Hobbies And Interests
Dead Zones
A major pollutant in marine ecosystems is runoff from coastal agriculture laden with fertilizer chemicals. A marine "dead zone" develops when an influx of chemical nutrients triggers an algal bloom, which subsequently consumes most of the water's dissolved oxygen, suffocating all other marine life. Restoring life to dead zones is accomplished by decreasing fertilizer use or diverting runoff. Soon after the Soviet Union's collapse halted regional distribution of chemical fertilizers, for example, a giant dead zone in the Black Sea completely rebounded.
Freshwater Pollution
Freshwater sources face similar threats as marine ecosystems from the agricultural industry, but reversing the effect on rivers and groundwater takes on new importance when drinking water is the intended use. Fresh water can be pumped to treatment plants, and contaminants removed through pressurized air or activated carbon filters. However, laws that prevent future contamination and allow natural processes to break down existing pollutants, as has happened as a result of Chicago's ban on detergent phosphates, remain the most effective method of reversing freshwater pollution.
Bioremediation
Planting vegetation that accumulates pollutants from the soil in its roots and leaves is another method of reversing the effects of pollution. Mustard greens and sunflowers are rapid accumulators and are used for bioremediation. Plants are grown and harvested several times until soil testing proves that contaminants have been reduced to safe levels. Even though the plants must be removed to a landfill afterward, Cornell University researchers have used bioremediation to reduce contamination in "brown fields," which are industrial areas that cannot be redeveloped due to highly toxic pollutants.
Air Pollution and Acid Rain
Coal-burning power plants have been responsible for acid rainfall around the world, most notably during the 1980s in the heavily polluted "Black Triangle" of Central Europe. When sulfur dioxide from unregulated Soviet industries combined with cloud particles, the resulting precipitation lowered pH levels in rivers, streams and reservoirs to toxic levels and sparked massive fish kills. By the 1990s, however, many waterways were potable again due to emissions regulations enforced by the Sulphur Protocol of European countries and the application of calcium to neutralize acidic waters.