Centrifuges for Wastewater Treatment

Centrifuges’ use in the treatment of wastewater enjoys a longstanding history. According to the United States Environmental Protection Agency’s (EPA’s) Office of Water, “Centrifuges have been used in wastewater treatment since the 1930s.” During that 80+ years of usage, centrifuges have helped separate wastewater solids from liquid, thereby ridding it of contaminants.

The EPA cites a two-step process whereby this treatment is achieved. That is, a combination of centrifugal thickening and dewatering at a very high speed “uses the force from rapid rotation of a cylindrical bowl.” Let’s take a closer look at these two phases of the process.

Phase 1: Centrifugal Thickening – Thickening is the first step in wastewater treatment. When it takes place before digestion or dewatering, it “reduces the tankage needed for digestion and storage by removing the water,” the EPA explains in a “Biosolids Technology Fact Sheet.”

Phase 2: Centrifugal Dewatering – This is where the primary separation occurs. During this step, additional water is removed, leaving behind a dry substance known as “cake.” Wastewater treatment facilities gain several advantages from this process.

• Advantage #1: Reduction in volume – Lower wastewater volume reduces storage and transportation costs.

• Advantage #2: Safer, easier disposal – Dewatering eliminates free liquids and reduces fuel requirements, lowering disposal costs.

• Advantage #3: Composting capability – The remaining “cake” can be mixed with a bulking agent for composting.

• Advantage #4: Reduced ponding and runoff – Helps prevent issues when wastewater is land-applied.

If your operations team hasn’t considered a centrifuge as part of your wastewater treatment plan, you may be missing out on these advantages. While the upfront investment may seem high, the long-term return on investment can be significant due to improved efficiency and higher solids concentration compared to other dewatering systems.

If a new system isn’t feasible, consider a used or reconditioned wastewater centrifuge as a cost-effective alternative.

Aaron Equipment’s centrifuge expert, Whitney Craig, can help guide you through your options—from decanter centrifuges to bottom dump centrifuges—as well as disc and filtering centrifuges.