Tianjin Northern Network News:Sunlight is the element for the survival of all things on the earth and the guarantee for human survival. For a long time, our utilization and research and development of sunlight have also made many contributions to social development, such as solar power plants, solar water heaters, light therapy in the medical field…
At Tianjin Vocational University, there is a team mainly composed of “post-00s”. In recent years, when they “dealt with” new pollutants in industrial wastewater, through continuous innovation and experimental verification, they invented a ” Solar photocatalyst”. Under the action of this catalyst, the degradation rate of new pollutants that are difficult to degrade in industrial wastewater can reach 90%, and there will be no secondary pollution.
Today, this young team has applied for 9 related technology invention patents, 4 of which have been authorized. At the end of October this year, their project competed with more than 400,000 projects from more than 2,000 undergraduate and vocational colleges across the country, and won the second prize in the 18th “Challenge Cup” national award. This achievement is also Tianjin higher vocational colleges have made another new breakthrough in the “Technological Invention Category” of the “Challenge Cup”, a heavyweight national competition.
Find a nemesis for “new pollutants”
A “teaching and mentoring” process spanning five years
“Our team has a nice name, which was given by the students themselves, and it’s called ‘Sunshine Green Energy’.” Speaking of the students’ achievements, project instructor Zhang Farong was full of pride. Among the current “Sunshine Green Energy” team, seven There are eight main members, the oldest is 21 years old, and the youngest is just a freshman, only 19 years old. “Our research started at the end of 2018, and it has been five years now. In fact, there were still a few ‘post-98s’ in the early stages of the research, but Throughout the research process, most people are born after 2000.”
The project researched by the “Sunshine Green Energy” team is called “Solar Photocatalyst – a Rising Star for Treating New Pollutants and Wastewater”. Zhang Farong went back to 2017 to study this topic. At that time, she had just resigned from the company where she had worked for nine years, entered Tianjin Vocational University, and became a teacher.
Zhang Farong (first from right) led his team to participate in the 18th “Challenge Cup” and their project won the second prize nationally.
After entering the school, relying on his doctoral degree from Nankai University and many years of corporate R&D experience, Zhang Farong joined some research projects, one of which was the treatment of new pollutants in pharmaceutical factory wastewater.
Risk prevention and control of new pollutants and pollution treatment are the focus of ecological and environmental protection during the 14th Five-Year Plan. The so-called new pollutants are toxic and harmful chemical substances with biological toxicity, environmental persistence, and bioaccumulation, which pose serious ecological and environmental risks. There are two main ways to deal with it. One is to add chemical reagents to the wastewater to allow pollutants to precipitate, but secondary pollution may occur during this process; the other is to use a filter membrane for physical filtration, but the pollutants that can be filtered out are very limited.
Zhang Farong said, “We were still working on a project on self-cleaning films for solar panels. That self-cleaning film added a reagent called titanium dioxide. Teacher Li Jiansheng in our group asked if we could try using titanium dioxide. So I started leading a research team.”
Zhang Farong, 44, has experienced the environmental pollution caused by industrial wastewater since he was a child. Zhang Farong’s hometown is in Shandong. When she was a child, there was a small river next to her house. The water was very clear. Every time her father picked her up from school, she would go to the river to pick up shells and catch fish. But later, a paper mill was built in the upper reaches of the river. Before long, the water in the creek turned brown and emitted an unpleasant smell. “Although the situation has improved now, new pollutants are constantly being discovered with the use of toxic and harmful chemicals. “
Nano titanium dioxide
The main component of the photocatalyst developed by the “Sunshine Green Energy” team is nano-titanium dioxide. Nano-titanium dioxide can produce a strong oxidizing free radical under the action of ultraviolet light. Zhang Farong likened this kind of free radical to be like a sharp knife, which can chop up toxic and harmful substances and eventually break them into carbon dioxide and water, so that new pollutants that are difficult to degrade in industrial wastewater can be completely oxidized and decomposed, and Nano titanium dioxide is non-toxic, harmless and low cost.
Zhang Farong said, “Now, in order to meet emission standards, some companies use the combustion method to treat sewage. The treatment cost per ton of sewage is as high as nearly 2,000 yuan, but with our photocatalyst, the treatment cost per ton is only dozens of yuan.”
To improve efficiency and recycling issues
They conducted hundreds of experiments
“During the research process, we also found that nano-titanium dioxide also has shortcomings. It can only absorb ultraviolet light, and ultraviolet light only accounts for about 5% of the solar spectrum. The utilization rate of sunlight is low, and it is difficult to recycle nano-titanium dioxide in water. . These problems will hinder its industrial application.” Meng Haotian, a 21-year-old team member, said, “In order to solve these problems, they conducted hundreds of experiments.”
Team members are conducting experimental data analysis and research
In 2021, Meng Haotian was admitted to the Chemical Safety Technology and Management Major of Tianjin Vocational University from Shanxi. In the eyes of many college classmates, he is diligent and studious. When he encounters a problem that he does not understand, he will always chase the teacher to get to the bottom of it. His enthusiasm was noticed by his teachers. On the recommendation of his chemistry teacher, he became a member of the “Sunshine Green Energy” team in his first semester.
Wu Donglei, a fellow from Shanxi, is a classmate with Meng Haotian. Not only is she beautiful, but she also studies very well. She is among the top three in the class in every exam. She also won school scholarships and national scholarships. In the first semester of her sophomore year, she On the recommendation of Meng Haotian, Wu Donglei also joined the “Sunshine Green Energy” team.
When the research is at its busiest, all members of the team will spend time in the laboratory every day except attending classes, eating, and sleeping, doing tasks such as mixing reagents, experimental observations, and recording experimental data. “Although sometimes I am tired, but when After a breakthrough is made in a certain experimental link, the sense of accomplishment will make us very happy.” Wu Donglei said with a smile.
Meng Haotian (back) and Wu Donglei (front) are conducting experiments
But breakthrough is not easy.
When solving the spectral response range of nano-titanium dioxide, the team decided to add graphene material. “Nano-titanium dioxide will generate electrons after absorbing light. If it is not quickly converted into free radicals, the electrons will ‘run’ away. Graphene has strong conductivity.” “We hope to use graphene to quickly transport electrons and convert free radicals.” Meng Haotian said that the theory was established, but the experimental process was not smooth. They conducted experiments for more than two months and tried various ratios, but they still failed. success. Later they discovered that graphene is insoluble in water. If they want to succeed, they need to replace it with hydrophilic graphene oxide material. “With the addition of graphene oxide and bismuth oxide and other materials, the spectral response of the photocatalyst material we prepared The range, from UV only, extends to UV and visible light.”
The efficiency problem is solved, what about the recycling problem? After trying various materials, they finally chose floating beads made of fly ash as a carrier. They applied the photocatalyst material on the floating beads and put them into industrial wastewater. After the photocatalyst material fully degraded the new pollutants, The floating beads are then fished out from the waste water. The fished out floating beads can also be reused, which greatly saves costs.
4 invention patents have been authorized
is being gradually promoted to the industrial field
Since the end of 2021, the “Sunshine Green Energy” team has successively applied for 9 invention patents, among which, “A highly active visible light catalyst for wastewater treatment and its preparation method” and “A method for the catalytic synthesis of p-hydroxyphenylglycine by solid phosphoric acid” Four invention patents, including “a clean production method of L-p-hydroxyphenylglycine” and “a synthesis method of amoxicillin production intermediates”, have been authorized.
One of the core invention patents obtained by the “Sunshine Green Energy” team
In a time-lapse video of an experiment shot by Meng Haotian, a cup of pink industrial wastewater, after adding their photocatalyst material, changed the color of the solution from dark to light after three hours of sunlight. The sewage chromaticity It dropped from 500 to below 50, and COD, an important indicator of organic pollution in water bodies, dropped from 500 to below 50.
“The photocatalyst we studied can degrade 90% of organic pollutants in wastewater after expanding the spectral response range and exposing it to light for 1 day without causing secondary pollution.” Zhang Farong said that the laboratory is a small test, and he wants to Verify research results, promote technology, and conduct pilot tests in enterprises.
In April this year, they conducted a pilot test in a chemical dye factory. The test results showed that the sewage color, COD, total nitrogen, and total phosphorus after treatment with photocatalysts were significantly reduced, which is in line with environmental protection. The discharge standards stipulated by the bureau were met, and there were no abnormalities that affected the water environment.
The team conducts pilot trials in the company and negotiates cooperation
Today, the “Sunshine Green Energy” team has negotiated with more than 30 industrial companies and signed cooperation agreements with 7 companies. “After being promoted and applied in industrial wastewater, we will provide agricultural wastewater, petroleum development wastewater, and pharmaceutical wastewater.” and other areas to expand.” Zhang Farong said.
At the end of this year, Meng Haotian and Wu Donglei, who are in their third year of college, will go to their respective internship companies. They have also decided to practice while preparing for the junior college-to-undergraduate examination. The new batch of “post-00s” will also take over the baton of research on “solar photocatalysts”. Move towards more areas of water pollution treatment. (Jinyun News reporter Bao Yan)
This news article has been translated from the original language to English by WorldsNewsNow.com.
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