An ultra-stable mineralizer and its application in repairing heavy metal polluted soil

Abstract

The invention discloses an ultra-stable mineralizer and its application for repairing heavy metal polluted soil. The ultra-stable mineralizer is prepared by rapidly adding an environmentally friendly metal ion-containing solution and a precipitant to a micro-liquid membrane reactor; during use, it can be implemented by means of sowing or slurry spraying. Ultra-stable mineralizer is slightly alkaline and will not cause soil acidification, so it is very suitable for southern areas with serious soil pollution. Compared with the adsorbent, the ultra-stable mineralizer prepared by the present invention has very high activity, and can quickly anchor heavy metal ions such as copper, cadmium and manganese in the soil to the ultra-stable by isomorphic substitution or dissolution-reconstruction. In the crystal lattice of the stabilizing agent, the mineralization forms hydrotalcite with a more stable structure, and it is extremely difficult for heavy metal ions to dissociate from it, and it is in a state of ultra-stable mineralization. In addition, due to the matching rule of ionic radius, the ultra-stable mineralizer prepared by the invention also shows good selectivity, and has a very good effect in the in-situ remediation of heavy metal pollution in soil.

Description

technical field [0001] The invention belongs to the field of inorganic material synthesis and soil remediation, and in particular relates to an ultra-stable mineralizer and its application in remediating heavy metal polluted soil. Background technique [0002] Soil is one of the basic elements to maintain the national economy and people's livelihood. However, due to the irregular disposal of pollutants, geological changes and other reasons, the situation of soil pollution in my country is severe. Data released by the state in 2014 showed that the proportion of contaminated soil in the country was 16.1%, of which agricultural land accounted for 19.4% (about 400 million mu), and some typical plots and surrounding land accounted for as much as 36.3%. The harm to human health caused by polluted soil is shocking, such as "rice with excessive cadmium". On August 31, 2018, my country's first soil law, the Soil Pollution Prevention and Control Law of the People's Republic of China...

AI Technical Summary

Problems solved by technology

[0004] Passivation agent is the core of in-situ passivation technology. Common passivation agents on the market, such as organic carbon, sepiolite, palygorskite, etc., mainly rely on the electrostatic attraction and surface adsorption of materials to passivate heavy metal ions. , this passivation method has a weak force and is easily affected by external conditions, resulting in the desorption of pollutants and the formation of pollution again.

In addition, due to the complexity of soil composition and the diversity of pollution sources, not only heavy metal ions but also a large number of other ions that are harmless or even beneficial exist in polluted soil, and various ions interfere with each other. Implementing passivation of heavy metal ions poses challenges

Furthermore, due to the large total area of ​​soil pollution, the economic cost must be considered while ensuring the repair effect. Conventional passivators are cheap in unit price but have small adsorption capacity, and are easy to desorb, which makes the amount and frequent use lead to a total High cost; MOF, MXene and other materials with excellent adsorption effect have cumbersome preparation process, harsh conditions, high cost, and it is difficult to achieve large-scale use

Images