A Review on the Efficiency of Denitrification Bioreactors in Nitrate Removal from Agricultural Drainage Water

One of the most important problems in drainage systems is the leaching of nitrate and its entry into surface water resources. Increased concentration of nitrate in water resources causes health problems to human and animals. The denitrification process, as one of the suitable solutions for nitrate removal from contaminated water, faces restrictions in agricultural soils due to lack of the carbon materials. Providing carbon in the soil promotes the process and removes more nitrate from the environment. The use of organic materials as cheap and affordable carbon is one of the best options for this purpose. In fact, biofuel reactor are a simple and relatively inexpensive technology in which carbon sources are used to facilitate denitrification. The intensity of denitrification in biological reactors depends on the type of carbon source, temperature, water soluble oxygen, hydraulic residence time and hydraulic parameters. Studies have shown that biological reactors are capable of removing up to 99 percent of nitrates in agricultural drainage. In recent years, numerous studies have been accomplished on the use of biological reactors and their ability and how they are applied to remove nitrates. In this paper, biological bioreactors of denitrification have been investigated as a method for removing nitrate from agricultural drainage.