China project SIGN: sino-German water supply network - Clean water from the source to the tap
In the framework of the project SIGN, Hydroisotop GmbH contributes with the subproject: "Isotopy from Water and Organic Material of the Tai lake” .
The purpose of the project is the development of conceptual management schemes for sustainable drinking water production from the lake water of the TaiHu. The Tai lake is located east of Shanghai in an economical very important and strongly growing region. With a mean depth of only 2 m, the Tai Lake is the third-largest freshwater lake in China. In 2007, an algae bloom in the lake, induced from antropogenic pollutions, caused a shortage of drinking water in the region (Yu Tao et al. 2013).
The in the Tai lake emerging problems, caused by growing industrialization and intensification of agriculture, are characteristic for many surface waters in China. Hence, the Tai lake can serve as measure for the development and application of research methods and conceptual management schemes.
The aims of the sub-project “Isotopy from Water and Organic Material of the Tai lake” are to study the water cycle (inflow and precipitation, evaporation and mixing processes, 2H/18O), which affects the nutrient contents and therefore the severity of eutrophication. In addition, the origin of nitrogen-bearing nutrients will be examined (15N, 13C, 34S) to yield a starting point for effective sanitation actions.
By the investigation of the isotopy of the organic material from lake water (dissolved organic carbon, algae and other primary producers; 15N, 13C, 34S) and sediment (137Cs, 15N, 13C, 34S, 2H/18O), it is supposed to comprehend historical changes of the Tai lake caused by anthropogenic impacts. Specifically in this regard, specific secondary transformation processes have to be identified and considered by the particular studied isotopic composition.
In the proposed research-project, Hydroisotop is involved as project partner in 4 work packages in close collaboration with Chinese and German Partners.
In detail, Hydroisotop targets the following sub-goals.
- Examination of lake water balance and lake dynamics by H/O-isotope composition (water budget, extended fundamental data for modelling of lake currents).
- Identify sources and transformations of the nutrients by C/N(S)-isotope composition (sources and transformations of N-species and dissolved organic carbon, algae growth, interactions, pollution transport).
- Study sediment/lake water interaction and history of the nutrient level of the Tai lake by C/N(S)- isotope composition of the sediment (transformation processes, mineralization), by H/O-isotope composition of sediment pore water (interaction) and by Cs/Pb-isotope based age-dating of the sediment (rate of sedimentation).
More information about this project can be found here.