A field investigation was performed to study the content, speciation and mobility of vanadium, as well as microbial response in soil from a stone coal smelting district in Hunan province of China. The results showed t...A field investigation was performed to study the content, speciation and mobility of vanadium, as well as microbial response in soil from a stone coal smelting district in Hunan province of China. The results showed that the contents of soil V ranged from 168 to 1538 mg/kg, which exceeded the maximum permissible value of Canadian soil quality for V. The mean soil V content from wasteland area reached 1421 mg/kg, and those from the areas related with slag heap, ore pile and smelting center were 380, 260 and 225 mg/kg, respectively. Based on the results of the modified BCR sequential extraction procedure, V contents in the mobile fractions varied from 19.2 to 637 mg/kg accounting for 7.4%-42.3% of total V, and those of V(+5) species were between 21.9 and 534.0 mg/kg. Soil enzyme activity and microbial basal respiration were adversely affected by high level of soil V. More attention should be paid to soil V pollution and potential hazardous surrounding the stone coal smelting district.展开更多
The Oronogo-Duenweg mining belt is a designated United States Environmental Protection Agency Superfund site due to lead-contaminated soil and groundwater by former mining and smelting operations.Sites that have under...The Oronogo-Duenweg mining belt is a designated United States Environmental Protection Agency Superfund site due to lead-contaminated soil and groundwater by former mining and smelting operations.Sites that have undergone remediation-in which the O,A,and B horizons have been removed alongside the lead contamination-have an exposed C horizon and are incalcitrant to revegetation efforts.Soils also continue to contain quantifiable Cd and Zn concentrations.To improve soil conditions and encourage successful site revegetation,our study employed three biochars,sourced from different feedstocks(poultry litter,beef cattle manure,and lodgepole pine),at two rates of application(2.5%,and 5%),coupled with compost(0%,2.5%and 5%application rates).Two plant species-switchgrass(Panicum virgatum)and buffalograss(Bouteloua dactyloides)-were grown in the amended soils.Amendment of soils with poultry litter biochar applied at 5%resulted in the greatest reduction of soil bioavailable Cd and Zn.Above-ground biomass yields were greatest with beef cattle manure biochar applied at 2.5%with 5%compost,or with 5%biochar at 2.5%and 5%compost rates.Maximal microbial biomass was achieved with 5%poultry litter biochar and 5%compost,and microbial communities in soils amended with poultry litter biochar distinctly clustered away from all other soil treatments.Additionally,poultry litter biochar amended soils had the highest enzyme activity rates forβ-glucosidase,N-acetyl-β-D-glucosaminidase,and esterase.These results suggest that soil reclamation using biochar and compost can improve mine-impacted soil biogeophysical characteristics,and potentially improve future remediation efforts.展开更多
Chlorine is often used in algal removal and deodorization of landscape waters,and occasionally used as an emergency treatment of heavily polluted sediments.However,the ecological impact of this practice has not been f...Chlorine is often used in algal removal and deodorization of landscape waters,and occasionally used as an emergency treatment of heavily polluted sediments.However,the ecological impact of this practice has not been fully studied and recognized.In this study,NaClO at 0.1 mmol/g based on dry weight sediment was evenly mixed into the polluted sediment,and then the sediment was incubated for 150 days to evaluate its microbial effect.Results showed that NaClO addition enhanced the release of TOC,TN,Cr and Cu from the sediment.The microbial richness in the examined sediment decreased continuously,and the Chao1 index declined from 4241 to 2731,in 150 days.The microbial community composition was also changed.The abundance of Proteobacteria and Bacteroidetes increased to 54.8%and 4.2%within 7 days compared to the control,and linear discriminant analysis(LDA)showed gram-negative bacteria and aerobic bacteria enriched after chlorination.The functional prediction with PICRUSt2 showed the functions of the microbial community underwent major adjustments,and the metabolic-related functions such as carbon metabolism,including pyruvate and methane metabolisms were significantly inhibited;besides,15 out of 22 analyzed key enzymes involved in C cycling and 6 out of 12 key enzymes or genes involved in N cycling were strongly impacted,and the enzymes and genes involved in carbon degradation and denitrification showed remarkable downregulation.It can be concluded that chlorination posed a seriously adverse effect on microbial community structure and function.This study deepens the understanding of the ecological effects of applying chlorine for environmental remediation.展开更多
A vast number of microorganisms colonize the leaf surface of terrestrial plants, known as the phyllosphere, and these microorganisms are thought to be of critical importance in plant growth and health. However, the ta...A vast number of microorganisms colonize the leaf surface of terrestrial plants, known as the phyllosphere, and these microorganisms are thought to be of critical importance in plant growth and health. However, the taxonomic identities and ecological functions of the microorganisms inhabiting the rice phyllosphere remain poorly understood. Using a massive, parallel pyrosequencing technique, we identified the phyllosphere bacterial taxa of four different rice varieties and investigated the microbial response to elevated CO2 （eCO2） in a rice field of a free-air CO2 enrichment （FACE） facility located in Jiangsu Province, China. The results showed that the dominant phylotype, the Enterobacteriaceae family of Gammaproteobacteria~ accounted for 70.6%-93.8% of the total bacterial communities in the rice phyllosphere. The dominant phylotype was stimulated by eCO2, with its relative abundance increasing from 70.6%-75.2% at ambient CO2 （aCO2） to 86.5%-93.8% at eCO2 in the phyllosphere of rice varieties IIYou084 （TY-084）, YangLiangYou6 （YLY-6）, and ZhenXian96 （ZX-96）. The rare phylotypes, including the bacterial taxa of Sphingobacteriaceae, Xanthomonadaceae, Oxalobacteraceae, Clostridiaceae, and Pseudomonadaceae, were suppressed and their relative abundance decreased from 13.4%-23.0% at aCO2 to 1.47% 6.11% at eGO2. Furthermore, the bacterial diversity indices decreased at eCO2 in the phyllosphere of the rice varieties TY-084, YLY-6, and ZX-96. In contrast, an opposite response pattern was observed for the rice variety of YangDao8 （YD-8）. In the phyllosphere of this variety, the relative abundance of the dominant phylotype, Enterobacteriaceae, decreased from 94.1% at aCO2 to 81.4% at eCO2, while that of the rare phylotypes increased from 3.37% to 6.59%. In addition, eCO2 appeared to stimulate bacterial diversity in the rice variety YD-8. Our results suggest that the phyllosphere microbial response to eCO2 might be relative abundance-dependent in paddy fields.展开更多
Biochar-based sulfidized nano-sized zero-valent iron(SNZVI/BC)can effectively immobilize cadmium(Cd)in contaminated paddy soils.However,the synergistic effects between biochar and SNZVI on Cd immobilization,as well as...Biochar-based sulfidized nano-sized zero-valent iron(SNZVI/BC)can effectively immobilize cadmium(Cd)in contaminated paddy soils.However,the synergistic effects between biochar and SNZVI on Cd immobilization,as well as the underlying mechanisms remain unclear.Herein,a soil microcosm incubation experiment was performed to investigate the immobilization performance of SNZVI/BC towards Cd in the contaminated paddy soil.Results indicated that the addition of SNZVI/BC at a dosage of 3%significantly lessened the concentration of available Cd in the contaminated soil from 14.9(without addition)to 9.9 mg kg^(−1)with an immobilization efficiency of 33.3%,indicating a synergistic effect.The sequential extraction results indicated that the proportion of the residual Cd in the contaminated soil increased from 8.1 to 10.3%,manifesting the transformation of the unstable Cd fractions to the steadier specie after application of SNZVI/BC.Also,the addition of SNZVI/BC increased soil pH,organic matter,and dissolved organic carbon,which significantly altered the bacterial community in the soil,enriching the relative abundances of functional microbes(e.g.,Bacillus,Clostridium,and Desulfosporosinus).These functional microorganisms further facilitated the generation of ammonium,nitrate,and ferrous iron in the contaminated paddy soil,enhancing nutrients’availability.The direct interaction between SNZVI/BC and Cd^(2+),the altered soil physicochemical properties,and the responded bacterial community played important roles in Cd immobilization in the contaminated soil.Overall,the biochar-based SNZVI is a promising candidate for the effective immobilization of Cd and the improvement of nutrients’availability in the contaminated paddy soil.展开更多
基金Project(41201492)supported by the National Natural Science Foundation of China
文摘A field investigation was performed to study the content, speciation and mobility of vanadium, as well as microbial response in soil from a stone coal smelting district in Hunan province of China. The results showed that the contents of soil V ranged from 168 to 1538 mg/kg, which exceeded the maximum permissible value of Canadian soil quality for V. The mean soil V content from wasteland area reached 1421 mg/kg, and those from the areas related with slag heap, ore pile and smelting center were 380, 260 and 225 mg/kg, respectively. Based on the results of the modified BCR sequential extraction procedure, V contents in the mobile fractions varied from 19.2 to 637 mg/kg accounting for 7.4%-42.3% of total V, and those of V(+5) species were between 21.9 and 534.0 mg/kg. Soil enzyme activity and microbial basal respiration were adversely affected by high level of soil V. More attention should be paid to soil V pollution and potential hazardous surrounding the stone coal smelting district.
基金The information in this document has been funded in part by the U.S.Environmental Protection Agency.
文摘The Oronogo-Duenweg mining belt is a designated United States Environmental Protection Agency Superfund site due to lead-contaminated soil and groundwater by former mining and smelting operations.Sites that have undergone remediation-in which the O,A,and B horizons have been removed alongside the lead contamination-have an exposed C horizon and are incalcitrant to revegetation efforts.Soils also continue to contain quantifiable Cd and Zn concentrations.To improve soil conditions and encourage successful site revegetation,our study employed three biochars,sourced from different feedstocks(poultry litter,beef cattle manure,and lodgepole pine),at two rates of application(2.5%,and 5%),coupled with compost(0%,2.5%and 5%application rates).Two plant species-switchgrass(Panicum virgatum)and buffalograss(Bouteloua dactyloides)-were grown in the amended soils.Amendment of soils with poultry litter biochar applied at 5%resulted in the greatest reduction of soil bioavailable Cd and Zn.Above-ground biomass yields were greatest with beef cattle manure biochar applied at 2.5%with 5%compost,or with 5%biochar at 2.5%and 5%compost rates.Maximal microbial biomass was achieved with 5%poultry litter biochar and 5%compost,and microbial communities in soils amended with poultry litter biochar distinctly clustered away from all other soil treatments.Additionally,poultry litter biochar amended soils had the highest enzyme activity rates forβ-glucosidase,N-acetyl-β-D-glucosaminidase,and esterase.These results suggest that soil reclamation using biochar and compost can improve mine-impacted soil biogeophysical characteristics,and potentially improve future remediation efforts.
基金This work was supported by the National Natural Science Foundation of China(Grant No.52091542).
文摘Chlorine is often used in algal removal and deodorization of landscape waters,and occasionally used as an emergency treatment of heavily polluted sediments.However,the ecological impact of this practice has not been fully studied and recognized.In this study,NaClO at 0.1 mmol/g based on dry weight sediment was evenly mixed into the polluted sediment,and then the sediment was incubated for 150 days to evaluate its microbial effect.Results showed that NaClO addition enhanced the release of TOC,TN,Cr and Cu from the sediment.The microbial richness in the examined sediment decreased continuously,and the Chao1 index declined from 4241 to 2731,in 150 days.The microbial community composition was also changed.The abundance of Proteobacteria and Bacteroidetes increased to 54.8%and 4.2%within 7 days compared to the control,and linear discriminant analysis(LDA)showed gram-negative bacteria and aerobic bacteria enriched after chlorination.The functional prediction with PICRUSt2 showed the functions of the microbial community underwent major adjustments,and the metabolic-related functions such as carbon metabolism,including pyruvate and methane metabolisms were significantly inhibited;besides,15 out of 22 analyzed key enzymes involved in C cycling and 6 out of 12 key enzymes or genes involved in N cycling were strongly impacted,and the enzymes and genes involved in carbon degradation and denitrification showed remarkable downregulation.It can be concluded that chlorination posed a seriously adverse effect on microbial community structure and function.This study deepens the understanding of the ecological effects of applying chlorine for environmental remediation.
基金Supported by the International S&T Cooperation Project of the Ministry of Science and Technology of China(No.2010DFA22770)the National Natural Science Foundation of China(No.41090281)
文摘A vast number of microorganisms colonize the leaf surface of terrestrial plants, known as the phyllosphere, and these microorganisms are thought to be of critical importance in plant growth and health. However, the taxonomic identities and ecological functions of the microorganisms inhabiting the rice phyllosphere remain poorly understood. Using a massive, parallel pyrosequencing technique, we identified the phyllosphere bacterial taxa of four different rice varieties and investigated the microbial response to elevated CO2 （eCO2） in a rice field of a free-air CO2 enrichment （FACE） facility located in Jiangsu Province, China. The results showed that the dominant phylotype, the Enterobacteriaceae family of Gammaproteobacteria~ accounted for 70.6%-93.8% of the total bacterial communities in the rice phyllosphere. The dominant phylotype was stimulated by eCO2, with its relative abundance increasing from 70.6%-75.2% at ambient CO2 （aCO2） to 86.5%-93.8% at eCO2 in the phyllosphere of rice varieties IIYou084 （TY-084）, YangLiangYou6 （YLY-6）, and ZhenXian96 （ZX-96）. The rare phylotypes, including the bacterial taxa of Sphingobacteriaceae, Xanthomonadaceae, Oxalobacteraceae, Clostridiaceae, and Pseudomonadaceae, were suppressed and their relative abundance decreased from 13.4%-23.0% at aCO2 to 1.47% 6.11% at eGO2. Furthermore, the bacterial diversity indices decreased at eCO2 in the phyllosphere of the rice varieties TY-084, YLY-6, and ZX-96. In contrast, an opposite response pattern was observed for the rice variety of YangDao8 （YD-8）. In the phyllosphere of this variety, the relative abundance of the dominant phylotype, Enterobacteriaceae, decreased from 94.1% at aCO2 to 81.4% at eCO2, while that of the rare phylotypes increased from 3.37% to 6.59%. In addition, eCO2 appeared to stimulate bacterial diversity in the rice variety YD-8. Our results suggest that the phyllosphere microbial response to eCO2 might be relative abundance-dependent in paddy fields.
基金Basic Research General Project of Guizhou Provincial Department of Science and Technology(ZK[2024]014)Basic Research Project of Guizhou Provincial Department of Science and Technology([2020]1Z037)+6 种基金Guizhou Provincial Science and Technology Projects(Qian Ke He Support([2022]222)The Youth Talent Growth Project of Guizhou Provincial Department of Education(2024)Special Fund for Outstanding Youth Talents of Science and Technology of Guizhou Province[YQK[2023]014]National Natural Science Foundation of China[Grant numbers 419772974227704041977117]Special Research Foundation of Natural Science(Special Post)of Guizhou University[(2023)04].
文摘Biochar-based sulfidized nano-sized zero-valent iron(SNZVI/BC)can effectively immobilize cadmium(Cd)in contaminated paddy soils.However,the synergistic effects between biochar and SNZVI on Cd immobilization,as well as the underlying mechanisms remain unclear.Herein,a soil microcosm incubation experiment was performed to investigate the immobilization performance of SNZVI/BC towards Cd in the contaminated paddy soil.Results indicated that the addition of SNZVI/BC at a dosage of 3%significantly lessened the concentration of available Cd in the contaminated soil from 14.9(without addition)to 9.9 mg kg^(−1)with an immobilization efficiency of 33.3%,indicating a synergistic effect.The sequential extraction results indicated that the proportion of the residual Cd in the contaminated soil increased from 8.1 to 10.3%,manifesting the transformation of the unstable Cd fractions to the steadier specie after application of SNZVI/BC.Also,the addition of SNZVI/BC increased soil pH,organic matter,and dissolved organic carbon,which significantly altered the bacterial community in the soil,enriching the relative abundances of functional microbes(e.g.,Bacillus,Clostridium,and Desulfosporosinus).These functional microorganisms further facilitated the generation of ammonium,nitrate,and ferrous iron in the contaminated paddy soil,enhancing nutrients’availability.The direct interaction between SNZVI/BC and Cd^(2+),the altered soil physicochemical properties,and the responded bacterial community played important roles in Cd immobilization in the contaminated soil.Overall,the biochar-based SNZVI is a promising candidate for the effective immobilization of Cd and the improvement of nutrients’availability in the contaminated paddy soil.
