Elevated concentrations of trifluoroacetate (TFA) of more than 100 mu g/L in a major German river led to the occurrence of more than 20 mu g/L TFA in bank filtration based tap waters. Several spatially resolved monitoring programs were conducted and discharges from an industrial company were identified as the point source of TFA contamination. Treatment options for TFA removal were investigated at full-scale waterworks and in laboratory batch tests. Commonly applied techniques like ozonation or granulated activated carbon filtration are inappropriate for TFA removal, whereas TFA was partly removed by ion exchange and completely retained by reverse osmosis. Further investigations identified wastewater treatment plants (WWTPs) as additional TFA dischargers into the aquatic environment. TFA was neither removed by biological wastewater treatment, nor by a retention soil filter used for the treatment of combined sewer overflows. WWTP influents can even bear a TFA formation potential, when appropriate CF3-containing precursors are present. Biological degradation and ozonation batch experiments with chemicals of different classes (flurtamone, fluopyram, tembotrione, fiufenacet, fluoxetine, sitagliptine and 4:2 fluorotelomer sulfonate) proved that there are yet overlooked sources and pathways of TFA, which need to be addressed in the future. (C) 2017 Elsevier Ltd. All rights reserved.
This study was carried out to determine hazards of particle-bound contaminants in rivers to retention areas close to public well fields in the context of flood events. The focus was on the assessment of soil contamination at a planned retention area. Soil core samples were chemically and biologically analyzed. Samples were fractionated to identify and compare contaminant loads and biological effects of soil and flood suspended particulate matter (SPM).
The presented study investigated on contamination of suspended particulate matter (SPM) in rivers that was sampled long-term and with higher frequency during a flood event at the river Rhine. It was conducted to determine in vitro biological effects as well as to identify and quantify compound classes and effective contaminants. Research was part of investigation on hazards of contaminants bound to SPM to inundated sites and retention areas that are inundated during flood events.
In Germany, the gasoline additive methyl tert-butyl ether (MTBE) is almost constantly detected in measurable concentrations in surface waters and is not significantly removed during riverbank filtration. The removal of MTBE from water has been the focus of many studies that mostly were performed at high concentration levels and centred in understanding the mechanisms of elimination. In order to assess the performance of conventional and advanced water treatment technologies for MTBE removal in the low concentration range further studies were undertaken. Laboratory experiments included aeration, granulated activated carbon (GAC) adsorption, ozonation and advanced oxidation processes (AOP). The results show that the removal of MTBE by conventional technologies is not easily achieved. MTBE is only removed by aeration at high expense. Ozonation at neutral pH values did not prove to be effective in eliminating MTBE at all. The use of ozone/H2O2 (AOP) may lead to a partly elimination of MTBE. However, the ozone/H2O2 concentrations required for a complete removal of MTBE from natural waters is much higher than the ozone levels applied nowadays in waterworks. MTBE is only poorly adsorbed on activated carbon, thus GAC filtration is not efficient in eliminating MTBE. A comparison with real-life data from German waterworks reveals that if MTBE is detected in the raw water it is most often found in the corresponding drinking water as well due to the poor removal efficiency of conventional treatment steps.
Aminopolycarboxylic acids, such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), diethylenetriaminepentaacetic acid (DTPA), 1,3-propylenediaminetetraacetic acid (1,3-PDTA), β-alaninediacetic acid (β-ADA), and methylglycinediacetic acid (MGDA), are used in large quantities in a broad range of industrial applications and domestic products in order to solubilize or inactivate various metal ions by complex formation. Due to the wide field of their application, their high polarity and partly low degradability, these substances reach the aquatic environment at considerable concentrations (in the μg/L-range) and have also been detected in drinking water. This review evaluates and summarizes the results of long-term research projects, monitoring programs, and published papers concerning the pollution of the aquatic environment by aminopolycarboxylates in Germany. Concentrations and loads of aminopolycarboxylates are presented for various types of water including industrial and domestic waste waters, surface waters (rivers and lakes), raw waters, and drinking waters.