The impact of nutrients on growth of nitrifying bacteria is investigated under extreme
circumstances encountered in premise plumbing. Growth of nitrifying bacteria used in
this study could not be maintained long-term on glass pipes during days of stagnation
between introduction of freshwater. However, if pieces of concrete were present,
growth was greatly stimulated. With continuous inoculation, nitrifying bacteria could
not oxidize ammonia in stainless steel and pure lead pipes for a month of exposure, but
could do so thereafter. Similar effects were observed after three months for galvanized
iron but not in copper pipe after five months. Studies of nitrification in glass pipe
revealed that zinc levels above 150 ppb and copper levels above 500 ppb inhibited
nitrification. Phosphorus levels below 1 ppm, calcium below 0.27 ppm and potassium
below 3.89 ppm were associated with lower levels of nitrification. Other elements
including magnesium, molybdenum, cobalt, manganese, chelated iron, iron, nickel,
chromium, tin, lead, aluminum did not have a strong effect on nitrification at levels
encountered in drinking water. Control of nutrients including phosphate could be an
important strategy to prevention of nitrification. Includes 22 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 400 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 16 |
| Published : | 11/01/2005 |
