Description: Finding Filter Fixes
In larger water resource recovery facilities, there can be numerous filter cells and several thousand square feet of media surface area. This can contribute to making the task of filter evaluation feel overwhelming and expensive.
PublisherWater Environment Federation
Word count162
Description: Finding Filter Fixes
One of the first operational parameters to be checked is the backwash rate and duration. Backwash rate charts based on water temperature and bed expansion have been developed by the American Water Works Association (Denver) and several media suppliers.
PublisherWater Environment Federation
Word count1,270
Description: Finding Filter Fixes
Observation of the surface of the filtration media before and after backwashing is a parameter that can be performed during the normal operation of the tertiary system. If a mound of media or depressions in the media surface are observed, then additional investigations should be undertaken to determine the cause of the uneven media surface.
PublisherWater Environment Federation
Word count245
Description: Finding Filter Fixes
When mixing of media and uneven filter surfaces at the end of a backwash cycle are coupled with other performance indicators, such as mudballs (see Figure 2, above), the filter media should be physically examined to determine the root causes and determine any other issues within the media and under drain system. Things to look for in these in-depth excavations include additional and larger...
PublisherWater Environment Federation
Word count530
Description: Finding Filter Fixes
Another reason to confirm the effective size and uniformity coefficient of the media is to match filter effluent to its desired use use. Over the years, the filter effluent use may have changed from discharge to a creek or river to reuse or land application.
PublisherWater Environment Federation
Word count126
Description: Finding Filter Fixes
During excavation in systems that have gravel support beds, care needs to be taken to not disturb the grade gravel support. This layer provides the foundation for the silica sand and anthracite media. If the gravel support layer is found to be uneven, it is another red flag that there are serious issues with the integrity of the entire media system in the filter.
PublisherWater Environment Federation
Word count169
Description: Finding Filter Fixes
If the filter under drain system is not damaged, cracked, or split and the gravel support media is uniform and has not been compromised, consideration should be given to cleaning the media. This can be accomplished in a couple of ways.
PublisherWater Environment Federation
Word count224
Description: Finding Filter Fixes
The focus of the systematic investigation of the filter systems is to develop a protocol to improve filter effluent quality and run time. Data compiled during the investigative phase can aid operators to make immediate changes in the operation, including run time and backwash sequence as well as to improve filter media bed conditions and avoid retaining suspended solids within the process. This...
PublisherWater Environment Federation
Word count160