76 Peter Stille and Graham Shields
This study clearly shows that the Sr isotope method is a valuable tool in the
investigation of hydrogeochemical exchange processes between different water
systems. In the special case of the potassium mines, chemical exchange processes
between groundwater and pit rinse water can be described and quantified.
4.3.3 Carbon Isotopes
~5J3C values decrease down river from -4 to -9 %~ PDB (see Sect. 1.1) avd reach a
minimal value of -10.7 %~ below Mainz (Fig. 4.24). Almost all tributaries show
lower ~5t3C values than the Rhine itself. The carbon isotope compositions are
strongly influenced by the input of organic carbon from local tributary, rivers. The
6~3C value of organic carbon is about -25 %0, whereas that of-carbon from
dissolved carbonate is about 0 %0. By applying these end members one can
calculate that the proportion of organic carbon in the Rhine climbs tYom i 8% in
the Alpine regions to 43% close to the entrance of the river Main into the Rhine.
60% of the carbon near Mainz originates from organic sources. The tributaries,
which are rich in organic carbon significantly influence the carbon budget of the
Rhine. Over fertilization and resultant enhanced biologic productivity are
respon.sible for such high concentrations of organic material in our waterways.
Such over production of organic, microbially degradable materials has the
consequence that there is a strong tendency for oxygen to be removed and CO_, to
be produced. This can be seen in COz analyses of Rhine water (Fig. 4.25; BLihl et
at. 1991). Over a distance of 500 km the amount of CO,_ in water dQubles because
of CO_- contributions from tributaries as can be seen from isotopic analyses of the
carbon in these tributaries.
4.4 C o n t a m i n a t i o n o f F l o w i n g W a t e r a n d G r o u n d w a t e r a f t e r t h e
R e a c t o r A c c i d e n t a t C h e r n o b y l
S h o w n U s i n g R e l e a s e d
R a d i o n u c l i d e s .
The most serious accident at a nuclear plant which led to the release of nuclear
energy in peace time occurred on April 26, 1986 in Chernobyl (Ukraine). During
this accident large quantities of radioactive materials were released into the
atmosphere and dispersed throughout almost the whole of Europe. This input of
large amounts of mother and daughter isotopes into the biosphere had the
consequence that both the soils and the hydrosphere experienced serious
contamination. These chemical and radioactive contaminants are not only
dangerous for humans, animals and plants but also weaken the microorganisms
which help to regulate the soil and the groundwater.
This study clearly shows that the Sr isotope method is a valuable tool in the
investigation of hydrogeochemical exchange processes between different water
systems. In the special case of the potassium mines, chemical exchange processes
between groundwater and pit rinse water can be described and quantified.
4.3.3 Carbon Isotopes
~5J3C values decrease down river from -4 to -9 %~ PDB (see Sect. 1.1) avd reach a
minimal value of -10.7 %~ below Mainz (Fig. 4.24). Almost all tributaries show
lower ~5t3C values than the Rhine itself. The carbon isotope compositions are
strongly influenced by the input of organic carbon from local tributary, rivers. The
6~3C value of organic carbon is about -25 %0, whereas that of-carbon from
dissolved carbonate is about 0 %0. By applying these end members one can
calculate that the proportion of organic carbon in the Rhine climbs tYom i 8% in
the Alpine regions to 43% close to the entrance of the river Main into the Rhine.
60% of the carbon near Mainz originates from organic sources. The tributaries,
which are rich in organic carbon significantly influence the carbon budget of the
Rhine. Over fertilization and resultant enhanced biologic productivity are
respon.sible for such high concentrations of organic material in our waterways.
Such over production of organic, microbially degradable materials has the
consequence that there is a strong tendency for oxygen to be removed and CO_, to
be produced. This can be seen in COz analyses of Rhine water (Fig. 4.25; BLihl et
at. 1991). Over a distance of 500 km the amount of CO,_ in water dQubles because
of CO_- contributions from tributaries as can be seen from isotopic analyses of the
carbon in these tributaries.
4.4 C o n t a m i n a t i o n o f F l o w i n g W a t e r a n d G r o u n d w a t e r a f t e r t h e
R e a c t o r A c c i d e n t a t C h e r n o b y l
S h o w n U s i n g R e l e a s e d
R a d i o n u c l i d e s .
The most serious accident at a nuclear plant which led to the release of nuclear
energy in peace time occurred on April 26, 1986 in Chernobyl (Ukraine). During
this accident large quantities of radioactive materials were released into the
atmosphere and dispersed throughout almost the whole of Europe. This input of
large amounts of mother and daughter isotopes into the biosphere had the
consequence that both the soils and the hydrosphere experienced serious
contamination. These chemical and radioactive contaminants are not only
dangerous for humans, animals and plants but also weaken the microorganisms
which help to regulate the soil and the groundwater.