Zn isotope is a useful tool for tracing biogeochemical processes as zinc plays important roles in the biogeochemistry of natural systems. However, the Zn isotope composition in the lake ecosystems has not been well ch...Zn isotope is a useful tool for tracing biogeochemical processes as zinc plays important roles in the biogeochemistry of natural systems. However, the Zn isotope composition in the lake ecosystems has not been well characterized. In order to resolve this problem, we investigate the Zn isotope compositions of suspended particulate matter(SPM) and biological samples collected from the Aha Lake and Hongfeng Lake, and their tributaries in summer and winter, aiming to explore the potential of this novel isotope system as a proxy for biogeochemical processes in aqueous environments. Concentration of dissolved Zn ranges from 0.65 to 5.06 μg/L and 0.74 to 12.04 μg/L for Aha Lake and Hongfeng Lake, respectively, while Zn(SPM) ranges from 0.18 to 0.70 mg/g and 0.24 to 0.75 mg/g for Aha Lake and Hongfeng Lake, respectively. The Zn isotope composition in SPM from Aha Lake and its main tributaries ranges from -0.18‰ to 0.27‰ and -0.17‰ to 0.46‰, respectively, and it varies from -0.29‰ to 0.26‰ and -0.04‰ to 0.48‰, respectively in Hongfeng Lake and its main tributaries, displaying a wider range in tributaries than lakes. These results imply that Zn isotope compositions are mainly affected by tributaries inputting into Aha Lake, while adsorption process by algae is the major factor for the Zn isotope composition in Hongfeng Lake, and ZnS precipitation leads to the light Zn isotope composition of SPM in summer. These data and results provide the basic information of the Zn isotope for the lake ecosystem, and promote the application of Zn isotope in biogeochemistry.展开更多
甲烷氧化菌是一类能够以甲烷作为唯一碳源和能量维持生存的微生物,其活动与生态系统中物质循环及能量流动密切相关。【目的】了解阿哈湖水库沉积物中甲烷氧化菌群落结构及代谢功能。【方法】采用宏基因组技术对环湖沉积物和湖心沉积物...甲烷氧化菌是一类能够以甲烷作为唯一碳源和能量维持生存的微生物,其活动与生态系统中物质循环及能量流动密切相关。【目的】了解阿哈湖水库沉积物中甲烷氧化菌群落结构及代谢功能。【方法】采用宏基因组技术对环湖沉积物和湖心沉积物进行研究。【结果】水库沉积物中主要的好氧甲烷氧化菌是甲基杆菌属(Methylobacter)(0.37%)和甲基单胞菌属(Methylomonas)(0.12%),主要的厌氧甲烷氧化菌是Candidatus_Methylomirabilis(0.12%),属于NC10门细菌中的亚硝酸盐反硝化型厌氧甲烷氧化菌,其中好氧甲烷氧化菌的pmoA基因为6.16×10^(7)copies/g,反硝化型厌氧甲烷氧化菌的16S rRNA基因为2.84×10^(7)copies/g。4种代谢的功能基因多样性表现为氮代谢>碳代谢>硫代谢>甲烷代谢,基于京都基因和基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)基因库进行注释得到6大类功能,发现18条与碳(包括甲烷)、氮、硫代谢有关的完整代谢途径。主坐标分析(principal coordinates analysis,PCoA)显示环湖沉积物与湖心沉积物之间的甲烷氧化菌种类和功能存在显著差异。影响甲烷氧化菌分布的主要环境因子为氧化还原电位、电导率和硫酸根。【结论】阿哈湖水库甲烷氧化菌以Ⅰ型好氧甲烷氧化菌为主,甲烷氧化菌群落代谢途径丰富,Ⅰ型和Ⅱ型甲烷氧化菌在对O2的适应性上有显著差异。相关研究可为湖泊水生态环境的保护和微生物资源的开发利用等方面提供一定的理论支撑。展开更多
The release of various harmful and poisonous elements from sediments to overlying water via pore water is one of the geochemical processes influencing and restricting the water quality of lakes. It is important for pr...The release of various harmful and poisonous elements from sediments to overlying water via pore water is one of the geochemical processes influencing and restricting the water quality of lakes. It is important for protecting and managing freshwater lakes to uncover and recognize the basic features and forming mechanism of this process.展开更多
采用Tessier连续提取法,对贵阳阿哈湖枯水季节表层沉积物中Pb、Fe、Cu、Zn、Mn、N i 6种重金属元素的5种化学形态进行了连续提取测定,分析了水体单元表层沉积物重金属元素的形态组合特征和人为污染状况。结果表明:采用Tessier方法对阿...采用Tessier连续提取法,对贵阳阿哈湖枯水季节表层沉积物中Pb、Fe、Cu、Zn、Mn、N i 6种重金属元素的5种化学形态进行了连续提取测定,分析了水体单元表层沉积物重金属元素的形态组合特征和人为污染状况。结果表明:采用Tessier方法对阿哈湖沉积物重金属元素形态进行提取,提取结果具有较高的精密度和稳定性;沉积物中重金属元素Pb、Zn、Fe、Mn、N i除残渣态外主要以Fe-Mn氧化物结合态为主,而Cu是以有机物结合态和残渣态为主。烂泥沟处重金属的人为污染最为严重。展开更多
The Aha Lake is a seasonal anoxic water system in the southwest of Guiyang City, Guizhou Province, China. Seasonal variations in SO42- concentrations and their isotopic compositions in lake water as well as in the tri...The Aha Lake is a seasonal anoxic water system in the southwest of Guiyang City, Guizhou Province, China. Seasonal variations in SO42- concentrations and their isotopic compositions in lake water as well as in the tributaries were investigated in this study. The results showed that sulfate concentrations in river water range from 0.94 to 6.52 mmol/L and their δ34S values range from -14.9‰ and 0.9‰, while lake water has sulfate concentrations ranging from 1.91 to 2.79 mmol/L, and δ34S values from -9.8‰ to -5.9‰. It is suggested that coal mining drainage is the major source of SO42- in the Aha Lake. Rainfall, sewage discharge, sulfide oxidation and gypsum dissolution have made only limited contributions. Different depth-dependent distributions of dissolved SO42- and δ34S were de-veloped for both DB and LJK in summer and winter. Due to water overturn, δ34S values display homogenous vertical distributions in winter and spring. While in summer and autumn, significant positive shifts of δ34S were clearly ob-served in epilimnion and bottom strata as a result of water stratification. High δ34S values in epilimnion may result from the retention of rainwater during water stratification. Dissimilatory sulfate reduction by bacteria was thought to be responsible for the increase of δ34S value in hypolimnion.展开更多
The Aha Lake, as a seasonally oxygen-absent man-made reservoir, has been polluted by acidic mining drainage and domestic sewages for a long time, with iron, manganese and sulfate excessively enriched in water and sedi...The Aha Lake, as a seasonally oxygen-absent man-made reservoir, has been polluted by acidic mining drainage and domestic sewages for a long time, with iron, manganese and sulfate excessively enriched in water and sediment. By means of microbe counting, the analysis of trace metals in pore water and electronic acceptors for or-ganic matter decomposing, we have found that strong bio-geochemical remobilization of trace metals occurred near the water-sediment interface. The microbial reduction of iron, manganese and sulfate took place in different parts throughout the sediment core with the extend of iron reduc-tion lower than that of sulfate reduction, which happened in the surficial sediments and hampered the upward release of some trace metals to some extent. Some trace metals in pore water, due to the 揹ual releasing?effects caused by the re-duction of Fe3+ and Mn4+ at varying depth, show a tendency of being enriched excessively in the upper 10 cm of sediment. In this study, we discussed the microbiological mechanism of trace metals enrichment in surficial sediments and the envi-ronmental condition, with an attempt to realize the unsteady mobilization of trace metals and their potential harm to overlying lake water in the Aha Lake, Guiyang.展开更多
基金supported by the National Natural Science Foundation of China(No.40903005)
文摘Zn isotope is a useful tool for tracing biogeochemical processes as zinc plays important roles in the biogeochemistry of natural systems. However, the Zn isotope composition in the lake ecosystems has not been well characterized. In order to resolve this problem, we investigate the Zn isotope compositions of suspended particulate matter(SPM) and biological samples collected from the Aha Lake and Hongfeng Lake, and their tributaries in summer and winter, aiming to explore the potential of this novel isotope system as a proxy for biogeochemical processes in aqueous environments. Concentration of dissolved Zn ranges from 0.65 to 5.06 μg/L and 0.74 to 12.04 μg/L for Aha Lake and Hongfeng Lake, respectively, while Zn(SPM) ranges from 0.18 to 0.70 mg/g and 0.24 to 0.75 mg/g for Aha Lake and Hongfeng Lake, respectively. The Zn isotope composition in SPM from Aha Lake and its main tributaries ranges from -0.18‰ to 0.27‰ and -0.17‰ to 0.46‰, respectively, and it varies from -0.29‰ to 0.26‰ and -0.04‰ to 0.48‰, respectively in Hongfeng Lake and its main tributaries, displaying a wider range in tributaries than lakes. These results imply that Zn isotope compositions are mainly affected by tributaries inputting into Aha Lake, while adsorption process by algae is the major factor for the Zn isotope composition in Hongfeng Lake, and ZnS precipitation leads to the light Zn isotope composition of SPM in summer. These data and results provide the basic information of the Zn isotope for the lake ecosystem, and promote the application of Zn isotope in biogeochemistry.
文摘甲烷氧化菌是一类能够以甲烷作为唯一碳源和能量维持生存的微生物,其活动与生态系统中物质循环及能量流动密切相关。【目的】了解阿哈湖水库沉积物中甲烷氧化菌群落结构及代谢功能。【方法】采用宏基因组技术对环湖沉积物和湖心沉积物进行研究。【结果】水库沉积物中主要的好氧甲烷氧化菌是甲基杆菌属(Methylobacter)(0.37%)和甲基单胞菌属(Methylomonas)(0.12%),主要的厌氧甲烷氧化菌是Candidatus_Methylomirabilis(0.12%),属于NC10门细菌中的亚硝酸盐反硝化型厌氧甲烷氧化菌,其中好氧甲烷氧化菌的pmoA基因为6.16×10^(7)copies/g,反硝化型厌氧甲烷氧化菌的16S rRNA基因为2.84×10^(7)copies/g。4种代谢的功能基因多样性表现为氮代谢>碳代谢>硫代谢>甲烷代谢,基于京都基因和基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)基因库进行注释得到6大类功能,发现18条与碳(包括甲烷)、氮、硫代谢有关的完整代谢途径。主坐标分析(principal coordinates analysis,PCoA)显示环湖沉积物与湖心沉积物之间的甲烷氧化菌种类和功能存在显著差异。影响甲烷氧化菌分布的主要环境因子为氧化还原电位、电导率和硫酸根。【结论】阿哈湖水库甲烷氧化菌以Ⅰ型好氧甲烷氧化菌为主,甲烷氧化菌群落代谢途径丰富,Ⅰ型和Ⅱ型甲烷氧化菌在对O2的适应性上有显著差异。相关研究可为湖泊水生态环境的保护和微生物资源的开发利用等方面提供一定的理论支撑。
基金Project supported by the National Natural Science Foundation of China.
文摘The release of various harmful and poisonous elements from sediments to overlying water via pore water is one of the geochemical processes influencing and restricting the water quality of lakes. It is important for protecting and managing freshwater lakes to uncover and recognize the basic features and forming mechanism of this process.
文摘采用Tessier连续提取法,对贵阳阿哈湖枯水季节表层沉积物中Pb、Fe、Cu、Zn、Mn、N i 6种重金属元素的5种化学形态进行了连续提取测定,分析了水体单元表层沉积物重金属元素的形态组合特征和人为污染状况。结果表明:采用Tessier方法对阿哈湖沉积物重金属元素形态进行提取,提取结果具有较高的精密度和稳定性;沉积物中重金属元素Pb、Zn、Fe、Mn、N i除残渣态外主要以Fe-Mn氧化物结合态为主,而Cu是以有机物结合态和残渣态为主。烂泥沟处重金属的人为污染最为严重。
基金supported by the Natural Science Foundation of China (Nos.40903008,90610037,40721002)the Open Research Fund of State Key Laboratory of Environmental Geochemistry,Chinese Academy of Sciences (SKLEG9006)the Chinese important special project (No.2009ZX07419-003)
文摘The Aha Lake is a seasonal anoxic water system in the southwest of Guiyang City, Guizhou Province, China. Seasonal variations in SO42- concentrations and their isotopic compositions in lake water as well as in the tributaries were investigated in this study. The results showed that sulfate concentrations in river water range from 0.94 to 6.52 mmol/L and their δ34S values range from -14.9‰ and 0.9‰, while lake water has sulfate concentrations ranging from 1.91 to 2.79 mmol/L, and δ34S values from -9.8‰ to -5.9‰. It is suggested that coal mining drainage is the major source of SO42- in the Aha Lake. Rainfall, sewage discharge, sulfide oxidation and gypsum dissolution have made only limited contributions. Different depth-dependent distributions of dissolved SO42- and δ34S were de-veloped for both DB and LJK in summer and winter. Due to water overturn, δ34S values display homogenous vertical distributions in winter and spring. While in summer and autumn, significant positive shifts of δ34S were clearly ob-served in epilimnion and bottom strata as a result of water stratification. High δ34S values in epilimnion may result from the retention of rainwater during water stratification. Dissimilatory sulfate reduction by bacteria was thought to be responsible for the increase of δ34S value in hypolimnion.
基金supported by the research project of the Chinese Academy of Sciences(KZCXZ-105).
文摘The Aha Lake, as a seasonally oxygen-absent man-made reservoir, has been polluted by acidic mining drainage and domestic sewages for a long time, with iron, manganese and sulfate excessively enriched in water and sediment. By means of microbe counting, the analysis of trace metals in pore water and electronic acceptors for or-ganic matter decomposing, we have found that strong bio-geochemical remobilization of trace metals occurred near the water-sediment interface. The microbial reduction of iron, manganese and sulfate took place in different parts throughout the sediment core with the extend of iron reduc-tion lower than that of sulfate reduction, which happened in the surficial sediments and hampered the upward release of some trace metals to some extent. Some trace metals in pore water, due to the 揹ual releasing?effects caused by the re-duction of Fe3+ and Mn4+ at varying depth, show a tendency of being enriched excessively in the upper 10 cm of sediment. In this study, we discussed the microbiological mechanism of trace metals enrichment in surficial sediments and the envi-ronmental condition, with an attempt to realize the unsteady mobilization of trace metals and their potential harm to overlying lake water in the Aha Lake, Guiyang.
