Formation and fate of critical transformation products of aminopolyphosphonates in environmental systems and water treatment processes.

• Applicants: Dr. Daniel Buchner; Professor Dr. Stefan Haderlein; Dr. Maik Jochmann
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 457490294

Aminopolyphosphonates (APPs) are strong complexing agents for metals with a wide range of applications in industry and households. They are relatively persistent and have a high water solubility, low volatility and a high affinity to mineral phases. Sorption on sewage sludge is therefore the most important elimination process in sewage treatment plants. The concentrations of amine polyphosphonates in German rivers are currently in the ng/L to low µg/L range. However, it is predicted that APP concentrations will increase as a result of rising production and utilization rates. New studies show that the herbicide glyphosate is a transformation product of important APPs. APPs in wastewater, especially DTPMP (amino-tris(methylenephosphonic acid) and EDTMP (ethylenediamine-tetra-(methylenephosphonic acid), thus represent a previously unnoticed source of glyphosate in the environment. A precise analysis of the degradation behavior of such APPs in environmental and technical systems and the associated formation of critical transformation products such as glyphosate is therefore urgently required. The subject of the proposed research is therefore a comprehensive investigation of the factors that control the product spectrum and the yield of critical APP transformation products such as glyphosate in aquatic natural and technical systems. Given the evidence of the herbicide glyphosate as a transformation product, this is of great importance to achieve a comprehensive understanding of the pathways of entry of this substance. We propose to investigate the effects of important environmental factors on degradation processes of APPs in carefully designed laboratory experiments using DTPMP and EDTMP. By combining isotope analysis and high-resolution mass spectrometry with other modern techniques, the transformation products of APPs will be identified for key sorption and transformation processes. With the help of established methods for component-specific isotope analysis (CSIA) and the development of a new C/N IsoOrbitrap method, the possibilities of source assignment, i.e. a differentiation of glyphosate from herbicide application and those resulting from the transformation from APPs, will be evaluated.

• DFG Programme: Research Grants