Double-layer persulfate sustained-release material and its preparation method

Patent metadata

Field	Value
Publication number	US-9457388-B2
Application number	US-201414334879-A
Country	US
Kind code	B2
Filing date	Jul 18, 2014
Priority date	Jul 18, 2013
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

The present invention involves a persulfate-release material used in the filler of permeable reactive barrier (PRB). This material presents double-layered structure characteristic: inner- and outer-layers are consisted of persulfate, cement, sand and water with different mass ratio. Two different types of moulds are used for the regulation of the shape of the two-layer structures, which guarantees the stability and reproducibility of its structures and properties. During the whole released process, the released rate become more uniform and stable by the use of this material. During the whole service period, the change of the released rate is very slow, and the service lifetime can be 1-10 years. This invention can both reduce the initial released rate and improve the later released rate, and thus the whole released rate can be more uniform, which can be an important method to promote the efficiency of the persulfate toward engineering application.

First claim

The invention claimed is:

1. A preparation method for a double-layer persulfate sustained-release, comprising:
(1) preparing an inner-layer material including mixing persulfate, cement, sand and water uniformly in a mass ratio of 1:(0.6-1):(1.5-2.5):(0.5-1);
(2) filling the inner-layer material prepared in step (1) into an inner-layer mould and removing the inner-layer mould after the inner-layer material was fixed into an inner-layer structure, wherein the inner-layer structure has a cubic structure with a side length of 1-8 cm;
(3) preparing an outer-layer material including mixing persulfate, cement, sand and water uniformly in a mass ratio of 1:(2-3):(1.2-1.5):(0.8-1.2); and
(4) embedding the inner-layer structure into the centre of an outer-layer mould and filling in the outer-layer mould with the outer-layer material prepared in step (3) to obtain a structure, wherein the structure obtained is a cube with a side length of 2-10 cm, and the structure obtained is further solidified for 1-2 days.

Assignees

• Chinese Res Acad Env Sciences

Inventors

• Xi Beidou
• Jiang Yonghai
• Yang Yu
• Li Mingxiao
• Ma Zhifei
• Zhang Lieyu
• Li Min
• Chen Fangyi

Classifications

• B28B1/008

  made from two or more materials having different characteristics or properties (casting for producing layered articles B28B1/16; feeding several succesive layers, optionally of different materials B28B13/022; coating B28B11/04; applying material to surfaces to form a permanent layer thereon B28B19/00) · CPC title

• B09C1/002 Primary

  involving in-situ ground water treatment · CPC title

• C02F2103/06

  Contaminated groundwater or leachate · CPC title

• C02F1/722

  Oxidation by peroxides · CPC title

• C02F2305/023

  Reactive oxygen species, singlet oxygen, OH radical · CPC title