Challenge

The Broward County North Regional Wastewater Treatment Plant, located in Pompano Beach, Fla., is doubling their dewatering capacity from 900 gpm to 1800 gpm in order to meet county growth projections.

Originally, the Plant operated plate and frame presses and vacuum filters that used lime and ferric chloride to condition the sludge prior to dewatering. In 1991, three belt filter presses were installed. These three units performed well for over 13 years and are still in operation today.

The capacity of the dewatering facility was expanded in 2000 with the installation of three more identical belt presses. A temporary outdoor belt filter press facility was constructed to operate the new belt filter presses.

Solution

The current expansion phase, scheduled to be online in late 2004, includes the installation of six additional belt filter presses—for a total of 12 units. The six units are the exact same model as the current units and are provided by Siemens Water Technologies of Holland, Mich.

The Linear Wedge belt filter press was selected based on its good operational record and to maintain replacement part compatibility with the existing presses.  Broward County Wastewater Treatment Plant Superintendent, Ralph Aliseo, said the operational reliability and ease of maintenance of the Linear Wedge belt filter press from Siemens Water Technologies are the main reasons the county has decided to continue using the same model.

The 12 belt filter presses will each operate at a capacity of about 200 gpm with a feed solids concentration of 2–3% and will produce a dewatered cake of 16–18% total solids.

Results

According to Ghislaine Carr, project manager with Hazen and Sawyer, P.C., “The latest purchase of six Siemens belt filter presses are part of a plant expansion that will bring the plant’s capacity to 100 mgd. The six new presses will be installed in a dewatering building constructed under this expansion. The three presses purchased in 2000 will be relocated in the new dewatering facility.

“The anaerobically digested sludge will be pumped to the dewatering building, and dewatered solids will be hauled away and land applied. The plant will operate nine units, with the original three units remaining for backup at this time,” added Carr. “Three additional machines may be installed in the future in the new dewatering facility, as the county intends to consolidate all dewatering operations at a single location.” Plant Superintendent Aliseo added that the Broward County facility plans to operate the belt filter press for 16 to 20 hours a day, six to seven days a week.

“The press is very durable and operator friendly,” said Aliseo. “The O&M is low, other than basic preventative maintenance and belt changes.”  The plant has the units set up to operate in an automatic polymer feed mode.