High values of ozone(O_(3))occur frequently in the dry spring season;thus,understanding the evolution characteristics of volatile organic compounds(VOCs)in spring is of great significance for preventing O_(3)pollution...High values of ozone(O_(3))occur frequently in the dry spring season;thus,understanding the evolution characteristics of volatile organic compounds(VOCs)in spring is of great significance for preventing O_(3)pollution.In this study,a total of 101 VOCs from April 16 to May 21,2019,were quantified using an online gas chromatography mass spectrometer/flame ionization detector(GCMS/FID).The results indicated that the observed concentration of total VOCs(TVOCs)was 30.4±17.0 ppbv,and it was dominated by alkanes(44.3%),followed by oxygenated VOCs(OVOCs)(17.4%),halocarbons(12.7%),aromatics(9.5%),alkenes(8.2%),acetylene(5.3%)and carbon disulfide(2.5%).The average mixing ratio of VOCs showed obvious diurnal variation(high at night,low during daytime).We conducted a source apportionment study based on 32 major VOCs using positive matrix factorization(PMF),and coal+biomass burning(25.2%),diesel exhaust(16.0%),gasoline exhaust+evaporation(17.4%),secondary+long-lived species(16.7%),biogenic sources(4.3%),industrial emissions(9.3%)and solvent use(11.2%)were identified as major sources of VOCs.In addition to local emissions,most of the atmospheric VOCs were derived from long-distance air masses(65.7%),and the average mixing ratio of VOCs in the northwest direction was 29.4 ppbv.Combined with the results of the potential source contribution function(PSCF)indicate that research should focus on the local emissions of combustion,transportation sources and solvents usage to control atmospheric VOCs.Additionally,transmission of the northwest air mass is an important component that cannot be ignored during spring in Beijing.展开更多
Hot springs are natural exposed points of the hydrothermal system. The hydrogeochemistry of hot springs can be used to interpret the formation of the hydrothermal system; and the ^(14)C dating can be used to evaluate ...Hot springs are natural exposed points of the hydrothermal system. The hydrogeochemistry of hot springs can be used to interpret the formation of the hydrothermal system; and the ^(14)C dating can be used to evaluate the renewability of the hydrothermal system. The hot springs exposed from fault zones in western Guangdong are classified as granite fissure water and clastic rock fissure water, which are sampled and tested. The results of water chemistry analysis show that hot spring water is mainly HCO_3-Na type in the beginning, while the mixing of seawater leads to the increase of Cl^-. Hydrogen and oxygen isotopes indicate that these hot springs mainly come from atmospheric precipitation, and water-rock interactions produce oxygen isotope exchange reactions, where a significant "oxygen drift" phenomenon can be observed. The relationship between δ^(13)C and HCO_3^- indicates that there is a deep source of CO_2 "dead carbon" in hot spring water. This systematic error is not considered in the existing ^(14)C dating correction models. The ^(14)C age of the deep source "dead carbon" correction proposed in this paper is close to the ^(14)C age of the reverse chemical simulation correction, the Gonfiantinie model, and the Mook model. The deep source "dead carbon" correction method can improve the systematic error. Therefore, the ^(14)C age corrected by the deep source "dead carbon" may be more representative in terms of the actual age of geothermal water.展开更多
In this paper, the reservoir temperatures of 14 hot spring samples collected from the northern segment of theRed River Fault are calculated by using the mixing-model of SiO2-geothermometer. Based on the features ofres...In this paper, the reservoir temperatures of 14 hot spring samples collected from the northern segment of theRed River Fault are calculated by using the mixing-model of SiO2-geothermometer. Based on the features ofreservoir temperatures and densities of hot springs, the northern segment of the Red River Fault is furtherdivided into 4 sub-segments. The influence of weakening effect of water on seismic activities is discussed fromthe view point of fault-weakening effect of water. It is suggested that the difference in seismic activity between various sub-segments is principally caused by the difference in intensity of the fault-weakening effect ofwater of these sub-segments. The Eryuan sub-segment where the reservoir temperatures are high and the hotsprings are dense corresponds to a slipped region, however, the Jianchuan and Midu sub-segments where thereservoir temperatures are lower and the hot springs are fewer as well as the Dan sub-segment where the hotspring are very few all correspond to locked regions. It is suggested that Dan sub-segment is the riskiest region for strong earthquake preparation, while the possibility for strong earthquake preparation is very little inthe Eryuan sub-segment.展开更多
A preliminary study was conducted to analyze the water quality of spring waters in rural watershed of Western Nepal. 155 spring water samples were collected from Jhimruk, Rangun, Bogtan-Lagam Karnali, Thuligad and Mid...A preliminary study was conducted to analyze the water quality of spring waters in rural watershed of Western Nepal. 155 spring water samples were collected from Jhimruk, Rangun, Bogtan-Lagam Karnali, Thuligad and Middle Karnali watershed. Collection and analysis occurred twice, once in pre-monsoon 2018 and post-monsoon 2018. Various physical and chemical parameters were analyzed by using standard water quality measurements and compared with the Nepal Drinking Water Quality Standard and the World Health Organization Standard Guideline. The results indicate that the turbidity was high during pre-monsoon season. The highest turbidity of 63.8 NTU was observed in the Bogtan-Lagam Karnali watershed. Two spring sources—one in Bogtan-Lagam Karnali and one in Middle Karnali exceeded the health standard for nitrate-N. The phosphate levels were high during the pre-monsoon season in Jhimruk and Rangun watershed in all the studied sites. Dissolved oxygen levels were relatively high during post-monsoon season. Results of the water quality index in all the studied sites revealed that the water quality ranges from being poor to good conditions in the spring sources. The results from this study suggested that the water bodies are relatively good and can be used for domestic purposes after suitable treatment.展开更多
The Ikogosi Warm Spring is a unique ecological niche in Western Nigeria with an average temperature and pH of 38°C and 5.8 respectively. It mixes with an adjacent cold spring (28°C & pH 7.6), about 100 m...The Ikogosi Warm Spring is a unique ecological niche in Western Nigeria with an average temperature and pH of 38°C and 5.8 respectively. It mixes with an adjacent cold spring (28°C & pH 7.6), about 100 meters from source, yielding a confluence body of water of 32°C and pH 7.7. To explore the bacterial community structure of this uncommon environment and to scan for potentially useful bacteria, metagenomes extracted directly from five samples (source and mid-point of warm spring;source and midpoint of cold spring, and the confluence) were analyzed. Using the MiSeq Illumina next generation sequencing protocols, the V3-V4 region of the 16S rRNA gene pool was sequenced and analyzed by QIIME (Quantitative Insights into Microbial Ecology) and R software. At least 11% (47,446) of all the sequences were unknown to any of the databases employed. Bacterial diversity and abundance at the source of both springs were extremely low, accounting for less than 0.07% of the total sequence reads at the confluence, 100 m downstream. In contrast to the highly diversified mesophilic confluence community where 21 different phyla were identified, only 4 and 5 phyla were recovered from the source-point of the warm spring and cold spring respectively. The most prevalent phyla in all samples were members of the versatile Proteobacteria (35% - 50% relative abundance), and the hardy Firmicutes (33% - 40%). Operational taxonomic units (OTUs) obtained from all the samples averaged at 1414. Temperature and pH were equally significant predictors of genomic diversity and richness, with the warm and cold spring sources having less than 5 bacteria phyla. Exiguobacterium sp. (a potential plastic degrader) and other deep rooted bacteria were found in the warm spring while the cold spring outflow contained among others such as Rubrobacter sp. and Chloroflexi sp. (which is close to the phylogenetic root of the domain Bacteria). Many taxonomically unresolved sequences could indicate the presence of potentially novel bacteria in this unique body of water and underscores the need to systematically mine these rare genetic reservoirs for biotechnological applications. Moreover, such tropical hydrothermal ecosystems could contain some unknown primitive bacteria at the origins of life.展开更多
Mapping of topography and land use/cover as well as spring water yield measurements were done for 2 dambo-spring fed micro-catchments in Incalaue river catchment.The springs are located near Ntimbo 1 and Lizongole hum...Mapping of topography and land use/cover as well as spring water yield measurements were done for 2 dambo-spring fed micro-catchments in Incalaue river catchment.The springs are located near Ntimbo 1 and Lizongole human settlement areas in Niassa Special Reserve(NSR).Community consultations were used to asses locally perceived knowledge of dambo-spring catchments dependence by these communities and wildlife;as well as changes and experiences.The Ntimbo 1 dambo-spring catchment(26.55 sq.km)has elevation gradient of 310 to 530 m a.s.l;and the area can topographically be linked to Incalaue river by delineation from a 90-meter spatial resolution Digital Elevation Model(DEM).The Lizongole dambo-spring catchment(1.33 sq.km)has elevation gradient of 300 to 360 m a.s.l and cannot easily be delineated from 90-meter DEM.Both catchments have the 6 vegetation classes existing in the area as well as farmlands and human settlement areas.There exists potential for wildlife-human water source conflict due to dambo dependence by humans and wildlife in the dry season.Ntimbo dambo-spring had a higher water yield per second than the Lizongole dambo-spring.There was no significant difference in spring yields of Ntimbo and Lizongole in the dry season(P<0.05).The Lizongole spring could not be gauged in the wet season because of the wet dambo valley wetland location.There was no significant reduction in water yield for Ntimbo spring during the dry season(P<0.05).The study suggests that Ntimbo spring could be from a confined aquifer;and Lizongole spring to be from a shallow unconfined aquifer.This study contributes understanding of the poorly-defined dambo areas by adding the role of groundwater in supporting micro-dambos which support herbaceous flora and graminivorous fauna as well as human populations in Incalaue basin in NSR especially in the dry season.展开更多
基金supported by the National Key Technology R&D Program of China(No.2017YFC0210000)the Young Talent Project of the Center for Excellence in Regional Atmospheric Environment,CAS(No.CERAE201802)+2 种基金the National Natural Science Foundation of China(Nos.41705113 and 41877312)the National Research Program for Key Issues in Air Pollution Control(No.DQGG0101)the Beijing Major Science and Technology Project(No.Z181100005418014)。
文摘High values of ozone(O_(3))occur frequently in the dry spring season;thus,understanding the evolution characteristics of volatile organic compounds(VOCs)in spring is of great significance for preventing O_(3)pollution.In this study,a total of 101 VOCs from April 16 to May 21,2019,were quantified using an online gas chromatography mass spectrometer/flame ionization detector(GCMS/FID).The results indicated that the observed concentration of total VOCs(TVOCs)was 30.4±17.0 ppbv,and it was dominated by alkanes(44.3%),followed by oxygenated VOCs(OVOCs)(17.4%),halocarbons(12.7%),aromatics(9.5%),alkenes(8.2%),acetylene(5.3%)and carbon disulfide(2.5%).The average mixing ratio of VOCs showed obvious diurnal variation(high at night,low during daytime).We conducted a source apportionment study based on 32 major VOCs using positive matrix factorization(PMF),and coal+biomass burning(25.2%),diesel exhaust(16.0%),gasoline exhaust+evaporation(17.4%),secondary+long-lived species(16.7%),biogenic sources(4.3%),industrial emissions(9.3%)and solvent use(11.2%)were identified as major sources of VOCs.In addition to local emissions,most of the atmospheric VOCs were derived from long-distance air masses(65.7%),and the average mixing ratio of VOCs in the northwest direction was 29.4 ppbv.Combined with the results of the potential source contribution function(PSCF)indicate that research should focus on the local emissions of combustion,transportation sources and solvents usage to control atmospheric VOCs.Additionally,transmission of the northwest air mass is an important component that cannot be ignored during spring in Beijing.
基金financially supported jointly by the National Natural Science foundation of China (Grant Nos.40602031,41440027)the China Geological Survey project (Grant No.1212011220014)
文摘Hot springs are natural exposed points of the hydrothermal system. The hydrogeochemistry of hot springs can be used to interpret the formation of the hydrothermal system; and the ^(14)C dating can be used to evaluate the renewability of the hydrothermal system. The hot springs exposed from fault zones in western Guangdong are classified as granite fissure water and clastic rock fissure water, which are sampled and tested. The results of water chemistry analysis show that hot spring water is mainly HCO_3-Na type in the beginning, while the mixing of seawater leads to the increase of Cl^-. Hydrogen and oxygen isotopes indicate that these hot springs mainly come from atmospheric precipitation, and water-rock interactions produce oxygen isotope exchange reactions, where a significant "oxygen drift" phenomenon can be observed. The relationship between δ^(13)C and HCO_3^- indicates that there is a deep source of CO_2 "dead carbon" in hot spring water. This systematic error is not considered in the existing ^(14)C dating correction models. The ^(14)C age of the deep source "dead carbon" correction proposed in this paper is close to the ^(14)C age of the reverse chemical simulation correction, the Gonfiantinie model, and the Mook model. The deep source "dead carbon" correction method can improve the systematic error. Therefore, the ^(14)C age corrected by the deep source "dead carbon" may be more representative in terms of the actual age of geothermal water.
文摘In this paper, the reservoir temperatures of 14 hot spring samples collected from the northern segment of theRed River Fault are calculated by using the mixing-model of SiO2-geothermometer. Based on the features ofreservoir temperatures and densities of hot springs, the northern segment of the Red River Fault is furtherdivided into 4 sub-segments. The influence of weakening effect of water on seismic activities is discussed fromthe view point of fault-weakening effect of water. It is suggested that the difference in seismic activity between various sub-segments is principally caused by the difference in intensity of the fault-weakening effect ofwater of these sub-segments. The Eryuan sub-segment where the reservoir temperatures are high and the hotsprings are dense corresponds to a slipped region, however, the Jianchuan and Midu sub-segments where thereservoir temperatures are lower and the hot springs are fewer as well as the Dan sub-segment where the hotspring are very few all correspond to locked regions. It is suggested that Dan sub-segment is the riskiest region for strong earthquake preparation, while the possibility for strong earthquake preparation is very little inthe Eryuan sub-segment.
文摘A preliminary study was conducted to analyze the water quality of spring waters in rural watershed of Western Nepal. 155 spring water samples were collected from Jhimruk, Rangun, Bogtan-Lagam Karnali, Thuligad and Middle Karnali watershed. Collection and analysis occurred twice, once in pre-monsoon 2018 and post-monsoon 2018. Various physical and chemical parameters were analyzed by using standard water quality measurements and compared with the Nepal Drinking Water Quality Standard and the World Health Organization Standard Guideline. The results indicate that the turbidity was high during pre-monsoon season. The highest turbidity of 63.8 NTU was observed in the Bogtan-Lagam Karnali watershed. Two spring sources—one in Bogtan-Lagam Karnali and one in Middle Karnali exceeded the health standard for nitrate-N. The phosphate levels were high during the pre-monsoon season in Jhimruk and Rangun watershed in all the studied sites. Dissolved oxygen levels were relatively high during post-monsoon season. Results of the water quality index in all the studied sites revealed that the water quality ranges from being poor to good conditions in the spring sources. The results from this study suggested that the water bodies are relatively good and can be used for domestic purposes after suitable treatment.
文摘The Ikogosi Warm Spring is a unique ecological niche in Western Nigeria with an average temperature and pH of 38°C and 5.8 respectively. It mixes with an adjacent cold spring (28°C & pH 7.6), about 100 meters from source, yielding a confluence body of water of 32°C and pH 7.7. To explore the bacterial community structure of this uncommon environment and to scan for potentially useful bacteria, metagenomes extracted directly from five samples (source and mid-point of warm spring;source and midpoint of cold spring, and the confluence) were analyzed. Using the MiSeq Illumina next generation sequencing protocols, the V3-V4 region of the 16S rRNA gene pool was sequenced and analyzed by QIIME (Quantitative Insights into Microbial Ecology) and R software. At least 11% (47,446) of all the sequences were unknown to any of the databases employed. Bacterial diversity and abundance at the source of both springs were extremely low, accounting for less than 0.07% of the total sequence reads at the confluence, 100 m downstream. In contrast to the highly diversified mesophilic confluence community where 21 different phyla were identified, only 4 and 5 phyla were recovered from the source-point of the warm spring and cold spring respectively. The most prevalent phyla in all samples were members of the versatile Proteobacteria (35% - 50% relative abundance), and the hardy Firmicutes (33% - 40%). Operational taxonomic units (OTUs) obtained from all the samples averaged at 1414. Temperature and pH were equally significant predictors of genomic diversity and richness, with the warm and cold spring sources having less than 5 bacteria phyla. Exiguobacterium sp. (a potential plastic degrader) and other deep rooted bacteria were found in the warm spring while the cold spring outflow contained among others such as Rubrobacter sp. and Chloroflexi sp. (which is close to the phylogenetic root of the domain Bacteria). Many taxonomically unresolved sequences could indicate the presence of potentially novel bacteria in this unique body of water and underscores the need to systematically mine these rare genetic reservoirs for biotechnological applications. Moreover, such tropical hydrothermal ecosystems could contain some unknown primitive bacteria at the origins of life.
文摘Mapping of topography and land use/cover as well as spring water yield measurements were done for 2 dambo-spring fed micro-catchments in Incalaue river catchment.The springs are located near Ntimbo 1 and Lizongole human settlement areas in Niassa Special Reserve(NSR).Community consultations were used to asses locally perceived knowledge of dambo-spring catchments dependence by these communities and wildlife;as well as changes and experiences.The Ntimbo 1 dambo-spring catchment(26.55 sq.km)has elevation gradient of 310 to 530 m a.s.l;and the area can topographically be linked to Incalaue river by delineation from a 90-meter spatial resolution Digital Elevation Model(DEM).The Lizongole dambo-spring catchment(1.33 sq.km)has elevation gradient of 300 to 360 m a.s.l and cannot easily be delineated from 90-meter DEM.Both catchments have the 6 vegetation classes existing in the area as well as farmlands and human settlement areas.There exists potential for wildlife-human water source conflict due to dambo dependence by humans and wildlife in the dry season.Ntimbo dambo-spring had a higher water yield per second than the Lizongole dambo-spring.There was no significant difference in spring yields of Ntimbo and Lizongole in the dry season(P<0.05).The Lizongole spring could not be gauged in the wet season because of the wet dambo valley wetland location.There was no significant reduction in water yield for Ntimbo spring during the dry season(P<0.05).The study suggests that Ntimbo spring could be from a confined aquifer;and Lizongole spring to be from a shallow unconfined aquifer.This study contributes understanding of the poorly-defined dambo areas by adding the role of groundwater in supporting micro-dambos which support herbaceous flora and graminivorous fauna as well as human populations in Incalaue basin in NSR especially in the dry season.
