Method for zero-valent metal and carbon combination internal electrolysis catalysis reduction of nitrate nitrogen in water zero-valent metal and carbon combination

Abstract

The invention belongs to the water processing technology application field, relates to a method for removing nitrate nitrogen in water, and especially relates to a method for the zero-valent metal and carbon combination internal electrolysis catalysis reduction of a pollutant nitrate nitrogen in water. A technological principle of the method is characterized in that the reductibility of a zero-valent metal elementary substance and the internal electrolysis effect of the zero-valent metal elementary substance and conductive substances comprising active carbon and the like are utilized to accelerate the transfer of electrons in a solid-liquid phase interface, so nitrate nitrogen is rapidly reduced and removed, and the zero-valent metal can prolong the service life because of the internal electrolysis effect, thereby the reaction efficiency is improved. The method is characterized in that the granular or powdery zero-valent metal and a carbon material are directly added to or are mixed and then added to water containing nitrate nitrogen, stirring is carried out in a certain strength under reacting, and nitrate is directly reduced on the surface of the metal, and is reducibly degraded under the action of nascent state hydrogen [H] generated by an electrode reaction in the internal electrolysis process. The method has the advantages of simple operation, convenient management, less secondary pollution and high reaction time and space efficiency.

Description

technical field [0001] The invention belongs to the application field of water treatment technology, and relates to a method for removing nitrate nitrogen in water, in particular to a method for electrolytically catalytically reducing pollutant nitrate nitrogen in water in a combination of zero-valent metal and carbon. Background technique [0002] Nitrate nitrogen is one of the ubiquitous groundwater pollutants, which mainly comes from the widespread use of a large number of synthetic nitrogen fertilizers in agriculture and the illegal discharge of certain industrial wastes. In recent years, the pollution of nitrate nitrogen in groundwater in my country has become increasingly prominent, and the content of nitrate nitrogen in groundwater in some areas has reached 40 mg / L (calculated as nitrogen). The harm of nitrate in drinking water is mainly to induce hyperferrinemia. At the same time, nitrate and nitrite are converted into nitrosamines, which have carcinogenic effects. ...

AI Technical Summary

Problems solved by technology

Among them, the simple metal reduction method is a denitrification method developed in recent years. It uses zero-valent metals as the reducing agent to directly reduce the nitrate ions in the solution to nitrogen without adding any chemicals. The reaction speed is fast and the process is simple. It is easy to operate, but the metal element reduction method has the disadvantages that the metal is easily deactivated and the reduction efficiency decreases.

For example, when zero-valent iron is used for treatment, as the reaction progresses, the metal surface is easily covered with a layer of oxide or precipitate, which hinders the metal reactivity and reduces the reaction rate.