Photocatalytic Technology: The "Nemesis" Of Organic Pollutants

< p > Wang Sheng, Professor of materials and textile School of Zhejiang Sci-Tech University, and his research team on photocatalytic nanomaterials have been working hard to find effective ways to remove organic pollutants, and finally found the "Nemesis" against organic pollutants, and successfully applied them to the governance of the Tong Wang River in Ningbo.

"Avoiding the two pollution is the biggest highlight of photocatalytic technology."

Wang Sheng introduced that the biggest characteristic of photocatalytic technology is to convert organic matter into carbon dioxide and water and other inorganic substances safely under the condition of sunlight. The whole process does not need other chemical AIDS, the reaction conditions are mild, and there is no two pollution.

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< p > "compared with inorganic substances such as metal ions, the organic matter in water is difficult to be treated with the existing treatment technology, and the photocatalysis technology appeared in the 70s of the last century showed an unparalleled advantage.

To control water, we must restore the balance of water ecology. The key is to remove the complex and refractory organic matter in water.

Wang Sheng said that the traditional physical adsorption method, chemical oxidation method, < a href= "http:// www.sjfzxm.com/news/index_c.asp" > microbial method < /a > and high temperature incineration method all have such or other defects, such as low efficiency, easy to produce two pollution, narrow scope of application and high energy consumption.

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< p > according to Wang Sheng, the photocatalyst represented by nanometer titanium dioxide has strong oxidizing and strong reducibility due to its strong positive oxidation and strong reduction caused by photoexcitation. It can decompose almost all organic pollutants into carbon dioxide. The whole process does not need other chemical AIDS, mild reaction conditions, no two pollution and low operation cost, and it can make full use of cheap and environment-friendly sunlight as the reaction light source.

This method of photocatalytic decomposition of < a href= "http://? Www.sjfzxm.com/news/index_c.asp > > /a > /a has been widely studied in the field of wastewater purification and exhaust purification, and has wide application prospects.

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< p > however, with the deepening of the research, Wang Sheng has encountered a dilemma. This is also a bottleneck that has long puzzled the application of photocatalytic technology to practical application.

Such a "convenient" photocatalytic technology is facing a practical application problem: no suitable container can be found to install photocatalyst.

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< p > it is understood that the strong redox of titanium dioxide excited by ultraviolet light has no selectivity for decomposed objects. If directly compounded into organic matrix materials, the service life of organic matrix materials will be shortened. If the titanium dioxide is directly dissolved in the reaction solution, a suspension system will be formed. Even if titanium dioxide has good reaction efficiency to organic pollutants, it will cause two pollution due to the failure to recover titanium dioxide.

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< p > "photocatalytic technology has not been popularized widely in Japan since its birth in Japan in 1972. That is why."

Wang Sheng said that scientists have never been able to find a suitable container for photocatalysts.

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< p > with constant attempts and efforts, an unusual way of thinking becomes clearer in Wang's mind: making a freely accessible nano space between silicon dioxide layer and nano titanium dioxide, and using this space as an effective reaction place to accelerate the reaction.

Through extensive experiments, Wang Sheng and his team finally succeeded in preparing hollow interfacial photocatalyst - titanium dioxide coated with core and shell structure.

The hollow structure avoids the shielding of the surface active point, thereby greatly improving its catalytic activity, and achieves the purpose of protecting the organic catalytic carrier without damaging the catalytic capacity.

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< p > Wang Sheng said that they have worked with enterprises to build a pilot plant for core and shell hollow nanomaterials, and have achieved practical results in the degradation of cyanobacteria and degradation of landfill leachate.

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< p > with the "container" problem being solved, the photocatalytic sewage treatment technology of Wang Sheng team was finally successfully applied to the regulation of Tong Wang River in Ningbo.

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< p > it is understood that the Wang Sheng team and Ningbo Tianhe ecological waterscape Technology Co., Ltd. are working together to regulate the Tong Wang River, and use and verify the advanced photocatalytic treatment technology that they have developed.

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< p > "to form various forms of photocatalytic special fibers, such as" artificial grass blanket "," artificial net bed "and so on, and place them in water.

Wang Sheng said, in this way, under the sunlight, the organic pollutants causing black and stink of the river will be cleaned up soon.

After that, microbes and submerged plants will be treated. The two technologies are mainly for other pollutants such as nitrogen, phosphorus and heavy metal ions.

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< p > according to the relevant departments, the main technical indicators of Tong Wang River will reach the category III standard of surface water, and the pparency reaches at least 1.5 meters. At the same time, it also pioneered the first successful application of photocatalytic technology to control river water in China.

It is reported that this safe and efficient photocatalytic water ecological restoration technology will play an important role in the "five water co governance" in Zhejiang province.

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