The water treatment industry is constantly faced with the difficult task of balancing the chemical
and microbial risks associated with drinking water contaminants. For example, higher doses of free
chlorine may make water safer from the microbial perspective by inactivating more pathogens, but the
chemical safety of the water will be compromised due to the increased production of disinfection byproducts (DBPs), which are suspected human carcinogens. Many water utilities will soon be forced to
modify their treatment process to comply with new federal and state regulations. Biological filtration is
a process already proven to reduce finished water levels of DBPs and other chemical contaminants, and
the recent experimental results of this research team indicates an enhanced ability of biofilters to remove
particles, including Cryptosporidium oocysts. Based on the advantages of biological filters in terms of
both chemical and microbial safety, it is foreseeable that many utilities may soon wish to switch to
biological filtration. Proper filter backwashing is essential to maintaining the performance of any
granular media filter, and backwashing is even more important to biological filters due to the behavior
of the biofilm on the media. It is also essential for maintaining enhanced organic and pathogen
removals. Distinctions between conventional and biological filters are made based on experimental
evidence and explained with a microscopic force model approach that includes hydration forces and
Born repulsion. Includes 34 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 320 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 20 |
| Published : | 06/16/2002 |
