MTBE: Relevant for Drinking Water Production?
Relevance of Methyl-tert-butylether (MTBE) For Groundwater As a Source For Drinking Water Production and Elimination of MTBE During Drinking Water Production
Abstract
MTBE has been in use as fuel oxygenate in the US since the mid-eighties. In Europe it is added to gasoline replacing organic lead compounds for enhancing the octane number. However, despite its positive effects on gasoline use (replacement of more harmful substances and more complete combustion especially of aromatic compounds) its use leads to problems in the aquatic environment if released into the environment. Because of its physicochemical properties (e.g. good water solubility, low Henry coefficient, low microbial degradability because of its chemical structure) it is often found in groundwater and other raw water sources for waterworks. In Germany, MTBE is almost constantly detected in measurable concentrations in surface waters and it is not significantly removed by river bank filtration. Furthermore MTBE occurs in the groundwater of urban areas or under areas that suffer from heavy traffic. Laboratory experiments show that natural and semi-natural treatment processes for drinking water production (e.g. bank filtration or stripping) are not able to remove MTBE reliably and cost efficiently. Even more advanced technologies such as activated carbon filtration and ozonation do not eliminate MTBE sufficiently. The application of "Advanced Oxidation Processes" (e.g. ozone/H2O2) may lead to a reduction of MTBE by production of OH-radicals. However, the ozone/H2O2 concentration required for a complete removal of MTBE from natural waters lies way above the ozone concentration nowadays applied in waterworks. Therefore, MTBE has to be considered "relevant to drinking water production" (a term created by German waterworks to categorise substances) and the addition of MTBE to the monitoring list is claimed. Moreover, the use of MTBE has to be reduced and it has to be replaced by substances which are more easily degraded by microbes.
MTBE has been in use as fuel oxygenate in the US since the mid-eighties. In Europe it is added to gasoline replacing organic lead compounds for enhancing the octane number. However, despite its positive effects on gasoline use (replacement of more harmful substances and more complete combustion especially of aromatic compounds) its use leads to problems in the aquatic environment if released into the environment. Because of its physicochemical properties (e.g. good water solubility, low Henry coefficient, low microbial degradability because of its chemical structure) it is often found in groundwater and other raw water sources for waterworks. In Germany, MTBE is almost constantly detected in measurable concentrations in surface waters and it is not significantly removed by river bank filtration. Furthermore MTBE occurs in the groundwater of urban areas or under areas that suffer from heavy traffic. Laboratory experiments show that natural and semi-natural treatment processes for drinking water production (e.g. bank filtration or stripping) are not able to remove MTBE reliably and cost efficiently. Even more advanced technologies such as activated carbon filtration and ozonation do not eliminate MTBE sufficiently. The application of "Advanced Oxidation Processes" (e.g. ozone/H2O2) may lead to a reduction of MTBE by production of OH-radicals. However, the ozone/H2O2 concentration required for a complete removal of MTBE from natural waters lies way above the ozone concentration nowadays applied in waterworks. Therefore, MTBE has to be considered "relevant to drinking water production" (a term created by German waterworks to categorise substances) and the addition of MTBE to the monitoring list is claimed. Moreover, the use of MTBE has to be reduced and it has to be replaced by substances which are more easily degraded by microbes.
Funding
Deutsche Vereinigung des Gas- und Wasserfaches e.V. (DVGW)
