检索结果-南通市图书馆

Effects of sludge dredging on the prevention and control of algae-caused black bloom in Taihu Lake,China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2013年第3期25卷 430-440页

作者： Wei He Jingge Shang Xin Lu chengxin fan State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences University of Chinese Academy of Sciences

Algae-caused black bloom （also known as black water agglomerate） has recently become a critical problem in some Chinese *** has been suggested that the occurrence of algae-caused black bloom was caused by the cooperation of nutrient-rich sediment with dead algae,and sludge dredging was adopted to control black bloom in some lakes of *** this article,based on the simulation of black bloom using a Y-shape apparatus for modeling natural conditions,both un-dredged and dredged sites in three areas of Taihu Lake,China were studied to estimate the effects of dredging on the prevention and control of black *** the experiment,drained algae were added to all six sites as an additional organic load;subsequently,the dissolved oxygen decreased rapidly,dropping to 0 mg/L at the sediment-water *** bloom did not occur in the dredged sites of Moon Bay and Nan Quan,whereas all three un-dredged sites at Fudu Port,Moon Bay and Nan Quan experienced black *** bloom also occurred at the dredged site of Fudu Port one day later than at the other sites,and the odor and color were lighter than at the other *** color and odor of the black water mainly result from the presence of sulfides such as metal sulfides and hydrogen sulfide,among other chemicals,under reductive *** color and odor of the water,together with the high concentrations of nutrients,were mainly caused by the decomposition of the algae and the presence of nutrient-rich ***,the removal of the nutrient-rich sediment by dredging can prevent the occurrence and control the degree of algae-caused black bloom in Taihu Lake.

关键词： Taihu Lake algae-caused black bloom sediment sludge dredging

Influence of Chironomid Larvae on oxygen and nitrogen fluxes across the sediment-water interface(Lake Taihu,China)

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2013年第5期25卷 978-985页

作者： Jingge Shang Lu Zhang Chengjun Shi chengxin fan State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences University of Chinese Academy of Sciences Jiangsu Xuyi Economic Development Zone Planning Construction Bureau

The microscale distribution of oxygen,the nitrogen flux and the denitrification rates in sediment inhabited by chironomid larvae（Tanypus chinensis） were measured in eutrophic Lake Taihu,*** presence of the chironomids in the sediment increased the oxygen diffusional flux from 10.4 ± 1.4 to 12.7 ± 2.5 mmol O 2 /（m 2 ·day）.The burrows of the larvae represented ＂hot spots＂ and strongly influenced the nitrogen cycles and diagenetic activity in the *** results indicate that the bioturbation effects of Tanypus chinensis chironomid larvae increased the capacity of the sediment as a sink for nitrate and a source for *** influx and ammonium outflux were increased 8.8 and 1.7 times,*** bioturbation,the amount of nitrate consumed was greater than the amount of ammonium *** total denitrification rate was also enhanced from 0.76 ± 0.34 to 5.50 ± 1.30 mmol N/（m 2 ·day）.The net effect was that the bioturbated sediments acted as a net sink for inorganic nitrogen under direct and indirect bioturbation effects compared to the control.

关键词： bioturbation chironomid larvae oxygen nitrogen Lake Taihu

Sulfur-containing amino acid methionine as the precursor of volatile organic sulfur compounds in algea-induced black bloom

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2013年第1期25卷 33-43页

作者： Xin Lu chengxin fan Wei He Jiancai Deng Hongbin Yin State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences University of School of the Chinese Academy of Sciences State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences

After the application of methionine, a progressive and significant increase occurred in five volatile organic sulfur compounds （VOSCs）： methanethiol （MESH）, dimethyl sulfide （DMS）, dime^yl disulfide （DMDS）, dimethyl trisulfide （DMTS） and dimethyl tetrasulfide （DMTeS）. Even in the untreated control without a methionine addition, methionine and its catabolites （VOSCs, mainly DMDS） were found in considerable amounts that were high enough to account for the water＇s offensive odor. However, blackening only occurred in two methionine-amended treatments. The VOSCs production was observed to precede black color development, and the reaching of a peak value for total VOSCs was often followed by water blackening. The presence of glucose stimulated the degradation of methionine while postponing the occurrence of the black color and inhibiting the production of VOSCs. In addition, DMDS was found to be the most abundant species produced after the addition of methionine alone, and DMTeS appeared to be the most important compound produced after the addition of methionine＋glucose. These results suggest that methionine acted as an important precursor of the VOSCs in lakes suffering from algea-induced black bloom. The existence of glucose may change the transformation pathway of methionine into VOSCs to form larger molecular weight compounds, such as DMTS and DMTeS.

关键词： algal blooms black bloom methionine volatile organic sulfur compounds sulfur-containing amino acid

Beyond hypoxia: Occurrence and characteristics of black blooms due to the decomposition of the submerged plant Potamogeton crispus in a shallow lake

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2014年第2期26卷 281-288页

作者： Qiushi Shen Qilin Zhou Jingge Shang Shiguang Shao Lei Zhang chengxin fan State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences University of Chinese Academy of Sciences College of Hydrology and Water Resource Hohai University

Organic matter-induced black blooms （hypoxia and an offensive odor） are a serious ecosystem disasters that have occurred in some large eutrophic shallow lakes in China. In this study, we investigated two separate black blooms that were induced by Potamogeton crispus in Lake Taihu, China. The main physical and chemical characteristics, including color- and odor-related substances, of the black blooms were analyzed. The black blooms were characterized by low dissolved oxygen concentration （close to 0 mg/L）, low oxidation-reduction potential, and relatively low pH of overlying water. Notably higher Fe^2＋ and ∑S2- were found in the black-bloom waters than in waters not affected by black blooms. The black color of the water may be attributable to the high concentration of these elements, as black FeS was considered to be the main substance causing the black color of blooms in freshwater lakes. Volatile organic sulfur compounds, including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, were very abundant in the black-bloom waters. The massive anoxic degradation of dead Potamogeton crispus plants released dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, which were the main odor-causing compounds in the black blooms. The black blooms also induced an increase in ammonium nitrogen and soluble reactive phosphorus levels in the overlying waters. This extreme phenomenon not only heavily influenced the original lake ecosystem but also greatly changed the cycling of Fe, S, and nutrients in the water column.

关键词： Black bloom hypoxia submerged plant volatile organic sulfur compounds lake

Efects of physical and chemical characteristics of surface sediments in the formation of shallow lake algae-induced black bloom

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2013年第12期25卷 2353-2360页

作者： Qiushi Shen Cheng Liu Qilin Zhou Jingge Shang Lei Zhang chengxin fan University of Chinese Academy of Sciences State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences

Surface sediments are closely related to lake black blooms. The dissolved oxygen （DO） distribution and its penetration depth in surface sediments as well as the migration and transformation of redox sensitive elements such as Fe and S at the sediment-water interface are important factors that could influence the formation of the black bloom. In this study, dredged and undredged sediment cores with different surface properties were used to simulate black blooms in the laboratory. The Micro Profiling System was employed to explore features of the DO and ∑H2S distribution at the sediment-water interface. Physical and chemical characteristics in sediments and pore waters were also analyzed. The results showed that sediment dredging effectively suppressed the black blooms. In the undredged treatment, DO penetration depth was only 50 μm. Fe^2＋ concentrations, ∑H2S concentrations, and ∑H2S production rates were remarkably higher in surface sediments and pore waters compared to control and dredged treatments. Furthermore, depletion of DO and accumulation of Fe^2＋ and ∑H2S in surface sediments and pore waters provided favorable redox environments and necessary material sources for the blooms. The study results proved that physical and chemical characteristics in surface sediments are important factors in the formation of the black bloom, and could provide scientific guidance for emergency treatment and long-term pre-control of black blooms.

关键词： black bloom sediment-water interface dredging sediment micro interface lake

Speciation of organic phosphorus in a sediment profile of Lake Taihu Ⅱ.Molecular species and their depth attenuation

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2013年第5期25卷 925-932页

作者： Shiming Ding Di Xu Xiuling Bai Shuchun Yao chengxin fan Chaosheng Zhang State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences College of Environment and Planning Henan University GIS Centre Ryan Institute and School of Geography and ArchaeologyNational University of IrelandGalwayIreland

The understanding of organic phosphorus（P） dynamics in sediments requires information on their species at the molecular level,but such information in sediment profiles is scarce.A sediment profile was selected from a large eutrophic lake,Lake Taihu（China）,and organic P species in the sediments were detected using solution phosphorus-31 nuclear magnetic resonance spectroscopy（31 P NMR） following extraction of the sediments with a mixture of 0.25 mol/L NaOH and 50 mmol/L EDTA（NaOH-EDTA） *** results showed that P in the NaOH-EDTA extracts was mainly composed of orthophosphate,orthophosphate monoesters,phospholipids,DNA,and *** of the major organic P compound groups and pyrophosphate showed a decreasing trend with the increase of *** half-life times varied from 3 to 27 years,following the order of orthophosphate monoesters 〉 phospholipids DNA 〉 *** component analysis revealed that the detected organic P species had binding phases similar to those of humic acid-associated organic P（NaOH-NRP HA）,a labile organic P pool that tends to transform to recalcitrant organic P pools as the early diagenetic processes *** demonstrated that the depth attenuation of the organic P species could be partly attributed to their increasing immobilization by the sediment solids,while their degradation rates should be significantly lower than what were suggested in previous studies.

关键词： organic phosphorus sediment half-life time 31 P NMR Lake Taihu

Speciation of organic phosphorus in a sediment profile of Lake Taihu I:Chemical forms and their transformation

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2013年第4期25卷 637-644页

作者： Di Xu Shiming Ding Bin Li Xiuling Bai chengxin fan Chaosheng Zhang State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences College of Forest Resources and Environment Nanjing Forestry University College of Environment and Planning Henan University GIS Centre Ryan Institute and School of Geography and ArchaeologyNational University of IrelandGalwayIreland

Organic phosphorus （nonreactive E NRP） is a major component of P in sediments, but information about its chemical forms and dynamic transformation is limited. The chemical forms and dynamic behaviors of NRP in a sediment profile from Lake Talhu, a freshwater and eutrophic lake in China, were investigated. Five forms of NRP in the sediments were extracted based on a chemical fractionation technique, including easily labile NRP （NaHCO3-NRP）, reactive metal oxide-bound NRP （HCl-NRP）, humic acid-associated NRP （NaOH-NRPnA）, fulvic acid-associated NRP （NaOH-NRPFA） and residual NRP （Res-TP）. There were notable transformations with increasing sediment depth from the labile NaHCOa-NRP and NaOH-NRP pools to the recalcitrant HCl-NRP and Res-TP pools, which caused the NRP to become increasingly recalcitrant as the early diagenetic processes proceeded. Further analyses showed that the relative changes in contents of organic matter and reactive Fe oxides in the sediment profile triggered a competition for binding NRP fractions and led to the transformation of NRP. The results highlighted the importance of abiotic processes in regulating the diagenesis of organic P and its stability in sediments.

关键词： organic phosphorus fractionation transformation Lake Taihu sediment

Impact of different benthic animals on phosphorus dynamics across the sediment-water interface

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第11期22卷 1674-1682页

作者： Lei Zhang Xiaozhi Gu chengxin fan Jingge Shang Qiushi Shen Zhaode Wang Ji Shen State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

As a diagenetic progress, bioturbation influences solute exchange across the sediment-water interface （SWI）. Different benthic animals have various mechanical activities in sediment, thereby they may have different effects on solute exchange across the SWI. This laboratory study examined the impacts of different benthic animals on phosphorus dynamics across the SWI. Tubificid worms and Chironomidae larvae were introduced as model organisms which, based on their mechanical activities, belong to upward-conveyors and gallery-diffusers, respectively. The microcosm simulation study was carried out with a continuous flow culture system, and all sediment, water, and worms and larvae specimens were sampled from Taihu Lake, China. To compare their bioturbation effects, the same biomass （17.1 g wet weight （ww）/m ^2 ） was adopted for worms and larvae. Worms altered no oxygen penetration depth in sediment, while larvae increased the O 2 penetration depth, compared to the control treatment. Their emergence also enhanced sediment O 2 uptake. The oxidation of ferrous iron in pore water produced ferric iron oxyhydroxides that adsorbed soluble reactive phosphorus （SRP） from the overlying water and pore water. Larvae built obviously oxidized tubes with about 2 mm diameter and the maximum length of 6 cm in sediment, and significantly decreased ferrous iron and SRP in the pore water compared to the control and worms treatments. Worms constructed no visually-oxidized galleries in the sediment in contrast to larvae, and they did not significantly alter SRP in the pore water relative to the control treatment. The adsorption of ferric iron oxyhydroxides to SRP caused by worms and larvae inhibited SRP release from sediment. Comparatively, worms inhibited more SRP release than larvae based on the same biomass, as they successively renewed the ferric iron oxyhydroxides rich oxidation layer through their deposition.

关键词： bioturbation oxygen pore water ferrous iron Tubificid worms Chironomidae larvae

Significance of dredging on sediment denitrification in Meiliang Bay,China:A year long simulation study

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第1期22卷 68-75页

作者： Jicheng Zhong chengxin fan Lu Zhang Edward Hall Shiming Ding Bao Li Guofeng Liu State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China Department of Freshwater Ecology University of Vienna Althanstr 14A-1090 Vienna Austria

An experiment for studying the effects of sediment dredging on denitrification in sediments was carried out through a one-year incubation of undredged （control） and dredged cores in laboratory. Dredging the upper 30 cm of sediment can significantly affect physico-chemical characteristics of sediments. Less degradation of organic matter in the dredged sediments was found during the experiment. Denitrification rates in the sediments were estimated by the acetylene blockage technique, and ranged from 21.6 to 102.7 nmol N2/（g dry weight （dw）-hr） for the undredged sediment and from 6.9 to 26.9 nmol N2/（g dw-hr） for dredged sediments. The denitrification rates in the undredged sediments were markedly higher （p 〈 0.05） than those in the dredged sediments throughout the incubation, with the exception of February 2006. The importance of various environmental factors on denitrification was assessed, which indicated that denitrification was regulated by temperature. Nitrate was probably the key factor limiting denitrification in both undredged and dredged sediments. Organic carbon played some role in determining the denitrification rates in the dredged sediments, but not in the undredged sediments. Sediment dredging influenced the mineralization of organic matter and denitrification in the sediment; and therefore changed the pattern of inherent cycling of nitrogen.

关键词： sediment dredging denitrification Taihu Lake