used to simulate the landslide propagation before entering the quarry, while Fluent (Ansys Inc., USA) is used to simulate the impulse wave generation and propagation. Output data from the DAN-W simulation are used as input parameters for wave modeling, and there is good agreement between the observed and simulated results of the landslide propagation. Notably, the locations affected by recordable waves according to the simulation correspond to those recorded by field investigation. © 2016 Springer-Verlag Berlin Heidelberg

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