Filter Backwash

Filter backwash is a key process in wastewater treatment facilities that
acts as a form of preventative maintenance.

What is Filter Backwashing?

Filter backwashing is a form of wastewater treatment preventative maintenance, where water is pumped backwards through the filter in order to prevent the filter media from becoming too dirty – or even unusable.

Types of filter backwashing

There are 2 main types of filter backwashing: continuous backwashing and semicontinuous backwashing.

Continous Backwashing. In continuous backwashing, water enters near the bottom of the tank, and suspended solids are filtered out as the raw water flows up through the media bed. As the filtrate reaches the top of the filter, it passes over the effluent and is discharged. A portion of the filtrate is diverted through the sand washer and used for cleaning and transferring the waste solids.
Semicontinous Backwashing. In this process, water is pumped below the sand filter; it's then sucked out from the top with a separate pump. The next step is having the backwash water be sent to the main distribution inlet header for reprocessing. The aeration blower provides air that's used in a semicontinuous pulsed-bed filter. The backwashing process will begin once the suspended solids in the effluent cease to filter to an acceptable level of the head.

Aeration technologies for Filter Backwash

Atlas Copco offers seven different blower and aeration technologies for wastewater and industrial applications. We fit the absolute best technology to you – no favoritism involved. Having a complete range means that the technology we select for you will be the most efficient product for your application over the cost of its lifetime, when you factor the cost of purchase, electricity usage, and service (downtime) costs. What’s more? We have the calculators to show you the complete payback analysis before you even part with one dollar.

Atlas Copco innovates in all aspects of compressed air and gas production. Our promise to you is we do more. What does that mean? Simply, we go further and deeper in every aspect of our offering to you and that promise extends way beyond just products. With a presence across the entire United States, and over 350 technicians on the road every day, Atlas Copco specializes in finding ways to make your wastewater and industrial processes more efficient.

Additional Wastewater Treatment Applications

Activated Sludge Process

Utilized in medium- to large-scale industrial plants, the activated sludge process separates the flocculants, or suspended solids, from the wastewater through sedimentation.

Diffused Aeration

In diffused aeration, aeration blowers pump compressed air through and released below the wastewater’s surface to make sure that bacteria receive a continual supply of air.

Closeup view of wastewater treatment facility

Membrane Bioreactors

Membrane bioreactors feature an ultrafine membrane filter installed at the discharge end of a standard aeration basin. Pumps installed on the membrane filters create a slight vacuum and pull the effluent through the membrane. The ultrafine holes in the membrane do not allow the biological microbes to pass through the membrane.

Sequencing Batch Reactor (SBR)

Sequencing batch reactors (SBR) are a version of activated sludge treatment where the treatment occurs in the reactor and clarifiers are not required.

Thumbmail_ZS in WWT_customer testimonial

Moving Bed Biofilm Reactor

Moving Bed Biofilm Reactor is a much more compact method of wastewater treatment that can be scaled to fit any size plant, and is a version of the traditional activated sludge system.

Port Washington WWTP - exterior shot of facility.

Anaerobic Digestion

Anaerobic digestion is used to treat the sludge created by the wastewater treatment process, as well as other biological waste.

Filter Backwash