Thanks to the compact footprint of the MDQ dewatering press, the process also requires significantly less space than the previously used sludge drying beds. During startup, the dry solids concentration increased from approximately 1% in the feed sludge to approximately 24% in the dewatered sludge cake.
Challenges of sludge drying beds
The Dyer Wastewater Treatment Plant in Tennessee is a small facility that primarily treats municipal wastewater from the city and surrounding area. Until recently, sludge generated at the plant was dried naturally on open-air sludge drying beds.
While this is a relatively simple method, it has several limitations. Sludge drying beds require considerable space and the process is highly dependent on weather conditions. Rainfall, temperature and humidity all affect the drying rate, making the time required to prepare sludge for further handling both lengthy and unpredictable.
These limitations led the Dyer Wastewater Treatment Plant to switch to mechanical sludge dewatering, allowing the process to run continuously, under controlled conditions and with greater predictability.
Implementing an MDQ Multi-Disc Screw Press at Dyer WWTP
The Dyer Wastewater Treatment Plant generates waste activated sludge (WAS) with an initial dry solids concentration of approximately 1.0%. Given the relatively small size of the facility, it was important to select a system that could provide the required capacity without the need for extensive infrastructure or a large installation footprint.
Based on the process parameters and site conditions, ESMIL specialists designed a system featuring an MDQ-202(1) Multi-Disc Screw Press and an inclined screw conveyor for transporting dewatered sludge.
The MDQ dewatering press provides a hydraulic capacity of approximately 15 GPM (3.4 m³/h), matching the plant’s current needs. During startup, the ESMIL team verified system performance under actual operating conditions and fine-tuned the process parameters based on the sludge characteristics and site conditions.
From 1% to 24% dry solids
During startup, sludge with an initial dry solids concentration of approximately 1.0% was dewatered to approximately 24% dry solids.
This level of dewatering significantly reduces the mass and volume of sludge requiring further handling. The dewatered sludge cake is easier to store, transport and manage, helping reduce costs associated primarily with transportation and disposal.
A compact sludge dewatering system for a small wastewater treatment plant
Implementing mechanical dewatering allowed the Dyer Wastewater Treatment Plant to move away from open-air sludge drying beds and significantly improve the overall process. Instead of relying on a time-consuming drying process that depends on weather conditions, sludge can now be dewatered continuously under controlled conditions and then transferred directly for transport and further handling.
The compact footprint of the MDQ dewatering press was another important factor. The system requires significantly less space than the previously used drying beds, allowing the plant to switch to mechanical dewatering without requiring a large area for the new equipment.
For small and medium-sized municipal wastewater treatment plants, the Dyer project demonstrates that improving sludge management does not necessarily require a large or complex system. Mechanical dewatering can be a practical upgrade for smaller facilities as well, replacing time-consuming natural drying methods with a more efficient, controlled process.
