There are many different chemicals and substances that may be beneficial when used in certain applications, but can become harmful when they enter water. One such compound is ammonia, which is composed of nitrogen and hydrogen. Ammonia is a colorless gas that has a strong odor and is known to be highly soluble when placed in water. This means that ammonia dissolves quickly when it enters the water supply. This particular gas is found in very low levels in humans and in nature. It is also often used as the primary compound in household cleaning solutions.
Nearly 90% of all ammonia produced in industrial settings is used directly in fertilizers. It is estimated that adults can consume an average of 18 mg of this compound per day without adverse health effects. Because ammonia is a byproduct of protein formed when protein begins to break down in the body, this substance is produced in the body every day as protein is digested.
Although ammonia has many benefits, it can also be corrosive and dangerous in certain circumstances. Ammonia is capable of entering wastewater from several different sources, including urine, manure, cleaning chemicals, process chemicals and amino acid products. When chemicals are used as fertilizers, this compound can leach into water supply systems in agricultural runoff. It can also enter underground aquifers through animal feedlot runoff.
If ammonia enters a piping system, it can cause extensive corrosion if the piping system is made of copper. Keep in mind that ammonia is not directly regulated by drinking water standards. This chemical is considered toxic to dialysis patients and fish.
When ammonia enters water, its toxicity varies depending on the exact pH of the water. It is possible for some ammonia to break down into ammonium ions, which are present with standard ammonia. When water temperature or pH changes, the molecule can change between the two types of ammonia.
Environmental impact of ammonia on water
Ammonia can have a significant environmental impact once it enters the water supply. High levels of ammonia can be present in water due to leaching of industrial process wastes and agricultural fertilizers into surface water through runoff. If you want to ensure that your water does not contain high levels of ammonia, it is believed that normal levels of ammonia are less than 0.2 milligrams per liter of water.
In forests and similar areas containing large amounts of iron deposits, ammonia levels may be about 3 milligrams per liter. The highest ammonia levels that can be found in nature are close to 12 milligrams per liter in some surface waters. Aquatic ecosystems may be negatively damaged if ammonia levels reach levels above 12 mg/l.
Some ammonia in water breaks down into ammonium ions. While ammonia is considered toxic to any aquatic ecosystem, ammonium ions are not toxic to them in any way. Since the molecules in ammonia and ammonium ions vary depending on the temperature and pH of the water, the toxicity of the water depends on several factors. If the water is slightly acidic at pH 6.0, the ratio of ammonia to ammonium is about 1/3,000. once the pH rises to 8.0 and becomes less acidic, the ratio of ammonia to ammonium is 1/30.
When studying the effects of ammonia on aquatic ecosystems, it is important to understand that aquatic plants take up ammonia directly into some of their structural molecules, which may include amino acids and proteins. Once this occurs, most plants are unable to excrete ammonia from their systems. When ammonia builds up in the plant’s blood and tissues, the high levels can eventually kill the plant in question. High ammonia levels in streams and lakes can also promote algae growth, which slows the growth of aquatic plants.
The effect of ammonia on water quality
When you drink water, high concentrations of ammonia can produce strange smells and tastes. These problems occur because ammonia promotes the growth of chloramines. These compounds are typically produced when ammonia and chlorine are put into drinking water for disinfection.
Ammonia concentrations in water may also increase due to contamination of water with animal waste, chemical runoff or fertilizers. Because ammonia is not considered toxic to humans at levels typically found in drinking water, EPA has not set an upper limit for this compound in public water supplies. Local municipalities often set their own limits for ammonia in drinking water, ranging from 0.25 to 32.0 milligrams per liter.
Ammonia recommendations for improving water quality
Although the EPA does not set any specific upper limits for ammonia in drinking water, they do make water quality recommendations for total ammonia nitrogen in water. These recommendations are not considered law, but can be used as a guide when you are trying to ensure that ammonia levels in your water are safe. Current EPA recommendations for TAN include.
- Acute standard magnitude – The EPA sets a short-term recommendation of 17 mg of TAN per liter of water, averaged over one hour at a water temperature of 20 degrees Celsius and a pH of 7.0. These limits can only be exceeded once every three years.
- Chronic Standard Scale – This long-term recommendation is set at 1.9 mg TAN per liter of water with the same pH and temperature as above. this measurement lasts for 30 days and can only be exceeded once in three years.
- Four-day average – The maximum average concentration of TAN over a four-day period should not exceed 4.8 TAN per liter of water.
Keep in mind that high ammonia levels in water are considered to indicate the presence of some amount of fecal contamination. The water may be contaminated with manure or fertilizer from nearby livestock. If this happens, the water will smell and taste very bad. As a result of this contamination, the potential for waterborne disease may increase. If ammonia and chlorine combine in the water, the reaction with other contaminants in the water may lead to the formation of carcinogens.
Ammonia in drinking water
Ammonia has been a common drinking water treatment method in municipal water treatment facilities. The disinfection properties of chlorine are enhanced when ammonia is added to the water, which is why this combination of compounds is used to disinfect contaminated water. As mentioned earlier, chloramines are produced from this combination of compounds. Digital ammonia sensors are often used to monitor.
A small amount of ammonia is not directly combined with chlorine, which means that it is present in the form of free ammonia. The free ammonia will then decompose into ammonium and ammonia. If the water temperature is 55-75 degrees Fahrenheit and the pH is 7.0-7.8, approximately 96% of the ammonia will be in the form of harmless ammonium ions.
Signs that ammonia may be present in drinking water
The four main signs that indicate high levels of ammonia in drinking water include
- Low chlorine levels – You can determine if your water has a high ammonia concentration by measuring the chlorine level in your water. You may receive a chlorine reading of 0.1 to 0.4 milligrams per liter. Meanwhile, total chlorine levels may range from 1.0-1.5 milligrams per liter. If the standard chlorine reading is too low, the water may contain high levels of ammonia.
- Low pH – If the pH of your drinking water is low, ammonia levels may be high.
- Bacterial growth – High ammonia levels may lead to increased bacterial growth, which may form colonies on any home water filter.
- Taste/Odor – The taste and odor of water may be unpleasant, which means that the water may contain high levels of ammonia. Your drinking water may have a musty and earthy taste, which is due to high ammonia levels that remove too much oxygen from the water.
If you drink water with very high ammonia levels for a long time, you may eventually develop ammonia poisoning, which can be harmful to your health. The main symptoms of ammonia poisoning are
- Pain and swelling in the ears, throat and nose
- Coughing, wheezing and chest pain
However, these problems are rare and should not occur if the water you drink contains low levels of ammonia.
Removing ammonia from water
If you want to remove ammonia from your water to ensure that it does not cause any adverse health effects, doing so can be a bit more complicated than the process of removing other contaminants. This measure may be necessary if the ammonia concentration is higher than your comfort level. While most high-tech filtration systems cannot properly remove ammonia, some distillation, ion exchange and reverse osmosis systems may be able to remove at least some of it.
While these systems are effective, they are relatively expensive and may be difficult to place in a home. Since ammonia is relatively safe for human health, obtaining one of these systems may not be worth the cost. Municipal water facilities mitigate some of the more harmful effects of elevated ammonia levels. If you want to remove chloramines and other harmful contaminants from your drinking water, consider purchasing a standard water purifier..
Ammonia in water treatment
The following table discusses the three most common treatment options. In addition to these Selecting reverse osmosis, ion exchange, and air stripping with pH adjustment may be appropriate applications in some cases. In order for air stripping to be active, the pH needs to be adjusted to 11.
|Treatment Type||Details||Important Considerations|
|The idea here is to add enough chlorine to convert all of the ammonia into nitrogen. Chlorine is converted to chlorine. Additional chlorine is added to maintain residual free chlorine in the distribution system.||For every 1 mg/L of ammonia, 8 ~ 12 mg/L of chlorine is required to complete the reaction. The use of high doses of chlorine will result in the formation of disinfection by-products.|
Competition from other chlorine-containing compounds (e.g. Fe, Mn, H2S, TOC) will result in higher chlorine doses being required.
|Chlorination||If you have about 0.5 mg N/L or less of naturally occurring ammonia, you can add chlorine to generate chloramines||If your color is due to organics (such as total organic carbon or TOC) or hydrogen sulfide (H2S), then this may not be the best option. You will still have color and odor problems after chlorine is added.|
|Microbes use oxygen to convert ammonia to nitrite, and then back to nitrates. This is called nitrification. Although nitrification is usually discouraged in distribution systems, the process encourages nitrification at the treatment plant to avoid subsequent effects on disinfection.||In order to achieve biological deamination, you need water with sufficient dissolved oxygen. This process lowers the pH and uses dissolved oxygen.|
A reactor vessel/pressure vessel is needed to keep the biological growth attached to the growth process.