Germany – Flocculating agents – Klärwerk Koblenz_Rahmenvertrag Flockierungsmittel

The subject of the tender is the supply and service of flocculant for the Koblenz sewage treatment plant. The Koblenz sewage treatment plant primarily treats municipal wastewater. According to the notice, it has an expansion size of 320,000 population equivalents (PE). However, with a population equivalent of around 154,000 PE (in 2022), it treats less load than originally planned. 126,000 inhabitants are actually connected (population number PN). The remaining 28,000 population equivalents (PE) are of industrial origin (PN + PE = PE). This results in an industrial proportion of the wastewater to be treated of around 18%. The main dischargers are the paper industry, the metal industry and a malt house. Mechanical sludge dewatering is carried out with two decanters (X4E-4/454, YOM 2023). The dewatering is to be carried out with the best possible dry solids content (DS) at optimal polymer consumption. The degree of separation is > 98% (according to DWA M-383); the centrate is returned to the sewage treatment plant. An emulsion polymer is used for thickening and dewatering. The excess sludge produced is mechanically thickened with three centrifuges (GEA UCD 346 YOM 2012) using emulsion polymers.