Proposed new EU (CEN) standards are published and open to comment, for wastewater treatment plants: chemical phosphorus precipitation and general data requirements. prEN 12255-13 covers “chemical treatment of wastewater by precipitation/flocculation for removal of phosphorus and suspended solids”. It defines terms such as “coagulant”, “tertiary treatment”, “precipitant”. The standard indicates that P-total discharge limits “typically range from 2 mg/l down to 0.25 mg/”. The standard provides guidance for design, chemical process options, selection of precipitation chemicals, storage – preparation and dosing of chemicals, mixing, control systems, reactor - sedimentation and filtration systems, and sludge production. prEN 12255-11 covers data necessary for planning, design, construction, compliance testing, etc. of wastewater treatment plants.
Both standards are now published as drafts, and comments can be input via national standards organisations.
As usual for CEN standards, the draft texts are not freely available, and prices vary depending on different national standards body website. Texts of both standards can be purchased for a total of 9.75€ from the Estonia standards organisation www.evs.ee