The substantial amount of greenhouse gas emissions from anthropogenic activities has caused the global mean surface temperature to increase by 0.99℃since the industrial revolution[1].China is committed to achieving c...The substantial amount of greenhouse gas emissions from anthropogenic activities has caused the global mean surface temperature to increase by 0.99℃since the industrial revolution[1].China is committed to achieving carbon neutrality by 2060 in response to climate change[2].Soil stores approximately 2344–3000 Pg(1015 g)of carbon at depths of 0–100 cm in terrestrial ecosystems,an amount approximately equivalent to twice the amount in the atmospheric carbon pool and three times that in the terrestrial biomass;therefore,even a small change in soil carbon stocks will exert significant impacts on atmospheric CO_(2)concentrations[3].展开更多
Water regulation of the Xiaolangdi Reservoir of the Yellow River was chosen as a case to investigate variations in concentrations and bioavailability of heavy metals caused by water conservancy projects in rivers. Wat...Water regulation of the Xiaolangdi Reservoir of the Yellow River was chosen as a case to investigate variations in concentrations and bioavailability of heavy metals caused by water conservancy projects in rivers. Water and suspended sediment(SPS) samples were collected at downstream sampling sites along the river during this period. Concentrations and speciation of Zn, Cr, Cu, Ni, and Pb in water and SPS samples were analyzed, and their bioaccumulation was studied with Daphnia magna. This study indicated that the exchangeable and carbonatebound fractions of heavy metals in SPS decreased along the studied stretch, and the dissolved heavy metal concentrations increased along the river with 1.6–15 folds. This is because sediment resuspension increased along the river during water regulation, giving rise to the increase of heavy metal release from SPS. The dissolved Zn, Cu, Ni, and Pb concentrations were significantly positively correlated with SPS concentrations, and their increase along the river was greater than Cr. The body burdens of heavy metals in D. magna exposed into samples collected from the reservoir outlet were 1.3–3.0 times lower than those from downstream stations, suggesting that the heavy metal bioavailability increased during water regulation.This should be considered in the reservoir operation.展开更多
Graphene oxide(GO) with unique characteristics grasps striking potentials in both academic and industrial applications. After being released into natural waters, the dispersity and stability of GO might be altered by ...Graphene oxide(GO) with unique characteristics grasps striking potentials in both academic and industrial applications. After being released into natural waters, the dispersity and stability of GO might be altered by the chemical conditions in the receiving water bodies. In this review, we summarized that the aggregation of GO in aquatic environments is mostly dependent on properties of nanoparticles(size,structure, and functional groups) and complex water chemistry(p H, temperature, light, ionic strength,and dissolved organic matter). The knowledge about the aggregation/stability of GO is still insufficient due to the variations in GO properties and complex system of natural waters. Although studies about environmental transformation of graphene-related materials can be accessed but a systematic study taking into consideration the various factors of GO and aquatic systems responsible for aggregation of GO is still lacking. Therefore, we summarized that GO homoaggregation or heteroaggregation with other solid particles can affect the distribution in different depths of rivers and toxicity toward plankton or benthic organisms. More studies are needed to investigate the stability of GO in the long term, the effect of other nanomaterial on GO aggregation, the alteration of water constituents at different regions/time and its effect on GO aggregation, to understand the transportation and impact of GO in the environment.展开更多
Shallow lake eutrophication is a global environmental issue. This study investigated the effects of water level variation and nutrient loadings on the growth and nutrient accumulation of Phragmites australis (reed) by...Shallow lake eutrophication is a global environmental issue. This study investigated the effects of water level variation and nutrient loadings on the growth and nutrient accumulation of Phragmites australis (reed) by field samplings in Baiyangdian Lake, the largest shallow lake of northern China. The field samplings were conducted in two sites of different nutrient loadings during the whole growth period of reeds, and three types of zones with different water depths were chosen for each site, including the terrestrial zone with water level below the ground, the ecotone zone with the water level varying from belowground to aboveground, and the submerged zone with water level above the ground. The result showed that reed growth was more limited by water level variation than nutrient loadings. The average stem lengths and diameters in terrestrial zones were about 26.3%-27.5% and 7.2%-12.0% higher than those in submerged zones, respectively. Similarly, the terrestrial status increased the aboveground biomass of reeds by 36.6%-51.8% compared with the submerged status. Both the nutrient concentrations and storages in the aboveground reeds were mainly influenced by the nutrient loadings in surface water and sediment rather than the water level variation of the reed growth environment, and the nutrient storages reached their maxima in late August or early September. It was observed that the maximum nitrogen storage occurred in the terrestrial zone with higher nutrient loadings, with the value of 74.5 g/m 2 . This study suggested that water level variation and nutrient loadings should be considered when using reeds to control and remediate eutrophication of shallow lakes.展开更多
The levels of six perfluoroalkyl substances(PFASs) in surface sediment and their vertical variations in dated sediment cores from the Haihe River were investigated; studied substances included perfluorooctanoic acid(P...The levels of six perfluoroalkyl substances(PFASs) in surface sediment and their vertical variations in dated sediment cores from the Haihe River were investigated; studied substances included perfluorooctanoic acid(PFOA),perfluorononanoic acid(PFNA),perfluorooctane sulfonate(PFOS),perfluorodecanoic acid(PFDA),perfluoroundecanoic acid(PFUnA),and perfluorododecanoic acid(PFDoA). Results showed that the total PFAS concentration in surface sediment ranged between 0.52 and 16.33 ng/g dry weight(dw) with an average of3.47 ng/g dw,with PFOS and PFOA as the dominant PFASs. In general,the PFAS concentrations in the mainstream increased from the upper to the lower reaches,except that a drop occurred downstream of the Erdao dam. Although the PFASs in the sediment cores did not show a clear decreasing or increasing trend with depth,the three cores had a similar vertical variation.The PFAS levels were relatively low in the surface sediment,and reached the first high point at8–20 cm as a result of the wide use of PFASs from 1990 to 2000. After that the PFAS levels decreased,and then increased to a second high point at about 40–48 cm,which might be caused by the leaching of PFASs in sediment. Because PFASs have hydrophilic groups and relatively high solubility,the PFASs will transfer from the upper to lower layers of sediment when water infiltration occurs,leading to the fluctuation of PFAS levels in sediment cores. This study suggests that both the temporal variation of sources and transfer processes of PFASs in sediments are important factors influencing the vertical variation of PFASs in sediment cores.展开更多
Many studies have investigated bioaccumulation and metabolism of polycyclic aromatic hydrocarbons(PAHs)in aquatic organisms.However,lack of studies investigated both processes simultaneously,and the interaction betwee...Many studies have investigated bioaccumulation and metabolism of polycyclic aromatic hydrocarbons(PAHs)in aquatic organisms.However,lack of studies investigated both processes simultaneously,and the interaction between these two processes is less understood so far.This study investigated the bioaccumulation kinetics of PAHs and metabolic enzyme activities,including total cytochrome P450(CYPs)and total superoxide dismutase(T-SOD),in zebrafish.Mature zebrafish were exposed to the mixture of phenanthrene and anthracene under constant concentration maintained by passive dosing systems for 16 days.The results showed that PAH concentrations in zebrafish experienced a peak value after exposure for 1.5 days,and then decreased gradually.The bioaccumulation equilibrium was achieved after exposure for 12 days.Both of the uptake rate constants(k_u)and the elimination rate constants(k_e)decreased after the peak value.The variation of PAH concentrations and metabolic enzyme activities in zebrafish had an interactive relationship.The activities of CYPs and T-SOD increased initially with the increase of PAH concentrations,but decreased to the lowest state when PAH concentrations reached the peak value.When the bioaccumulation equilibrium of PAHs was achieved,CYPs and T-SOD activities also reached the steady state.In general,CYPs and T-SOD activities were activated after exposure to PAHs.The decrease of PAH concentrations in zebrafish after the peak value may be attributed to the great drop of k_uand the variation of CYPs activities.This study suggests that an interactive relationship exists between bioaccumulation kinetics of PAHs and metabolic enzyme activities in aquatic organisms.展开更多
Climate change is supposed to have influences on water quality and ecosystem.However,only few studies have assessed the effect of climate change on environmental toxic contaminants in urban lakes.In this research,resp...Climate change is supposed to have influences on water quality and ecosystem.However,only few studies have assessed the effect of climate change on environmental toxic contaminants in urban lakes.In this research,response of several toxic contaminants in twelve urban lakes in Beijing,China,to the seasonal variations in climatic factors was studied.Fluorides,volatile phenols,arsenic,selenium,and other water quality parameters were analyzed monthly from2009 to 2012.Multivariate statistical methods including principle component analysis,cluster analysis,and multiple regression analysis were performed to study the relationship between contaminants and climatic factors including temperature,precipitation,wind speed,and sunshine duration.Fluoride and arsenic concentrations in most urban lakes exhibited a significant positive correlation with temperature/precipitation,which is mainly caused by rainfall induced diffuse pollution.A negative correlation was observed between volatile phenols and temperature/precipitation,and this could be explained by their enhanced volatilization and biodegradation rates caused by higher temperature.Selenium did not show a significant response to climatic factor variations,which was attributed to low selenium contents in the lakes and soils.Moreover,the response degrees of contaminants to climatic variations differ among lakes with different contamination levels.On average,temperature/precipitation contributed to 8%,15%,and 12%of the variations in volatile phenols,arsenic,and fluorides,respectively.Beijing is undergoing increased temperature and heavy rainfall frequency during the past five decades.This study suggests that water quality related to fluoride and arsenic concentrations of most urban lakes in Beijing is becoming worse under this climate change trend.展开更多
Future climate change will affect the environmental fate of hydrophobic organic contaminants(HOCs)and associated human health risks,yet the extent of these effects remains unknown.Here,we couple a high-resolution envi...Future climate change will affect the environmental fate of hydrophobic organic contaminants(HOCs)and associated human health risks,yet the extent of these effects remains unknown.Here,we couple a high-resolution environmental multimedia model with a bioaccumulation model to study the multimedia distribution of 16 priority polycyclic aromatic hydrocarbons(PAHs),a group of HOCs,and assess future PAH-related human health risks under varying climate change scenarios over China at a continental scale.After removing the effects of PAH emission changes,we find that the total PAH concentrations would decrease in the air,freshwater,sediment,soil,and organisms,while the high-molecular-weight PAH would increase in the air with climate warming from 1.5°C to 4°C.Consequently,the multi-pathway exposure human health risks predominately influenced by dietary ingestion are expected to decrease by 1.7%–20.5%,while the respiratory risks are projected to rise by 0.2%–5.8%in the future.However,the persistently high multi-pathway human health risks underscore the need for reducing future PAH emissions by 69%compared with 2009 levels in China.Our study demonstrates the urgency of limiting PAH emissions under future climate change for public health and highlights the importance of including the contribution of dietary ingestion in human health risk assessment.展开更多
基金supported by the National Key Research and Development(R&D)Program of China(2017YFA0605000)the National Natural Science Foundation of China(52039001)。
基金supported by the National Key Research and Development Program of China(2017YFA0605000)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2019ZT08L213).
文摘The substantial amount of greenhouse gas emissions from anthropogenic activities has caused the global mean surface temperature to increase by 0.99℃since the industrial revolution[1].China is committed to achieving carbon neutrality by 2060 in response to climate change[2].Soil stores approximately 2344–3000 Pg(1015 g)of carbon at depths of 0–100 cm in terrestrial ecosystems,an amount approximately equivalent to twice the amount in the atmospheric carbon pool and three times that in the terrestrial biomass;therefore,even a small change in soil carbon stocks will exert significant impacts on atmospheric CO_(2)concentrations[3].
基金supported by the National Key R&D Program of China(No.2017YFA0605001)the National Natural Science Foundation of China(No.91547207)the Fund for Innovative Research Group of the National Natural Science Foundation of China(No.51721093)
文摘Water regulation of the Xiaolangdi Reservoir of the Yellow River was chosen as a case to investigate variations in concentrations and bioavailability of heavy metals caused by water conservancy projects in rivers. Water and suspended sediment(SPS) samples were collected at downstream sampling sites along the river during this period. Concentrations and speciation of Zn, Cr, Cu, Ni, and Pb in water and SPS samples were analyzed, and their bioaccumulation was studied with Daphnia magna. This study indicated that the exchangeable and carbonatebound fractions of heavy metals in SPS decreased along the studied stretch, and the dissolved heavy metal concentrations increased along the river with 1.6–15 folds. This is because sediment resuspension increased along the river during water regulation, giving rise to the increase of heavy metal release from SPS. The dissolved Zn, Cu, Ni, and Pb concentrations were significantly positively correlated with SPS concentrations, and their increase along the river was greater than Cr. The body burdens of heavy metals in D. magna exposed into samples collected from the reservoir outlet were 1.3–3.0 times lower than those from downstream stations, suggesting that the heavy metal bioavailability increased during water regulation.This should be considered in the reservoir operation.
基金financially supported by the National Key R&D Program of China (No. 2021YFC3200401)the National Natural Science Foundation of China (Nos. 21677015, 52170024 and 22006031)the Natural Science Foundation of Hebei Province (No. B2019204315)。
文摘Graphene oxide(GO) with unique characteristics grasps striking potentials in both academic and industrial applications. After being released into natural waters, the dispersity and stability of GO might be altered by the chemical conditions in the receiving water bodies. In this review, we summarized that the aggregation of GO in aquatic environments is mostly dependent on properties of nanoparticles(size,structure, and functional groups) and complex water chemistry(p H, temperature, light, ionic strength,and dissolved organic matter). The knowledge about the aggregation/stability of GO is still insufficient due to the variations in GO properties and complex system of natural waters. Although studies about environmental transformation of graphene-related materials can be accessed but a systematic study taking into consideration the various factors of GO and aquatic systems responsible for aggregation of GO is still lacking. Therefore, we summarized that GO homoaggregation or heteroaggregation with other solid particles can affect the distribution in different depths of rivers and toxicity toward plankton or benthic organisms. More studies are needed to investigate the stability of GO in the long term, the effect of other nanomaterial on GO aggregation, the alteration of water constituents at different regions/time and its effect on GO aggregation, to understand the transportation and impact of GO in the environment.
基金supported by the Major State Basic Research Development Program (No.2010CB951104)the Program for New Century Excellent Talents in University (No. NCET-09-0233)the National Water Pollution Control and Treatment Project in China (No.2008ZX07209-009)
文摘Shallow lake eutrophication is a global environmental issue. This study investigated the effects of water level variation and nutrient loadings on the growth and nutrient accumulation of Phragmites australis (reed) by field samplings in Baiyangdian Lake, the largest shallow lake of northern China. The field samplings were conducted in two sites of different nutrient loadings during the whole growth period of reeds, and three types of zones with different water depths were chosen for each site, including the terrestrial zone with water level below the ground, the ecotone zone with the water level varying from belowground to aboveground, and the submerged zone with water level above the ground. The result showed that reed growth was more limited by water level variation than nutrient loadings. The average stem lengths and diameters in terrestrial zones were about 26.3%-27.5% and 7.2%-12.0% higher than those in submerged zones, respectively. Similarly, the terrestrial status increased the aboveground biomass of reeds by 36.6%-51.8% compared with the submerged status. Both the nutrient concentrations and storages in the aboveground reeds were mainly influenced by the nutrient loadings in surface water and sediment rather than the water level variation of the reed growth environment, and the nutrient storages reached their maxima in late August or early September. It was observed that the maximum nitrogen storage occurred in the terrestrial zone with higher nutrient loadings, with the value of 74.5 g/m 2 . This study suggested that water level variation and nutrient loadings should be considered when using reeds to control and remediate eutrophication of shallow lakes.
基金supported by the Major State Basic Research Development Program (No.2010CB951104)the National Science Foundation for Distinguished Young Scholars (No.51325902)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education (No.20110003110030)the National Natural Science Foundation of China (No.51279010)
文摘The levels of six perfluoroalkyl substances(PFASs) in surface sediment and their vertical variations in dated sediment cores from the Haihe River were investigated; studied substances included perfluorooctanoic acid(PFOA),perfluorononanoic acid(PFNA),perfluorooctane sulfonate(PFOS),perfluorodecanoic acid(PFDA),perfluoroundecanoic acid(PFUnA),and perfluorododecanoic acid(PFDoA). Results showed that the total PFAS concentration in surface sediment ranged between 0.52 and 16.33 ng/g dry weight(dw) with an average of3.47 ng/g dw,with PFOS and PFOA as the dominant PFASs. In general,the PFAS concentrations in the mainstream increased from the upper to the lower reaches,except that a drop occurred downstream of the Erdao dam. Although the PFASs in the sediment cores did not show a clear decreasing or increasing trend with depth,the three cores had a similar vertical variation.The PFAS levels were relatively low in the surface sediment,and reached the first high point at8–20 cm as a result of the wide use of PFASs from 1990 to 2000. After that the PFAS levels decreased,and then increased to a second high point at about 40–48 cm,which might be caused by the leaching of PFASs in sediment. Because PFASs have hydrophilic groups and relatively high solubility,the PFASs will transfer from the upper to lower layers of sediment when water infiltration occurs,leading to the fluctuation of PFAS levels in sediment cores. This study suggests that both the temporal variation of sources and transfer processes of PFASs in sediments are important factors influencing the vertical variation of PFASs in sediment cores.
基金supported by the National Science Foundation for Distinguished Young Scholars (No.51325902)the National Natural Science Foundation of China (No.91547207)the National Natural Science Foundation for Innovative Research Group (No.51421065)
文摘Many studies have investigated bioaccumulation and metabolism of polycyclic aromatic hydrocarbons(PAHs)in aquatic organisms.However,lack of studies investigated both processes simultaneously,and the interaction between these two processes is less understood so far.This study investigated the bioaccumulation kinetics of PAHs and metabolic enzyme activities,including total cytochrome P450(CYPs)and total superoxide dismutase(T-SOD),in zebrafish.Mature zebrafish were exposed to the mixture of phenanthrene and anthracene under constant concentration maintained by passive dosing systems for 16 days.The results showed that PAH concentrations in zebrafish experienced a peak value after exposure for 1.5 days,and then decreased gradually.The bioaccumulation equilibrium was achieved after exposure for 12 days.Both of the uptake rate constants(k_u)and the elimination rate constants(k_e)decreased after the peak value.The variation of PAH concentrations and metabolic enzyme activities in zebrafish had an interactive relationship.The activities of CYPs and T-SOD increased initially with the increase of PAH concentrations,but decreased to the lowest state when PAH concentrations reached the peak value.When the bioaccumulation equilibrium of PAHs was achieved,CYPs and T-SOD activities also reached the steady state.In general,CYPs and T-SOD activities were activated after exposure to PAHs.The decrease of PAH concentrations in zebrafish after the peak value may be attributed to the great drop of k_uand the variation of CYPs activities.This study suggests that an interactive relationship exists between bioaccumulation kinetics of PAHs and metabolic enzyme activities in aquatic organisms.
基金supported by the Major State Basic Research Development Program(No.2010CB951104)the National Science Foundation for Distinguished Young Scholars(No.51325902)the National Natural Science Foundation of China(No.51279010)
文摘Climate change is supposed to have influences on water quality and ecosystem.However,only few studies have assessed the effect of climate change on environmental toxic contaminants in urban lakes.In this research,response of several toxic contaminants in twelve urban lakes in Beijing,China,to the seasonal variations in climatic factors was studied.Fluorides,volatile phenols,arsenic,selenium,and other water quality parameters were analyzed monthly from2009 to 2012.Multivariate statistical methods including principle component analysis,cluster analysis,and multiple regression analysis were performed to study the relationship between contaminants and climatic factors including temperature,precipitation,wind speed,and sunshine duration.Fluoride and arsenic concentrations in most urban lakes exhibited a significant positive correlation with temperature/precipitation,which is mainly caused by rainfall induced diffuse pollution.A negative correlation was observed between volatile phenols and temperature/precipitation,and this could be explained by their enhanced volatilization and biodegradation rates caused by higher temperature.Selenium did not show a significant response to climatic factor variations,which was attributed to low selenium contents in the lakes and soils.Moreover,the response degrees of contaminants to climatic variations differ among lakes with different contamination levels.On average,temperature/precipitation contributed to 8%,15%,and 12%of the variations in volatile phenols,arsenic,and fluorides,respectively.Beijing is undergoing increased temperature and heavy rainfall frequency during the past five decades.This study suggests that water quality related to fluoride and arsenic concentrations of most urban lakes in Beijing is becoming worse under this climate change trend.
基金supported by the National Key Research and Development Program of China(2017YFA0605001)the National Natural Science Foundation of China(52039001,92047303 and 41977359)
文摘Future climate change will affect the environmental fate of hydrophobic organic contaminants(HOCs)and associated human health risks,yet the extent of these effects remains unknown.Here,we couple a high-resolution environmental multimedia model with a bioaccumulation model to study the multimedia distribution of 16 priority polycyclic aromatic hydrocarbons(PAHs),a group of HOCs,and assess future PAH-related human health risks under varying climate change scenarios over China at a continental scale.After removing the effects of PAH emission changes,we find that the total PAH concentrations would decrease in the air,freshwater,sediment,soil,and organisms,while the high-molecular-weight PAH would increase in the air with climate warming from 1.5°C to 4°C.Consequently,the multi-pathway exposure human health risks predominately influenced by dietary ingestion are expected to decrease by 1.7%–20.5%,while the respiratory risks are projected to rise by 0.2%–5.8%in the future.However,the persistently high multi-pathway human health risks underscore the need for reducing future PAH emissions by 69%compared with 2009 levels in China.Our study demonstrates the urgency of limiting PAH emissions under future climate change for public health and highlights the importance of including the contribution of dietary ingestion in human health risk assessment.