Arsenic contaminated soil remediation method

Abstract

The invention discloses an arsenic contaminated soil remediation method. The method comprises steps as follows: firstly, soil of arsenic contaminated land parcel is digged out and treated by a crusher, and soil particles with size being 2-5 mm are obtained; a sodium citrate solution is prepared, the prepared sodium citrate solution is added to the soil particles in a ratio being 1L / kg, mixing andstirring are performed for 30 min, and a soil and solution mixture is obtained; a hydrogen iodide solution is added to the soil and solution mixture and stirred sufficiently, arsenate ions in the soilor arsenic acid and iodide ions react under the acidic condition to generate iodine and arsenious acid or arsenite; the obtained soil is filtered, fed into a vacuum heat treatment device, heated to 460 DEG C or higher and subjected to heat insulation for 30 min, arsenious acid or arsenite in the soil are converted into arsenious oxide, elementary iodine and arsenious oxide in the soil are volatilized from the soil and separated from the soil, then the soil is cooled to the room temperature, and remediated clean soil is obtained. The method has the advantages of being simple, feasible and goodin remediation effect, and arsenic can be removed from the soil.

Description

Technical field: [0001] The invention relates to the technical field of soil pollution restoration, in particular to a method for restoration of arsenic-contaminated soil. technical background: [0002] There are 1.8 to 2 million cancer cases and 1.4 to 1.5 million deaths in the country every year, which is related to the excessive pollution of agricultural products to a certain extent. Soil heavy metal pollution has gradually become the focus of public attention. [0003] Soil arsenic pollution mainly comes from atmospheric deposition, sewage irrigation and spraying of arsenic-containing pesticides. The content of arsenic in China's surface soil is distributed in a north-south direction. The arsenic content in the soil at higher altitudes is higher than that at lower altitudes. It decreases from the Qinghai-Tibet Plateau, Southwest China, and South China to the Northeast. Geochemical linkages. Among them, in a local area, as the topography goes from high to low, the cont...

AI Technical Summary

Problems solved by technology

However, there are generally problems such as low restoration efficiency, high treatment cost, and inability to effectively remove soil heavy metal pollution sources.