The Ordovician karst groundwater in the Qiligou basin is an important water supply source. This groundwater has been seriously contaminated in recent years by Cfl4 from a pesticide plant located in the recharge area. ...The Ordovician karst groundwater in the Qiligou basin is an important water supply source. This groundwater has been seriously contaminated in recent years by Cfl4 from a pesticide plant located in the recharge area. The highest concentration of CCl4 in the groundwater is 3909.2μg/L. Large scale tracer experiments were carried out to study the conveying conduits for Cfl4 in the basin on May 1-6, 2005. Nontoxic, edible glucose was used as a tracer and it was detected by spectrophotometric techniques. Well area of the basin, was employed for injecting the tracer X-61, located near the pesticide plant in the southern recharge Ten wells widely located in the groundwater runoff area were used as observing and sampling wells. The results show that the migration of the pollutants is controlled by the water hydrodynamic field and by the development of karst conduits. The tracer did not enter the up-drainage wells, X-49 and X-47, near the injection point because the water levels at these wells are higher than at the injection point. The adjacent well X-62 is close to the injection site, but the tracer reached the well after eleven hours. Wells X-43, X-59, X-58, YY-1 and X-57, located in the syncline axis runoff area, are respectively 2.5, 3.5, 4.33, 4.38 and 5.44 kilometers from the in- jection site. The time for initial appearance of tracer was 4, 4, 2, 6 and 4 hours, respectively. The maximum runoff velocity （well X-58） is over two kilometers per hour, indicating that the karst conduits are well developed along the syncline basin axis. These conduits are the main conveying conduits for groundwater and Cfl4. Closer wells were not necessarily the first to receive tracer. This shows the inhomogeneity in karst development which causes complex runoff, and pollutant migration, patterns.展开更多
The effectiveness of an injection-based remediation strategy is primarily governed by accurate understanding of reagent delivery and ensuring uniform distribution within the reactive zone. In IRZ （in situ reactive z...The effectiveness of an injection-based remediation strategy is primarily governed by accurate understanding of reagent delivery and ensuring uniform distribution within the reactive zone. In IRZ （in situ reactive zone） design, the required reagent strength, injection volumes, injection rates, injection frequency, injection and monitoring well spacing, and the cost and time to achieve remediation goals are governed by the hydrogeology of the site. A properly designed tracer test is capable of providing critical above mentioned site-specific information, to assist with full scale design of an IRZ. This paper describes that implementing tracer testing to support remedial design can result in enhanced design efficiency, added assurance in full-scale implementation and ultimately resulted in substantial cost savings. Therefore, it is recommended that the broader practitioner community adopt this technique as a best practice for effective and optimum in situ remediation system design.展开更多
In a rectangular fluidized bed combustor, the tracer gas is injected continuously into the bed from a point source at the center of the distributor plate. In this study, a general governing equation is formulated for ...In a rectangular fluidized bed combustor, the tracer gas is injected continuously into the bed from a point source at the center of the distributor plate. In this study, a general governing equation is formulated for tracer gas dispersion in the bed. An analytical solution is derived to estimate the dispersion coefficients, Dxand Dy, in a horizontal plane. The concentration profiles at different sampling heights with various gas velocities are plotted.Subsequently, to estimate the dispersion coefficients, surface fitting of the obtained analytical solution to the experimental data is performed. The dispersion coefficients obtained from this model are compared with those of a conventional model. Additionally, the effect of walls, bed height and gas injection rate on the dispersion coefficients in a horizontal plane is investigated, and the effect of distributor design on the dispersion coefficients in a horizontal plane is investigated with different tracer positions. It is found that Dxand Dyare nearly equivalent at a lower tracer gas ratio of the injected gas to the total gas flow rate. It is also demonstrated that the effect of bed height on Dxis minor. This model is also able to estimate the dispersion coefficients in the case of a multihorizontal nozzle distributor.展开更多
In order to investigate the transformation among the precipitation,groundwater,and surface water in the Sanjiang Plain,Northeast China,precipitation and groundwater samples which were collected at the meteorological s...In order to investigate the transformation among the precipitation,groundwater,and surface water in the Sanjiang Plain,Northeast China,precipitation and groundwater samples which were collected at the meteorological station of the Sanjiang Mire Wetland Experimental Station,Chinese Academy of Sciences and the surface water which collected from the Wolulan River were used to identify the transformation of three types of water.The isotope composition of different kinds of water sources were analyzed via stable isotope(deuterium and oxygen-18) investigation of natural water.The results show a clear seasonal difference in the stable isotopes in precipitation.During the cold half-year,the mean stable isotope in precipitation in the Sanjiang Plain reaches its minimum with the minimum temperature.The δ18O and δD values are high in the rainy season.In the Wolulan River,the evaporation is the highest in August and September.The volume of evaporation and the replenishment to the river is mostly same.The groundwater is recharged more by the direct infiltration of precipitation than by the river flow.The results of this study indicate that the water bodies in the Sanjiang Plain have close hydrologic relationships,and that the transformation among each water system frequently occurs.展开更多
[Objective] The research aimed to study the application of chemical tracing experiment technique in leakage detection of hydraulic engineering.[Method] According to the current situation of Sanyuan Western Suburb Rese...[Objective] The research aimed to study the application of chemical tracing experiment technique in leakage detection of hydraulic engineering.[Method] According to the current situation of Sanyuan Western Suburb Reservoir in Xianyang City of Shaanxi Province,three sections （L1,L2 and L3） were set.KI was selected as the chemical tracer to carry out the tracing and detection research.[Result] There was no obvious leakage phenomenon in L1,L2 and L3 sections.The impermeability of rock in some dam abutments was bad.[Conclusion] The leakage reason of Western Suburb Reservoir was that the impermeability of rock in some dam abutments couldn’t satisfy seepage requirement.After the reservoir was put into operation,the water level in front of dam rose,and the ground water level of dam abutment also rose.The penetration water pressure correspondingly increased,and the water content of bank slope at the downstream of dam increased.展开更多
Infiltration and localization of preferential infiltration zones at the dam abutment are measured using radioactive tracer tests of flow in boreholes, meanwhile interconnection between boreholes and the energing water...Infiltration and localization of preferential infiltration zones at the dam abutment are measured using radioactive tracer tests of flow in boreholes, meanwhile interconnection between boreholes and the energing water points is analysed. The theory and practice of radioactive tracer synthetic detective method are described to give methods and calculation formulae used under the condition of stable flow in single well to measure permeability coefficient and hydrostatic heads. Major single hole techniques including measurement for seepage line, velocity, rate of seepage flow and relationship of recharge of groundwater in aquifers are introduced briefly.The possibilities offered by natural tracers are analysed, including electric-conduct,pH-value and temperature of water as well as stable isotopes (D, 18O) and tritium.Furthermore, the sensibilities of this theory and methods were confirmed by detecting seepage flow field of Xinanjiang Dam.展开更多
A hydrochemical and tracer study （uranine injection） was conducted in Jurassic limestone of the Posht-e-Naz area in the Alborz belt to evaluate hydraulic relations between a large diameter （about 100m） sinkhole an...A hydrochemical and tracer study （uranine injection） was conducted in Jurassic limestone of the Posht-e-Naz area in the Alborz belt to evaluate hydraulic relations between a large diameter （about 100m） sinkhole and springs and aquifer parameters. A main goal of the project was to find out the source of turbidity of the Emarate drinking water supply spring （SP4） in rainy season. Springs discharge were measured and hydrochemical investigation were carried out. The uranine tracer was injected and eight springs, three wells and the Neka River were selected and totally 989 samples in 107 days were collected. Hydrochemical data demonstrated a relative connection between sinkhole （Shl） and spring （SP4）. The results of the tracing by sampling water indicated only a hydraulic connection between Sange- Nou spring （SP8） and injection point, while the charcoal packets analysis revealed tracer exits from spring numbers SP1, SP3, SP4, SP5, SP8, in wells W1 and W2, and in the Neka River. The concentration - time curves of charcoal packets for qualitative analysis and exit tracer for quantitative analysis is also assessed.展开更多
Accelerated soil erosion and land degradation represent major environmental problems for agricultural lands.Reliable information on the rates of soil loss is urgently needed.The traditional techniques for documenting ...Accelerated soil erosion and land degradation represent major environmental problems for agricultural lands.Reliable information on the rates of soil loss is urgently needed.The traditional techniques for documenting rates of soil loss may meet this need,but face many limitations.The fallout radionuclides,especially 137 Cs and 210 Pb ex,are increasingly used as effective tracers to quantify soil erosion rates,and they represent a valuable complement to the existing classical methods.This paper aims to introduce the basis for assessing soil erosion rates on cultivated and uncultivated slopes by using 137 Cs and 210 Pb ex measurements,to compare the 137 Cs and 210 Pb ex reference inventories,and to report several case studies undertaken in the hilly area of Sichuan Basin and the Three Gorges area of China.展开更多
基金Project 40373044 supported by the National Natural Science Foundation of China
文摘The Ordovician karst groundwater in the Qiligou basin is an important water supply source. This groundwater has been seriously contaminated in recent years by Cfl4 from a pesticide plant located in the recharge area. The highest concentration of CCl4 in the groundwater is 3909.2μg/L. Large scale tracer experiments were carried out to study the conveying conduits for Cfl4 in the basin on May 1-6, 2005. Nontoxic, edible glucose was used as a tracer and it was detected by spectrophotometric techniques. Well area of the basin, was employed for injecting the tracer X-61, located near the pesticide plant in the southern recharge Ten wells widely located in the groundwater runoff area were used as observing and sampling wells. The results show that the migration of the pollutants is controlled by the water hydrodynamic field and by the development of karst conduits. The tracer did not enter the up-drainage wells, X-49 and X-47, near the injection point because the water levels at these wells are higher than at the injection point. The adjacent well X-62 is close to the injection site, but the tracer reached the well after eleven hours. Wells X-43, X-59, X-58, YY-1 and X-57, located in the syncline axis runoff area, are respectively 2.5, 3.5, 4.33, 4.38 and 5.44 kilometers from the in- jection site. The time for initial appearance of tracer was 4, 4, 2, 6 and 4 hours, respectively. The maximum runoff velocity （well X-58） is over two kilometers per hour, indicating that the karst conduits are well developed along the syncline basin axis. These conduits are the main conveying conduits for groundwater and Cfl4. Closer wells were not necessarily the first to receive tracer. This shows the inhomogeneity in karst development which causes complex runoff, and pollutant migration, patterns.
文摘The effectiveness of an injection-based remediation strategy is primarily governed by accurate understanding of reagent delivery and ensuring uniform distribution within the reactive zone. In IRZ （in situ reactive zone） design, the required reagent strength, injection volumes, injection rates, injection frequency, injection and monitoring well spacing, and the cost and time to achieve remediation goals are governed by the hydrogeology of the site. A properly designed tracer test is capable of providing critical above mentioned site-specific information, to assist with full scale design of an IRZ. This paper describes that implementing tracer testing to support remedial design can result in enhanced design efficiency, added assurance in full-scale implementation and ultimately resulted in substantial cost savings. Therefore, it is recommended that the broader practitioner community adopt this technique as a best practice for effective and optimum in situ remediation system design.
基金The financial support from the Ministry of Science and Technology under Grant MOST 105-3113-E-033-001
文摘In a rectangular fluidized bed combustor, the tracer gas is injected continuously into the bed from a point source at the center of the distributor plate. In this study, a general governing equation is formulated for tracer gas dispersion in the bed. An analytical solution is derived to estimate the dispersion coefficients, Dxand Dy, in a horizontal plane. The concentration profiles at different sampling heights with various gas velocities are plotted.Subsequently, to estimate the dispersion coefficients, surface fitting of the obtained analytical solution to the experimental data is performed. The dispersion coefficients obtained from this model are compared with those of a conventional model. Additionally, the effect of walls, bed height and gas injection rate on the dispersion coefficients in a horizontal plane is investigated, and the effect of distributor design on the dispersion coefficients in a horizontal plane is investigated with different tracer positions. It is found that Dxand Dyare nearly equivalent at a lower tracer gas ratio of the injected gas to the total gas flow rate. It is also demonstrated that the effect of bed height on Dxis minor. This model is also able to estimate the dispersion coefficients in the case of a multihorizontal nozzle distributor.
基金Under the auspices of Major Science and Technology Program for Water Pollution Control and Treatment(No.2012ZX07201004)National Natural Science Foundation of China(No.41101470)
文摘In order to investigate the transformation among the precipitation,groundwater,and surface water in the Sanjiang Plain,Northeast China,precipitation and groundwater samples which were collected at the meteorological station of the Sanjiang Mire Wetland Experimental Station,Chinese Academy of Sciences and the surface water which collected from the Wolulan River were used to identify the transformation of three types of water.The isotope composition of different kinds of water sources were analyzed via stable isotope(deuterium and oxygen-18) investigation of natural water.The results show a clear seasonal difference in the stable isotopes in precipitation.During the cold half-year,the mean stable isotope in precipitation in the Sanjiang Plain reaches its minimum with the minimum temperature.The δ18O and δD values are high in the rainy season.In the Wolulan River,the evaporation is the highest in August and September.The volume of evaporation and the replenishment to the river is mostly same.The groundwater is recharged more by the direct infiltration of precipitation than by the river flow.The results of this study indicate that the water bodies in the Sanjiang Plain have close hydrologic relationships,and that the transformation among each water system frequently occurs.
文摘[Objective] The research aimed to study the application of chemical tracing experiment technique in leakage detection of hydraulic engineering.[Method] According to the current situation of Sanyuan Western Suburb Reservoir in Xianyang City of Shaanxi Province,three sections （L1,L2 and L3） were set.KI was selected as the chemical tracer to carry out the tracing and detection research.[Result] There was no obvious leakage phenomenon in L1,L2 and L3 sections.The impermeability of rock in some dam abutments was bad.[Conclusion] The leakage reason of Western Suburb Reservoir was that the impermeability of rock in some dam abutments couldn’t satisfy seepage requirement.After the reservoir was put into operation,the water level in front of dam rose,and the ground water level of dam abutment also rose.The penetration water pressure correspondingly increased,and the water content of bank slope at the downstream of dam increased.
文摘Infiltration and localization of preferential infiltration zones at the dam abutment are measured using radioactive tracer tests of flow in boreholes, meanwhile interconnection between boreholes and the energing water points is analysed. The theory and practice of radioactive tracer synthetic detective method are described to give methods and calculation formulae used under the condition of stable flow in single well to measure permeability coefficient and hydrostatic heads. Major single hole techniques including measurement for seepage line, velocity, rate of seepage flow and relationship of recharge of groundwater in aquifers are introduced briefly.The possibilities offered by natural tracers are analysed, including electric-conduct,pH-value and temperature of water as well as stable isotopes (D, 18O) and tritium.Furthermore, the sensibilities of this theory and methods were confirmed by detecting seepage flow field of Xinanjiang Dam.
文摘A hydrochemical and tracer study （uranine injection） was conducted in Jurassic limestone of the Posht-e-Naz area in the Alborz belt to evaluate hydraulic relations between a large diameter （about 100m） sinkhole and springs and aquifer parameters. A main goal of the project was to find out the source of turbidity of the Emarate drinking water supply spring （SP4） in rainy season. Springs discharge were measured and hydrochemical investigation were carried out. The uranine tracer was injected and eight springs, three wells and the Neka River were selected and totally 989 samples in 107 days were collected. Hydrochemical data demonstrated a relative connection between sinkhole （Shl） and spring （SP4）. The results of the tracing by sampling water indicated only a hydraulic connection between Sange- Nou spring （SP8） and injection point, while the charcoal packets analysis revealed tracer exits from spring numbers SP1, SP3, SP4, SP5, SP8, in wells W1 and W2, and in the Neka River. The concentration - time curves of charcoal packets for qualitative analysis and exit tracer for quantitative analysis is also assessed.
基金by the National Key Technology R&D Program (2011BAD31B03)the Important National Science & Technology Specific Projects (2009ZX07104-002-06)the ActionPlan for West Development of Chinese Academy of Sciences (KZCX2-XB3-09)
文摘Accelerated soil erosion and land degradation represent major environmental problems for agricultural lands.Reliable information on the rates of soil loss is urgently needed.The traditional techniques for documenting rates of soil loss may meet this need,but face many limitations.The fallout radionuclides,especially 137 Cs and 210 Pb ex,are increasingly used as effective tracers to quantify soil erosion rates,and they represent a valuable complement to the existing classical methods.This paper aims to introduce the basis for assessing soil erosion rates on cultivated and uncultivated slopes by using 137 Cs and 210 Pb ex measurements,to compare the 137 Cs and 210 Pb ex reference inventories,and to report several case studies undertaken in the hilly area of Sichuan Basin and the Three Gorges area of China.
