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.1” 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 the 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 – Here is where the nitty gritty work takes place. During this step, additional water is removed, leaving behind a dry substance known as “cake.” But what purpose does dewatering serve? Wastewater storage and treatment plants will enjoy many benefits from using centrifuges to dewater their wastewater.

• Advantage #1: A reduction in volume – When every inch of space counts, the amount of room being taken up by wastewater can really add up. Both storing and transporting wastewater can be expensive propositions. The smaller the volume of water being stored and transported, the more money that can be saved.
  
  
• Advantage #2: Disposal that is not only safer and easier but also kinder to the environment – Here is another way in which business owners can save on their wastewater. Because centrifugal dewatering “eliminates free liquids” and “reduces fuel requirements,” the costs of disposal is reduced whether the wastewater ends up at a landfill or the residuals are incinerated.
  
  
• Advantage #3: Able to be composted – The cake that is left behind after dewatering can be missed with a bulking agent to produce “sufficient void space and volatile solids for composting.”
  
  
• Advantage #4: Ponding and runoff elimination – These common issues that occur when a liquid like wastewater is “land applied on the surface rather than injected” is mitigated.

If your business operations manager hasn’t already considered a centrifuge as part of your wastewater treatment plan, you may be missing out on these many advantages. The cost investment may seem out of reach at first glance but the return on investment will more than pay off over the long run. The higher solids concentration that is achieved in comparison to other dewatering systems is unparalleled.

If you feel as though your operations could benefit from a centrifuge for wastewater treatment but you still believe you just can’t justify the cost of a new centrifugal system, you may want to consider a used wastewater centrifuge or reconditioned-to-new wastewater centrifuge.

Aaron Equipment’s centrifuge expert, Whitney Craig, can be contacted for advice and help steer you through your many wastewater centrifuge options from decanter centrifuges to bottom dump centrifuges. Whitney also has expertise in disc and filtering centrifuges.