Written by Chuck Wanstrom, May 2018
The city of Bradenton, Florida, operates a wastewater treatment plant that processes roughly eight million gallons per day. The plant had historically aerobically digested their biosolids and dewatered them to 15% dry solids content using two, 2.0-meter belt filter presses. Due to the age of the belt filter presses, the maintenance expenditures were continually increasing and creating a burden not only in expenses, but also on personnel time to keep the equipment functioning.
Bradenton began a search to identify new dewatering techniques that could replace the aging belt filter presses. Several pilot studies were completed and Schwing Bioset was invited to run their screw press pilot. The pilot proved successful with results of up to 21% dry solids. The Schwing Bioset screw presses were also able to fit within the confines of the available space on the second floor of the existing dewatering building.
The Schwing Bioset equipment was chosen as the best value and was procured under a sole source contract. The two new FSP902 screw presses were designed into the existing dewatering building and were commissioned early in 2018. The dewatered biosolids exceed the old belt presses cake performance and reduces the city’s hauling and disposal costs while at the same time reducing the amount of wash water required and significantly reducing the maintenance load to city staff.