Ravinnepäästöt

Ravinnepäästöt refers to the release of nutrients, primarily nitrogen and phosphorus, into the environment. These nutrients are essential for plant and animal life but become problematic when present in excessive amounts. The main sources of ravinnepäästöt are agricultural runoff, wastewater discharge from urban areas and industries, and atmospheric deposition.

In agriculture, fertilizers containing nitrogen and phosphorus are widely used to enhance crop growth. When rainfall or irrigation washes over treated fields, these nutrients can be carried into nearby water bodies such as rivers, lakes, and coastal waters. Animal husbandry also contributes significantly, as manure and slurry can leach into groundwater or run off into surface water.

Wastewater treatment plants, while designed to remove pollutants, may not always eliminate all nutrients. Discharges from these facilities, as well as untreated sewage, can introduce substantial amounts of nitrogen and phosphorus into aquatic ecosystems. Industrial processes can also release nutrient-rich effluents.

Atmospheric deposition occurs when nitrogen compounds emitted from sources like vehicle exhaust and industrial combustion are transported through the air and then fall to the ground, often in rain or snow.

The impact of excessive ravinnepäästöt is a significant environmental concern. In aquatic environments, these excess nutrients can lead to eutrophication, a process where algal blooms occur. These blooms deplete dissolved oxygen in the water when they decompose, creating hypoxic or anoxic conditions that are harmful or lethal to fish and other aquatic organisms. This can lead to dead zones and a loss of biodiversity.