A kind of modifier for complex heavy metal polluted soil and its preparation and use method

Abstract

The invention discloses an ameliorant for compound heavy metal polluted soil and preparation and an application method thereof. The ameliorant is composed of the following materials (by weight): 30-55% of steel slag powder, 20-50% of calcium superphosphate powder and 5-30% of phosphate-loaded biochar. The invention has the following advantages: firstly, the ameliorant can remarkably reduce mobility and toxicity leaching content of heavy metal in heavy metal polluted soil and is especially applicable to acidic pollution sites with high content of heavy metal and various kinds of pollutants; after the polluted soil is ameliorated, resource utilization of the soil as an environment-friendly material can be achieved, and the environmental risk of secondary development and utilization of the pollution sites is remarkably reduced; the raw materials of the ameliorant are easily available; cost is low; and the ameliorant is simple to prepare and convenient to use, has stable effects, and can be promoted and applied at large scale in solidification and stabilization restoration of composite pollution sites.

Description

technical field [0001] The invention relates to the field of environmental geotechnical engineering, in particular to a modifier for composite heavy metal polluted soil and a preparation and use method. Background technique [0002] With the adjustment of urban functions and urban layout in our country, enterprises originally located in urban centers and suburbs, such as chemical plants, metal smelting plants, and electroplating plants, have gradually shut down or retreated from cities to parks. However, the production process of industries and enterprises for many years , A large amount of pollutants have accumulated in the land left after their relocation, which not only brings resistance to the efficient use of the leftover land, but also brings serious safety hazards to the surrounding environment. In recent years, the "Soil Pollution Prevention and Control Action Plan" (Soil Ten Articles) promulgated by the government also regards the restoration of contaminated soil as...

AI Technical Summary

Problems solved by technology

Commonly used modifiers mainly include materials such as cement, lime, and phosphate, which have a good effect on the solidification and stabilization of heavy metals, but there are also a large number of disadvantages, such as high energy consumption for cement production and high greenhouse gas emissions; lime and phosphate are Non-renewable natural minerals, high cost, etc.; and a large amount of phosphate will seriously change the soil structure and further cause phosphorus pollution of groundwater and surface water

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