Phosphorous is necessary for plant growth, but too much of it in lakes and other surface waters leads to eutrophication - a process of rapid algae growth that lowers the dissolved oxygen concentration in the affected area.

The USGS has a good description of phosphorous in surfaces waters, and Iowa State University has a website that discusses sources of phosphorous entering waterways. There are also examples of how eutrophication can occur on a really big scale - in the Black Sea, and at the mouth of the Mississippi River in the Gulf of Mexico, forming a "dead zone".

Please read about phosphorous at these sites prior to lab on Thursday. At the beginning of lab we'll discuss how we can study sources of phosphorous in our local area. Then we'll get our phosphate assay standard curve working. If there's time, you can collect some surface water samples from around campus.

Before the next week's lab, you could also collect additional samples from around campus or the surrounding area. Then on we'll use the phosphate assay to measure total phosphates in your samples.
Last modified: Monday, December 19, 2011, 9:18 AM