Biological deoxidation denitrification method in oxidative environment groundwater and device thereof

Abstract

The invention relates to a biological deoxidation denitrification device in oxidative environment groundwater. The device is a double-layer double-media permeable reactive barrier, the permeable reactive barrier is formed by an upstream layer and a downstream layer, the upstream layer is loaded with pine barks, and the downstream layer is loaded with zero valent iron. The invention also provides a biological deoxidation-heterotrophic / autotrophic denitrification combination method in the oxidative environment groundwater. The method comprises a process that the biological deoxidation denitrification device is laid in nitrate nitrogen polluted oxidative environment groundwater pollution plumage downstream soil and an underground water layer, and the device is vertical with the flow direction of the underground water.

Description

technical field [0001] The invention relates to a method for removing oxygen and denitrification for biological restoration of polluted groundwater, in particular to a novel combined method and device for combining biological oxygen removal-heterotrophic / autotrophic denitrification. Background technique [0002] Nitrate nitrogen (NO 3 -N) is one of the most common pollutants in groundwater worldwide, and its pollution has become a worldwide environmental and health problem. High concentrations of NO were found in groundwater on 6 continents except Antarctica 3 -N. Human intake of high NO 3 -N can cause serious illness and even death. long-term exposure to NO 3 -N and nitrite nitrogen (NO 2 -N) can cause polyuria, spleen hemorrhage, "blue baby syndrome" and so on. During 1945-1970, there were 2,000 cases of "blue baby disease" in the world, of which 8% died. In addition, NO 3 -N and NO 2 -N is the precursor of nitroso compounds (N-nitroso Compounds, NOCs). NOCs can...

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Problems solved by technology

[0007] 1. The solubility of hydrogen is low, the utilization rate is low, and the matrix transfer and material transfer from the gas phase to the liquid phase are limited;

[0008] 2. Injection system is required, the price of hydrogen is expensive, and the cost of engineering and operation and maintenance is high;

[0009] 3. The availability of carbon dioxide in groundwater is limited;

[0010] 4. Hydrogen reacts with O during use, transportation and storage 2 Flammable and explosive after mixing

[0014] ZVI in the form of iron shavings, nano-iron, granular iron, cast iron, iron filings and iron powder is used for NO 3 The study of -N chemical reduction and autotrophic denitrification has attracted the attention of researchers [Cheng et al., Reduction of nitrate to ammonia by zero-valent iron, Chemosphere, 1997, 35: 2689-2695; Till et al., Fe (0)-supported autotrophic denitrification, Environmental Science and Technology, 1998, 32: 634-639; Huang et al., Nitrate reduction by metallic iron, Water Research, 1998, 32: 2257-2264.; Westerhoff and James, Nitrate removal in zero-valent iron packed columns, Water Research, 2003, 37: 1818-1830.; Choe et al., Nitrate reduction by zero-valent iron under different pH regimes, Applied Geochemistry, 2004, 19: 335-342; Yang and Lee, Chemical reduction of nitrate by nanosized iron: kinetics and pathways, Water Research, 2005, 39: 884-894; Ahn et al., Enhanced reduction of nitrate by zero-valent iron at elevated temperatures, Journal of Hazardous Materials, 2008, 156:17-22], however, ZVI in the form of sponge iron has not been reported

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