Building a new wastewater treatment plant involves much more than constructing another piece of infrastructure. It is during the design phase that critical decisions are made that will influence plant performance for decades. Selecting the right technology from the outset has a direct impact not only on process performance but also on long-term operating costs.
One of the most important design considerations is sludge handling. For the new wastewater treatment plant in Lolo, Montana, the owner required a complete activated sludge dewatering system designed to process sludge with an inlet solids concentration of approximately 0.7% DS.
In addition to achieving the required dewatering performance, the system needed to provide low operating costs and simple day-to-day operation. To meet these requirements, ESMIL designed, manufactured and supplied a complete sludge dewatering system based on the ESMIL–Tsurumi MDQ Multi-Disc Screw Press, together with all supporting equipment.
Design requirements
The system was designed to dewater activated sludge with an inlet solids concentration of approximately 0.7% DS. The primary objective was to achieve operating parameters that would ensure both reliable process performance and economical long-term operation.
The design specifications included:
- Capacity: 165 lb DS/h
- Dewatered cake solids: 16-20%
- Solids capture: ≥95%
Each of these design parameters has a direct impact on plant operation. Higher cake solids reduce the amount of sludge requiring transportation and disposal, resulting in lower and more predictable operating costs. High solids capture minimizes solids loss in the filtrate, while properly sized system capacity ensures reliable operation of the entire process. These requirements formed the basis for selecting the dewatering technology.
Selected solution: ESMIL-Tsurumi MDQ sludge dewatering system
Based on the project requirements and process evaluation, ESMIL engineers developed a complete sludge dewatering system centered around the ESMIL-Tsurumi MDQ-401 CLS Multi-Disc Screw Press. The system also includes a polymer preparation unit and an ESMIL screw conveyor for transporting the dewatered sludge.
All equipment was selected and integrated as a single process system, ensuring reliable interaction between individual components and stable operation of the complete dewatering line.
Lower operating costs with ESMIL-Tsurumi MDQ technology
The cost of sludge dewatering extends well beyond the initial equipment purchase. The overall value of the investment depends largely on the operating costs incurred throughout the life of the system.
ESMIL–Tsurumi MDQ technology helps reduce operating costs through:
- Low-speed operation that minimizes power consumption
- A self-cleaning filter disc system that reduces wash water usage
- A durable design that provides long service life while minimizing maintenance requirements
As a result, the owner receives a solution that not only meets the required process performance but also helps reduce the total cost of ownership of the sludge dewatering system.
Manufactured in the USA
The equipment was manufactured at ESMIL Corp.’s facility in Ohio in accordance with U.S. standards, including ASME, AWS, BABA and UL.
Domestic manufacturing ensures compliance with U.S. project specifications and regulatory requirements while providing a shorter supply chain, direct access to local engineering support and readily available service and spare parts.
Conclusion
Following installation, the system underwent startup and performance testing, confirming proper operation and achievement of the specified design criteria. After successful startup, the complete sludge dewatering system was placed into operation.
Designing a new wastewater treatment plant requires consideration not only of process performance but also of long-term operational requirements. The selected dewatering technology should provide reliable operation while delivering predictable operating costs throughout the life of the facility.
The Lolo project demonstrates that ESMIL equipment is increasingly being specified during the design phase of new wastewater treatment plants, where long-term operating efficiency is considered just as important as process performance.
