Sludge dewatering is a critical step in wastewater management operations. By separating sludge into liquid and solid components, it decreases waste weight and volume, resulting in improved processing efficiency and reduced operational costs. However, conventional dewatering systems, which typically use mechanical means to dehydrate sludge cakes, are limited in their water removal capacities; they leave behind huge amount of water in the sludge cakes. That’s why many dewatering facilities incorporate second stage dewatering systems—such as ELODE® systems—into their processing lines. These machines are engineered to remove water from sludge cake that has already been processed by first stage units, resulting in greater sludge dryness and lower final cake weight, both of which can lead to substantial savings in sludge transportation, storage, and disposal costs.
What Is Sludge Dewatering?
Sludge dewatering is a preliminary waste processing step meant to separate liquids from solids to facilitate subsequent treatment operations. It is not in itself a wastewater treatment. The resulting sludge cakes and wastewater still contain any contaminants that were present before the material underwent dewatering, so additional processing may be necessary before they can be stored or disposed. The primary objective of this process is reducing the amount of water in the sludge waste, which decreases its weight and volume and, consequently, makes it easier to treat and transport.
There are many sludge dewatering technologies available, such as centrifuges, filters, geomembranes, and presses. Each employs different separation mechanisms, making it suitable for distinct applications. For example, filters, membranes, and presses push or press sludge through the screening component to extract as much moisture as possible, while centrifuges spin to separate the sludge into its individual components based on density. Regardless of the sludge dewatering technology utilized, once the waste has been separated using traditional systems, it may be sent to second stage dewatering lines that use thermal, electrical, or chemical mechanisms for further water reduction.
What Makes ELODE Systems Unique?
The ELODE system is an advanced second stage sludge dewatering system. It is designed to further dewater sludge cakes produced by conventional dewatering equipment (e.g., belt presses, centrifuges, and screw presses). Some of the characteristics that differentiate it from other systems include:
- It extracts water from the sludge cake through the use of an electrical potential difference. Drawing on technology that combines the processes of electroosmosis and electrophoresis, it is highly effective at dehydrating sludge cake. Unlike conventional dewatering systems, it removes both free and absorbed water from the sludge, which allows it to improve sludge dryness by some of 20% solids or higher which reduce sludge cake weight by more than 50% in three minutes.
- It achieves dehydration with relatively low energy consumption. It is a non-thermal dewatering system, meaning it does not use heat to remove water from the sludge. As a result, unlike thermal dryers, it does not lose a large portion of the energy input as heat.
Due to their unique design, ELODE systems offer significant cost savings for sludge disposal, transportation, and storage costs, leading to a fast return on investment (ROI) for many customers. Some of the industries that regularly utilize them for second stage dewatering operations include:
- Food and beverage processing
- Municipal water management
- Painting and dyeing
- Paper mills
How Do ELODE Systems Work?
The ELODE system is based on a dewatering technology that draws on mechanisms of electro-osmosis (i.e., the migration of liquid through a solid toward the cathode) and electrophoresis (i.e., the migration of solid particles through a liquid due to their electrical surface charge). It consists of three main components: the sludge conveying belt, the anode drum, and the cathode caterpillar. It works as such:
- Sludge cake is extruded onto the sludge conveying belt.
- The sludge cake is fed between the anode drum and the cathode caterpillar.
- A direct current is applied to the anode drum and cathode caterpillar, resulting in the creation of an electrical potential difference.
- The electrical potential difference causes the negatively charged sludge particles to migrate to the positively charged anode drum and the positively charged water to migrate to the negatively charged cathode caterpillar.
The system is highly effective and efficient. As it removes both free and absorbed water, it is able to discharge sludge cakes with a solids content of 40% or higher. This quality makes it ideal for use in secondary processes to attain higher cake solids from sludge dewatered using conventional dewatering devices.
Benefits of Using ELODE Systems
There are many benefits to using an ELODE system as a second stage processing unit alongside conventional sludge dewatering systems, such as:
- Greater solids contents. While the performance of an ELODE system may vary from application to application, it typically discharges cakes with solids contents of 40% or more. As a result, the cakes are generally drier and lighter than those produced by mechanical-based systems.
- Lower energy consumption. Compared to thermal sludge dryers, ELODE systems are much more energy efficient. They use electricity to drive water out of sludge on a molecular level rather than heat energy to evaporate the water away. The latter requires nine times more energy to perform than the former.
- Smaller footprint. ELODE systems have small footprints, which allows them to be easily integrated into existing lines and facilities.
- Easier operation and maintenance. ELODE systems have a low complexity, fully automated design, which makes them easy to use and maintain.
- Faster return on investment (ROI). Due to their high water reduction rates, low energy consumption, and ease of use/maintenance, ELODE systems can offer considerable cost savings for sludge treatment, disposal, transportation, and storage operations. As a result, customers can quickly achieve full ROI.
Optimize Your Sludge Dewatering Operations With ELODE Today
Looking to improve your facility’s sludge dewatering operations? ELODE is the ideal solution. Whether you’re processing municipal wastewater, food wastewater, or other organic sludge, our advanced non-thermal dewatering systems can help you dewater your sludge cakes at low energy costs. You can reduce your transportation, storage, and disposal costs without increasing your processing costs. To learn more about our sludge dewatering systems and how they can benefit you, contact us today.