Degradation of plastic micro-beads in wastewater by ultrasonic iron-nitrogen doped titanium dioxide

Abstract

The invention provides degradation of plastic micro-beads in wastewater by ultrasonic iron-nitrogen doped titanium dioxide, wherein a photocatalyst is ultrasonic iron-nitrogen doped titanium dioxide hollow microspheres, the particle size of the ultrasonic iron-nitrogen doped titanium dioxide hollow microsphere is 100-600 nm, the pore diameter of the microsphere is 5-15 nm, and the specific surfacearea of the ultrasonic iron-nitrogen doped titanium dioxide hollow microsphere is 200-400 m<2> / g. According to the invention, the iron-nitrogen doped titanium dioxide hollow microspherete photocatalyst is prepared by using trabutyl titanate as a titanium source and ferric nitrate and carbamide as an iron source and a nitrogen source through a two-step process of an ultrasonic hydrothermal methodand a calcining method, and the photocatalytic reaction of the photocatalyst and the ultrasonic degradation process are combined to synergistically degrade plastic micro-beads in wastewater, so that excellent photocatalytic degradation efficiency is achieved, and the method has huge application value in the field of degradation treatment of the plastic micro-beads in the wastewater.

Description

technical field [0001] The invention relates to the technical field of photocatalyst preparation and wastewater treatment, in particular to a method for degrading plastic microbeads in wastewater by ultrasonic iron-nitrogen-doped titanium dioxide. Background technique [0002] Plastic Microbeads (Plastic Microbeads) usually refer to plastic solids with a particle size of less than 5 mm and are insoluble in water, usually made of organic polymers (such as polyethylene, polypropylene, polymethyl methacrylate, polystyrene, polyurethane, Nylon) is often used as fillers, film-forming agents, thickeners and suspending agents in personal care and cosmetics. Generally speaking, plastic microbeads are difficult to biodegrade and have a half-life of hundreds of years. Not only will they pollute Environment, poses a threat to marine life, affects ecological balance, and may also affect human health through the food chain. The current wastewater treatment equipment has a very limited ab...

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Problems solved by technology

[0002] Plastic Microbeads (Plastic Microbeads) usually refer to plastic solids with a particle size of less than 5 mm and are insoluble in water, usually made of organic polymers (such as polyethylene, polypropylene, polymethyl methacrylate, polystyrene, polyurethane, Nylon) is often used as fillers, film-forming agents, thickeners and suspending agents in personal care and cosmetics. Generally speaking, plastic microbeads are difficult to biodegrade and have a half-life of hundreds of years. Not only will they pollute Environment, poses a threat to marine life, affects ecological balance, and may also affect human health through the food chain. The current wastewater treatment equipment has a very limited ability to filter out plastic microbeads. In addition to destroying the water environment with sewage discharge, plastic microbeads can also be deposited into In soil, polluted soil, water and soil pollution by plastic microbeads can further affect the ecological balance

[0003] As a photocatalyst, nano-titanium dioxide can use ultraviolet light as a light source to perform photocatalytic reactions with pollutants such as plastics, degrade the pollutants into small molecules of non-toxic substances, and avoid secondary pollution to the environment. It is limited to the ultraviolet region (<380 nm) and has the defects of high density, easy sinking in water, low light source utilization rate and difficult recovery, which limits its application and promotion, so it is necessary to modify titanium dioxide photocatalyst

[0004] The invention patent application with the application number CN104492469A discloses a preparation method of iron-nitrogen-doped titanium dioxide composite photocatalyst. The preparation method first prepares titanium dioxide powder, then adds triethylamine to it, desolventizes through a rotary evaporator, and then dries A nitrogen-doped titanium dioxide composite photocatalyst is obtained, and under the action of ferric nitrate, the product iron nitrogen doped titanium dioxide composite photocatalyst is finally obtained, but the photocatalyst prepared by this method has the defects of high density and low light source utilization in wastewater

[0005] The invention patent with application number CN201810114902.6 discloses a kind of N-TiO with hollow structure 2 The preparation method of photocatalyst, this method uses the ionic liquid of 1-butyl-3-methylimidazolium tetrafluoroborate as solvent, microwave absorbing agent and fluorine source, nitrogen source, under the condition of microwave-assisted heating, synthesize hollow structure of titanium dioxide, and then place the obtained mixture in an inert gas atmosphere for calcination, and use the nitrogen source in the ionic liquid to synthesize TiO 2 Doping modification to prepare N-TiO with a hollow structure 2 , but the photocatalytic efficiency of the photocatalyst has not been significantly improved

[0006] The invention patent with the application number CN201511030931.7 discloses a Fe, N co-doped titanium dioxide mesoporous microsphere array visible light photocatalyst and its preparation method. The preparation method uses a two-step template method to prepare three-dimensional ordered iron and nitrogen co-doping Mesoporous TiO 2 Microsphere array, but this method has the disadvantages of high density and low light source utilization in wastewater

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