Ammonium
Ammonium is a polyatomic ion with a chemical formula of NH4+, that is formed by adding an H+ ion to ammonia (NH3). Ammonia enters the water from aquatic animals’ wastes, decaying plants, and food, and is also actively transported from fish gills. It is then converted to ammonium in water by bacteria. Ammonium interferes with sodium potassium ATPase channels in nerves, meaning it is toxic, killing the fish and affecting the development of tissues in the liver, gills, and kidneys. In addition, it damages plant cells, which cause the leaf edges of the plant to curl, and eventually die. Moreover, it slows down the growth of the roots of plants and the growth rates of fish. Some organisms, such as mussels, find it difficult to remove ammonium from their system, therefore it is converted in the urea cycle to urea, which is less toxic and more efficiently stored.
Interpreting Ammonium Levels
The level of ammonium in a river helps one to draw a conclusion about the health of the river. If a river is found to have high levels of ammonium, greater than 0.1 mg/L, it is usually considered to be an unhealthy river. Our tests were carried out using an ammonium probe connected to a Lab Quest. The probe was soaked for 30 minutes and then calibrated before use. When calibrated, it was simply placed in the sample of water collected to give a reading.
Our Results
The ammonium readings were relatively low in all five rivers. The lowest reading was 0.0 mg/L found in all rivers, and the highest was 2.2 mg/L in one of the 10 trials done at Wards Creek. The average of the five rivers is 0.1 mg/L, and the standard deviation is 0.3 mg/L. Therefore, these low readings can conclude that the five rivers are healthy.
Works Cited:
"Ammonium Toxicity." Ammonium Toxicity. Accessed March 30, 2016. http://www.pthorticulture.com/en/training-center/ammonium-toxicity/.
​"Pure Water Gazette Water Treatment Issues." Ammonia in Water. Accessed March 30, 2016. http://www.purewateroccasional.net/wtiammonia.html.