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Synthesis of Modified Maghemite and Jacobsite Nanoparticles磁赤鐵礦和錳鐵礦納米材料的合成和修復及其在工業廢水重金屬處理與再生上的應用

In heavy metal producing industries such as electroplating, metal-finishing, steels, chemical manufacturing, leather tanning, the handling of effluent has always been the main concern. Improper treatment to the wastewater before it is drained out into rivers or oceans will cause a great pollution and can endanger the marine life.

The present invention provides methods for the production of the maghemite nanoparticles, and their application for removing Cr (VI), Cu (II), and Ni (II) selectively from wastewater. It is a new system combining magnetic separation with nano-particle adsorption technique. Since the absorbent has high surface area and ferromagnetic properties, it therefore acquires high adsorption capacity for heavy metal and magnetic separation. Most of the magnetic materials applied nowadays for wastewater treatment have the disadvantages of small adsorption capacity due to large size. The nano-sized magnetic particles in this invention overcome this problem and can produce larger specific surface area. Thereby, it results in high adsorption capacity for metal removal.

The high adsorption capacity is also due to high active sites, very short adsorption time resulted from external adsorption, simple and rapid separation of magnetic nanoparticles from treated water with a magnet, efficient recovery of adsorbent, and reuse of heavy metals without secondary pollutants generated.

The invention can be used in industrial wastewater treatment and in improving the manufacturing process in metal processing industries.
Technology Benefits
1. Superior removal capacity
2. Lower capital and operating costs
3. Easier technical adaptation and maintenance
4. Environmental-friendly system
Technology Application
- Industrial wastewater treatment
- Improvement on manufacturing process in metal processing industries
- Demand and consumption of heavy metals in industries
Supplementary Information
Patent Number: US7622423B1
Application Number: US2006520149A
Inventor: Hu, Jing | Lo, Man Chi | Chen, Guohua
Priority Date: 12 Sep 2006
Priority Number: US7622423B1
Application Date: 12 Sep 2006
Publication Date: 24 Nov 2009
IPC Current: B01J002002
US Class: 502406 | 423493
Assignee Applicant: The Hong Kong University of Science & Technology
Title: Synthesis of modified maghemite and jacobsite nanoparticles
Usefulness: Synthesis of modified maghemite and jacobsite nanoparticles
Summary: The nanoparticle is useful for removing and recovering heavy metals from industrial wastewater i.e. the aluminum-doped or modified maghemite nanoparticles are useful to adsorb heavy metals such as hexavalent chromium found in wastewater.
Novelty: Preparing e.g. metal-doped maghemite nanoparticles, useful to e.g. recover heavy metals from industrial wastewater, comprises dissolving hydrated ferrous- and ferric-chloride in water, adding base, isolating nanoparticles and purifying
Sub Category
Chemical/Material Application
Application Date
12 Sep 2006
Application No.
US 11/520149
Patent Information
US 7622423
ID No.
Hong Kong

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