facebook icon youtube icon Loading
Monday, December 09, 2013
Improved Backwash Filter System
Water Filtration is the process of passing water through material such as a bed of sand, coal, or other granular substance to remove impurities from the water before we drink it. These impurities consist of suspended particles (fine silts and clays), biological material (bacteria and plankton) among others in the water being treated. The filtration process occurs after processes that remove most of the larger materials out of the raw water. The filter media used in the filtration process must be changed approximately every 25 years.

BackwashfilterOnce a filter becomes dirty, it has to be taken out of service and backwashed. To clean the filter, water is passed quickly upward through the filter, opposite the normal direction (called
back flushing or backwashing) to remove embedded particles. Prior to this step, compressed air may be blown up through the bottom of the filter to break up the compacted filter media to aid the backwashing process; this is known as air scouring. This contaminated water can be disposed of, or it can be recycled by mixing with the raw water entering the plant. The filtration process equipment to include filter media, under-drain system and filter valves need to be properly maintained and replaced when the equipment life cycle is reached. 

Just this year, Columbus Water Works completed a major renovation to the North Columbus Water Resources Facility (NCWRF) replacing the plants’ aged water filtration system components.  The project replaced the filter media with new media, replaced the under-drain system with a new under-drain system with the use of an “air scour backwash system”, and replaced several filter valves that had reached the end of their useful life.   This new air scour backwash system utilizes blowers to supply air through durable stainless steel piping to the filter. The new backwash system now uses water and air to clean the filter which has resulted in decreased water usage needed to backwash the thirty (30) filters. These features have provided measureable reductions in backwash cycles and processed water use and electricity use. Through the increased efficiency, this project has been estimated to provide an
annual savings of $81,000.

Verification Image:
Please enter the code shown above:

© 2020 Columbus Water Works, All Rights Reserved.