Pestizide in Oberflächenwässern — Befunde in Talsperren und in Uferfiltraten Pesticides in Surface Water — Analytical Results for Drinking Water Reservoirs and Bank Filtrate Waters

The results of a series of investigations are presented, performed by the governmental chemical laboratory Karlsruhe (CLUA) in order to determine pesticides in drinking water for purposes of food monitoring. 231 samples of 8 municipal water supplies (groundwater wells/no bank filtrate) and 34 private water supplies close to the bank of the river Rhine (groundwater wells/partly bank filtrate) were analysed. The sampling sites were located between Mannheim and Greffern, Germany. In 1986 high amounts of atrazine and simazine were determined in the drinking water wells of several private water supplies, especially at the sampling sites in the south. The likewise high chloride content of the samples was taken as a proof of bank filtrate contributing to the water. The decrease of atrazine load in the river water of the Rhine since 1987 has its parallel in the analytical results for the concerned drinking water wells. Obviously the pesticide contamination of water from bank filtrate pumping wells is mainly depending on the pesticide load of the river water. The application of fertilizers and pesticides in the fields seems not to be a significant source of the pesticide contamination of dringing waters derived from bank filtrate water. For reasons of public health a monitoring of pesticide content in bank filtrate pumping wells of private water supplies is recommended.     

Les écosystèmes microbiens marqueurs des variations des niveaux lacustres en contexte de fan-deltas. Exemple du rift rhénan méridional (Europe occidentale)

The Rhine Graben begins to develop in the Upper Eocene. During the first paroxysmal stage a belt of sandstones and conglomerates, the so-called Conglomé-rats cotiers, is deposited on the rift border. In the graben an euryhaline lacustrine basin regulates the extension of fan-deltas which are developing along the boundary faults of the rift.Stromatolites preferentially colonize the littoral fringe of the lake where they find indurated substratums. So they appear to be excellent markers of the transgressive movements of the lake and its palaeomargins. The stromatolites also allow an excellent sequential subdivision to reconstruct the history of the basin.

     

Die gaschromatographische Bestimmung von Diethylentriaminpentaessigsäure in Oberflächenwasser

Gaschromatographic Determination of Diethylenetriaminepentaacetic Acid in Surface Water. A method for the determination of diethylenetriaminepentaacetic acid (DTPA) is reported. The determination is based on the preconcentration on a strong base anion exchange resin, esterification with n-propanol and following gaschromatographic separation using a N-selective detector. The sensitivity of the method, including enrichment, is 1 μg/L in river water. The identity of DTPA in river water was proved by mass spectrography. The method can be used also for the quantitative determination of nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA), cyclohexanediaminetetraacetic acid (CDTA) and ethyleneglycolbis-(2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA). The method was used to examine river water. An investigation along the river Rhine, taking grab samples from January and february 1992 showed that DTPA was present in some sampling places in similiar concentrations as NTA and EDTA.     

Pesticides in the River Rhine Pestizide im Rhein

Since 1987 significant decrease of pesticide concentrations in the river Rhine has been observed. This is due to the improvement of waste water treatment processes and the closing of some pesticide production sites in the Rhine basin area. Whereas in the last years point pollution from waste water effluents was the dominant source for pesticide input into the river, nowadays the nonpoint pollution (diffuse runoff) becomes more and more important. This leads to seasonal occurrence or to higher concentration peaks after application in agriculture. Only for atrazine and its metabolite desethylatrazine very low ?background”?-levels could regularly be found along the river and all over the year. Furthermore pesticide metabolites and byproducts seem to be interesting for evaluating pesticide pollution in the river Rhine.