Written by Tom Welch
The Decatur, AR, WWTP had existing dewatering technology that proved to be undersized and inefficient. With the additional demands of a new plant upgrade, Operations staff were struggling to meet current dewatering requirements.
The Design Build team and Owner selected an FSP 802 screw press from Schwing Bioset to replace the existing equipment. The new equipment was installed in the same building with primarily service connection modifications. The screw press started operating in November of 2018.
The improvements in the dewatering operations are remarkable, as it is saving Decatur operational expenses in every category. Dry solids content of the dewatered biosolids have improved from an average of 13% to 17%, resulting in less cake to haul. Solids capture rate has improved from less than 80% to 95%, resulting in a lower return load to the plant. Polymer usage is now at 18 pounds active per dry ton, which is well below the consumption rate of the previous technology reducing polymer expenditures.
In addition to these performance improvements, the dewatering capacity has more than doubled. Where it used to take at least two days to load a 25-ton trailer, the plant can now fill a trailer in 6.5 hours, reducing operator efforts in turn.
With the widest range of machine sizes for several applications, and mobile pilot units available for testing your materials, Schwing Bioset is your comprehensive solutions provider for dewatering.