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Bian G.-G.,Fujian Environmental Protection Bureau | Liu G.-X.,CAS Wuhan Institute of Hydrobiology | Chen K.-H.,Longyan Environmental Monitoring Station
Zhongguo Huanjing Kexue/China Environmental Science

In the early December, 2009, a dinoflagellate bloom caused by Peridiniopsis sp. was found for the first time in Longtan Lake, which is located in Long Kong Dong water-eroded cave scenery spot, Longyan City, Fujian Province. The cell density of the dinoflagellate reached as high as 1.11×107cells/L during the bloom. By a series of urgent disposal procedures, the blooming dinoflagellate as well as other microalgae was eventually eliminated, after which investigations were instantly carried out to explore the cause of the bloom. Nutrients concentrations in the upstream rivulet and the cave underground water did not exceed the levels of Class II water in National Criteria for groundwater water quality, but markedly increased in the lake water, especially the concentrations of TN and TP. Thus it was suggested that nutrient accumulation, hence the proliferation of dinoflagellate, had been accelerated due to the alteration of rivulet flow pattern by water impoundment in Longtan Lake, and therefore mainly accounting for the bloom event. Moreover, an unexpected temperature increase in the lake water right before and during the bloom may to some extent help to explain the bloom occurrence. The results indicated that endogenous release of nutrients accumulated in lake sediments had made great contribution to the outbreak of the dinoflagellate bloom, and TP might be a primary restriction factor for the bloom. Source

Li Y.,CAS Research Center for Eco Environmental Sciences | Cao W.-Z.,CAS Research Center for Eco Environmental Sciences | Zhang Y.-Z.,Fujian Provincial Institute of Environmental Science | Li W.-Q.,Xiamen University | And 3 more authors.
Zhongguo Huanjing Kexue/China Environmental Science

Based on site monitoring chemical data of lake water and sediments during an algal bloom in the Longtan Lake, causes and mechanisms of eutrophication in shallow upstream lakes were discussed by comparing the Longtan Lake in upstream of the Jiulong River with deep eutrophic lakes and large shallow downstream eutrophic lakes in China. The shallow upstream lake is characterized as relatively simple nutrient inputs and high susceptivity to climatic variability (such as temperature), redox conditions, and strong lag effects of the external total phosphorus inputs. Therefore, attention must be paid to the sediments nutrient releases, especially, the bound phosphorus of sediments when remediating eutrophication in shallow upstream lakes. Source

Fang C.-S.,Jilin University | Chen F.-D.,Jilin University | Chen K.-H.,Longyan Environmental Monitoring Station | Xiao Z.-S.,Longyan Environmental Monitoring Station | Wang J.,Jilin University
Zhongguo Huanjing Kexue/China Environmental Science

In order to determine the main pollution sources of atmospheric particles in Longyan City, elemental compositions of 10 kinds of dust samples were analyzed through enrichment factor analysis and R-cluster analysis. Component spectrum of each dust sample were significantly different. However, concentrations of metallic elements contained in those samples all exceeded the normal levels. The enrichment factor (EF) values of W and Bi in kaolin mining respectively were 255.32, 520.12. That of Bi in red soil reached 173.41. And the EF value of Sb in coal ash was 119.98. This is mainly due to the contribution of motor vehicle exhaust, steel mills and coal combustion, etc. This analysis revealed that main origins of atmospheric particles in Longyan City are road and soil dust, cement dust, metallurgical dust, and fodder dust. Source

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