TECHNICAL FIELD

This present invention relates to a catalyst and a wastewater treatment method, and particularly, although not exclusively, to a catalyst having an amorphous matrix for use in industrial wastewater treatment.

BACKGROUND

Contamination occurring in aqueous-based solutions has become a serious concern over a long time. In particular, problems associated with the disposal of industrial wastewater have been drawing attentions. The substances in industrial wastewater may include organic matter and toxic pollutants posing negative impacts to the environment. The release of inadequately treated wastewater into natural water bodies may lead to degradation of aquatic ecosystems as well as public health problems.

Various methods may be used to treat wastewater. For example, before discharging of wastewater, a catalyst may be used to improve the efficiency to remove contaminants from wastewater and convert the contaminants into non-toxic substances that can be returned to the water cycle.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there is provided a catalyst comprising a metallic glass matrix comprising iron and phosphorous; wherein when the catalyst performs a catalytic reaction with a reactant, the metallic glass activates at least some of the reactant, and at least a portion of the catalyst at a surface of the metallic glass matrix transforms to a surface layer including a material property different from that of the metallic glass matrix being covered by the surface layer; and wherein the surface layer is arranged to maintain an amorphous structure of the metallic glass matrix and to facilitate the catalytic reaction and stability to occur at the surface layer.

In an embodiment of the first aspect, the catalyst has a mainly amorphous phase.

In an embodiment of the first aspect, the catalyst may have a trace of small nanocrystalline phase, or crystalline phase that is of nano-scale.

In an embodiment of the first aspect, an atomic component of the catalyst is iron-based.

In an embodiment of the first aspect, the atomic component of the catalyst at least comprises phosphorus.

In an embodiment of the first aspect, the atomic component of the catalyst is in the range of iron (60-85%), silicon (0-20%), boron (0-20%), phosphorus (1-20%) and carbon (0-10%).

In an embodiment of the first aspect, the material structure of the surface layer includes at least a porous structure being transformed during the catalytic reaction, such as during a wastewater treatment process.

In an embodiment of the first aspect, the porous structure may include a nanocrystalline phase.

In an embodiment of the first aspect, the porous structure is arranged to facilitate chemical reactants to pass therethrough.

In an embodiment of the first aspect, the material property includes a material composition.

In an embodiment of the first aspect, the surface layer has iron content lower than that in the metallic glass matrix.

In an embodiment of the first aspect, the surface layer further has oxide content higher than that in the metallic glass matrix.

In an embodiment of the first aspect, the material composition gradually changes from the portion of the metallic glass matrix to a portion of the surface layer.

In an embodiment of the first aspect, the surface layer comprises a top cover layer and an interlayer formed between the top cover layer and the metallic glass matrix.

In an embodiment of the first aspect, the interlayer includes a dense amorphous structure with an atomic density higher than that of the top cover layer includes the porous structure.

In an embodiment of the first aspect, the interlayer includes a plurality of adsorption sites arranged to facilitate the catalytic reaction to occur at.

In an embodiment of the first aspect, the plurality of adsorption sites includes a plurality of Fe sites each containing a first or a second neighbor of P atom.

In an embodiment of the first aspect, the catalyst further comprises a substantially flat shape.

In an embodiment of the first aspect, the reactant includes a treatment reagent and a target substance to be treated by the treatment reagent, and wherein the target substance is treated by the treatment reagent upon the metallic glass matrix activates the treatment reagent.

In an embodiment of the first aspect, the metallic glass matrix activates the treatment reagent by transforming the treatment reagent to radicals of the treatment reagent.

In an embodiment of the first aspect, the treatment reagent includes a persulfate and/or a peroxymonosulfate.

In an embodiment of the first aspect, treating the target substance by the activated treatment reagent occurs at the surface layer.

In an embodiment of the first aspect, the target substance includes waste water pollutants.

In accordance with a second aspect of the present invention, there is provided a method of fabricating a catalyst, comprising the steps of: melting an alloy comprising iron and phosphorous; and melt-spinning the melted alloy to form an amorphous structure of the metallic glass catalyst.

In an embodiment of the second aspect, the step of melting the alloy comprises arc-melting the alloy.

In an embodiment of the second aspect, the step of melt-spinning the melted alloy comprises further melting the melted alloy in a quartz crucible.

In an embodiment of the second aspect, the melted alloy is further melted under a temperature of 1200 to 1500° C.

In an embodiment of the second aspect, the step of melt-spinning the melted alloy further comprises ejecting the further melted alloy onto a rotated copper roll surface.

In an embodiment of the second aspect, the further melted alloy is ejected onto the rotated copper roll surface with a speed of 23 to 39 ms−1.

In an embodiment of the second aspect, the method further comprises the step of rapid quenching the further melted alloy ejected onto the rotated copper roll surface.

In an embodiment of the second aspect, an atomic component of the alloy is iron-based.

In an embodiment of the second aspect, the atomic component of the alloy at least comprises phosphorus.

In an embodiment of the second aspect, the atomic component of the alloy is in the range of iron (60-85%), silicon (0-20%), boron (0-20%), phosphorus (1-20%) and carbon (0-10%).

In an embodiment of the second aspect, the catalyst comprises a substantially flat shape.

In an embodiment of the second aspect, the catalyst is 10-80 μm in thickness.

In an embodiment of the second aspect, the catalyst is used in industrial wastewater treatment.

