Preparation method of soil remediation agent based on phosphorus recovery product and soil remediation method

Abstract

The invention discloses a preparation method of a soil remediation agent based on a phosphorus recovery product and a soil remediation method. The soil remediation method comprises the following steps that a, adding a nitrogen source and a magnesium source or a potassium source and the magnesium source into phosphorus-containing wastewater, adjusting the pH value of the wastewater to be higher than 7, colecting precipitates after precipitation reaction, and obtaining the phosphorus recovery product after drying; wherein the molar ratio of N or K : P : Mg is 10: 1: 1; and b, doping the phosphorus recovery product and plant ash into water-containing heavy metal contaminated soil, uniformly mixing, and completing soil remediation after a heavy metal passivation process. The phosphorus recovery product is used as a soil heavy metal passivator, the cation exchange capacity of the passivator in polluted soil is increased, release of phosphorus is promoted, the activity of heavy metal in the soil is reduced, meanwhile, the phosphorus recovery product has low solubility, soluble phosphate is replaced by the phosphorus recovery product, the problem of soil acidification during application can be reduced, phosphorus leaching can be reduced, and eutrophication of a surface water body is reduced.

Description

technical field [0001] The invention belongs to the technical field of soil remediation, and in particular relates to a method for preparing a soil remediation agent based on phosphorus recovery products and a soil remediation method. Background technique [0002] Soil heavy metal pollution refers to human activities, the content of trace harmful elements in the soil exceeds the background value, and the excessive content caused by excessive deposition is collectively referred to as soil heavy metal pollution. Heavy metal pollution in soil usually comes from the waste water discharged by mining, smelting and other industrial and mining enterprises, improper disposal of waste residues and farmland irrigation with substandard waste water. Through surface runoff, leaching and plant absorption, it is enriched to the human body through the food chain, endangering health. Heavy metal pollution in soil has the characteristics of hidden, long-term and irreversible, which has caused ...

AI Technical Summary

Problems solved by technology

However, the application of soluble phosphates (such as phosphoric acid, diammonium hydrogen phosphate, etc.) will cause soil acidification, and excessive phosphorus leaching may become a potential source of surface water eutrophication

The use of insoluble phosphates (such as tricalcium phosphate and apatite, etc.) will bring about the precipitation of a large amount of apatite minerals, which will adversely affect the soil structure