Patent Application
20140183138
1. Field of the Invention
The present invention relates to compositions for treating wastewater, and particularly to a method and nanocomposite for treating wastewater, the nanocomposite being a mixture of multi-wall carbon nanotubes and ferrite nanoparticles.
2. Description of the Related Art
Due to a wide variety of manufacturing processes, contaminated wastewater has become a great concern, not only to the environment, but as a potential toxin for both human and animal life which may be exposed to the wastewater. Aniline is a particularly toxic byproduct often found in wastewater. Aniline-containing wastewater is presently treated using photo-decomposition, electrolysis, adsorption, oxidation, biodegradation, and combinations of these processes. Each, however, is relatively inefficient and is costly, both in terms of resources and financial costs.
There is great interest in the use of multi-walled carbon nanotubes for the removal of pollutants from water. However, the formation of multi-walled carbon nanotubes composites can be difficult, and the removal thereof from the water being treated is also quite difficult. Magnetic separation is an efficient process for the removal of nanocomposites from water, as well as pollutants seeded with a magnetic material such as magnetite (Fe3O4), using a high gradient magnetic separator. Thus, it would be desirable to provide a nanocomposite with magnetic properties, and which also efficiently adsorbs organic matter, such as aniline, from wastewater.
Thus, a method and nanocomposite for treating wastewater solving the aforementioned problems is desired.
The method and nanocomposite for treating wastewater relates to a method of treating wastewater containing organic matter with a magnetic nanocomposite and a method of making the magnetic nanocomposite. In order to make the magnetic nanocomposite, nickel nitrate, iron nitrate and citric acid are dissolved in deionized water to form a metal nitrate and citric acid solution. An ammonia solution is selectively added to the nitrate and citric acid solution to form a pH balanced solution having a pH of 7.0. The pH balanced solution is then heated to form a gel, which is dried and then ignited to form a powdered NiFe2O4 combustion product. The powdered NiFe2O4 combustion product is then mixed with multi-walled carbon nanotubes to form a magnetic nanocomposite, such that the magnetic nanocomposite includes approximately 75 wt % of the multi-walled carbon nanotubes and approximately 25 wt % of the NiFe2O4.
The magnetic nanocomposite may then be mixed into a volume of aniline-containing wastewater for adsorption of the aniline by the nanocomposite. A magnetic field is then applied to the mixture to magnetically separate the magnetic nanocomposite and the adsorbed aniline from the wastewater, and the magnetic nanocomposite and the adsorbed aniline may then be easily removed from the wastewater.
These and other features of the present invention will become readily apparent upon further review of the following specification and drawings.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
The method and nanocomposite for treating wastewater relates to a method of treating aniline-containing wastewater with a magnetic nanocomposite, to the nanocomposite, and to a method of making the magnetic nanocomposite. The nanocomposite includes nanoparticles of magnetite (NiFe2O4), which are made by a sol gel process. In order to make the magnetic nanocomposite, nickel nitrate [Ni(NO3)2.6H2O], iron nitrate [Fe(NO3)2.9H2O] and citric acid (C6H8O7.H2O) are dissolved in deionized water to form a metal nitrate and citric acid solution. The metal nitrates and the citric acid are provided in a 1:1 molar ratio.
An ammonia solution is selectively added to the metal nitrate and citric acid solution to form a pH balanced solution having a pH of 7.0. The pH balanced solution is then heated at a temperature of approximately 80° C. to form a gel, which is dried and then ignited to form a powdered NiFe2O4 combustion product. When the dried gel is ignited at any point, the combustion rapidly propagates forward and is left to completely combust, forming a loose powder of nanoparticle size. Preferably, complete ignition is performed in a muffle furnace at a temperature of approximately 700° C. Complete combustion is found to take approximately two hours.
The powdered NiFe2O4 combustion product is then thoroughly mixed with multi-walled carbon nanotubes to form a magnetic nanocomposite, such that the magnetic nanocomposite is a homogenous mixture including approximately 75 wt % of the multi-walled carbon nanotubes and approximately 25 wt % of the NiFe2O4.
The magnetic nanocomposite may then be mixed into a volume of aniline-containing wastewater for adsorption of the aniline by the magnetic nanocomposite. A magnetic field is then applied to the mixture to magnetically separate the magnetic nanocomposite and the adsorbed aniline from the wastewater, and the magnetic nanocomposite and the adsorbed aniline may then be easily removed from the wastewater.
The NiFe2O4 on its own has a saturation magnetization of 30.2 EMU per gram, a remanent magnetization of 11.70 EMU per gram, and a magnetic coercivity of 162 Oe (measured by a vibrating sample magnetometer). The multi-walled carbon nanotubes, on their own, have a saturation magnetization of 0.1 EMU per gram, a remanent magnetization of 0.04 EMU per gram, and a magnetic coercivity of 68 Oe. The mixed nanocomposite has a saturation magnetization of 3.2 EMU per gram, a remanent magnetization of 1.15 EMU per gram, and a magnetic coercivity of 164 Oe.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
