Reducing agent for regeneration of reaction material for processing nitrates in underground water and injection technology

Abstract

A reducing agent for regeneration of a reaction material for processing nitrates in underground water is characterized in that the reducing agent has the molecular formula of C6H8O6, is in the state of a solid powder, is a widely-applied food additive, is easy to dissolve in water and forms a true solution with a certain concentration; and by adding the reducing agent into high-valent iron (Fe<3+>), the basic reaction process is as follows: Fe(OH)3(precipitate)+3H<+> -> Fe<3+>+3H2O, 2Fe<3+>+C6H8O6 -> C6H6O6+2Fe<2+>+2H<+>, so that Fe<3+> is reduced into Fe<2+>, and the capability for processing nitrites is recovered. The injection technology of the reducing agent C6H8O6 comprises the following steps: step 1, firstly dissolving the reducing agent C6H8O6 in water, so as to form a C6H8O6 solution with a certain concentration; step 2, drilling a perfusion hole (1) on an original-earth layer (2) for in-situ processing of nitrites in underground water and the reaction material (3), and putting a perfusion pipe (13) into the perfusion hole (1); and step 3, under the effect of a constant-pressure pump (11), perfusing the perfusion pipe with the reducing agent C6H8O6 (12). According to the reducing agent and the injection technology, Fe<3+> is reduced into Fe<2+>, regeneration utilization of the reaction material is realized, and the original functions of an on-site processing well of polluted underground water are recovered.

Description

technical field [0001] The invention belongs to the technical field of groundwater treatment, in particular to a reducing agent for the reduction and regeneration of groundwater nitrate reaction materials and a reducing agent injecting process. Background technique [0002] Groundwater is one of the important sources of drinking water. Shallow groundwater is used as a source of drinking water especially in vast rural areas and urban suburbs. Its quality is related to the health of drinkers. Therefore, the country has stipulated strict drinking water standards to ensure the quality of drinking water. It stipulates that the content of nitrate as a water source should not exceed 20mg / l. However, in the process of agricultural cultivation in recent years, a large number of nitrogen fertilizers have been used, and excessive use and accumulation for many years have caused a large amount of excess nitrate to exist in the soil. With the movement of rainfall and groundwater, the gr...

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Problems solved by technology

According to the research, it is Fe2+ that mainly reacts with nitrate, but due to the limitation of the number of materials used and the limit of service life, Fe2+ gradually decreases, and the ability of related composite materials to remove nitrate also gradually decreases

The results of relevant groundwater remediation projects show that the service life of general groundwater remediation projects is 7 to 10 years. When the service life is exceeded, Fe 2+ It is also gradually reduced to high-valent iron (Fe 3+ ) and lose the ability to respond. Internationally, after the dielectric material fails, it will be replaced again, which will consume a lot of manpower, financial and material resources

In the laboratory, iron powder is reduced to make Fe 3+ reduced to Fe 2+ There is some research, but it is difficult to implement in field engineering

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