|
| |
|
| |
|
|
|
November 20, 2005Graceland, blueberries - and an orange creekHow fruit waste turns a stream orangeThe orange in the stream looks like rust, which is no coincidence. The chemical process that turned blueberry syrup into a stream-killing pollutant is similar to what happens when iron or steel is left exposed to air or water.Iron rarely exists in a metallic state in soils but instead shows up as an iron oxide, or an iron molecule joined with an oxygen molecule. That’s a compound of iron that is generally stable in nature. But in the presence of nutrient compounds, like the soluble sugars found in blueberry waste, bacteria proliferate and seek out oxygen. Bacteria attack compounds of iron leaving the metallic iron to flow into the groundwater. The iron then moves with the groundwater until the water is aerated, or infused with oxygen. When iron molecules flow from an underground aquifer into a stream, oxygen molecules reattach, forming iron oxide in the stream. That turns the stream orange, similar to the color of iron or steel when it is exposed to air and water and rusts. Compiled from interviews with the Michigan Department of Environmental Quality and information from DEQ documents. See Related Stories:
|
|
