The GeBeMA project aimed to develop a comprehensive method for determining microplastics (MP) in wastewater from treatment plants. "Comprehensive method" implies the development and validation of an end-to-end procedure covering everything from the collection of representative solid samples from the wastewater and sample preparation to the final analysis. The method was designed to be practical and cost-effective, and suitable for the routine determination of MP in wastewater at treatment plants. Specific project objectives included comparing two MP analysis methods EA-OEM (Elemental Analysis – Overdetermined Equation Method) and TED-GC-MS applying the comprehensive method to the influent and effluent of a combined sewer system treatment plant, and conducting long-term measurements to investigate temporal variations in microplastic levels.

The project provided insights regarding sampling at the influent and effluent of a treatment plant specifically concerning suitable sampling locations and methods as well as variations in plant loading over the course of a single day and across multiple days. These findings led to the project's key outcome: a Standard Operation Procedure (SOP) for the comprehensive method used to determine microplastics in treatment plant influent and effluent.