Soil heavy metal composite passivator and its preparation method, use method and application

Patent metadata

Field	Value
Publication number	US-10501690-B2
Application number	US-201816181037-A
Country	US
Kind code	B2
Filing date	Nov 5, 2018
Priority date	Nov 15, 2017
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

A soil heavy metal composite passivator and its preparation method, use method and application. The passivator is a powder particle obtained mainly by mixing modified palygorskite, biomass charcoal, quicklime and fungus residue in a mass ratio of 1:(0.3˜0.5):(0.5˜0.8):(0.2˜0.4), with an average particle size of 0.5˜1 mm. The invention further provides preparation and use methods for the above soil heavy metal composite passivator. The soil heavy metal composite passivator according to the invention can effectively passivate heavy metal pollution in farmland soil and reduce bioavailability of various heavy metals in soil so as to recover ecological and industrial functions of the soil and improve crop quality. Material selected in the present invention are safe and environmental-friendly, realized “waste control by waste itself”, have long service life, and do not cause secondary pollution to soil.

First claim

What is claimed is:

1. A soil heavy metal composite passivator obtained mainly by mixing modified palygorskite, biomass charcoal, quicklime and fungus residue uniformly in a mass ratio of 1:(0.3˜0.5):(0.5˜0.8):(0.2˜0.4).

2. The soil heavy metal composite passivator according to claim 1 , wherein the modified palygorskite is obtained by modifying palygorskite through a silane coupling agent;
the said biomass charcoal is obtained by pressurized pyrolysis of poultry feathers;
the fungus residue is obtained by composting a medium obtained from cultivation of edible fungi.

3. The soil heavy metal composite passivator according to claim 1 , wherein the passivator is in the form of powder particles with an average particle size of 0.5˜1 mm.

4. The soil heavy metal composite passivator of claim 2 , where the silane coupling agent is chloropropyltrimethoxysilane.

5. A method for remediating heavy metal-polluted soil, the method comprising treating the heavy metal-polluted soil with soil heavy metal composite passivator of claim 1 .

6. The method of claim 5 wherein treating the heavy metal-polluted soil comprise:
mixing the soil heavy metal composite passivator with heavy metal-polluted soil uniformly in a mass ratio of 1:(10˜50) to provide a contaminated soil mixture;
adding water to the contaminated soil mixture so that the water retention rate was 60˜65%; whereby, after 5˜30 days of reaction, heavy metal ions in the contaminated soil mixture are converted into more stable organic bound and residual forms.

7. A method for preparing a soil heavy metal composite passivator, comprising: mixing palygorskite modified through a coupling agent, biomass charcoal obtained by pyrolysis, quicklime, and composted fungus residue uniformly in a mass ratio of 1:(0.3˜0.5):(0.5˜0.8):(0.2˜0.4).

8. The method according to claim 7 , wherein preparing of the modified palygorskite comprises steps of:
(1) immersing palygorskite in an acid solution, filtering and drying;
(2) under protection of N 2 , subjecting the dried palygorskite to coupling reaction in an organic solution containing a silane coupling agent;
(3) filtering the resultant, washing with an organic solvent and drying, and then, pulverizing into particles with an average particle size of 0.5˜1 mm for use.

9. The method according to claim 7 , wherein preparing of the biomass charcoal comprises steps of:
(1) placing pretreated poultry feathers in a crucible for compacting, sealing and pressurized pyrolysis, wherein the poultry feathers are selected from one or more of chicken feathers, duck feathers and goose feathers;
(2) crushing the pyrolysis resultant into particles with an average particle size of 0.5˜1 mm for use.

10. The method according to claim 7 , wherein preparing of the fungus residue comprises steps of:
(1) composting and decaying a medium obtained from cultivation of edible fungi;
(2) drying and pulverizing the decayed compost into particles with an average particle size of 0.5˜1 mm for use.

11. The method according to claim 10 , wherein in the step (1), during a first period of composting, compost is turned over once a day; thereafter, during a later second period of composting, the compost is turned over once every 2˜3 days; and water is sprayed for the compost material while it is turned over each time so as to keep the moisture content at 60˜65%.

Assignees

• Chinese Res Acad Env Sciences

Inventors

• Jiang Yonghai
• Lian Xinying
• Xi Beidou
• Yang Yu
• Han Xu
• Huan Huan
• Xia Fu

Classifications

• B09C2101/00

  In situ · CPC title

• B09C1/08 Primary

  chemically · CPC title

• C09K17/44 Primary

  the inorganic compound being cement · CPC title

• C09K17/40 Primary

  containing mixtures of inorganic and organic compounds · CPC title