Currently, water quality is mostly determined centrally using instrumental analytical methods. In our working group, decentralized, digitally networked and cost-effective sensors are to be researched and developed, which determine the total pollution, but also individual substances or substance groups (inorganic and organic) in real-time in a complex matrix.
The chemical oxygen demand (COD) is a sum parameter and can be found in numerous German and European laws and directives (AbwV, AbwAG, GrwV, OGewV, European Water Framework Directive). It is suitable for the evaluation and regulation of the totality of organic water pollutants. In addition, COD has an important function as a control parameter in process optimization (energy savings, cost reduction) of municipal and industrial wastewater treatment plants as well as in the bioeconomy.
Due to the many shortcomings of the dichromate method, a novel electrochemical measuring system is being developed in the Braeutigam group, which links the (sono-)electrochemically in-situ generated hydroxyl radicals and the amount of degraded organic (pollutants) in a measuring signal (e.g. current intensity, voltage). In addition to the further development of the continuously operating, chemical-free and sustainable measurement method and design, the expansion of the linear working range and a reduction of the detection limit are focused on in particular. Further approaches are found in the continuous determination of organic trace substances with electrochemical and optical methods.
