Composite material for catalytic treatment of contaminated soil and water and catalytic treatment method thereof

Patent metadata

Field	Value
Publication number	US-10435317-B2
Application number	US-201715447038-A
Country	US
Kind code	B2
Filing date	Mar 1, 2017
Priority date	Dec 23, 2016
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

Metal-free materials, manufacturing thereof, method using thereof for (in-situ or ex-situ) catalytically treating contaminated soil or waters, including remediation of groundwater contaminated by haloalkenes, haloalkanes, nitro-compounds, and nitrophenol using sulfide as a reductant. Metal-free materials are manufactured with industrial scrap syrup or biomass. Method using the metal-free materials for in-situ treatment consists with the processes of adding materials into the contaminated medium, introducing sulfide into the contaminated medium, and reductive reacting contaminants with sulfide catalyzed by the metal-free materials. Specially, the formation of in-situ reaction zone is the key point of in situ treatment by retaining the catalyst in the contaminated medium. Method using the metal-free materials for ex-situ treatment consists steps of adding materials and sulfide into the contaminated fluid, intermingling the contaminated fluid with materials in a vessel, reacting contaminants with sulfide catalyzed by the metal-free material.

First claim

What is claimed is:

1. A method for an in situ remediation of a contaminated medium, comprising: dispersing metal-free catalyst particles into an aqueous solution with sulfide and obtaining a mixture; injecting the mixture of the metal-free catalyst particles and the aqueous solution with sulfide into permeable zones of the contaminated medium; retaining the metal-free catalyst particles in the contaminated medium when the metal-free catalyst particles go through the contaminated medium; forming an in situ reaction zone and reacting the contaminated medium continuously; and increasing the rate of diffusion of contaminants of less permeable zones;
wherein the metal-free catalyst particles are prepared by a method comprising the following steps:
a) drying a biomass in the air to obtain dehydrated biomass;
b) carbonizing the dehydrated biomass at 800° C. in a tube furnace under nitrogen flow for 6 h;
c) recovering the carbonized biomass by treating with 4 mol/L HNO 3 solution at 70° C. for 6 h, washing with deionized water, and drying at 110° C. to obtain a sample; and
d) treating the sample at 800° C. under nitrogen flow for 6 h to produce the metal-free catalyst particles.

2. The method of claim 1 , wherein the biomass comprises corn stalk, sorghum stalk, alfalfa, wormwood, soybean hull, and branches of catalpa tung.

3. The method of claim 2 , wherein the biomass comprises alfalfa or wormwood.

4. The method of claim 1 , wherein the aqueous solution with sulfide comprises the metal-free catalyst particles in aqueous solution with sodium sulfide, potassium sulfide, calcium sulfide, sodium sulfite or sodium hyposulfate.

5. The method of claim 1 , wherein the weight ratio between the metal-free catalyst particles and the sulfide is 1-1.2:20-30.

6. The method of claim 1 , wherein the average diameter of the metal-free catalyst particles ranges from 0.1 um to 1 um.

7. The method of claim 1 , wherein the contaminated medium comprises one or more of haloalkenes, haloalkanes, nitro-compounds, nitrophenol, chloronitrobenzene or heavy metals.

8. The method of claim 1 , further comprising: adding a cosolvent to the contaminated medium.

Assignees

• Univ Jilin

Inventors

• Liu Na
• Ding Longzhen
• Zhang Pengpeng

Classifications

• C02F2101/38

  containing nitrogen · CPC title

• B01J27/24

  Nitrogen compounds · CPC title

• C02F2103/007

  Contaminated open waterways, rivers, lakes or ponds · CPC title

• B01J37/084

  Decomposition of carbon-containing compounds into carbon · CPC title

• C02F2103/06

  Contaminated groundwater or leachate · CPC title