Application Report #20 (Bioset and Screw Press)
It’s a dilemma faced by many wastewater treatment facilities but hits small to mid-sized plants particularly hard. Finding the most cost-effective way to dispose of biosolids is a problem which, left unaddressed, can adversely impact a plant’s economic and environmental viability.
The Immokalee Water and Sewer District (IWSD) was looking at just such a challenge in 2006 when it was utilizing drying beds to create a Class B biosolid and spending roughly half a million dollars annually to dewater and haul excess sludge from that process to a regional landfill. A pending change in regulations regarding application of such biosolids, coupled with a realization that they were not only squandering the economic potential held in those biosolids but also perpetuating a practice whose time for replacement had clearly come, the District looked at a number of alternatives.
It found its answer in a facility redesign centered around use of the Bioset process (Schwing Bioset, Somerset, WI) to create a Class A biosolid. Today Immokalee WWTP has a handle on its disposal, has reduced associated charges by better than two-thirds, and is using that newly-created product for area application.