Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice sy...Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.展开更多
Iron-oxidizing strain(FeOB)and iron modified biochars have been shown arsenic(As)reme-diation ability in the environment.However,due to the complicated soil environment,few field experiment has been conducted.The stud...Iron-oxidizing strain(FeOB)and iron modified biochars have been shown arsenic(As)reme-diation ability in the environment.However,due to the complicated soil environment,few field experiment has been conducted.The study was conducted to investigate the potential of iron modified biochar(BC-FeOS)and biomineralization by a new found FeOB to remediate As-contaminated paddy field.Compared with the control,the As contents of G_(B)(BC-FeOS),G_(F)(FeOB),G_(FN)(FeOB and nitrogen fertilizer),G_(BF)(BC-FeOS and FeOB)and G_(BFN)(BC-FeOS,FeOB and nitrogen fertilizer)treatments in pore water decreased by 36.53%-80.03%and the microbial richness of iron-oxidizing bacteria in these treatments increased in soils at the rice maturation stage.The concentrations of available As of G_(B),G_(F),G_(FN),G_(BF) and G_(BFN) at the tillering stage were significantly decreased by 10.78%-55.48%.The concentrations of non-specifically absorbed and specifically absorbed As fractions of G_(B),G_(F),G_(FN),G_(BF) and G_(BFN) in soils were decreased and the amorphous and poorly crystalline hydrated Fe and Al oxidebound fraction was increased.Moreover,the As contents of G_(B),G_(F),G_(FN),G_(BF) and G_(BFN) in rice grains were significantly decreased(*P<0.05)and the total As contents of G_(FN),G_(BF) and G_(BFN) were lower than the standard limit of the National Standard for Food Safety(GB 2762-2017).Compared with the other treatments,G_(BFN) showed the greatest potential for the effective remediation of As-contaminated paddy fields.展开更多
Nonferrous metal smelting has led to multi-metal pollution at many sites,which strongly threatens ecosystem and human health.Stabilization is a widely used method for remediating contaminated sites in China,Europe,and...Nonferrous metal smelting has led to multi-metal pollution at many sites,which strongly threatens ecosystem and human health.Stabilization is a widely used method for remediating contaminated sites in China,Europe,and the United States.Ochrobactrum EEELCW01 has been reported for the good performance of arsenic stabilization previously,meanwhile few research on the simultaneous stabilization and remediation of multiple metals at lead-zinc smelting sites has been studied.Therefore,in this study,Ochrobactrum EEELCW01-loaded iron-modified biochar(B-FeOB)was prepared as a remediation material to stabilize multiple metals in the smelting contaminated soils.The findings demonstrated that the leaching of metals in the soil decreased in the order Pb(96.99%)>Cd(74.03%)>Zn(66.87%)>As(51.94%)at 90 days after B-FeOB addition.Compared with those in the control,FeOB and Fe-BC treatments,the bioavailability of metals in the soils with B-FeOB treatment decreased over the long term in a continuous manner,and the mobility of Pb,Cd,As,and Zn decreased after 90 days.B-FeOB reduced the heavy metal toxicity by promoting a metal fraction transformation in the soils from weakly bound fraction to highly bound fraction,and the effect of stabilization was more apparent for Pb.After 90 days,the percentage of Pb in the acid-soluble fraction decreased by 25%,while the percentage in the residual fraction increased by 20%.Compared with natural aging,both dry-wet cycle aging and chemical oxidative aging increased the leaching of metals in the soils.After a simulated 5-year natural aging period,metal leaching remained at a low level with B-FeOB treatment.The results suggest that B-FeOB has potential applications in remediating soils contaminated by lead-zinc smelting.This paper provides a scientific basis for the long term synergistic multi-metal stabilization in smelting contaminated soils.展开更多
Arsenic contamination in water poses a significant global health risk,especially in regions with mining activities,such as the Legal Amazon.This study investigated the efficacy of iron-impregnated biochar,derived from...Arsenic contamination in water poses a significant global health risk,especially in regions with mining activities,such as the Legal Amazon.This study investigated the efficacy of iron-impregnated biochar,derived from three abundant fruit wastes native to the Legal Amazon region(baru,cupuaçu,and pequi),in removing As(V)from water.The biochars were characterized by techniques including elemental analysis,Brunauer–Emmett–Teller(BET)surface area determination,Fourier transform infrared spectroscopy(FTIR),and scanning electron microscopy(SEM).The results indicate that iron impregnation significantly modified the surface properties of the biochar,leading to an increase in surface area and the introduction of new functional groups.A response surface methodology,employing a central composite design(CCD),was utilized to optimize the adsorption process by varying the biochar dosage(g L^(−1)),the initial concentration of As(V)(µg L^(−1)),and the pH.The findings demonstrate that all three iron-modified biochars exhibit high arsenic removal efficiencies,exceeding 90%under all tested conditions.The optimal conditions for each biochar varied,suggesting that the unique surface chemistry and porosity resulting from the different biomass sources play critical roles in the adsorption performance.Furthermore,a comparative analysis revealed the differences in adsorption capacities among the biochars,with the Cupuaçu shell biochar showing the highest efficiency.Overall,these results highlight the potential of utilizing readily available fruit waste to develop sustainable and effective adsorbents for arsenic remediation.The FeCl_(3) impregnation method proved simple yet effective,showing a particular promise for applications in resource-limited communities.展开更多
Iron-modified corn straw biochar was used as an adsorbent to remove phosphorus from agricultural runoff. When agricultural runoffs with a total phosphorus （TP） concentration of 1.86 mg.L-1 to 2.47 mg.L-1 were filter...Iron-modified corn straw biochar was used as an adsorbent to remove phosphorus from agricultural runoff. When agricultural runoffs with a total phosphorus （TP） concentration of 1.86 mg.L-1 to 2.47 mg.L-1 were filtered at a hydraulic retention time of 2 h through a filtration column packed with the modified biochar, a TP removal efficiency of over 99% and an effluent TP concentration of less than 0.02mg.L-1 were achieved. The isotherms of the phosphorus adsorption by the modified biochar fitted the Freundlich equation better than the Langmuir equation. The mechanism of the phosphorus adsorbed by the modified biochar was analyzed by using various technologies, i.e. scanning electron microscopy （SEM）, X-ray diffraction （XRD） analysis, X-ray photoelectron spectroscopy （XPS）, and Fourier transform infrared spectroscopy （FTIR）. The results indicated that the surface of the modified biochar was covered by small iron granules, which were identified as Fe304. The results also showed that new iron oxides were formed on the surface of the modified biochar after the adsorption of phosphorus. Moreover, new bonds of Fe- O-P and P-C were found, which suggested that the new iron oxides tend to be Fe5（PO4）4（OH）3. Aside from removing phosphorus, adding the modified biochar into soil also improved soil productivity. When the modified biochar-to-soil rate was 5%, the stem, root, and bean of broad bean plants demonstrated increased growth rates of 91%, 64%, and 165%, respectively.展开更多
基金Project(2019YFC1803601)supported by the National Key Research and Development Program of ChinaProject(41771512)supported by the National Natural Science Foundation of ChinaProject(2018RS3004)supported by Hunan Science&Technology Innovation Program,China。
文摘Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.
基金This work was supported by the National Natural Science Foundation of China(No.41771512)the Dean’s Research Fund 2020/21(Project code:04626)of the Education University of Hong Kong.
文摘Iron-oxidizing strain(FeOB)and iron modified biochars have been shown arsenic(As)reme-diation ability in the environment.However,due to the complicated soil environment,few field experiment has been conducted.The study was conducted to investigate the potential of iron modified biochar(BC-FeOS)and biomineralization by a new found FeOB to remediate As-contaminated paddy field.Compared with the control,the As contents of G_(B)(BC-FeOS),G_(F)(FeOB),G_(FN)(FeOB and nitrogen fertilizer),G_(BF)(BC-FeOS and FeOB)and G_(BFN)(BC-FeOS,FeOB and nitrogen fertilizer)treatments in pore water decreased by 36.53%-80.03%and the microbial richness of iron-oxidizing bacteria in these treatments increased in soils at the rice maturation stage.The concentrations of available As of G_(B),G_(F),G_(FN),G_(BF) and G_(BFN) at the tillering stage were significantly decreased by 10.78%-55.48%.The concentrations of non-specifically absorbed and specifically absorbed As fractions of G_(B),G_(F),G_(FN),G_(BF) and G_(BFN) in soils were decreased and the amorphous and poorly crystalline hydrated Fe and Al oxidebound fraction was increased.Moreover,the As contents of G_(B),G_(F),G_(FN),G_(BF) and G_(BFN) in rice grains were significantly decreased(*P<0.05)and the total As contents of G_(FN),G_(BF) and G_(BFN) were lower than the standard limit of the National Standard for Food Safety(GB 2762-2017).Compared with the other treatments,G_(BFN) showed the greatest potential for the effective remediation of As-contaminated paddy fields.
基金supported by the National Natural Science Foundation of China(42177392)the Hunan Science Fund for Distinguished Young Scholars(2023JJ10063)+1 种基金the Dean’s Research Fund of the Education University of Hong Kong(ref:IRS-4,2022-23ref:IRS-6,2023-24).
文摘Nonferrous metal smelting has led to multi-metal pollution at many sites,which strongly threatens ecosystem and human health.Stabilization is a widely used method for remediating contaminated sites in China,Europe,and the United States.Ochrobactrum EEELCW01 has been reported for the good performance of arsenic stabilization previously,meanwhile few research on the simultaneous stabilization and remediation of multiple metals at lead-zinc smelting sites has been studied.Therefore,in this study,Ochrobactrum EEELCW01-loaded iron-modified biochar(B-FeOB)was prepared as a remediation material to stabilize multiple metals in the smelting contaminated soils.The findings demonstrated that the leaching of metals in the soil decreased in the order Pb(96.99%)>Cd(74.03%)>Zn(66.87%)>As(51.94%)at 90 days after B-FeOB addition.Compared with those in the control,FeOB and Fe-BC treatments,the bioavailability of metals in the soils with B-FeOB treatment decreased over the long term in a continuous manner,and the mobility of Pb,Cd,As,and Zn decreased after 90 days.B-FeOB reduced the heavy metal toxicity by promoting a metal fraction transformation in the soils from weakly bound fraction to highly bound fraction,and the effect of stabilization was more apparent for Pb.After 90 days,the percentage of Pb in the acid-soluble fraction decreased by 25%,while the percentage in the residual fraction increased by 20%.Compared with natural aging,both dry-wet cycle aging and chemical oxidative aging increased the leaching of metals in the soils.After a simulated 5-year natural aging period,metal leaching remained at a low level with B-FeOB treatment.The results suggest that B-FeOB has potential applications in remediating soils contaminated by lead-zinc smelting.This paper provides a scientific basis for the long term synergistic multi-metal stabilization in smelting contaminated soils.
基金supported by the Pro-Rectory of Research(PROPESQ)of UFT through public notice(No.088/2022)the Coordination for the Improvement of Higher Education–Brazil(CAPES)(No.001).
文摘Arsenic contamination in water poses a significant global health risk,especially in regions with mining activities,such as the Legal Amazon.This study investigated the efficacy of iron-impregnated biochar,derived from three abundant fruit wastes native to the Legal Amazon region(baru,cupuaçu,and pequi),in removing As(V)from water.The biochars were characterized by techniques including elemental analysis,Brunauer–Emmett–Teller(BET)surface area determination,Fourier transform infrared spectroscopy(FTIR),and scanning electron microscopy(SEM).The results indicate that iron impregnation significantly modified the surface properties of the biochar,leading to an increase in surface area and the introduction of new functional groups.A response surface methodology,employing a central composite design(CCD),was utilized to optimize the adsorption process by varying the biochar dosage(g L^(−1)),the initial concentration of As(V)(µg L^(−1)),and the pH.The findings demonstrate that all three iron-modified biochars exhibit high arsenic removal efficiencies,exceeding 90%under all tested conditions.The optimal conditions for each biochar varied,suggesting that the unique surface chemistry and porosity resulting from the different biomass sources play critical roles in the adsorption performance.Furthermore,a comparative analysis revealed the differences in adsorption capacities among the biochars,with the Cupuaçu shell biochar showing the highest efficiency.Overall,these results highlight the potential of utilizing readily available fruit waste to develop sustainable and effective adsorbents for arsenic remediation.The FeCl_(3) impregnation method proved simple yet effective,showing a particular promise for applications in resource-limited communities.
文摘Iron-modified corn straw biochar was used as an adsorbent to remove phosphorus from agricultural runoff. When agricultural runoffs with a total phosphorus （TP） concentration of 1.86 mg.L-1 to 2.47 mg.L-1 were filtered at a hydraulic retention time of 2 h through a filtration column packed with the modified biochar, a TP removal efficiency of over 99% and an effluent TP concentration of less than 0.02mg.L-1 were achieved. The isotherms of the phosphorus adsorption by the modified biochar fitted the Freundlich equation better than the Langmuir equation. The mechanism of the phosphorus adsorbed by the modified biochar was analyzed by using various technologies, i.e. scanning electron microscopy （SEM）, X-ray diffraction （XRD） analysis, X-ray photoelectron spectroscopy （XPS）, and Fourier transform infrared spectroscopy （FTIR）. The results indicated that the surface of the modified biochar was covered by small iron granules, which were identified as Fe304. The results also showed that new iron oxides were formed on the surface of the modified biochar after the adsorption of phosphorus. Moreover, new bonds of Fe- O-P and P-C were found, which suggested that the new iron oxides tend to be Fe5（PO4）4（OH）3. Aside from removing phosphorus, adding the modified biochar into soil also improved soil productivity. When the modified biochar-to-soil rate was 5%, the stem, root, and bean of broad bean plants demonstrated increased growth rates of 91%, 64%, and 165%, respectively.
