Phosphoric acid is a key ingredient in fertilizer production and contains many rare earth elements(REEs).Recovering REEs from phosphoric acid can prevent the accumulation of these elements in the soil and help bridge ...Phosphoric acid is a key ingredient in fertilizer production and contains many rare earth elements(REEs).Recovering REEs from phosphoric acid can prevent the accumulation of these elements in the soil and help bridge the gap between supply and demand.In this concern,a new material called Si-6G PAMAMPPAAM dendrimers modified silica gel terminated with phenylphosphonic acid-amide moieties was developed and its ability to adsorb Nd(Ⅲ)and Er(Ⅲ)from the phosphoric acid solution was investigated.K inetics and isotherm of the uptake process were investigated to explo re the so rption characte ristics.The attained results show that both metal ions exhibit the same adsorption performance,and the uptake process is depicted as a chemisorption,monolayer,uniform,and homogeneous process.The equilibrium state is achieved within 120 min,and the maximum uptake capacity is 16.7 mg Nd(Ⅲ)/g,and 14.0 mg Er(Ⅲ)/g.Sorption thermodynamics is an endothermic,spontaneous,and feasible uptake process.Nitric acid(1.0 mol/L)is found to be efficient for adsorbing about 94.3%and 92.5%of neodymium(Ⅲ)and erbium(Ⅲ)respectively,and the prepared Si-6G PAMAM-PPAAM demonstrates excellent stability over five consecutive sorption/desorption cycles.Preliminary tests on commercial phosphoric acid demonstrate that Si-6G PAMAM-PPAAM retains its effective REEs uptake from a complex comm ercial phosph oric acid solution.展开更多
Helium sorption cooler technology is a key means to realize highly reliable low-vibration very lowtemperature environments,which have important applications in fields such as quantum computing and space exploration.Th...Helium sorption cooler technology is a key means to realize highly reliable low-vibration very lowtemperature environments,which have important applications in fields such as quantum computing and space exploration.The laboratory designed a superfluid suppression small hole and a multi-ribbed condenser,developed a reliable-performance helium sorption cooler(HSC),and conducted experimental studies.Experimental results show that the prototype can achieve the lowest cooling temperature of 873 mK without load by filling 6MPa helium at room temperature.The low-temperature hold time is 26 h,and the temperature fluctuation is within 0.8 mK.The cooling power of the helium sorption cooler is 1 mW@0.98 K@3.5 h.Experimental results indicate that when the charging pressure is reduced to 4MPa,theminimum temperature decreases to 836mK,and the hold time shortens to 16 h.When the pre-cooling temperature increases from 3.9 to 4.9 K,the hold time is reduced to 3 h.展开更多
Co-contamination of chlorinated hydrocarbons and arsenic is frequently observed in the chemically contaminated sites and their surroundings in China.However,the interaction between these complex contaminants in soil r...Co-contamination of chlorinated hydrocarbons and arsenic is frequently observed in the chemically contaminated sites and their surroundings in China.However,the interaction between these complex contaminants in soil remains is unclear.This study collected ten background soils with varying properties from various regions throughout China,and investigated the sorption and desorption process of trichloroethylene(TCE)in the exogenous arsenate(As(V))contaminated soils.The results of the batch experiments demonstrated that TCE was rapidly adsorbed by soil organic matter(SOM).Both SOM and minerals contributed to the slow sorption equilibrium process.The sorption isotherms were linear,while the desorption isotherms were non-linear.In Heilongjiang(HLJ)soil,As(V)contamination increased the TCE sorption contribution of black carbon and decreased the contribution of minerals.During the aging process of As(V)in soils,SOM was replaced by AsO_4~(3-),which formed complexes with soil Fe/Al oxides,resulting in a significant increase in hydroxyl groups and hydrophilicity of the soil surface.This hindered the hydrophobic sorption of TCE.Additionally,As(V)contamination affected soil geotechnical properties,and the Ascations precipitation could block the sorption micropores.The collective results of these processes caused a reduction in the sorption of TCE on the majority of As(V)-contaminated soils(702-5854 mg/kg)in comparison to background soils(1194-6374 mg/kg).The systematic investigation of sorption-desorption behaviors of TCE in As(V)-contaminated soils will provide a scientific basis for the calculation of soil environmental capacity of heavy metalorganic combined contamination in the future.展开更多
This work investigates a combined cooling,heating,and power(CCHP)generation system utilizing waste energy.A cascade-CCHP system is developed,consisting of a 23.65-kWe organic Rankine cycle(ORC),a 4.00-kW adsorption ch...This work investigates a combined cooling,heating,and power(CCHP)generation system utilizing waste energy.A cascade-CCHP system is developed,consisting of a 23.65-kWe organic Rankine cycle(ORC),a 4.00-kW adsorption chiller,a 4.11-kW absorption chiller,a 15.99-kW drying room,and an incinerator of 150 kg/h.A net energy production of 36.08 kWh is achieved from a CCHP energy efficiency of 9.98%.The levelized cost for producing a total energy output of 2,020,592 kWh over a lifespan of 20 years is approximately 0.106 USD/kWh.The life cycle assessment(LCA)yields a single score of approximately 0.000151 Pt,mainly attributed to raw materials used in the construction process of 87.16%.In addition,the combustion ash is processed into concrete blocks measuring 39 cm×19 cm×7 cm,in accordance with the Industrial Product Standard(TIS)58-2533,with a water absorption value below 5%and a compressive strength exceeding 25 kg/cm2.The CCHP system demonstrates a novel method of waste-to-energy(WtE),and the construction material from waste combustion ash can also support a new concept of waste-to-zero(WtZ).展开更多
The effect of using 2%and 10%sodium hydroxide solution as surface treatment of rape straw on its water vapor adsorption properties is analyzed in the relative humidity(RH)range of 0%to 98%.Scanning electron microscopy...The effect of using 2%and 10%sodium hydroxide solution as surface treatment of rape straw on its water vapor adsorption properties is analyzed in the relative humidity(RH)range of 0%to 98%.Scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and Fourier-transform infrared spectroscopy(FTIR)are used to investigate the morphological,chemical and structural changes of the treated straw surface.The mineral particles formed on the surface after the treatment are analyzed using X-ray diffraction(XRD).The application of sodium hydroxide solution results in the disruption of the straw surface.As the concentration of sodium hydroxide increases,the disruption of the straw surface increases,and the ability of the straw to adsorb water vapor also increases over the entire RH range.In addition to the surface disruption and chemical changes caused by the alkaline treatment,the differences in the equilibrium moisture content of treated and untreated rape straw can also be attributed to the formation of minerals on the straw surface,namely calcite for the 2%sodium hydroxide solution,and gaylussite and thermonatrite for the 10%solution.展开更多
Spinal cord injury presents a significant challenge in regenerative medicine due to the complex and deli-cate nature of neural tissue repair.This study aims to design a conductive hydrogel embedded with magnetic MgFe_...Spinal cord injury presents a significant challenge in regenerative medicine due to the complex and deli-cate nature of neural tissue repair.This study aims to design a conductive hydrogel embedded with magnetic MgFe_(2)O_(4) nanoparticles to establish a bioelectrically active and spatially stable microenvironment that promotes spinal cord regeneration through computational analysis(BIOVIA Materials Studio).Hydrogels,known for their biocompatibility and extracellular matrix-mimicking properties,support essential cellular behaviors such as adhesion,proliferation,and migration.The integration of MgFe_(2)O_(4) nanoparticles imparts both electrical conductivity and magnetic responsiveness,enabling controlled transmission of electrical signals that are crucial for guiding cellular processes like differentiation and directed migration.Furthermore,the hydrogel acts as a delivery medium,facilitating the adsorption of MgFe_(2)O_(4) nanoparticles onto spinal tissue through strong Van der Waals and intramolecular interactions.The computational simulations revealed a robust adsorption profile,with a binding distance of 20.180Åand a cumulative adsorption energy of 2740.42 kcal/mol,indicating stable nanoparticle-tissue interactions.Pressure-dependent sorption analysis further demonstrated that reduced pressure conditions enhance adsorption strength,promoting tighter material-tissue integration.The adverse Van der Waals energy and increased intramolecular energy observed under these conditions underscore the importance of optimized adsorption settings for functional tissue interface formation.Altogether,the conductive hydrogel-MgFe_(2)O_(4) composite system offers a promising therapeutic platform by combining structural support,electrical stimulation,and magnetic guidance,thereby enhancing cell-material interactions and fostering an environment conducive to spinal cord tissue repair.展开更多
Connate water strongly restricts shale gas enrichment and production,and most artificially injected water is confined in shale pore networks owing to low water recovery during hydraulic fracturing,which leads to a mor...Connate water strongly restricts shale gas enrichment and production,and most artificially injected water is confined in shale pore networks owing to low water recovery during hydraulic fracturing,which leads to a more complex pore water distribution.However,previous studies have focused on the water vapor sorption of gas shales rather than liquid pore water.This study clarifies the occurrence and distribution of pore water and the controlling factors by conducting thermogravimetry(TGA)under liquid water saturation and water vapor sorption experiments on four gas shales from the Wufeng Formation in South China.Nuclear magnetic resonance(NMR)T_(2)and T_(1)-T_(2)technologies were used to monitor the dynamic changes and states of moisture,and the microscopic pore structures during water vapor sorption were detected using low-temperature nitrogen adsorption-desorption.The results indicate that TGA is adequate for determining the adsorbed,bound,and movable water contents.These four gas shales are characterized by high adsorbed and movable water contents,and some bound water.The adsorbed water primarily occurs in tiny pores(<100 nm),controlled by organic matter,followed by clay mine rals.The movable water,typically associated with quartz,primarily exists in pores of>100 nm,particularly macropores of>1000 nm.The bound water predominantly correlates with pores ranging from 10 to 2000 nm in clay minerals.The water vapor sorption process of the gas shale is well clarified.Water molecules primarily adsorb on the clay mineral's hydrophilic surface,followed by oxygen functional groups in the organic matter.Therefore,clay mine rals control water vapor sorption at low relative humidity(RH<0.75),whereas organic matter primarily affects vapor sorption at high RH.The TGA of liquid wate r-saturated gas shales can clarify the water distributions in full-scale pore networks,whereas the water vapor sorption method primarily discloses the moisture in small nanopores(<100 nm)but ignores most bound and movable water.This paper provides insight into liquid water distribution and occurre nce states within shale pore netwo rks,contributing to a better understanding of gas-wate r-rock interaction systems in-situ and hydraulic fracturing shale gas formations.展开更多
By means of the synthetic approach of non－polar or weak polar oil－sorbed polymers，the gel sorption resin（GSR） and the multiporous sorption resin（MSR） were prepared．The structure of the resins，sorption power...By means of the synthetic approach of non－polar or weak polar oil－sorbed polymers，the gel sorption resin（GSR） and the multiporous sorption resin（MSR） were prepared．The structure of the resins，sorption power，sorption speed，desorption，and sorption of organic compounds from sewage，exhaust gas and soil were discussed．Moreover，the resins were used to decrease LOD and BOD5 values of water waste from sewage factory．Theyare a klndof potential materials for environmental control．展开更多
The adsorption of Pd(Ⅱ), Pt(IV) and Cu(Ⅱ) in static and dynamic conditions on chemically modified silica containing sulfide sulfur (number of grafted functional groups of the sorbent was 0.2 (CMS-S 0.2) and 0 3 mmol...The adsorption of Pd(Ⅱ), Pt(IV) and Cu(Ⅱ) in static and dynamic conditions on chemically modified silica containing sulfide sulfur (number of grafted functional groups of the sorbent was 0.2 (CMS-S 0.2) and 0 3 mmol/g (CMS-S 0.3)) was studied. It is established that an increase in the acidity of the sorption of Pd(Ⅱ) and Pt(Ⅳ) decreases, whereas the Cu(Ⅱ) does not change. Time to reach the constant values of the sorption is 15 min. In equal conditions, the sorption decreases in the number of Pd(Ⅱ)>Pt(IV)>Cu(Ⅱ). Based on retrieved data suggested that the sorption of Pd(Ⅱ) proceeds according the coordination mechanism. In the case of sorption from solutions with a high palladium content can be polymerization of adsorbed complexes in the sorbent phase. Worked out the optimal conditions for the separation of pairs of Pd(Ⅱ)-Pt(Ⅳ) and Pd(Ⅱ)-Cu(Ⅱ) under dynamic conditions with the extraction of palladium(Ⅱ) in the eluate is above 95%.展开更多
Norfloxacin sorption and the factors （soil organic matter （SOM）, pH, and exogenous copper （Cu） influencing the sorption were investigated in a black soil （soil B）, a fluvo-aquic soil （soil F）, and a red soil ...Norfloxacin sorption and the factors （soil organic matter （SOM）, pH, and exogenous copper （Cu） influencing the sorption were investigated in a black soil （soil B）, a fluvo-aquic soil （soil F）, and a red soil （soil R）. With increasing norfloxacin concentrations, sorption amount of norfloxacin increased in both the bulk soils and their SOM-removed soils, but the sorption capacity of SOM-removed soils was higher than that of their corresponding bulk soils, indicating that the process of norfloxacin sorption in soil was influenced by the soil properties including SOM. The sorption data in all bulk soils and SOM-removed soils were fitted to Freundlich and Langmuir models. The correlation coefficients suggested that the experimental data fitted better to Freundlich equation than to Langmuir equation. Furthermore, the data from soil F and SOM-removed F could not be described by Langmuir equation. The norfloxacin sorption amount decreased in soil B and soil F, whereas it increased in soil R as solution pH increased. The maximum KD and Koc were achieved in soil R when the equilibrium solution pH was 6. The norfloxacin sorption was also influenced by the exogenous Cu^2＋, which depended on the soil types and Cu^2＋ concentrations. With increasing Cu^2＋ concentrations in solution, generally, sorption amount, KD and Koc for norfloxacin in soils increased and were up to a peak at 100 mg/L Cu^2＋, and then the sorption amount decreased regardless of norfloxacin levels.展开更多
Biochar derived from partial combustion of vegetation is ubiquitous and potentially effective in sequestration of environmental contaminants. Biochars were prepared by burning of red gum （Eucalyptus spp.） woodchips ...Biochar derived from partial combustion of vegetation is ubiquitous and potentially effective in sequestration of environmental contaminants. Biochars were prepared by burning of red gum （Eucalyptus spp.） woodchips at 450 and 850℃ （labeled as BC450 and BC850）. These two biochars were found to possess markedly different properties in terms of surface area and porosity. Short-term equilibration tests （24 hr） were conducted to assess the sorption-desorption behavior of pyrimethanil in the soil amended with various amounts of biochar of each type, with a special focus on the desorption behavior of the sorbed pesticide through four times successive desorption by dilution. Sorption coefficient and isotherm nonlinearity of the amended soils progressively increased with the content of biochar in the soil. Biochar BC850 with higher surface area and microporosity showed a stronger effect on the reversibility of sorption pesticide. The soils amended with 5% BC450 and 1% BC850 had nearly the same sorption capacity for pyrimethanil; however, their desorption processes were very different with 13.65% and 1.49% of the sorbed pesticide being released, respectively. This study suggested that biochar in soil could be an important factor for immobilization of a pesticide and thus affecting its environment fate in soil.展开更多
Adsorption experiments were carried out to investigate the sorption behaviors of naphthalene and phenanthrene in six different soils and to determine the effects of temperature, linear alkylbenzene sulfonate （LAS） a...Adsorption experiments were carried out to investigate the sorption behaviors of naphthalene and phenanthrene in six different soils and to determine the effects of temperature, linear alkylbenzene sulfonate （LAS） and cetylrimethyl ammonium bromide （CTAB） on sorption. The results show that for a given sorbent phenanthrene exhibited greater nonlinear and stronger sorption than naphthalene. There was a strong negative correlation for the Koc values with organic carbon content （foc）. The increase of temperature was not favorable to sorption. Sorption decreased along with the increasing aqueous LAS concentration from 0 to 1000 mg/L. At low CTAB concentration （〈 100 mg/L）, the adsorption increased as CTAB hemimicelles formed on the soil surface. At high concentration, CTAB decreased the adsorption by occupying active hydrophobic adsorption sites and solubilization of naphthalene and phenanthrene.展开更多
文摘Phosphoric acid is a key ingredient in fertilizer production and contains many rare earth elements(REEs).Recovering REEs from phosphoric acid can prevent the accumulation of these elements in the soil and help bridge the gap between supply and demand.In this concern,a new material called Si-6G PAMAMPPAAM dendrimers modified silica gel terminated with phenylphosphonic acid-amide moieties was developed and its ability to adsorb Nd(Ⅲ)and Er(Ⅲ)from the phosphoric acid solution was investigated.K inetics and isotherm of the uptake process were investigated to explo re the so rption characte ristics.The attained results show that both metal ions exhibit the same adsorption performance,and the uptake process is depicted as a chemisorption,monolayer,uniform,and homogeneous process.The equilibrium state is achieved within 120 min,and the maximum uptake capacity is 16.7 mg Nd(Ⅲ)/g,and 14.0 mg Er(Ⅲ)/g.Sorption thermodynamics is an endothermic,spontaneous,and feasible uptake process.Nitric acid(1.0 mol/L)is found to be efficient for adsorbing about 94.3%and 92.5%of neodymium(Ⅲ)and erbium(Ⅲ)respectively,and the prepared Si-6G PAMAM-PPAAM demonstrates excellent stability over five consecutive sorption/desorption cycles.Preliminary tests on commercial phosphoric acid demonstrate that Si-6G PAMAM-PPAAM retains its effective REEs uptake from a complex comm ercial phosph oric acid solution.
基金supported by the Hundred Talents Programof the Chinese Academy of Sciences,the Pre-Research Project JZX7Y20220414101801the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB35000000)the National Natural Science Foundation Projects(No.51806231).
文摘Helium sorption cooler technology is a key means to realize highly reliable low-vibration very lowtemperature environments,which have important applications in fields such as quantum computing and space exploration.The laboratory designed a superfluid suppression small hole and a multi-ribbed condenser,developed a reliable-performance helium sorption cooler(HSC),and conducted experimental studies.Experimental results show that the prototype can achieve the lowest cooling temperature of 873 mK without load by filling 6MPa helium at room temperature.The low-temperature hold time is 26 h,and the temperature fluctuation is within 0.8 mK.The cooling power of the helium sorption cooler is 1 mW@0.98 K@3.5 h.Experimental results indicate that when the charging pressure is reduced to 4MPa,theminimum temperature decreases to 836mK,and the hold time shortens to 16 h.When the pre-cooling temperature increases from 3.9 to 4.9 K,the hold time is reduced to 3 h.
基金supported by the National Key R&D Program(Nos.2021YFC1809101 and 2022YFC3701404)the Fundamental Research Funds for the Central Universities(No.2022300301)。
文摘Co-contamination of chlorinated hydrocarbons and arsenic is frequently observed in the chemically contaminated sites and their surroundings in China.However,the interaction between these complex contaminants in soil remains is unclear.This study collected ten background soils with varying properties from various regions throughout China,and investigated the sorption and desorption process of trichloroethylene(TCE)in the exogenous arsenate(As(V))contaminated soils.The results of the batch experiments demonstrated that TCE was rapidly adsorbed by soil organic matter(SOM).Both SOM and minerals contributed to the slow sorption equilibrium process.The sorption isotherms were linear,while the desorption isotherms were non-linear.In Heilongjiang(HLJ)soil,As(V)contamination increased the TCE sorption contribution of black carbon and decreased the contribution of minerals.During the aging process of As(V)in soils,SOM was replaced by AsO_4~(3-),which formed complexes with soil Fe/Al oxides,resulting in a significant increase in hydroxyl groups and hydrophilicity of the soil surface.This hindered the hydrophobic sorption of TCE.Additionally,As(V)contamination affected soil geotechnical properties,and the Ascations precipitation could block the sorption micropores.The collective results of these processes caused a reduction in the sorption of TCE on the majority of As(V)-contaminated soils(702-5854 mg/kg)in comparison to background soils(1194-6374 mg/kg).The systematic investigation of sorption-desorption behaviors of TCE in As(V)-contaminated soils will provide a scientific basis for the calculation of soil environmental capacity of heavy metalorganic combined contamination in the future.
基金National Research Council of Thailand(NRCT)and the School of Renewable Energy and Maejo University for the project to produce and develop graduates in renewable energy for ASEAN countries for graduate students(2021).
文摘This work investigates a combined cooling,heating,and power(CCHP)generation system utilizing waste energy.A cascade-CCHP system is developed,consisting of a 23.65-kWe organic Rankine cycle(ORC),a 4.00-kW adsorption chiller,a 4.11-kW absorption chiller,a 15.99-kW drying room,and an incinerator of 150 kg/h.A net energy production of 36.08 kWh is achieved from a CCHP energy efficiency of 9.98%.The levelized cost for producing a total energy output of 2,020,592 kWh over a lifespan of 20 years is approximately 0.106 USD/kWh.The life cycle assessment(LCA)yields a single score of approximately 0.000151 Pt,mainly attributed to raw materials used in the construction process of 87.16%.In addition,the combustion ash is processed into concrete blocks measuring 39 cm×19 cm×7 cm,in accordance with the Industrial Product Standard(TIS)58-2533,with a water absorption value below 5%and a compressive strength exceeding 25 kg/cm2.The CCHP system demonstrates a novel method of waste-to-energy(WtE),and the construction material from waste combustion ash can also support a new concept of waste-to-zero(WtZ).
基金supported by the Czech Science Foundation,under project No.20-12166S.
文摘The effect of using 2%and 10%sodium hydroxide solution as surface treatment of rape straw on its water vapor adsorption properties is analyzed in the relative humidity(RH)range of 0%to 98%.Scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and Fourier-transform infrared spectroscopy(FTIR)are used to investigate the morphological,chemical and structural changes of the treated straw surface.The mineral particles formed on the surface after the treatment are analyzed using X-ray diffraction(XRD).The application of sodium hydroxide solution results in the disruption of the straw surface.As the concentration of sodium hydroxide increases,the disruption of the straw surface increases,and the ability of the straw to adsorb water vapor also increases over the entire RH range.In addition to the surface disruption and chemical changes caused by the alkaline treatment,the differences in the equilibrium moisture content of treated and untreated rape straw can also be attributed to the formation of minerals on the straw surface,namely calcite for the 2%sodium hydroxide solution,and gaylussite and thermonatrite for the 10%solution.
基金the“Young Talent Research Grant”:(600-RMC/YTR/5/3(004/2022)Universiti Teknologi Mara(UiTM)for providing the financial support.
文摘Spinal cord injury presents a significant challenge in regenerative medicine due to the complex and deli-cate nature of neural tissue repair.This study aims to design a conductive hydrogel embedded with magnetic MgFe_(2)O_(4) nanoparticles to establish a bioelectrically active and spatially stable microenvironment that promotes spinal cord regeneration through computational analysis(BIOVIA Materials Studio).Hydrogels,known for their biocompatibility and extracellular matrix-mimicking properties,support essential cellular behaviors such as adhesion,proliferation,and migration.The integration of MgFe_(2)O_(4) nanoparticles imparts both electrical conductivity and magnetic responsiveness,enabling controlled transmission of electrical signals that are crucial for guiding cellular processes like differentiation and directed migration.Furthermore,the hydrogel acts as a delivery medium,facilitating the adsorption of MgFe_(2)O_(4) nanoparticles onto spinal tissue through strong Van der Waals and intramolecular interactions.The computational simulations revealed a robust adsorption profile,with a binding distance of 20.180Åand a cumulative adsorption energy of 2740.42 kcal/mol,indicating stable nanoparticle-tissue interactions.Pressure-dependent sorption analysis further demonstrated that reduced pressure conditions enhance adsorption strength,promoting tighter material-tissue integration.The adverse Van der Waals energy and increased intramolecular energy observed under these conditions underscore the importance of optimized adsorption settings for functional tissue interface formation.Altogether,the conductive hydrogel-MgFe_(2)O_(4) composite system offers a promising therapeutic platform by combining structural support,electrical stimulation,and magnetic guidance,thereby enhancing cell-material interactions and fostering an environment conducive to spinal cord tissue repair.
基金This study was financially supported by the National Natural Science Foundation of China(42302160)the PhD Scientific Research and Innovation Foundation of the Education Department of Hainan Province Joint Project of Sanya Yazhou Bay Science and Technology City(HSPHDSRF-2024-07-001)Educational Reform of Hainan Higher Education Institutions(Hnjg2024-276)。
文摘Connate water strongly restricts shale gas enrichment and production,and most artificially injected water is confined in shale pore networks owing to low water recovery during hydraulic fracturing,which leads to a more complex pore water distribution.However,previous studies have focused on the water vapor sorption of gas shales rather than liquid pore water.This study clarifies the occurrence and distribution of pore water and the controlling factors by conducting thermogravimetry(TGA)under liquid water saturation and water vapor sorption experiments on four gas shales from the Wufeng Formation in South China.Nuclear magnetic resonance(NMR)T_(2)and T_(1)-T_(2)technologies were used to monitor the dynamic changes and states of moisture,and the microscopic pore structures during water vapor sorption were detected using low-temperature nitrogen adsorption-desorption.The results indicate that TGA is adequate for determining the adsorbed,bound,and movable water contents.These four gas shales are characterized by high adsorbed and movable water contents,and some bound water.The adsorbed water primarily occurs in tiny pores(<100 nm),controlled by organic matter,followed by clay mine rals.The movable water,typically associated with quartz,primarily exists in pores of>100 nm,particularly macropores of>1000 nm.The bound water predominantly correlates with pores ranging from 10 to 2000 nm in clay minerals.The water vapor sorption process of the gas shale is well clarified.Water molecules primarily adsorb on the clay mineral's hydrophilic surface,followed by oxygen functional groups in the organic matter.Therefore,clay mine rals control water vapor sorption at low relative humidity(RH<0.75),whereas organic matter primarily affects vapor sorption at high RH.The TGA of liquid wate r-saturated gas shales can clarify the water distributions in full-scale pore networks,whereas the water vapor sorption method primarily discloses the moisture in small nanopores(<100 nm)but ignores most bound and movable water.This paper provides insight into liquid water distribution and occurre nce states within shale pore netwo rks,contributing to a better understanding of gas-wate r-rock interaction systems in-situ and hydraulic fracturing shale gas formations.
文摘By means of the synthetic approach of non－polar or weak polar oil－sorbed polymers，the gel sorption resin（GSR） and the multiporous sorption resin（MSR） were prepared．The structure of the resins，sorption power，sorption speed，desorption，and sorption of organic compounds from sewage，exhaust gas and soil were discussed．Moreover，the resins were used to decrease LOD and BOD5 values of water waste from sewage factory．Theyare a klndof potential materials for environmental control．
文摘The adsorption of Pd(Ⅱ), Pt(IV) and Cu(Ⅱ) in static and dynamic conditions on chemically modified silica containing sulfide sulfur (number of grafted functional groups of the sorbent was 0.2 (CMS-S 0.2) and 0 3 mmol/g (CMS-S 0.3)) was studied. It is established that an increase in the acidity of the sorption of Pd(Ⅱ) and Pt(Ⅳ) decreases, whereas the Cu(Ⅱ) does not change. Time to reach the constant values of the sorption is 15 min. In equal conditions, the sorption decreases in the number of Pd(Ⅱ)>Pt(IV)>Cu(Ⅱ). Based on retrieved data suggested that the sorption of Pd(Ⅱ) proceeds according the coordination mechanism. In the case of sorption from solutions with a high palladium content can be polymerization of adsorbed complexes in the sorbent phase. Worked out the optimal conditions for the separation of pairs of Pd(Ⅱ)-Pt(Ⅳ) and Pd(Ⅱ)-Cu(Ⅱ) under dynamic conditions with the extraction of palladium(Ⅱ) in the eluate is above 95%.
基金supported by the National Key Basic Research Support Foundation of China (No.2005CB121105), the Ministry of Science and Technology of China (No. 2006BAD05B05)the International Foundation for Science (No. C/4076).
文摘Norfloxacin sorption and the factors （soil organic matter （SOM）, pH, and exogenous copper （Cu） influencing the sorption were investigated in a black soil （soil B）, a fluvo-aquic soil （soil F）, and a red soil （soil R）. With increasing norfloxacin concentrations, sorption amount of norfloxacin increased in both the bulk soils and their SOM-removed soils, but the sorption capacity of SOM-removed soils was higher than that of their corresponding bulk soils, indicating that the process of norfloxacin sorption in soil was influenced by the soil properties including SOM. The sorption data in all bulk soils and SOM-removed soils were fitted to Freundlich and Langmuir models. The correlation coefficients suggested that the experimental data fitted better to Freundlich equation than to Langmuir equation. Furthermore, the data from soil F and SOM-removed F could not be described by Langmuir equation. The norfloxacin sorption amount decreased in soil B and soil F, whereas it increased in soil R as solution pH increased. The maximum KD and Koc were achieved in soil R when the equilibrium solution pH was 6. The norfloxacin sorption was also influenced by the exogenous Cu^2＋, which depended on the soil types and Cu^2＋ concentrations. With increasing Cu^2＋ concentrations in solution, generally, sorption amount, KD and Koc for norfloxacin in soils increased and were up to a peak at 100 mg/L Cu^2＋, and then the sorption amount decreased regardless of norfloxacin levels.
文摘Biochar derived from partial combustion of vegetation is ubiquitous and potentially effective in sequestration of environmental contaminants. Biochars were prepared by burning of red gum （Eucalyptus spp.） woodchips at 450 and 850℃ （labeled as BC450 and BC850）. These two biochars were found to possess markedly different properties in terms of surface area and porosity. Short-term equilibration tests （24 hr） were conducted to assess the sorption-desorption behavior of pyrimethanil in the soil amended with various amounts of biochar of each type, with a special focus on the desorption behavior of the sorbed pesticide through four times successive desorption by dilution. Sorption coefficient and isotherm nonlinearity of the amended soils progressively increased with the content of biochar in the soil. Biochar BC850 with higher surface area and microporosity showed a stronger effect on the reversibility of sorption pesticide. The soils amended with 5% BC450 and 1% BC850 had nearly the same sorption capacity for pyrimethanil; however, their desorption processes were very different with 13.65% and 1.49% of the sorbed pesticide being released, respectively. This study suggested that biochar in soil could be an important factor for immobilization of a pesticide and thus affecting its environment fate in soil.
基金supported by the National NaturalScience Foundation of China (No. 40372109)the National Basic Research Program (973) of China (No.2004CB418502).
文摘Adsorption experiments were carried out to investigate the sorption behaviors of naphthalene and phenanthrene in six different soils and to determine the effects of temperature, linear alkylbenzene sulfonate （LAS） and cetylrimethyl ammonium bromide （CTAB） on sorption. The results show that for a given sorbent phenanthrene exhibited greater nonlinear and stronger sorption than naphthalene. There was a strong negative correlation for the Koc values with organic carbon content （foc）. The increase of temperature was not favorable to sorption. Sorption decreased along with the increasing aqueous LAS concentration from 0 to 1000 mg/L. At low CTAB concentration （〈 100 mg/L）, the adsorption increased as CTAB hemimicelles formed on the soil surface. At high concentration, CTAB decreased the adsorption by occupying active hydrophobic adsorption sites and solubilization of naphthalene and phenanthrene.
