More than 5,000 filters and centrifuges dewater municipal wastewater sludge in the U.S.
Most of the 16,000 publicly owned wastewater treatment plants in the U.S. are small and do not mechanically dewater sewage sludge. Nevertheless more than 5,000 filters and centrifuges are in use at the larger plants.
July 19, 2001 — Most of the 16,000 publicly owned wastewater treatment plants in the U.S. are small and do not mechanically dewater sewage sludge. Nevertheless more than 5,000 filters and centrifuges are in use at the larger plants.
A new online database compiled by the McIlvaine Company provides details on belt filter presses, centrifuges, vacuum filters, and plate and frame or recessed chamber filter presses installed in U.S. municipal wastewater treatment plants. Plants smaller than 5 MGD nearly all use belt filter presses. The majority of the largest plants on the other hand use centrifuges.
The development of centrifuges to achieve dry solids content of more than 30% has led to the selection on this type of dewatering device where the sludge is incinerated or where sludge would otherwise have to be thermally dried.
Not surprisingly, the most populous states have the most installations. In New York for example there are 130 facilities utilizing 300 belt filter presses, 27 facilities utilize centrifuges. However these 27 facilities produce 133,000 dry tons of sludge per year vs. 185,000 tpy for facilities with belt presses. New York City alone operates more than 50 centrifuges. 13 facilities in New York State operate plate and frame filter presses and only 6 facilities have vacuum filters.
The largest supplier of centrifuges in the U.S. is Alfa Laval (including the former Sharples). This company has nearly 600 units in service in U.S. municipal wastewater plants. Eimco (including the former Bird and KHD) and GEA (Westfalia, Centrico) round out the top three suppliers in the U.S.
Ashbrook and Andritz are the two top suppliers of belt filter presses. USFilter and Eimco are the top suppliers of plate and frame and recessed chamber filter presses for municipal applications.
U.S. Municipal Wastewater Treatment Plant Database includes plant size, location, addresses, description of unit processes, names of dewatering equipment suppliers and equipment size and model numbers. More information on this online database is provided at: www.mcilvainecompany.com.