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Qiulan Zhang
School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China

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Journal article
Published: 20 July 2021 in Water
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The hydrochemistry and quality of local shallow groundwater was assessed within the Xinzhou basin in Shanxi, North China. Piper diagrams, correlation analysis, principal component analysis, chloro-alkaline indices, ion proportion diagrams, and Gibbs diagrams were used to reveal the hydrochemical characteristics and evolution mechanisms of groundwater. Besides, two indicators of sodium adsorption ratio and soluble sodium percentage, USSL and Wilcox diagrams, and water quality index models were used to evaluate the groundwater quality for irrigation and drinking. In general, groundwater in most areas of the basin is fresh water with total dissolved solid lower than 1000 mg/L. But there are salt water in some parts of the southern basin, with total dissolved solid higher than 1000 mg/L, due to industrial and domestic pollution. The hydrochemical facies of groundwater in most areas are HCO3-Ca and mixed HCO3-Ca·Mg·Na types, while it is HCO3·SO4·Cl-Na type in a small part of the basin. Nitrate pollution widely occurred in the basin because of the use of nitrogenous fertilizers. The dominant mechanism controlling the evolution of groundwater chemistry compositions was the weathering of rock minerals. It mainly reflected in the dissolution of carbonate minerals. And the carbonate dissolution is the major origins of HCO3, Ca2+, and Mg2+ in groundwater. However, Na-Ca exchange is the important source of Na+. Shallow groundwater was suitable for irrigation and drinking except for some southern parts of the basin. These results will be helpful for the protection and efficient management of groundwater in the Xinzhou basin.

ACS Style

Guanyin Shuai; Jingli Shao; Yali Cui; Qiulan Zhang; Yuntong Guo. Hydrochemical Characteristics and Quality Assessment of Shallow Groundwater in the Xinzhou Basin, Shanxi, North China. Water 2021, 13, 1993 .

AMA Style

Guanyin Shuai, Jingli Shao, Yali Cui, Qiulan Zhang, Yuntong Guo. Hydrochemical Characteristics and Quality Assessment of Shallow Groundwater in the Xinzhou Basin, Shanxi, North China. Water. 2021; 13 (14):1993.

Chicago/Turabian Style

Guanyin Shuai; Jingli Shao; Yali Cui; Qiulan Zhang; Yuntong Guo. 2021. "Hydrochemical Characteristics and Quality Assessment of Shallow Groundwater in the Xinzhou Basin, Shanxi, North China." Water 13, no. 14: 1993.

Journal article
Published: 22 April 2021 in Sustainability
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Qingtu Lake is located between Tengger Desert and Badain Jilin Desert, Gansu Province, Northwest China. It is the terminal lake of Shiyang River. In recent years, Qingtu lake has maintained a certain area of water surface and vegetation by artificial water conveyance. It is of great significance in preventing the convergence of the two deserts and restraining the trend of ecological deterioration of Shiyang River Basin. The relationship between the water surface area and the ecological water conveyance have not been thoroughly investigated. This study analyzed the spatial and temporal distribution of water surface area of Qingtu Lake and surrounding reeds by interpreting remote sensing data; the change of water surface area under the influence of meteorological factors and water conveyance by linear regression; the water conveyance to maintain current water surface area by water balance method, as well as the reasonable ecological water delivery in high flow year, normal flow year and low flow year by the means of analyzing the upstream inflow and water consumption in Minqin Basin. The results showed that there is a significant correlation between the water surface area of Qingtu Lake, evaporation and ecological water conveyance, and the minimum and maximum water surface areas generally appear before and after water delivery, indicating that the ecological water delivery and evaporation are the two main factors affecting the water surface area change of Qingtu Lake. The result calculated by linear regression indicated that the ecological water delivery volume to maintain current water surface area of Qingtu Lake is 3.146 × 107 m3/yr, while the value was 3.136 × 107 m3/yr calculated by water balance method. These two results are similar and can be verified with each other. Reasonable ecological water conveyance of Qingtu Lake in high flow year, normal flow year and low flow years were 4 × 107 m3/yr, 3.2 × 107 m3/yr and 2.3 × 107 m3/yr, respectively.

ACS Style

Yuntong Guo; Jingli Shao; Qiulan Zhang; Yali Cui. Relationship between Water Surface Area of Qingtu Lake and Ecological Water Delivery: A Case Study in Northwest China. Sustainability 2021, 13, 4684 .

AMA Style

Yuntong Guo, Jingli Shao, Qiulan Zhang, Yali Cui. Relationship between Water Surface Area of Qingtu Lake and Ecological Water Delivery: A Case Study in Northwest China. Sustainability. 2021; 13 (9):4684.

Chicago/Turabian Style

Yuntong Guo; Jingli Shao; Qiulan Zhang; Yali Cui. 2021. "Relationship between Water Surface Area of Qingtu Lake and Ecological Water Delivery: A Case Study in Northwest China." Sustainability 13, no. 9: 4684.

Journal article
Published: 12 November 2020 in Water
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The human activities and urbanization process have changed the underlying surface of urban areas, which would affect the recharge of groundwater through rainfall infiltration and may further influence the groundwater environment. Accordingly, it is imperative to investigate the variation of hydrological cycle under the condition of underlying surface change. Based on the high-precision remote sensing data of 2000, 2005, 2010 and 2015, and Soil and Water Assessment Tool (SWAT) model, this work firstly studied the land use change and the corresponding changes in runoff generation mechanism and rainfall infiltration coefficient in Su-Mi-Huai area, Beijing, China. Meanwhile, SWAT-MODFLOW semi-loose coupling model was applied to analyze the water balance in the study area in typical hydrological years. The results showed that the area of the construction land (urban and rural residential land) increased by 1.04 times from 2000 to 2015, which is mainly attributed to the conversion of cultivated land to construction land in the plain area. This change caused the runoff in the area to increase by 7 × 106 m3, the runoff coefficient increased by 17.9%, and the precipitation infiltration coefficient was less than the empirical value determined by lithology. Compared with 2000, the average annual precipitation infiltration coefficient in 2018 decreased by 6.5%. Under the influence of urbanization process, the maximum reduction rate of precipitation infiltration recharge is up to 38%. The study investigated the response of surface runoff and precipitation infiltration recharge to land use change, which can provide helps for water resources managers to coordinate the relationship between land use change and rational water resources planning.

ACS Style

Linlin Zhang; Caiyuan Wang; Guixing Liang; Yali Cui; Qiulan Zhang. Influence of Land Use Change on Hydrological Cycle: Application of SWAT to Su-Mi-Huai Area in Beijing, China. Water 2020, 12, 3164 .

AMA Style

Linlin Zhang, Caiyuan Wang, Guixing Liang, Yali Cui, Qiulan Zhang. Influence of Land Use Change on Hydrological Cycle: Application of SWAT to Su-Mi-Huai Area in Beijing, China. Water. 2020; 12 (11):3164.

Chicago/Turabian Style

Linlin Zhang; Caiyuan Wang; Guixing Liang; Yali Cui; Qiulan Zhang. 2020. "Influence of Land Use Change on Hydrological Cycle: Application of SWAT to Su-Mi-Huai Area in Beijing, China." Water 12, no. 11: 3164.

Journal article
Published: 21 October 2020 in Water
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The inefficient use of single energy and cold accumulation in the shallow geothermal field seriously affect the efficient operation of the ground source heat pump system (GSHPS). The operation of solar-assisted GSHPS can effectively solve the above problems. In this paper, a shallow geothermal utilization project in Nan cha Village, Ping Gu District of Beijing, is chosen as the study area. A three-dimensional numerical model of groundwater flow and heat transfer considering ambient temperature and backfill materials is established, and the level of model integration and validation are novel features of this paper. The thermal response test data in summer and winter conditions are used to validate the model. The results show that increasing hydraulic gradient has a positive impact on the heat exchange. The mixture of sand and barite powder is recognized as a more efficient and economical backfill material. The changes of thermal influence radius, heat balance, and shallow geothermal field are simulated and analyzed by three schemes. It is demonstrated that the thermal influence radius is 5 m, 3.9 m and 3.9 m for Scheme 1, Scheme 2 and Scheme 3, respectively. The ground temperature is always lower than the initial formation temperature in Scheme 1 and Scheme 2; however, under Scheme 3 it is higher than the initial values. The closer the hole wall is, the larger the difference between the initial formation temperature and the ground temperature, and vice versa. The thermal equilibrium of Scheme 1, Scheme 2 and Scheme 3 is −728 × 106 KJ, −269 × 106 KJ and +514 × 106 KJ. Through comprehensive analysis of the above three factors, Scheme 3 is regarded as the most reasonable scheme for a solar system to assist GSHPS.

ACS Style

Yaobin Zhang; Jia Zheng; Aihua Liu; Qiulan Zhang; Jingli Shao; Yali Cui. Numerical Simulation of Shallow Geothermal Field in Operating of a Ground Source Heat Pump System—A Case Study in Nan Cha Village, Ping Gu District, Beijing. Water 2020, 12, 2938 .

AMA Style

Yaobin Zhang, Jia Zheng, Aihua Liu, Qiulan Zhang, Jingli Shao, Yali Cui. Numerical Simulation of Shallow Geothermal Field in Operating of a Ground Source Heat Pump System—A Case Study in Nan Cha Village, Ping Gu District, Beijing. Water. 2020; 12 (10):2938.

Chicago/Turabian Style

Yaobin Zhang; Jia Zheng; Aihua Liu; Qiulan Zhang; Jingli Shao; Yali Cui. 2020. "Numerical Simulation of Shallow Geothermal Field in Operating of a Ground Source Heat Pump System—A Case Study in Nan Cha Village, Ping Gu District, Beijing." Water 12, no. 10: 2938.

Journal article
Published: 17 July 2020 in Sustainability
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The Chinese government hopes to implement groundwater table control to realize the sustainable utilization of groundwater resources based on controlling the current groundwater exploitation amount. In this study, a method to determine the control index of the groundwater table is proposed. In the method, the reasonable relationship between the groundwater table and groundwater exploitation amount is ensured using the groundwater numerical simulation model. The operability of the index determination is improved using a surrogate numerical model, and the annual hydrological dynamic is simplified to three scenarios of dry, flat, and wet. To verify this method, the Minqin Basin in Northwest China was chosen as a typical study area. It is assumed that the control index of groundwater exploitation in 2020 is 85,000103m3. Then, the preset annual water table index is calculated as [−0.70, 0.62, 1.13, −1.25, 1.36, 3.09] m [−0.77, 0.53, 1.05, −1.33, 1.27, 2.96] m, and [−0.83, 0.46, 0.99, −1.40, 1.20, 2.85] m for the chosen six monitoring wells, varying over the years with wet, flat, and dry scenarios. This method can ensure high precision, operability, and dynamic management when determining the control index of the groundwater table and satisfy the demand of managers.

ACS Style

Xiaowei Wang; Jingli Shao; Yali Cui; Qiulan Zhang. Application of a Surrogate Model for a Groundwater Numerical Simulation Model for Determination of the Annual Control Index of the Groundwater Table in China. Sustainability 2020, 12, 5752 .

AMA Style

Xiaowei Wang, Jingli Shao, Yali Cui, Qiulan Zhang. Application of a Surrogate Model for a Groundwater Numerical Simulation Model for Determination of the Annual Control Index of the Groundwater Table in China. Sustainability. 2020; 12 (14):5752.

Chicago/Turabian Style

Xiaowei Wang; Jingli Shao; Yali Cui; Qiulan Zhang. 2020. "Application of a Surrogate Model for a Groundwater Numerical Simulation Model for Determination of the Annual Control Index of the Groundwater Table in China." Sustainability 12, no. 14: 5752.

Journal article
Published: 22 May 2020 in Water
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To overcome the large time and memory consumption problems in large-scale high-resolution contaminant transport simulations, an efficient approach was presented to parallelize the modular three-dimensional transport model for multi-species (MT3DMS) (University of Alabama, Tuscaloosa, AL, USA) program on J adaptive structured meshes applications infrastructures (JASMIN). In this approach, a domain decomposition method and a stencil-based method were used to accomplish parallel implementation, while a ghost cell strategy was used for communication. The MODFLOW-MT3DMS coupling mode was optimized to achieve the parallel coupling of flow and contaminant transport. Five types of models were used to verify the correctness and test the parallel performance of the method. The developed parallel program JMT3D (China University of Geosciences (Beijing), Beijing, China) can increase the speed by up to 31.7 times, save memory consumption by 96% with 46 processors, and ensure that the solution accuracy and convergence do not decrease as the number of domains increases. The BiCGSTAB (Bi-conjugate gradient variant algorithm) method required the least amount of time and achieved high speedup in most cases. Coupling the flow and contaminant transport further improved the efficiency of the simulations, with a 33.45 times higher speedup achieved on 46 processors. The AMG (algebraic multigrid) method achieved a good scalability, with an efficiency above 100% on hundreds of processors for the simulation of tens of millions of cells.

ACS Style

Xingwei Liu; Qiulan Zhang; Tangpei Cheng. Accelerating Contaminant Transport Simulation in MT3DMS Using JASMIN-Based Parallel Computing. Water 2020, 12, 1480 .

AMA Style

Xingwei Liu, Qiulan Zhang, Tangpei Cheng. Accelerating Contaminant Transport Simulation in MT3DMS Using JASMIN-Based Parallel Computing. Water. 2020; 12 (5):1480.

Chicago/Turabian Style

Xingwei Liu; Qiulan Zhang; Tangpei Cheng. 2020. "Accelerating Contaminant Transport Simulation in MT3DMS Using JASMIN-Based Parallel Computing." Water 12, no. 5: 1480.

Original paper
Published: 14 March 2020 in Arabian Journal of Geosciences
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The paper examined the effects of colloid size and molar ratio of Ca2+/Na+ on the retention and release of colloids under transients in ionic strength (IS). Column experiments were conducted to elucidate the transport behavior of three-sized polystyrene latex microspheres (300 nm, 500 nm, and 1000 nm) by varied molar ratios of Ca2+/Na+. Colloid concentration breakthrough curves showed the retention of colloids enhanced with the increase of molar ratio and the decrease of colloid size, which can be explained by Derjaguin–Landau–Verwey–Overbeek theory and the existence of nanoscale surface roughness. When the IS of the eluting solution was reduced from 10 to 1 mM, and when the eluting solution changed to ultrapure water, peak concentrations of colloid release were observed. Colloid recovery rates during the injection of ultrapure water were low, and substantial proportion of colloid still retained in the column even after the injection of ultrapure water, which suggested a stronger influence caused by the primary minimum compared with the secondary minimum on the retention of colloid. A modified numerical model considering the processes of Langmuirian dynamics blocking associated with a conservative tracer equation was successfully developed to simulate the transport process of all the experiments.

ACS Style

Qiulan Zhang; Yingxue Yu; Yali Cui. The role of particle size and molar ratio of Ca2+/Na+ in the retention and remobilization of colloids in saturated porous media. Arabian Journal of Geosciences 2020, 13, 1 -10.

AMA Style

Qiulan Zhang, Yingxue Yu, Yali Cui. The role of particle size and molar ratio of Ca2+/Na+ in the retention and remobilization of colloids in saturated porous media. Arabian Journal of Geosciences. 2020; 13 (6):1-10.

Chicago/Turabian Style

Qiulan Zhang; Yingxue Yu; Yali Cui. 2020. "The role of particle size and molar ratio of Ca2+/Na+ in the retention and remobilization of colloids in saturated porous media." Arabian Journal of Geosciences 13, no. 6: 1-10.

Journal article
Published: 13 September 2019 in Sustainability
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In the karst area of southern China, karst water is important for supporting the sustainable production and home living for the local residents. Consequently, it is of significance to fully understand the water cycle, so as to make full use of water resources. In karst areas, epikarst and conduits are developed, participating in the hydrological cycle actively. For conventional lumped hydrologic models, it is difficult to simulate the hydrological cycle accurately. These models neglect to consider the variation of underlying surface and weather change. Meanwhile, for the original distributed hydrological model, the existence of epikarst and underground conduits as well as inadequate data information also make it difficult to achieve accurate simulation. To this end, the framework combining the advantages of lumped model–reservoir model and distributed hydrologic model–Soil and Water Assessment Tool (SWAT) model is established to simulate the water cycle efficiently in a karst area. Xianghualing karst watershed in southern China was selected as the study area and the improved SWAT model was used to simulate the water cycle. Results show that the indicators of ENS and R2 in the calibration and verification periods are both above 0.8, which is evidently improved in comparison with the original model. The improved SWAT model is verified to have better efficiency in describing the hydrological cycle in a typical karst area.

ACS Style

Yufeng Wang; Jingli Shao; Chuntian Su; Yali Cui; Qiulan Zhang. The Application of Improved SWAT Model to Hydrological Cycle Study in Karst Area of South China. Sustainability 2019, 11, 5024 .

AMA Style

Yufeng Wang, Jingli Shao, Chuntian Su, Yali Cui, Qiulan Zhang. The Application of Improved SWAT Model to Hydrological Cycle Study in Karst Area of South China. Sustainability. 2019; 11 (18):5024.

Chicago/Turabian Style

Yufeng Wang; Jingli Shao; Chuntian Su; Yali Cui; Qiulan Zhang. 2019. "The Application of Improved SWAT Model to Hydrological Cycle Study in Karst Area of South China." Sustainability 11, no. 18: 5024.

Journal article
Published: 19 April 2019 in Water
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The characteristics of groundwater systems are highly complex. It will take substantial computational resources and running time to optimize a groundwater numerical simulation model. In this study, in order to realize the coupling of simulation and optimization models, the improved backpropagation (BP) neural network was used as a surrogate model of a groundwater numerical simulation; the improved BP neural network was trained with the groundwater level drawdown–pumping volume data output of the simulation model. The method was applied to the water resource optimal allocation in the near future of Wenshang County, Shandong Provence of China. The results show that the water level drawdown output of the improved BP neural network model fits the results of the simulation model well, showing that the improved BP neural network can effectively be the surrogate of a groundwater numerical simulation to be embedded in an optimization model. The improved simulation and optimization technique can make full use of water resources in the whole area. Under an assurance rate of 50%, both water shortage and water shortage rate reduced to zero in the whole area. Under an assurance rate of 75%, water shortage and water shortage rate reduced to about 10% of the conventional scheme, which dramatically improves the comprehensive benefit of the whole area.

ACS Style

Yufeng Wang; Yali Cui; Jingli Shao; Qiulan Zhang; Wang; Cui; Shao. Study on Optimal Allocation of Water Resources Based on Surrogate Model of Groundwater Numerical Simulation. Water 2019, 11, 831 .

AMA Style

Yufeng Wang, Yali Cui, Jingli Shao, Qiulan Zhang, Wang, Cui, Shao. Study on Optimal Allocation of Water Resources Based on Surrogate Model of Groundwater Numerical Simulation. Water. 2019; 11 (4):831.

Chicago/Turabian Style

Yufeng Wang; Yali Cui; Jingli Shao; Qiulan Zhang; Wang; Cui; Shao. 2019. "Study on Optimal Allocation of Water Resources Based on Surrogate Model of Groundwater Numerical Simulation." Water 11, no. 4: 831.

Journal article
Published: 01 August 2017 in Chemical Engineering Science
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ACS Style

Qiulan Zhang; S. Majid Hassanizadeh. The role of interfacial tension in colloid retention and remobilization during two-phase flow in a polydimethylsiloxane micro-model. Chemical Engineering Science 2017, 168, 437 -443.

AMA Style

Qiulan Zhang, S. Majid Hassanizadeh. The role of interfacial tension in colloid retention and remobilization during two-phase flow in a polydimethylsiloxane micro-model. Chemical Engineering Science. 2017; 168 ():437-443.

Chicago/Turabian Style

Qiulan Zhang; S. Majid Hassanizadeh. 2017. "The role of interfacial tension in colloid retention and remobilization during two-phase flow in a polydimethylsiloxane micro-model." Chemical Engineering Science 168, no. : 437-443.

Journal article
Published: 28 May 2017 in Water
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To reduce the gap between groundwater demand and supply caused by agricultural groundwater over-exploitation, the Prepaid Smart Meter System (PSMS) is being strongly implemented by the Chinese government in northern China. This study reports the analysis and results of PSMS field surveys in six typical provinces in northern China as well as domestic literature reviews. Based on the architecture and implementation policies of the system, the implementation differences between areas and the influencing factors were analyzed, particularly the acknowledgment of farmers, the installation proportion of tube wells, the social benefits. Great achievements have been gained in the implementation, and the management targets have been achieved, including accurately metering overall irrigation groundwater production, assisting in the total amount control and quota management, reducing groundwater exploitation, and improving water use efficiency. However, shortcomings remain in the implementation process, such as single initial investment channels, imperfect policy system construction, a lack of retrieving and analyzing data, and the unbalanced development between areas. Countermeasures and suggestions for these problems are discussed in this article.

ACS Style

Xiaowei Wang; Jingli Shao; Frank Van Steenbergen; Qiulan Zhang. Implementing the Prepaid Smart Meter System for Irrigated Groundwater Production in Northern China: Status and Problems. Water 2017, 9, 379 .

AMA Style

Xiaowei Wang, Jingli Shao, Frank Van Steenbergen, Qiulan Zhang. Implementing the Prepaid Smart Meter System for Irrigated Groundwater Production in Northern China: Status and Problems. Water. 2017; 9 (6):379.

Chicago/Turabian Style

Xiaowei Wang; Jingli Shao; Frank Van Steenbergen; Qiulan Zhang. 2017. "Implementing the Prepaid Smart Meter System for Irrigated Groundwater Production in Northern China: Status and Problems." Water 9, no. 6: 379.

Journal article
Published: 19 January 2017 in Water
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In this work, the hydrogeochemistry and environmental isotopic compositions of thermal and mineral springs in Arxan, northeastern China, were used to assess the genesis of the thermal system hosted by deep-seated faults. The reservoir temperature was calculated using the mineral saturation index and geothermometers. According to isotopic analysis, the spring water was of meteoric origin. Sixteen springs in the Arxan geothermal system with outlet temperatures ranging from 10.9 to 41.0 °C were investigated. The water samples can be classified into four groups by using a Piper diagram. The aquifer in which the Group I and Group III samples were obtained was a shallow cold aquifer of the Jurassic system, which is related to the local groundwater system and contains HCO3–Ca·Na groundwater. The Group II and Group IV samples were recharged by deeply circulating meteoric water with HCO3–Na and HCO3·SO4–Na·Ca groundwater, respectively. The springs rise from the deep basement faults. The estimated thermal reservoir temperature is 50.9–68.8 °C, and the proportion of shallow cold water ranges from 54% to 87%. A conceptual flow model based on hydrogeochemical results and hydrogeological features is given to describe the geothermal system of the Arxan springs.

ACS Style

Xiaomin Gu; Qiulan Zhang; Yali Cui; Jingli Shao; Yong Xiao; Peng Zhang; Jinxing Liu. Hydrogeochemistry and Genesis Analysis of Thermal and Mineral Springs in Arxan, Northeastern China. Water 2017, 9, 61 .

AMA Style

Xiaomin Gu, Qiulan Zhang, Yali Cui, Jingli Shao, Yong Xiao, Peng Zhang, Jinxing Liu. Hydrogeochemistry and Genesis Analysis of Thermal and Mineral Springs in Arxan, Northeastern China. Water. 2017; 9 (1):61.

Chicago/Turabian Style

Xiaomin Gu; Qiulan Zhang; Yali Cui; Jingli Shao; Yong Xiao; Peng Zhang; Jinxing Liu. 2017. "Hydrogeochemistry and Genesis Analysis of Thermal and Mineral Springs in Arxan, Northeastern China." Water 9, no. 1: 61.

Journal article
Published: 11 April 2016 in SpringerPlus
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Based on the geo-statistical theory and ArcGIS geo-statistical module, datas of 30 groundwater level observation wells were used to estimate the decline of groundwater level in Beijing piedmont. Seven different interpolation methods (inverse distance weighted interpolation, global polynomial interpolation, local polynomial interpolation, tension spline interpolation, ordinary Kriging interpolation, simple Kriging interpolation and universal Kriging interpolation) were used for interpolating groundwater level between 2001 and 2013. Cross-validation, absolute error and coefficient of determination (R(2)) was applied to evaluate the accuracy of different methods. The result shows that simple Kriging method gave the best fit. The analysis of spatial and temporal variability suggest that the nugget effects from 2001 to 2013 were increasing, which means the spatial correlation weakened gradually under the influence of human activities. The spatial variability in the middle areas of the alluvial-proluvial fan is relatively higher than area in top and bottom. Since the changes of the land use, groundwater level also has a temporal variation, the average decline rate of groundwater level between 2007 and 2013 increases compared with 2001-2006. Urban development and population growth cause over-exploitation of residential and industrial areas. The decline rate of the groundwater level in residential, industrial and river areas is relatively high, while the decreasing of farmland area and development of water-saving irrigation reduce the quantity of water using by agriculture and decline rate of groundwater level in agricultural area is not significant.

ACS Style

Yong Xiao; Xiaomin Gu; Shiyang Yin; Jingli Shao; Yali Cui; Qiulan Zhang; Yong Niu. Geostatistical interpolation model selection based on ArcGIS and spatio-temporal variability analysis of groundwater level in piedmont plains, northwest China. SpringerPlus 2016, 5, 425 .

AMA Style

Yong Xiao, Xiaomin Gu, Shiyang Yin, Jingli Shao, Yali Cui, Qiulan Zhang, Yong Niu. Geostatistical interpolation model selection based on ArcGIS and spatio-temporal variability analysis of groundwater level in piedmont plains, northwest China. SpringerPlus. 2016; 5 (1):425.

Chicago/Turabian Style

Yong Xiao; Xiaomin Gu; Shiyang Yin; Jingli Shao; Yali Cui; Qiulan Zhang; Yong Niu. 2016. "Geostatistical interpolation model selection based on ArcGIS and spatio-temporal variability analysis of groundwater level in piedmont plains, northwest China." SpringerPlus 5, no. 1: 425.

Journal article
Published: 01 September 2015 in Journal of Environmental Quality
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Colloid attachment is an important retention mechanism. It is influenced by colloid size, pore size, and flow rate, among other factors. In this work, we studied colloid attachment experimentally under various flow rates, as well as colloid release in response to a rapid change of flow rate. Colloid transport experiments under saturated conditions and with different flow rates were conducted in a physical micromodel. The micromodel was made of polydimethylsiloxane (PDMS), which is a hydrophobic polymer. Colloids were hydrophilic fluorescent carboxylate-modified polystyrene latex microspheres with a mean diameter of 300 nm. We could directly observe the movement of colloids within the pores using a confocal microscope. We also obtained concentration breakthrough curves by measuring the fluorescence intensity at the outlet of the micromodel. In addition, our experiments were simulated using a pore-network modeling, PoreFlow, based on the pore structure of the micromodel. Local colloid concentrations were calculated by solving local mass balance equations for all network elements and then averaging resulting concentrations over the whole micromodel. The measured breakthrough curves were successfully simulated using PoreFlow. Observed and calculated breakthrough curves showed that colloid attachment rate was smaller for larger flow rate. Temporally enhance colloid release (remobilization of attached colloids) was observed when the flow rate was increased by a factor of 10. But no colloid remobilization was observed when the flow rate decreased by a factor of 10. Copyright © 2015. . Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

ACS Style

Qiulan Zhang; Amir Raoof; S. M. Hassanizadeh. Pore-Scale Study of Flow Rate on Colloid Attachment and Remobilization in a Saturated Micromodel. Journal of Environmental Quality 2015, 44, 1376 -1383.

AMA Style

Qiulan Zhang, Amir Raoof, S. M. Hassanizadeh. Pore-Scale Study of Flow Rate on Colloid Attachment and Remobilization in a Saturated Micromodel. Journal of Environmental Quality. 2015; 44 (5):1376-1383.

Chicago/Turabian Style

Qiulan Zhang; Amir Raoof; S. M. Hassanizadeh. 2015. "Pore-Scale Study of Flow Rate on Colloid Attachment and Remobilization in a Saturated Micromodel." Journal of Environmental Quality 44, no. 5: 1376-1383.

Research article
Published: 11 September 2014 in Water Resources Research
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The goal of this research was to investigate the difference in behavior of hydrophilic and hydrophobic colloids during transport in two‐phase flow, in general, and their attachment and remobilization characters, in particular. Experiments were performed in a hydrophobic polydimethylsiloxane (PDMS) micromodel. Water and fluorinert‐FC43 were used as the two immiscible liquids. Given the fact that PDMS is a hydrophobic material, fluorinert was the wetting phase and water was the nonwetting phase in this micromodel. As model colloids, we used hydrophilic polystyrene carboxylate‐modified microspheres (dispersible in water) and hydrophobic fluorous‐modified silica microspheres (dispersible in fluorinert) in separate experiments. Using a confocal laser scanning microscope, we directly observed fluid distribution and colloid movement within pores of the micromodel. We also obtained concentration breakthrough curves by measuring the fluorescent intensities in the outlet of the micromodel. The breakthrough curves during steady‐state flow showed that the colloid attachment rate is inversely related to the background saturation of the fluid in which the colloids were dispersed. Our visualization results showed that the enhanced attachment of hydrophilic colloids at lower water saturations was due to the retention at the fluorinert‐water interface and fluorinert‐water‐solid contact lines. This effect was observed to be much less in the case of hydrophobic colloids (dispersed in fluorinert). In order to explain the colloids behavior, we calculated interaction potential energies of colloids with PDMS surfaces, fluid‐fluid interfaces, and fluid‐fluid‐solid contact lines. Also, balance of forces that control colloid, including DLVO, hydrodynamic, and surface tension forces, were determined. Our calculations showed that there is a stronger repulsive energy barrier between hydrophobic colloids and fluorinert‐water interface and solid‐fluid interface, compared with the hydrophilic colloids. Moreover, hydrophobic colloids were seen to aggregate due to strong attractive forces among them. These aggregates had even less tendency to attach to various interfaces, due to an increase in the corresponding energy barrier. For the colloid retention at fluid‐fluid‐solid contact lines, we found that the role of DLVO interactions was less important than capillary forces. During transient events, we found that attached colloids become remobilized. The colloids deposited on the solid‐fluid interface were detached by the moving fluid‐fluid‐solid contact lines. But, this happened only when the liquid containing colloids was being displaced by the other liquid. We simulated breakthrough curves using a model based on a coupled system of equations for two‐phase flow, advection‐dispersion of colloids, adsorption to and desorption from fluid‐fluid interfaces and fluid‐solid interfaces. Very good agreements were obtained among measured breakthrough curves, visualization results, and numerical modeling.

ACS Style

Qiulan Zhang; S. M. Hassanizadeh; B. Liu; J. F. Schijven; N. K. Karadimitriou. Effect of hydrophobicity on colloid transport during two-phase flow in a micromodel. Water Resources Research 2014, 50, 7677 -7691.

AMA Style

Qiulan Zhang, S. M. Hassanizadeh, B. Liu, J. F. Schijven, N. K. Karadimitriou. Effect of hydrophobicity on colloid transport during two-phase flow in a micromodel. Water Resources Research. 2014; 50 (10):7677-7691.

Chicago/Turabian Style

Qiulan Zhang; S. M. Hassanizadeh; B. Liu; J. F. Schijven; N. K. Karadimitriou. 2014. "Effect of hydrophobicity on colloid transport during two-phase flow in a micromodel." Water Resources Research 50, no. 10: 7677-7691.

Journal article
Published: 06 December 2013 in Water Resources Research
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ACS Style

Qiulan Zhang; S. M. Hassanizadeh; N. K. Karadimitriou; Amir Raoof; Bing Liu; P. J. Kleingeld; A. Imhof. Retention and remobilization of colloids during steady-state and transient two-phase flow. Water Resources Research 2013, 49, 8005 -8016.

AMA Style

Qiulan Zhang, S. M. Hassanizadeh, N. K. Karadimitriou, Amir Raoof, Bing Liu, P. J. Kleingeld, A. Imhof. Retention and remobilization of colloids during steady-state and transient two-phase flow. Water Resources Research. 2013; 49 (12):8005-8016.

Chicago/Turabian Style

Qiulan Zhang; S. M. Hassanizadeh; N. K. Karadimitriou; Amir Raoof; Bing Liu; P. J. Kleingeld; A. Imhof. 2013. "Retention and remobilization of colloids during steady-state and transient two-phase flow." Water Resources Research 49, no. 12: 8005-8016.

Journal article
Published: 01 July 2013 in Journal of Colloid and Interface Science
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As a representation of a porous medium, a closed micro-fluidic device made of polydimethylsiloxane (PDMS), with uniform wettability and stable hydrophobic properties, was designed and fabricated. A flow network, with a mean pore size of 30 μm, was formed in a PDMS slab, covering an area of 1 mm × 10 mm. The PDMS slab was covered and bonded with a 120-μm-thick glass plate to seal the model. The glass plate was first spin-coated with a thin layer, roughly 10 μm, of PDMS. The micro-model was treated with silane in order to make it uniformly and stably hydrophobic. Fluorescent particles of 300 μm in diameter were used as colloids. It is known that more removal of colloids occurs under unsaturated conditions, compared to saturated flow in soil. At the same time, the change of saturation has been observed to cause remobilization of attached colloids. The mechanisms for these phenomena are not well understood. This is the first time that a closed micro-model, made of PDMS with uniform and stable wettability, has been used in combination with confocal microscopy to study colloid transport under transient two-phase flow conditions. With confocal microscopy, the movement of fluorescent particles and flow of two liquids within the pores can be studied. One can focus at different depths within the pores and thus determine where the particles exactly are. Thus, remobilization of attached colloids by moving fluid-fluid interfaces was visualized. In order to allow for the deposition and subsequent remobilization of colloids during two-phase flow, three micro-channels for the injection of liquids with and without colloids were constructed. An outlet channel was designed where effluent concentration breakthrough curves can be quantified by measuring the fluorescence intensity. A peak concentration also indicated in the breakthrough curve with the drainage event. The acquired images and breakthrough curve successfully confirmed the utility of the combination of such a PDMS micro-model and confocal microscopy for the visualization of colloid transport in a flow network filled with two fluids, and in particular, the colloids retention, mobilization, and transport under transient flow conditions.

ACS Style

Qiulan Zhang; N.K. Karadimitriou; S.M. Hassanizadeh; P.J. Kleingeld; A. Imhof. Study of colloids transport during two-phase flow using a novel polydimethylsiloxane micro-model. Journal of Colloid and Interface Science 2013, 401, 141 -147.

AMA Style

Qiulan Zhang, N.K. Karadimitriou, S.M. Hassanizadeh, P.J. Kleingeld, A. Imhof. Study of colloids transport during two-phase flow using a novel polydimethylsiloxane micro-model. Journal of Colloid and Interface Science. 2013; 401 ():141-147.

Chicago/Turabian Style

Qiulan Zhang; N.K. Karadimitriou; S.M. Hassanizadeh; P.J. Kleingeld; A. Imhof. 2013. "Study of colloids transport during two-phase flow using a novel polydimethylsiloxane micro-model." Journal of Colloid and Interface Science 401, no. : 141-147.