Chemical leaching repairing method for removing heavy metal and arsenic from soil

Abstract

The invention discloses a chemical eluent and a restoration method thereof for eliminating heavy metal and arsenic in soil simultaneously, the chemical eluent is prepared by three chemical agents, namely, EDTA, ammonia and oxalic acid, and after the preparing process, the molarity of the EDTA and the oxalic acid are respectively 0.005 to 0.05mol / L and 0.05 to 0.5mol / L, while the molar ratio between the EDTA and oxalic acid is 1:1. The formula of the chemical eluent is simple and the effect is obvious; the heavy metals such as cadmium, copper, lead and zinc, etc., and arsenic existing in the form of negative ion in the soil can be eliminated by one time elution and the eliminating effect is good. When being used for the heavy metal polluted soil, the chemical eluent is characterized by low cost and high restoration, etc.; the chemical eluent used by the invention can adjust parameters such as the density of the eluent, processing time and liquid-solid ratio, etc. according to different variety and content of the heavy metals contained in the polluted soil. The soil after the leaching treatment is washed by water, and then can be refilled in the original position; therefore, no secondary pollution can be caused.

Description

technical field [0001] The invention relates to a chemical washing agent capable of simultaneously removing heavy metals and arsenic in soil and a restoration method thereof. Background technique [0002] Due to the hidden, long-term and irreversible characteristics of soil heavy metal pollution, it is difficult to control once it is polluted. Over the past ten years in my country, phytoremediation technology for heavy metal-contaminated soil has attracted a lot of attention due to its low cost and environmental friendliness. However, heavy metal hyperaccumulating plants have the characteristics of slow growth, low biomass, special growth environment, limited by local climatic conditions and available plant species, and it is difficult to meet the requirements of rapid treatment of industrial wasteland. Therefore, the soil leaching technology with wide adaptability and rapidity has always been a difficult and hot research topic in the world, and has been widely studied in t...

AI Technical Summary

Problems solved by technology

There is no report on the remediation method of contaminated soil containing arsenic, cadmium, copper, lead, zinc, etc. that exist in the form of anions at the same time.

There is also no report that a kind of leaching agent can simultaneously treat the polluted soil containing multiple heavy metals in the form of anions and cations.

There are few studies on soil leaching technology in our country, and they are all in the stage of small laboratory tests, and there is no demonstration project yet.