Hydroxyquinone compounds, such as 1,4-dihydroxyanthraquinone and alizarin sulfonate, are widely used in dye manufacturing, pharmaceutical manufacturing, and other industries. However, the treatment of hydroxyquinone-c...Hydroxyquinone compounds, such as 1,4-dihydroxyanthraquinone and alizarin sulfonate, are widely used in dye manufacturing, pharmaceutical manufacturing, and other industries. However, the treatment of hydroxyquinone-containing wastewater has seldom been examined. This study used a precipitation method with barium salt to treat nano-silver industrial wastewater. The results show that barium chloride was a suitable reagent for significantly degrading COD and color from nano-silver wastewater. When the initial pH value was 10.5, 8 g of BaCl2·2H2O were added to 100 mL of wastewater. After reaction at 15℃ for 1 h, the removal efficiencies of COD and color in the nano-silver wastewater were 85.6% and 97.1%, respectively. Simulated wastewater containing sodium alizarin-3-sulfonate (ARS) or purpurin was used to further investigate the removal mechanism of hydroxyquinone compounds. Fourier transform infrared spectroscopy, X-ray diffraction, and some related experiments showed that hydroxyquinone compounds can directly react with barium ions in the solution so as to transfer from wastewater to precipitate. In addition, the newly produced barium sulfate particles have positive surface charges, which can improve the removal efficiency of hydroxyquinone compounds due to electrostatic attraction.展开更多
Static experiments and dynamic displacement experiments were conducted to quantitatively determine the amount of precipitate generated by the CO_(2)-formation water reaction at different temperatures,pressures,and sca...Static experiments and dynamic displacement experiments were conducted to quantitatively determine the amount of precipitate generated by the CO_(2)-formation water reaction at different temperatures,pressures,and scaling ion concentrations during CO_(2) flooding in the Chang 8 block of Changqing Oilfield,the influence of precipitate on the physical properties of reservoirs was investigated,and the corresponding mathematical characterization model was established.The mathematical characterization equation was used to correct the numerical simulation model of E300 module in Eclipse software.The distribution pattern of inorganic salt precipitates during continuous CO_(2) flooding in Chang 8 block was simulated,and the influence of inorganic salt precipitates on oil recovery was predicted.The inorganic salt precipitate generated during CO_(2)-formation water reaction was mainly CaCO_(3),and the pressure difference and scaling ion concentration were proportional to the amount of precipitate generated,while the temperature was inversely proportional to the amount of precipitate.The rate of core porosity change before and after CO_(2) flooding was positively correlated with temperature and flooding pressure difference.The core porosity increase in the CO_(2)-formation water-core reaction experiment was always lower than that of CO_(2)-distilled water-core reaction experiment because of precipitation.The area around the production wells had the most precipitates generated with the injection of CO_(2).The oil field became poor in development because of the widely distributed precipitate and the recovery decreased to 33.45% from 37.64% after 20-year-CO_(2) flooding when considering of precipitation.展开更多
1 Introduction The main production of Yabulai salt lake was original salt and recycled salt many years ago.After decade’s production,the sale lake resource is more and more deficient.Glauber’s salt and magnesium sal...1 Introduction The main production of Yabulai salt lake was original salt and recycled salt many years ago.After decade’s production,the sale lake resource is more and more deficient.Glauber’s salt and magnesium salt are concentrated in brine now.It could affect the quality of the salt.In recent years,research had done much work to展开更多
Water flooding and pressure maintenance are recommended to improve oil recovery practices after low recovery of petroleum reservoirs occurs during primary production.Salt crystal formation is a frequent occurrence whe...Water flooding and pressure maintenance are recommended to improve oil recovery practices after low recovery of petroleum reservoirs occurs during primary production.Salt crystal formation is a frequent occurrence when using these techniques.Several experimental,numerical,and theoretical studies have been done on the mechanisms underlying scaling and permeability reduction in porous media;however,there has not been a satisfactory model developed.This study developed a phenomenological model to predict formation damage caused by salt deposition.Compared with existing models,which provide a scaling tendency,the proposed model predicts the profile of scale deposition.The salt precipitation model simulates reactive fluid flow through porous media.A thermodynamic,kinetic,and flow hydrodynamic model was developed and coupled with the ion transport equation to describe the movement of ions.Further,a set of carefully designed dynamic experiments were conducted and the data were compared with the model predictions.Model forecasts and experimental data were observed to have an average absolute error(AAE)ranging from 0.68%to 5.94%,which indicates the model's suitability.展开更多
Cyclic metallurgical process for separation and recovery of Cr from vanadium precipitated solution by precipitation with PbCO_(3)and leaching with Na_(2)CO_(3)was investigated.The concentration of Cr residue in the so...Cyclic metallurgical process for separation and recovery of Cr from vanadium precipitated solution by precipitation with PbCO_(3)and leaching with Na_(2)CO_(3)was investigated.The concentration of Cr residue in the solution decreases from 2.360 to 0.001 g/L by adding PbCO_(3)into vanadium precipitated solution according to Pb/Cr molar ratio of 2.5,adjusting the pH to 3.0 and stirring for 180 min at 30℃.Then,the precipitates were leached with hot Na_(2)CO_(3)solution to obtain leaching solution containing Na_(2)CrO_(4)and leaching residue containing PbCO_(3).The leaching efficiency of Cr reaches 96.43%by adding the precipitates into 0.5 mol/L Na_(2)CO_(3)solution with the mass ratio of liquid to solid(L/S)of 10:1 mL/g and stirring for 60 min under pH 9.5 at 70℃.After filtration,leaching residue is reused in Cr precipitation and leaching solution is used to circularly leach the Cr precipitates until Na_(2)CrO_(4)approaches the saturation.Finally,the product of Na_(2)CrO_(4)·4H_(2)O is obtained by evaporation and crystallization of leaching solution.展开更多
A kind of fine and quasi-spherical Y2O3:Eu3+ phosphor was prepared by firing a preparative precursor at 1 200 ℃ for 2 h with the molten salts of Na2CO3, S and NaCl. The precursor was obtained by homogeneous precipita...A kind of fine and quasi-spherical Y2O3:Eu3+ phosphor was prepared by firing a preparative precursor at 1 200 ℃ for 2 h with the molten salts of Na2CO3, S and NaCl. The precursor was obtained by homogeneous precipitation of yttrium and europium with oxalic acid when using EDTA, citric acid or starch as complexant. The structure and morphology of the phosphors were characterized by XRD and SEM, respectively. The influence of complexing environment, firing temperature and molten salts on formation of the phosphor Y2O3:Eu3+ was discussed. The result show that the prepared Y2O3:Eu3+ phosphor is of quasi-spherical structure with size of 2-3 μm. Its luminescent intensity is 30% higher than that of the same phosphor prepared by the same procedure but without molten salts, and is 5% higher than that of commercial Y2O3:Eu3+ red phosphor.展开更多
1 Introduction Dangxiongcuo salt lake(Figure 1),which is located in the southwest of Tibet,China,is rich in valuable mineral elements like lithium,potassium,boron,rubidium,caesium
Salt Lake brine pump is one of the key equipment in salt lake brine extraction device.As the salt lake brine is a kind of high concentration solution with a variety of chemical constituents,the flow and agitation of s...Salt Lake brine pump is one of the key equipment in salt lake brine extraction device.As the salt lake brine is a kind of high concentration solution with a variety of chemical constituents,the flow and agitation of saturated展开更多
Soil salinization,caused by salt migration and accumulation underneath the soil surface,will corrode structures.To analyze the moisture-salt migration and salt precipitation in soil under evaporation conditions,a math...Soil salinization,caused by salt migration and accumulation underneath the soil surface,will corrode structures.To analyze the moisture-salt migration and salt precipitation in soil under evaporation conditions,a mathematical model consisting of a series of theoretical equations is briefly presented.The filling effect of precipitated salts on tortuosity factor and evaporation rate are taken into account in relevant equations.Besides,a transition equation to link the solute transport equation before and after salt precipitation is proposed.Meanwhile,a new relative humidity equation deduced from Pitzer ions model is used to modify the vapor transport flux equation.The results show that the calculated values are in good agreement with the published experimental data,especially for the simulation of volume water content and evaporation rate of Toyoura sand,which confirm the reliability and applicability of the proposed model.展开更多
1 Introduction China is a country which has many salt lakes.Tibet is the area where have numerous salt lake,because the sources of water have multiple chemical type,resulting in Tibet salt
基金supported by the National Natural Science Foundation of China(Grant No.51868029)the Yunnan Applied Basic Research Projects(Grant No.2016FB093)
文摘Hydroxyquinone compounds, such as 1,4-dihydroxyanthraquinone and alizarin sulfonate, are widely used in dye manufacturing, pharmaceutical manufacturing, and other industries. However, the treatment of hydroxyquinone-containing wastewater has seldom been examined. This study used a precipitation method with barium salt to treat nano-silver industrial wastewater. The results show that barium chloride was a suitable reagent for significantly degrading COD and color from nano-silver wastewater. When the initial pH value was 10.5, 8 g of BaCl2·2H2O were added to 100 mL of wastewater. After reaction at 15℃ for 1 h, the removal efficiencies of COD and color in the nano-silver wastewater were 85.6% and 97.1%, respectively. Simulated wastewater containing sodium alizarin-3-sulfonate (ARS) or purpurin was used to further investigate the removal mechanism of hydroxyquinone compounds. Fourier transform infrared spectroscopy, X-ray diffraction, and some related experiments showed that hydroxyquinone compounds can directly react with barium ions in the solution so as to transfer from wastewater to precipitate. In addition, the newly produced barium sulfate particles have positive surface charges, which can improve the removal efficiency of hydroxyquinone compounds due to electrostatic attraction.
文摘Static experiments and dynamic displacement experiments were conducted to quantitatively determine the amount of precipitate generated by the CO_(2)-formation water reaction at different temperatures,pressures,and scaling ion concentrations during CO_(2) flooding in the Chang 8 block of Changqing Oilfield,the influence of precipitate on the physical properties of reservoirs was investigated,and the corresponding mathematical characterization model was established.The mathematical characterization equation was used to correct the numerical simulation model of E300 module in Eclipse software.The distribution pattern of inorganic salt precipitates during continuous CO_(2) flooding in Chang 8 block was simulated,and the influence of inorganic salt precipitates on oil recovery was predicted.The inorganic salt precipitate generated during CO_(2)-formation water reaction was mainly CaCO_(3),and the pressure difference and scaling ion concentration were proportional to the amount of precipitate generated,while the temperature was inversely proportional to the amount of precipitate.The rate of core porosity change before and after CO_(2) flooding was positively correlated with temperature and flooding pressure difference.The core porosity increase in the CO_(2)-formation water-core reaction experiment was always lower than that of CO_(2)-distilled water-core reaction experiment because of precipitation.The area around the production wells had the most precipitates generated with the injection of CO_(2).The oil field became poor in development because of the widely distributed precipitate and the recovery decreased to 33.45% from 37.64% after 20-year-CO_(2) flooding when considering of precipitation.
基金financial support of National Nature Science Foundation (21376178)TIDA giant growth plan (2011-XJR13020)+3 种基金Tianjin Science and technology support program (12ZCDZSF06900)Tianjin University of Science and Technology fund for scientific research (20120119)Tianjin education commission program (20130509)Research fund for the doctoral program of higher education of China (20131208120001)
文摘1 Introduction The main production of Yabulai salt lake was original salt and recycled salt many years ago.After decade’s production,the sale lake resource is more and more deficient.Glauber’s salt and magnesium salt are concentrated in brine now.It could affect the quality of the salt.In recent years,research had done much work to
文摘Water flooding and pressure maintenance are recommended to improve oil recovery practices after low recovery of petroleum reservoirs occurs during primary production.Salt crystal formation is a frequent occurrence when using these techniques.Several experimental,numerical,and theoretical studies have been done on the mechanisms underlying scaling and permeability reduction in porous media;however,there has not been a satisfactory model developed.This study developed a phenomenological model to predict formation damage caused by salt deposition.Compared with existing models,which provide a scaling tendency,the proposed model predicts the profile of scale deposition.The salt precipitation model simulates reactive fluid flow through porous media.A thermodynamic,kinetic,and flow hydrodynamic model was developed and coupled with the ion transport equation to describe the movement of ions.Further,a set of carefully designed dynamic experiments were conducted and the data were compared with the model predictions.Model forecasts and experimental data were observed to have an average absolute error(AAE)ranging from 0.68%to 5.94%,which indicates the model's suitability.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(No.51974369)NSFC-STINT(No.52111530192)+1 种基金Postgraduate Research Innovation Project of Central South University,China(No.2019zzts244)the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University,China(No.CSUZC202029).
文摘Cyclic metallurgical process for separation and recovery of Cr from vanadium precipitated solution by precipitation with PbCO_(3)and leaching with Na_(2)CO_(3)was investigated.The concentration of Cr residue in the solution decreases from 2.360 to 0.001 g/L by adding PbCO_(3)into vanadium precipitated solution according to Pb/Cr molar ratio of 2.5,adjusting the pH to 3.0 and stirring for 180 min at 30℃.Then,the precipitates were leached with hot Na_(2)CO_(3)solution to obtain leaching solution containing Na_(2)CrO_(4)and leaching residue containing PbCO_(3).The leaching efficiency of Cr reaches 96.43%by adding the precipitates into 0.5 mol/L Na_(2)CO_(3)solution with the mass ratio of liquid to solid(L/S)of 10:1 mL/g and stirring for 60 min under pH 9.5 at 70℃.After filtration,leaching residue is reused in Cr precipitation and leaching solution is used to circularly leach the Cr precipitates until Na_(2)CrO_(4)approaches the saturation.Finally,the product of Na_(2)CrO_(4)·4H_(2)O is obtained by evaporation and crystallization of leaching solution.
基金Project(50372086) supported by the National Natural Science Foundation of China
文摘A kind of fine and quasi-spherical Y2O3:Eu3+ phosphor was prepared by firing a preparative precursor at 1 200 ℃ for 2 h with the molten salts of Na2CO3, S and NaCl. The precursor was obtained by homogeneous precipitation of yttrium and europium with oxalic acid when using EDTA, citric acid or starch as complexant. The structure and morphology of the phosphors were characterized by XRD and SEM, respectively. The influence of complexing environment, firing temperature and molten salts on formation of the phosphor Y2O3:Eu3+ was discussed. The result show that the prepared Y2O3:Eu3+ phosphor is of quasi-spherical structure with size of 2-3 μm. Its luminescent intensity is 30% higher than that of the same phosphor prepared by the same procedure but without molten salts, and is 5% higher than that of commercial Y2O3:Eu3+ red phosphor.
基金supported by project of G1316 from National Natural Science Foundation of ChinaK1322 from the Institute of Mineral Resources, Chinese Academy of Geological Sciences
文摘1 Introduction Dangxiongcuo salt lake(Figure 1),which is located in the southwest of Tibet,China,is rich in valuable mineral elements like lithium,potassium,boron,rubidium,caesium
基金support of Jiangsu Province ordinary university graduate research innovation projects
文摘Salt Lake brine pump is one of the key equipment in salt lake brine extraction device.As the salt lake brine is a kind of high concentration solution with a variety of chemical constituents,the flow and agitation of saturated
基金the National Key Research and Development Program of China(Grant No.2018YFC0809605)the National Natural Science Foundation of China(Grant Nos.41230630,41601074)+1 种基金the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(Grant No.QYZDY-SSW-DQC015)the Program of the State Key Laboratory of Frozen Soil Engineering(Grant No.SKLFSE-ZT-23).
文摘Soil salinization,caused by salt migration and accumulation underneath the soil surface,will corrode structures.To analyze the moisture-salt migration and salt precipitation in soil under evaporation conditions,a mathematical model consisting of a series of theoretical equations is briefly presented.The filling effect of precipitated salts on tortuosity factor and evaporation rate are taken into account in relevant equations.Besides,a transition equation to link the solute transport equation before and after salt precipitation is proposed.Meanwhile,a new relative humidity equation deduced from Pitzer ions model is used to modify the vapor transport flux equation.The results show that the calculated values are in good agreement with the published experimental data,especially for the simulation of volume water content and evaporation rate of Toyoura sand,which confirm the reliability and applicability of the proposed model.
文摘1 Introduction China is a country which has many salt lakes.Tibet is the area where have numerous salt lake,because the sources of water have multiple chemical type,resulting in Tibet salt
基金supports from the National Natural Science Foundation of China(Nos.52204268,51974365,91962223)the Natural Science Foundation of Hunan Province,China(Nos.2020JJ5747,2020JJ5749)+3 种基金the Innovation-driven Project of Central South University,China(No.2020CX039)the National“111”Project of China(No.B14034)the Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources,China(No.2018TP1002)the Young Elite Scientists Sponsorship Program by CAST,China(No.2019QNRC001).
