Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions.Biodegradable and environmentally friendly materials,such as calcium lignosulfonate(CaLS),calcium poly(aspartic a...Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions.Biodegradable and environmentally friendly materials,such as calcium lignosulfonate(CaLS),calcium poly(aspartic acid)(PASP-Ca),and calcium polyγ-glutamic acid(γ-PGA-Ca),are known to effectively ameliorate soil acidity.However,their effectiveness in inhibiting soil acidification has not been studied.This study aimed to evaluate the effect of CaLS,PASP-Ca,andγ-PGA-Ca on the resistance of soil toward acidification as directly and indirectly(i.e.,via nitrification)caused by the application of HNO_(3)and urea,respectively.For comparison,Ca(OH)_(2)and lignin were used as the inorganic and organic controls,respectively.Among the materials,γ-PGA-Ca drove the substantial improvements in the pH buffering capacity(pHBC)of the soil and exhibited the greatest potential in inhibiting HNO_(3)-induced soil acidification via protonation of carboxyl,complexing with Al~(3+),and cation exchange processes.Under acidification induced by urea,CaLS was the optimal one in inhibiting acidification and increasing exchangeable acidity during incubation.Furthermore,the sharp reduction in the population sizes of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)confirmed the inhibition of nitrification via CaLS application.Therefore,compared to improving soil pHBC,CaLS may play a more important role in suppressing indirect acidification.Overall,γ-PGA-Ca was superior to PASP-Ca and CaLS in enhancing the soil pHBC and the its resistance to acidification induced by HNO_(3) addition,whereas CaLS was the best at suppressing urea-driven soil acidification by inhibiting nitrification.In conclusion,these results provide a reference for inhibiting soil re-acidification in intensive agricultural systems.展开更多
Three electrokinetic（EK） experiments were designed to study the remediation efficiency of Cr（Ⅲ） by EK-oxidation method and to investigate the influence of complexes and p H buffer solution in EK-oxidation process...Three electrokinetic（EK） experiments were designed to study the remediation efficiency of Cr（Ⅲ） by EK-oxidation method and to investigate the influence of complexes and p H buffer solution in EK-oxidation process. Sediments Cr（Ⅲ） can be oxidized into Cr（Ⅵ） effectively by KMn O4, but the oxidation efficiency is not proportional to the dose of oxidant, and chemical oxidation process leads to a bit lower buffering capacity of the sediment. Compared with the simple EK remediation, the removal efficiency of total Cr in the sediments increased 32.6% by EK-oxidation method, and the concentrations of total chromium in the sediment showed increasing trend from the cathode to the anode after EK-oxidation treatment. The p H control and KMn O4 improved the removal of Cr（Ⅵ） and total Cr from the sediments. Due to stronger complexation action of citric acid with Cr（Ⅲ） in sediments, citric acid in the catholyte obviously increased the removal rate of total Cr in sediments. Finally, the removal rate of total Cr from sediments reached 60.9% by adding complex and controlling the p H of cathode and anode pond solution on EK-oxidation processes.展开更多
H_(2)O-induced side reactions and dendrite growth occurring at the Zn anode-electrolyte interface(AEI)limit the electrochemical performances of aqueous zinc ion batteries.Herein,methionine(Met)is introduced as an elec...H_(2)O-induced side reactions and dendrite growth occurring at the Zn anode-electrolyte interface(AEI)limit the electrochemical performances of aqueous zinc ion batteries.Herein,methionine(Met)is introduced as an electrolyte additive to solve the above issues by three aspects:Firstly,Met is anchored on Zn anode by amino/methylthio groups to form a H_(2)O-poor AEI,thus increasing the overpotential of hydrogen evolution reaction(HER);secondly,Met serves as a pH buffer to neutralize the HER generated OH-,thereby preventing the formation of by-products(e.g.Zn_(4)SO_(4)(OH)_(6)·xH_(2)O);thirdly,Zn^(2+) could be captured by carboxyl group of the anchored Met through electrostatic interaction,which promotes the dense and flat Zn deposition.Consequently,the Zn||Zn symmetric cell obtains a long cycle life of 3200 h at 1.0 mA cm^(-2),1.0 mAh cm^(-2),and 1400 h at 5.0 mA cm^(-2),5.0 mAh cm^(-2).Moreover,Zn||VO_(2) full cell exhibits a capacity retention of 91.0%after operating for 7000 cycles at 5.0 A g^(-1).This study offers a novel strategy for modulating the interface microenvironment of AEI via integrating the molecular adsorption,pH buffer,and Zn^(2+) capture strategies to design advanced industrial-oriented batteries.展开更多
Aqueous zinc-ion batteries(AZIBs)have developed rapidly in recent years but still face several challenges,including zinc dendrites growth,hydrogen evolution reaction,passivation and corrosion.The pH of the electrolyte...Aqueous zinc-ion batteries(AZIBs)have developed rapidly in recent years but still face several challenges,including zinc dendrites growth,hydrogen evolution reaction,passivation and corrosion.The pH of the electrolyte plays a crucial role in these processes,significantly impacting the stability and reversibility of Zn^(2+)deposition.Therefore,pH-buffer tris(hydroxymethyl)amino methane(tris)is chosen as a versatile electrolyte additive to address these issues.Tris can buffer electrolyte pH at Zn/electrolyte interface by protonated/deprotonated nature of amino group,optimize the coordination environment of zinc solvate ions by its strong interaction with zinc ions,and simultaneously create an in-situ stable solid electrolyte interface membrane on the zinc anode surface.These synergistic effects effectively restrain dendrite formation and side reactions,resulting in a highly stable and reversible Zn anode,thereby enhancing the electrochemical performance of AZIBs.The Zn||Zn battery with 0.15 wt%tris additives maintains stable cycling for 1500 h at 4 mA·cm^(−2) and 1120 h at 10 mA·cm^(−2).Furthermore,the Coulombic efficiency reaches~99.2%at 4 mA·cm^(−2)@1 mAh·cm^(−2).The Zn||NVO full batteries also demonstrated a stable specific capacity and exceptional capacity retention.展开更多
The commercial application of aqueous zinc-ion batteries(AZIBs)is hindered by dendrite growth,side reaction of hydrogen evolution reaction(HER),and corrosion passivation of zinc anode.In this work,trace inorganic addi...The commercial application of aqueous zinc-ion batteries(AZIBs)is hindered by dendrite growth,side reaction of hydrogen evolution reaction(HER),and corrosion passivation of zinc anode.In this work,trace inorganic additive ammonium hydrogen borate(AB)was introduced into 2 M ZnSO_(4) electrolyte to construct a water-deficient pH buffer layer with electrostatic shielding effect at anode-solution interface.The buffer layer can effectively reduce the water content at the interface and maintain the interfacial pH stable,thereby suppressing the HER and the corrosion of anode.In addition,the NH_(4)^(+) n the additive also demonstrates an electrostatic shielding effect,which alleviates the“tip effect”and increases the nucleation overpotential of the zinc anode.As a result,the buffer layer can induce the uniform deposition of zinc and restrict the growth of dendrites,realizing a highly reversible zinc anode.Under this electrolyte system,the zinc symmetric battery can cycle stably for 7266 h at a current density of 5 mA·cm^(-2),and the cumulative deposition capacity could reach 18.17 Ah·cm^(-2).Even under the condition of a high depth of discharge(DOD)of 78.54%,it still maintained an excellent cycle life of 450 h.The zinc-copper half-cell can stably cycle 1400 times at a current density of 10 mA·cm^(-2) and delivers an ultra-high Coulombic efficiency of 99.70%.The Zn||MnO_(2) full cell retains a capacity retention rate of 76.68%after 900 cycles at a current density of 1 A·g^(−1),indicating its promising application potential.展开更多
Soil flooding and drainage can cause the reduction and oxidation of iron(Fe),as well as the immobilization and mobilization of cadmium(Cd).However,the impact of Fe(Ⅱ)oxidation following microbial Fe(Ⅲ)reduction on C...Soil flooding and drainage can cause the reduction and oxidation of iron(Fe),as well as the immobilization and mobilization of cadmium(Cd).However,the impact of Fe(Ⅱ)oxidation following microbial Fe(Ⅲ)reduction on Cd mobility remains unclear.In this study,we examined the behavior of Cd during microbial reduction of Fe(Ⅲ)oxides and subsequent chemical re-oxidation of Fe(Ⅱ)using batch reactor systems.The bacterium Shewanella oneidensis MR-1was incubated with ferrihydrite,lepidocrocite,goethite,or hematite anaerobically and then aerobically in media containing 212μg L^(-1)Cd,with or without pH buffering(initial pH=7.0).Compared to the control systems without MR-1,microbial Fe(Ⅲ)reduction significantly promoted the immobilization of dissolved Cd,as well as the conversion of dissolved and adsorbed Cd to strongly bound Cd that could not be extracted by.0.4 mol L^(-1)HCl.The mechanisms of Cd immobilization were different during the microbial reduction of different Fe(Ⅲ)oxides.The buffering of system pH affected the phase of Fe oxides formed at the reduction and oxidation stages in the systems containing MR-1 and ferrihydrite or lepidocrocite.Nevertheless,in all the systems containing MR-1 and Fe oxides,irrespective of pH buffering,the concentration of dissolved Cd dropped to<1μg L^(-1)after 35 d of anaerobic incubation and remained<4μg L^(-1)after subsequent 72 h of aerobic incubation.This suggests that Fe(Ⅱ)oxidation after microbial Fe(Ⅲ)reduction(generating 0.025-0.22 g L^(-1)Fe(Ⅱ))does not result in Cd release.展开更多
Soil acid and alkali buffer capacity, as a major indicator for evaluating its vulnerability and resistibility to acidification and alkalization, is an important factor affecting the sustainable agriculture, through kn...Soil acid and alkali buffer capacity, as a major indicator for evaluating its vulnerability and resistibility to acidification and alkalization, is an important factor affecting the sustainable agriculture, through knowledge on which soil acidification process can be predicted and modified. In this study, titration curve method was adopted to investigate the pH buffer capacity （pHBC） of fluvor-aquic soil, and separate titration curves were established by adding incremental amounts of either standardized hydrochloric acid （HC1） （0.12 mol L^-1） or sodium hydroxide （NaOH） （0.10 mol L^-1） to soil suspended in deionized water （soil：solution = 1：5）. Soil pH was measured after 7 d resuspension and isothermal equilibrium （T = 25℃）. Linear regressions were fitted to the linear portion of each titration curve and the slopes of these lines were derived as the soil pHBC. The results showed that significant correlations between the amounts of adding acid or alkali and each pH change were presented, and titration curve method was feasible for measurement of pHBC on typical fluvor-aquic soil in Huang-Huai-Hai Plain, and the coefficients of determination were higher than the similar researches on acid soil （R^2 = 0.96）. The slope-derived pHBC of acid and alkali were 158.71 and 25.02 mmol kg^-1, respectively. According to the classification of soil buffer systems, the soil tested belongs to the calcium carbonate buffer system, carbonates contribute the most to pHBC, and the contribution of soil organic matter relatively less than it.展开更多
Unstable pH of nutrient solution in hydroponic systems is a major obstacle to production.To simplify the management of nutrient solution pH and attenuate negative effects of pH on plant growth,this study investigated ...Unstable pH of nutrient solution in hydroponic systems is a major obstacle to production.To simplify the management of nutrient solution pH and attenuate negative effects of pH on plant growth,this study investigated the effect of different buffer salt additions on nutrient solution pH,ion uptake,growth and photosynthesis of Yamazaki lettuce,with the equivalent concentrations of macro-element unchanged.The results indicated that the pH of nutrient solution was buffered to varying degrees by the 2 mol/L HCO_(3)^(-),1 mol/L HCO_(3)^(-),and 0.33 mol/L HPO_(4)^(2-)The 0.33 mol/L HPO_(4)^(2-)treatment fluctuated most with a pH of 1.74 units,while the addition of HCO_(3)^(-)buffered nutrient solution pH was better,with higher pH values(7.2-7.7).The CK-pH control solution,1 mol/L HCO_(3)^(-)and 0.33 mol/L HPO_(4)^(2-)treatments all promoted the uptake of ion and then the growth of lettuce was better in comparison with the CK-pH no adjustment treatment,while the 2 mol/L HCO_(3)^(-)treatment inhibited K uptake and reduced the availability of Fe,the shoot and root fresh weight of lettuce decreased by 21.3%and 10.1%,respectively.In addition,although the chlorophyll content and net photosynthetic rate under 1 mol/L HCO_(3)^(-)and 0.33 mol/L HPO_(4)^(2-)treatments were significantly lower than the CK-pH control solution treatment,there were no significant differences in leaf length and leaf number of lettuce among them,and shoot fresh weight per plant was 83.09,82.95,and 78.92 g,respectively.In conclusion,adding 1 mol/L HCO_(3)^(-)to the nutrient solution in a single dosage not only buffered the pH of nutrient solution better but also promoted ion uptake,it had no negative effects on the growth,photosynthesis and ion uptake of hydroponic lettuce in comparison with the CK-pH control solution treatment.Therefore,1 mol/L HCO_(3)^(-)can be used as a buffer during the growth of hydroponic lettuce and reduce frequent addition of acids or alkalis,and then simplify the management of nutrient solution for hydroponic lettuce production.展开更多
Aqueous zinc-ion batteries(AZIBs)have garnered extensive attention as promising energy storage systems because of the advantages of low cost and high safety.However,severe parasitic reactions at the Zn anode surface p...Aqueous zinc-ion batteries(AZIBs)have garnered extensive attention as promising energy storage systems because of the advantages of low cost and high safety.However,severe parasitic reactions at the Zn anode surface pose a huge challenge for the practical application of AZIBs,especially the intricate hydrogen evolution reaction(HER)and Zn dendrite growth.Herein,zwitterionic taurine with isoelectric point property is introduced as an electrolyte additive to construct a passivation layer by adapting its net charge to the microenvironment variation for stabilizing the Zn anode.The experimental and theoretical results reveal that taurine can not only in-situ form a hydrophobic and zincophilic layer on the Zn anode surface via the chelation with Zn^(2+)in the alkaline interfacial microenvironment,but also buffer the pH change dynamically,thus effectively suppressing the HER and Zn dendrite growth.As a consequence,the taurine-containing electrolyte enables a stable cycling of Zn anodes in symmetric Zn∥Zn cells for more than 1800 h under a deep plating/stripping condition(5 mA cm^(-2)and 5 mAh cm^(-2)).More encouragingly,the full cells coupled with the NH_(4)V_(4)O_(10)cathode can also exhibit an excellent capacity retention of 89.8%after 1200 cycles.This efficient strategy with an environmental adaptive additive offers valuable insights for mitigating the side reactions to achieve practical AZIBs and beyond.展开更多
基金supported by the Major project of Ministry of Agriculture and Rural Affairs of the People’s Republic of China(No.NK2022180401)the major project of Ministry of Agriculture and Rural Affairs of the People’s Republic of China(No.NK2022180404)。
文摘Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions.Biodegradable and environmentally friendly materials,such as calcium lignosulfonate(CaLS),calcium poly(aspartic acid)(PASP-Ca),and calcium polyγ-glutamic acid(γ-PGA-Ca),are known to effectively ameliorate soil acidity.However,their effectiveness in inhibiting soil acidification has not been studied.This study aimed to evaluate the effect of CaLS,PASP-Ca,andγ-PGA-Ca on the resistance of soil toward acidification as directly and indirectly(i.e.,via nitrification)caused by the application of HNO_(3)and urea,respectively.For comparison,Ca(OH)_(2)and lignin were used as the inorganic and organic controls,respectively.Among the materials,γ-PGA-Ca drove the substantial improvements in the pH buffering capacity(pHBC)of the soil and exhibited the greatest potential in inhibiting HNO_(3)-induced soil acidification via protonation of carboxyl,complexing with Al~(3+),and cation exchange processes.Under acidification induced by urea,CaLS was the optimal one in inhibiting acidification and increasing exchangeable acidity during incubation.Furthermore,the sharp reduction in the population sizes of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)confirmed the inhibition of nitrification via CaLS application.Therefore,compared to improving soil pHBC,CaLS may play a more important role in suppressing indirect acidification.Overall,γ-PGA-Ca was superior to PASP-Ca and CaLS in enhancing the soil pHBC and the its resistance to acidification induced by HNO_(3) addition,whereas CaLS was the best at suppressing urea-driven soil acidification by inhibiting nitrification.In conclusion,these results provide a reference for inhibiting soil re-acidification in intensive agricultural systems.
基金Supported by the“Twelfth Five-Year”National Science and Technology Major Projects(2014ZX07104-005)
文摘Three electrokinetic（EK） experiments were designed to study the remediation efficiency of Cr（Ⅲ） by EK-oxidation method and to investigate the influence of complexes and p H buffer solution in EK-oxidation process. Sediments Cr（Ⅲ） can be oxidized into Cr（Ⅵ） effectively by KMn O4, but the oxidation efficiency is not proportional to the dose of oxidant, and chemical oxidation process leads to a bit lower buffering capacity of the sediment. Compared with the simple EK remediation, the removal efficiency of total Cr in the sediments increased 32.6% by EK-oxidation method, and the concentrations of total chromium in the sediment showed increasing trend from the cathode to the anode after EK-oxidation treatment. The p H control and KMn O4 improved the removal of Cr（Ⅵ） and total Cr from the sediments. Due to stronger complexation action of citric acid with Cr（Ⅲ） in sediments, citric acid in the catholyte obviously increased the removal rate of total Cr in sediments. Finally, the removal rate of total Cr from sediments reached 60.9% by adding complex and controlling the p H of cathode and anode pond solution on EK-oxidation processes.
基金supported by the National Natural Science Foundation of China(22479031,22162004)the Natural Science Foundation of Guangxi(2022JJD120011).
文摘H_(2)O-induced side reactions and dendrite growth occurring at the Zn anode-electrolyte interface(AEI)limit the electrochemical performances of aqueous zinc ion batteries.Herein,methionine(Met)is introduced as an electrolyte additive to solve the above issues by three aspects:Firstly,Met is anchored on Zn anode by amino/methylthio groups to form a H_(2)O-poor AEI,thus increasing the overpotential of hydrogen evolution reaction(HER);secondly,Met serves as a pH buffer to neutralize the HER generated OH-,thereby preventing the formation of by-products(e.g.Zn_(4)SO_(4)(OH)_(6)·xH_(2)O);thirdly,Zn^(2+) could be captured by carboxyl group of the anchored Met through electrostatic interaction,which promotes the dense and flat Zn deposition.Consequently,the Zn||Zn symmetric cell obtains a long cycle life of 3200 h at 1.0 mA cm^(-2),1.0 mAh cm^(-2),and 1400 h at 5.0 mA cm^(-2),5.0 mAh cm^(-2).Moreover,Zn||VO_(2) full cell exhibits a capacity retention of 91.0%after operating for 7000 cycles at 5.0 A g^(-1).This study offers a novel strategy for modulating the interface microenvironment of AEI via integrating the molecular adsorption,pH buffer,and Zn^(2+) capture strategies to design advanced industrial-oriented batteries.
基金supported by the Fund of Xuzhou Science and Technology Key R&D Program(Social Development)Project(No.KC22289)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_2783).
文摘Aqueous zinc-ion batteries(AZIBs)have developed rapidly in recent years but still face several challenges,including zinc dendrites growth,hydrogen evolution reaction,passivation and corrosion.The pH of the electrolyte plays a crucial role in these processes,significantly impacting the stability and reversibility of Zn^(2+)deposition.Therefore,pH-buffer tris(hydroxymethyl)amino methane(tris)is chosen as a versatile electrolyte additive to address these issues.Tris can buffer electrolyte pH at Zn/electrolyte interface by protonated/deprotonated nature of amino group,optimize the coordination environment of zinc solvate ions by its strong interaction with zinc ions,and simultaneously create an in-situ stable solid electrolyte interface membrane on the zinc anode surface.These synergistic effects effectively restrain dendrite formation and side reactions,resulting in a highly stable and reversible Zn anode,thereby enhancing the electrochemical performance of AZIBs.The Zn||Zn battery with 0.15 wt%tris additives maintains stable cycling for 1500 h at 4 mA·cm^(−2) and 1120 h at 10 mA·cm^(−2).Furthermore,the Coulombic efficiency reaches~99.2%at 4 mA·cm^(−2)@1 mAh·cm^(−2).The Zn||NVO full batteries also demonstrated a stable specific capacity and exceptional capacity retention.
基金supported by National Natural Science Foundation of China(No.52274298,and 21908049)Hunan Provincial Natural Science Foundation of China(2022JJ40035)+1 种基金Open Funding of State Environmental Protection Key Laboratory of Monitoring for Heavy Metal Pollutants(No.SKLMHM202301)Open Fund of State Key Laboratory of Advanced Metallurgy(University of Science and Technology Beijing,No.K1:24-09).
文摘The commercial application of aqueous zinc-ion batteries(AZIBs)is hindered by dendrite growth,side reaction of hydrogen evolution reaction(HER),and corrosion passivation of zinc anode.In this work,trace inorganic additive ammonium hydrogen borate(AB)was introduced into 2 M ZnSO_(4) electrolyte to construct a water-deficient pH buffer layer with electrostatic shielding effect at anode-solution interface.The buffer layer can effectively reduce the water content at the interface and maintain the interfacial pH stable,thereby suppressing the HER and the corrosion of anode.In addition,the NH_(4)^(+) n the additive also demonstrates an electrostatic shielding effect,which alleviates the“tip effect”and increases the nucleation overpotential of the zinc anode.As a result,the buffer layer can induce the uniform deposition of zinc and restrict the growth of dendrites,realizing a highly reversible zinc anode.Under this electrolyte system,the zinc symmetric battery can cycle stably for 7266 h at a current density of 5 mA·cm^(-2),and the cumulative deposition capacity could reach 18.17 Ah·cm^(-2).Even under the condition of a high depth of discharge(DOD)of 78.54%,it still maintained an excellent cycle life of 450 h.The zinc-copper half-cell can stably cycle 1400 times at a current density of 10 mA·cm^(-2) and delivers an ultra-high Coulombic efficiency of 99.70%.The Zn||MnO_(2) full cell retains a capacity retention rate of 76.68%after 900 cycles at a current density of 1 A·g^(−1),indicating its promising application potential.
基金supported by the National Natural Science Foundation of China(Nos.41977273 and U21A20291)the Major Research Plan of the Shandong Science Foundation,China(No.ZR2020ZD19)。
文摘Soil flooding and drainage can cause the reduction and oxidation of iron(Fe),as well as the immobilization and mobilization of cadmium(Cd).However,the impact of Fe(Ⅱ)oxidation following microbial Fe(Ⅲ)reduction on Cd mobility remains unclear.In this study,we examined the behavior of Cd during microbial reduction of Fe(Ⅲ)oxides and subsequent chemical re-oxidation of Fe(Ⅱ)using batch reactor systems.The bacterium Shewanella oneidensis MR-1was incubated with ferrihydrite,lepidocrocite,goethite,or hematite anaerobically and then aerobically in media containing 212μg L^(-1)Cd,with or without pH buffering(initial pH=7.0).Compared to the control systems without MR-1,microbial Fe(Ⅲ)reduction significantly promoted the immobilization of dissolved Cd,as well as the conversion of dissolved and adsorbed Cd to strongly bound Cd that could not be extracted by.0.4 mol L^(-1)HCl.The mechanisms of Cd immobilization were different during the microbial reduction of different Fe(Ⅲ)oxides.The buffering of system pH affected the phase of Fe oxides formed at the reduction and oxidation stages in the systems containing MR-1 and ferrihydrite or lepidocrocite.Nevertheless,in all the systems containing MR-1 and Fe oxides,irrespective of pH buffering,the concentration of dissolved Cd dropped to<1μg L^(-1)after 35 d of anaerobic incubation and remained<4μg L^(-1)after subsequent 72 h of aerobic incubation.This suggests that Fe(Ⅱ)oxidation after microbial Fe(Ⅲ)reduction(generating 0.025-0.22 g L^(-1)Fe(Ⅱ))does not result in Cd release.
基金supported by the National Basic Research Project of China (2005CB121103)
文摘Soil acid and alkali buffer capacity, as a major indicator for evaluating its vulnerability and resistibility to acidification and alkalization, is an important factor affecting the sustainable agriculture, through knowledge on which soil acidification process can be predicted and modified. In this study, titration curve method was adopted to investigate the pH buffer capacity （pHBC） of fluvor-aquic soil, and separate titration curves were established by adding incremental amounts of either standardized hydrochloric acid （HC1） （0.12 mol L^-1） or sodium hydroxide （NaOH） （0.10 mol L^-1） to soil suspended in deionized water （soil：solution = 1：5）. Soil pH was measured after 7 d resuspension and isothermal equilibrium （T = 25℃）. Linear regressions were fitted to the linear portion of each titration curve and the slopes of these lines were derived as the soil pHBC. The results showed that significant correlations between the amounts of adding acid or alkali and each pH change were presented, and titration curve method was feasible for measurement of pHBC on typical fluvor-aquic soil in Huang-Huai-Hai Plain, and the coefficients of determination were higher than the similar researches on acid soil （R^2 = 0.96）. The slope-derived pHBC of acid and alkali were 158.71 and 25.02 mmol kg^-1, respectively. According to the classification of soil buffer systems, the soil tested belongs to the calcium carbonate buffer system, carbonates contribute the most to pHBC, and the contribution of soil organic matter relatively less than it.
基金funded by the Beijing Capital Agriculture Group Self-Supporting Science and Technology Projects[Grant No.SNSPKJ 2022(01)]Chinese Universities Scientific Fund(Grant No.2023TC087).
文摘Unstable pH of nutrient solution in hydroponic systems is a major obstacle to production.To simplify the management of nutrient solution pH and attenuate negative effects of pH on plant growth,this study investigated the effect of different buffer salt additions on nutrient solution pH,ion uptake,growth and photosynthesis of Yamazaki lettuce,with the equivalent concentrations of macro-element unchanged.The results indicated that the pH of nutrient solution was buffered to varying degrees by the 2 mol/L HCO_(3)^(-),1 mol/L HCO_(3)^(-),and 0.33 mol/L HPO_(4)^(2-)The 0.33 mol/L HPO_(4)^(2-)treatment fluctuated most with a pH of 1.74 units,while the addition of HCO_(3)^(-)buffered nutrient solution pH was better,with higher pH values(7.2-7.7).The CK-pH control solution,1 mol/L HCO_(3)^(-)and 0.33 mol/L HPO_(4)^(2-)treatments all promoted the uptake of ion and then the growth of lettuce was better in comparison with the CK-pH no adjustment treatment,while the 2 mol/L HCO_(3)^(-)treatment inhibited K uptake and reduced the availability of Fe,the shoot and root fresh weight of lettuce decreased by 21.3%and 10.1%,respectively.In addition,although the chlorophyll content and net photosynthetic rate under 1 mol/L HCO_(3)^(-)and 0.33 mol/L HPO_(4)^(2-)treatments were significantly lower than the CK-pH control solution treatment,there were no significant differences in leaf length and leaf number of lettuce among them,and shoot fresh weight per plant was 83.09,82.95,and 78.92 g,respectively.In conclusion,adding 1 mol/L HCO_(3)^(-)to the nutrient solution in a single dosage not only buffered the pH of nutrient solution better but also promoted ion uptake,it had no negative effects on the growth,photosynthesis and ion uptake of hydroponic lettuce in comparison with the CK-pH control solution treatment.Therefore,1 mol/L HCO_(3)^(-)can be used as a buffer during the growth of hydroponic lettuce and reduce frequent addition of acids or alkalis,and then simplify the management of nutrient solution for hydroponic lettuce production.
基金supported by the National Natural Science Foundation of China(12275189)Collaborative Innovation Center of Suzhou Nano Science&Technology+1 种基金the 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices。
文摘Aqueous zinc-ion batteries(AZIBs)have garnered extensive attention as promising energy storage systems because of the advantages of low cost and high safety.However,severe parasitic reactions at the Zn anode surface pose a huge challenge for the practical application of AZIBs,especially the intricate hydrogen evolution reaction(HER)and Zn dendrite growth.Herein,zwitterionic taurine with isoelectric point property is introduced as an electrolyte additive to construct a passivation layer by adapting its net charge to the microenvironment variation for stabilizing the Zn anode.The experimental and theoretical results reveal that taurine can not only in-situ form a hydrophobic and zincophilic layer on the Zn anode surface via the chelation with Zn^(2+)in the alkaline interfacial microenvironment,but also buffer the pH change dynamically,thus effectively suppressing the HER and Zn dendrite growth.As a consequence,the taurine-containing electrolyte enables a stable cycling of Zn anodes in symmetric Zn∥Zn cells for more than 1800 h under a deep plating/stripping condition(5 mA cm^(-2)and 5 mAh cm^(-2)).More encouragingly,the full cells coupled with the NH_(4)V_(4)O_(10)cathode can also exhibit an excellent capacity retention of 89.8%after 1200 cycles.This efficient strategy with an environmental adaptive additive offers valuable insights for mitigating the side reactions to achieve practical AZIBs and beyond.
