How the Right Cationic Polyacrylamide Cut Biosolids Disposal Costs by 21% at a UK Municipal Sewage Works
November 2025. I got the call on a Wednesday evening — the kind that comes just as you’re settling in with a cup of tea and have absolutely no intention of going anywhere. The works manager at a large municipal sewage treatment works in the East Midlands — I’ll call it Fenside Water Recycling Centre, though that’s not its actual name — was, to put it diplomatically, not having a good week. Their two Alfa Laval centrifuges had been underperforming for the better part of four months. Cake solids were hovering around 18.1% dry solids on a good day, sometimes dipping below 17%. Their polyacrylamide consumption had crept up as operators tried to compensate by pushing the dose higher, and energy consumption on the centrifuge circuit was running noticeably above the site’s own benchmark figures. ...