EAST MOLINE SLUDGE PRESSES
This project was implemented due to the failing vacuum filters at the East Moline Regional Wastewater Treatment Plant. The vacuum filters were state-of-the-art when they were installed in the original construction 30 years ago.
The sludge filter process consisted of adding the aggressive chemicals ferric chloride and hydrated lime to the sludge and then processing the sludge mix through the filters. A vacuum was applied to "pull" the water out of the sludge. The nature of the chemicals were corroding the filter equipment which was worn and in need of replacement.
This system could dewater the sludge to 15-17% solids. The majority of the solids included lime and ferric chloride that were used in the dewatering. The City was paying on a volume basis to dispose of the sludge at the landfill, and much of the cost was the disposal of the lime and ferric chloride. The plant personnel did an excellent job of keeping the filter system in operation.
Our Role
Ament, Inc. reviewed the existing sludge process operation and determined there were better ways to dewater the sludge.
Ament worked with the City to select the new sludge equipment, ran a pilot test, prepared a bid package, and prepared plans and specifications for installation and construction. The project also consisted of demolition and removal of the existing sludge pumps.
- Duplicated system components to allow for independent equipment operations.
- Project was 8% under original budget.
- Project was a joint effort between contractor, City and Ament, Inc.
- City personnel Sworked effectively with the contractor to get the project completed.
- City personnel used the trailer mounted dewatering unit to familiarize themselves with the new system.
- The contractor worked diligently to complete the project on time and within budget
Project Benefits
- Personnel can operate all sludge press related systems from the control panel located in the control room
- Reduced operations costs
- Payback period of 6.3 years
- Landfill disposal fee savings of $26,114 in a six month period
- Operating and Chemical cost savings of $13,028 in six months
- Estimated yearly savings of $139,674
Project Challenges
Replacement was conducted in an existing structure- Sludge dewatering production was maintained with use of a trailer mounted unit
- Sludge presses had to be placed on the second floor through wall openings
- Condensed construction schedule
- System startup was challenging due to polymer material separation. Poor quality polymer material was supplied initially.
