The presence of Fe(Ⅲ)or oxygen can affect the biochar-mediated degradation of pollutants.However,the effects of changes in the form and species of Fe(Ⅲ)on the degradation of pollutants have not been systematically i...The presence of Fe(Ⅲ)or oxygen can affect the biochar-mediated degradation of pollutants.However,the effects of changes in the form and species of Fe(Ⅲ)on the degradation of pollutants have not been systematically investigated.Therefore,this study investigated biochar-mediated p-nitrophenol(PNP)degradation,which is influenced by species of Fe(Ⅲ)at pH 2.5,5.7,and 8.0.At pH 2.5,the anoxic degradation of PNP by biochar was 9.30 mg g^(−1).Fe(Ⅲ)could compete for electrons from biochar;therefore,PNP degradation was reduced 29%.Comparison with O2,the higher redox potential of Fe(Ⅲ)prevents the occurrence of a Fenton-like reaction.Consequently,the degradation of PNP decreased by 77%.At pH 5.7,the degradation of PNP(9.62 mg g^(−1))by biochar was greatest,but after Fe(Ⅲ)was introduced into the system,most of the Fe(Ⅲ)precipitated,which significantly inhibited PNP degradation by 18%and 66%under anaerobic and aerobic conditions,respectively.Oxygen can take electrons from biochar to form⋅O2−to reduce PNP;therefore,PNP degradation is the same under anaerobic and aerobic conditions.Interestingly,at pH 8.0,the addition of Fe(Ⅲ)significantly increased the apparent degradation of PNP by 41%and 15%under anaerobic and aerobic conditions,respectively.Acidification experiment revealed that the increase in PNP degradation was due to the co-precipitates Fe(Ⅲ)with PNP on the biochar surface.This study demonstrated that additional caution should be taken when estimating the biochar-mediated degradation performance of organic pollutants in practical environmental applications,especially when Fe(Ⅲ)coexist in the system.展开更多
The response of soil microorganisms and plants in soil ecosystems to biochar is well recognised.However,biochars’impact on large soil animal,such as ants,is inadequately understood,with only limited studies focusing ...The response of soil microorganisms and plants in soil ecosystems to biochar is well recognised.However,biochars’impact on large soil animal,such as ants,is inadequately understood,with only limited studies focusing on the abundance and mortality rates of some specific ant species.In this study,soil physicochemical properties,and ant community diversity and functional characteristics were compared between experimental plots with and without biochar application.No significant differences in soil(soil physicochemical properties)or ants(ant community richness,species abundance,and morphological characteristics)were observed between the two plots before biochar application.However,the biochar-treated plot soil surface temperatures,pH,and soil water content were significantly higher after 48 weeks.Biochar application promoted Cardiocondyla nuda(by 426%)and Formica japonica abundance(by 93%),but decreased Solenopsis invicta invasive ant species richness(by 54%),consistent with the fact that changes in soil properties were more beneficial to the former two species.In addition,in biochar-treated plots,F.japonica and S.invicta generally showed larger body size(18%and 6.7%),larger eyes(2.7%and 4.0%),and longer femurs(6.3%and 7.9%),which enabled them to respond better to potential barriers,such as plants.Our results highlighted that,besides species abundance and community structure,certain ant functional morphological indicators were also informative in evaluating biochar ecological implications.展开更多
Microcystins(MCs)are one of the most prevalent cyanotoxins and pose significant risks to aquatic ecosystems and human health,particularly in lakes used as drinking water sources.However,knowledge about the MC concentr...Microcystins(MCs)are one of the most prevalent cyanotoxins and pose significant risks to aquatic ecosystems and human health,particularly in lakes used as drinking water sources.However,knowledge about the MC concentrations in plateau lakes experiencing high solar radiation is scarce.This study investigated the spatial-temporal distribution of MCs in eight Yunnan Plateau lakes in China,focusing on their relationships with environmental factors.Water samples(n=63)were collected during summer and winter seasons and analyzed for MC concentrations along with a suite of environmental variables.Results revealed significant seasonal and spatial variations in MC concentrations,with higher levels in eutrophic lakes Dianchi,Erhai,and Xingyunhu.Notably,mean MC concentrations in Lake Dianchi during summer and Erhai during winter exceeded the World Health Organization’s provisional guideline of 1μg/L for drinking water.Seasonal analyses revealed distinct regulatory mechanisms:MC concentrations in summer were positively correlated with total phosphorus,total nitrogen,turbidity,and chlorophyll a,reflecting the influence of eutrophication on cyanobacterial growth.While solar radiation intensity(SRI)exhibited a dual role:moderate SRI in winter was associated with higher MC levels,whereas higher SRI in summer suppressed MC production,likely due to photoinhibition or MC degradation.Strikingly,water temperature showed no significant correlation with MC concentrations,suggesting that high solar radiation in the Yunnan Plateau may override temperature-dependent effects on cyanobacterial growth.These findings highlight the importance of nutrient management and the regulatory role of solar radiation in regulating MC production in high-altitude lakes.The study underscores the need for region-specific strategies to mitigate cyanobacterial risks,particularly in drinking water source lakes,by integrating nutrient control and the unique light regime of plateau ecosystems.展开更多
基金supported by the National Natural Science Foundation of China(42267003)Yunnan Science and Technology Planning Project(Grant No.202303AC100010).
文摘The presence of Fe(Ⅲ)or oxygen can affect the biochar-mediated degradation of pollutants.However,the effects of changes in the form and species of Fe(Ⅲ)on the degradation of pollutants have not been systematically investigated.Therefore,this study investigated biochar-mediated p-nitrophenol(PNP)degradation,which is influenced by species of Fe(Ⅲ)at pH 2.5,5.7,and 8.0.At pH 2.5,the anoxic degradation of PNP by biochar was 9.30 mg g^(−1).Fe(Ⅲ)could compete for electrons from biochar;therefore,PNP degradation was reduced 29%.Comparison with O2,the higher redox potential of Fe(Ⅲ)prevents the occurrence of a Fenton-like reaction.Consequently,the degradation of PNP decreased by 77%.At pH 5.7,the degradation of PNP(9.62 mg g^(−1))by biochar was greatest,but after Fe(Ⅲ)was introduced into the system,most of the Fe(Ⅲ)precipitated,which significantly inhibited PNP degradation by 18%and 66%under anaerobic and aerobic conditions,respectively.Oxygen can take electrons from biochar to form⋅O2−to reduce PNP;therefore,PNP degradation is the same under anaerobic and aerobic conditions.Interestingly,at pH 8.0,the addition of Fe(Ⅲ)significantly increased the apparent degradation of PNP by 41%and 15%under anaerobic and aerobic conditions,respectively.Acidification experiment revealed that the increase in PNP degradation was due to the co-precipitates Fe(Ⅲ)with PNP on the biochar surface.This study demonstrated that additional caution should be taken when estimating the biochar-mediated degradation performance of organic pollutants in practical environmental applications,especially when Fe(Ⅲ)coexist in the system.
基金supported by the National Natural Science Foundation of China(42130711 and 42067055)Yunnan Major Scientific and Technological Projects(202202AG050019).
文摘The response of soil microorganisms and plants in soil ecosystems to biochar is well recognised.However,biochars’impact on large soil animal,such as ants,is inadequately understood,with only limited studies focusing on the abundance and mortality rates of some specific ant species.In this study,soil physicochemical properties,and ant community diversity and functional characteristics were compared between experimental plots with and without biochar application.No significant differences in soil(soil physicochemical properties)or ants(ant community richness,species abundance,and morphological characteristics)were observed between the two plots before biochar application.However,the biochar-treated plot soil surface temperatures,pH,and soil water content were significantly higher after 48 weeks.Biochar application promoted Cardiocondyla nuda(by 426%)and Formica japonica abundance(by 93%),but decreased Solenopsis invicta invasive ant species richness(by 54%),consistent with the fact that changes in soil properties were more beneficial to the former two species.In addition,in biochar-treated plots,F.japonica and S.invicta generally showed larger body size(18%and 6.7%),larger eyes(2.7%and 4.0%),and longer femurs(6.3%and 7.9%),which enabled them to respond better to potential barriers,such as plants.Our results highlighted that,besides species abundance and community structure,certain ant functional morphological indicators were also informative in evaluating biochar ecological implications.
基金supported by the Yunnan Provincial Department of Science and Technology(202401AS070119,202103AC100001,202449CE340003)Yunnan Provincial Department of Human Resources and Social Security(202505AO120004)+4 种基金Yunnan Provincial Council of Academicians and Experts Workstations(202405AF140006)Scientific Research and Innovation Project of Postgraduate Students in the Academic Degree of Yunnan University(KC23234416).H.W.P.was supported by the US National Science Foundation,projects(1840715,2108917,2418066)the US National Institutes of Health(1P01ES028939-06).S.A.W.thanks the New Zealand Ministry of Business,Innovation and Employment research programme Our Lakes,Our Future(CAWX2305)for support.E.J.is thankful to the support of the Chinese Academy of Sciences President’s International Fellowship Initiative(PIFI)Yunnan Provincial Council of Academicians and Experts Workstations(202405AF140006)Yunnan Provincial Department of Human Resources and Social Security(202505AO120004).
文摘Microcystins(MCs)are one of the most prevalent cyanotoxins and pose significant risks to aquatic ecosystems and human health,particularly in lakes used as drinking water sources.However,knowledge about the MC concentrations in plateau lakes experiencing high solar radiation is scarce.This study investigated the spatial-temporal distribution of MCs in eight Yunnan Plateau lakes in China,focusing on their relationships with environmental factors.Water samples(n=63)were collected during summer and winter seasons and analyzed for MC concentrations along with a suite of environmental variables.Results revealed significant seasonal and spatial variations in MC concentrations,with higher levels in eutrophic lakes Dianchi,Erhai,and Xingyunhu.Notably,mean MC concentrations in Lake Dianchi during summer and Erhai during winter exceeded the World Health Organization’s provisional guideline of 1μg/L for drinking water.Seasonal analyses revealed distinct regulatory mechanisms:MC concentrations in summer were positively correlated with total phosphorus,total nitrogen,turbidity,and chlorophyll a,reflecting the influence of eutrophication on cyanobacterial growth.While solar radiation intensity(SRI)exhibited a dual role:moderate SRI in winter was associated with higher MC levels,whereas higher SRI in summer suppressed MC production,likely due to photoinhibition or MC degradation.Strikingly,water temperature showed no significant correlation with MC concentrations,suggesting that high solar radiation in the Yunnan Plateau may override temperature-dependent effects on cyanobacterial growth.These findings highlight the importance of nutrient management and the regulatory role of solar radiation in regulating MC production in high-altitude lakes.The study underscores the need for region-specific strategies to mitigate cyanobacterial risks,particularly in drinking water source lakes,by integrating nutrient control and the unique light regime of plateau ecosystems.
