As the human population continues to grow, the pressure to feed the increasing number of mouths grows as well. The demand for higher-yielding crops has led to more intense fertilization which in turn has led to increased nitrogen pollution. Nitrogen pollution of groundwater and surface water is more prevalent than all other aquatic pollutants combined. In fact, it is estimated that agriculture accounts for over 80% of the nitrate discharged by the Mississippi river. The nitrate facilitates explosive algal growth resulting in a “dead zone” of hundreds of square miles of hypoxic sea in the Gulf of Mexico.
Many of the world’s shallow seas are suffering similar effects, but large-scale nitrate removal has been very difficult to treat economically. Zeolites modified to remove anions are showing enormous promise as cost-effective nitrate control.
EXAMPLES OF AGRICULTURAL TREATMENT WITH ZEOLITE-ANAMMOX
Wastewater treatment from dairies, pig farms, etc. to remove ammonia and nitrate.
Removal of ammonia and/or nitrate for water recycling and water re-use.
Controlling fertilizer run-off by trapping ammonia and/or nitrate.
Zeolite-based soil amendments converting conventionally applied fertilizer to slow release nitrogenous fertilizers.
Use of zeolites and modified zeolites to reduce nitrogen pollution of surface waters and groundwater.