Circulating well system for treating VOCs and DNAPLs in polluted underground water

Abstract

The invention provides a circulating well system for treating VOCs and DNAPLs in polluted underground water. An upper-section permeable sieve pore and a lower-section permeable sieve pore are formed in a circulating well pipe, the upper-section permeable sieve pore is a water outlet and corresponds to the underground water level, and the lower-section permeable sieve pore is a water inlet and corresponds to the lower boundary of an underground water polluted area; a gas injection pipe is arranged in the circulating well pipe, the lower end of the gas injection pipe extends to the lower-sectionpermeable sieve hole; a gas phase extraction pipe is arranged in the circulating well pipe and is used for extracting VOCs-containing gas escaping from ascending bubbles in underground water; chemical injection pipes are mounted in a filter material outside a sieve pipe at the upper part of the circulating well pipe, and the bottoms of the chemical injection pipes are close to the bottom of the upper-section permeable sieve hole. Microbial agents in the chemical injection pipes are evenly dispersed in the underground water environment under the action of circulating water at a drain port, andthe situation that a multifunctional circulating well unit is scrapped due to the fact that a biological film is formed at a circulating well screen pipe and the circulating well screen pipe is blocked is avoided. A wedge-shaped collector is arranged at the bottom of a circulating well water inlet screen pipe, and DNAPLs in underground water can be collected.

Description

technical field [0001] The invention relates to a circulating well system for treating VOCs and DNAPLs in polluted groundwater. Background technique [0002] With the acceleration of the implementation of the policies of "retreating from the second to the third" and "industrial transfer" in the process of urbanization in my country, a large number of heavily polluting industries have been closed and relocated, resulting in a large number of leftover soil and groundwater polluted plots in and around the city. At present, the technologies for treating polluted groundwater mainly include ex-situ remediation technologies such as extraction and treatment, in-situ remediation technologies such as chemical oxidation and groundwater aeration, and the application of these technologies has obvious limitations. [0003] The groundwater circulation well technology integrates aeration, air lift and stripping technologies, which overcomes the long period of groundwater pumping and treatme...

AI Technical Summary

Problems solved by technology

Due to the special structural requirements of the multifunctional circulation well, the circulating circulation well pipe needs to be sieved up and down and wrapped with a screen with a small aperture. The common multifunctional circulating well microbial agent injection pipe is directly installed in the well and injected. If the value is too high, it is very easy to produce a biological film attached to the surface of the screen to block the screen tube, thereby scrapping the circulation well

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