『Abstract
A system of connected lignite mining pits (part of the former
Goitsche mining complex, Germany) was flooded with river water
between 1999 and 2002. A considerable accumulation of acid associated
with oxidized sulfides in sediments was been as a critical point
for the development of the lake water. To characterize the components
contributing to the supply of dissolved lake water SO4
hydro-chemical and isotope investigations with respect to groundwater,
pore water in the sulfide bearing sediments, river water and lake
water were performed. δ34S of pore water SO4
that was dominated by oxidized pyrites ranges around -25‰ VCDT
and differs strongly from river water SO4
with about +4.4‰. Thus, interactions between lake water and sediments
were particularly pronounced during the first phase of fooding.
For this period, a more quantitative estimation of the SO4 components in the lake water was difficult because
of the heterogeneous SO4 distributions between
the different sub-basins of the lake and according to the flooding
process itself. Later, a component separation was attempted following
mixing of the whole lake, which first occurred in spring 2002.
A very heterogeneous groundwater environment with respect to highly
variable SO4 concentrations and δ34S
values and changing interaction with the forming lakes proved
to be one of the most important limitations in the calculations
of the mixing.』
1. Introduction
2. Investigation area and hydrogeological characteristics
3. The flooding process
4. Experiments and methods
4.1. Groundwater
4.2. Pore water in friedersdorf amber-bearing silt
4.3. Lake water
4.4. River water
4.5. Isotope and chemical analysis
5. Results and discussion
5.1. Groundwater characteristics
5.2. Initial lake water
5.3. Pore water in the friedersdorf amber-bearing silt
5.4. δ34S and sulfate in primary flooding water
5.5. Lake water
5.6. Sulfate sinks in the Lake Goitche
6. Estimation of sulfate components
7. Conclusions
Acknowledgements
References