Taiwan is the world’s second largest producer of displays. In recent years, since quantum dots (QDs) have played a more important role due to popularization of consumer electronics, business and government in Taiwan devoted lots of resources to research and development of QDs.
Currently, cadmium-based QDs hold high market share of all types of QDs and chemical synthesis is the main way of production. In the chemical manufacturing process, large amount of wastewater which is toxic to not only environment but also human body would be the by-product and cause potential pollution problem. Besides the pollution problem, manufacturing process is complicated, fill of business secret and is also difficult for public to understand. There were few cases of cadmium-rice happened in Taiwan and resulted in public being afraid of heavy metal.
Despite the appearance of heavy-metal-free QD, cadmium-based QD still takes the position of mainstream QDs products because it performs better in effectiveness and is easier in producing.What we want to do is deceasing the harm to the environment in the chemical manufacturing process, create an opened manufacturing process for public promotion.We start to build a virtuous cycle by reusing cadmium in water, and turn it into QDs in eco-friendly biosynthesis way.
And so the BioSQUAD began.
To have deeper understanding about environment pollution which is caused by wastewater, we had interviewed with Yu-Ming Hsu, an expert in local environmental issue in residential college of National Tsing Hua University(NTHU), and professor ReiAn Don, who works in environmental engineering in NTHU.
We confirmed that in Taiwan, wastewater is major cause of polluted soil which directly affects on crops. When factory discharged toxic wastewater, water that contained Cadmium would run into irrigation system, result in soil contamination which means crops would be grown in a toxic environment. And although this is the main reason of pollution, local resident or farmer usually know nothing about water quality of the water they used. General public lack awareness of environment pollution and make them easy to be harmed.
On the other hand, when it comes to sewage treatment, most larger scales companies usually had sewage treatment by themselves, while small company would choose outsourcing to treatment plant for lower the cost. For the former, company would care about their corporate image and avoid creating a negative one. For the latter, some treatment plant would discharge untreated water illegally, and it became the main reason of water pollution.
Next step we would discuss how to enhance understanding of the links between environment pollution and water to general public, and try to figure out what cause the illegally discharged wastewater.
There are three elements that company will concern when they have sewage disposal: regulations, corporate image, feasibility. Disposal must conform to standards of Environmental Protection Administration, and lower the cost as much as possible because sewage disposal is private good to the company. Yet if toxic wastewater discharge into environment, it would turn into public good and pass on cost to society.
For corporate image part: Recently, customers put more and more attention on eco-friendly and sustainable issue, makes it become an important element when company want to export their products.
For feasibility part: The government ask company which has produce large amount of sewage need to recycle it at least 70%. Before drain water down to treatment plant, company would have the first treatment, then the water would run into sewage treatment plant, after primary sedimentation, biological reactor, secondary sedimentation, by physical, biological, chemical processes, remove toxic contaminants and produce solid waste and treated wastewater.Well-treated wastewater should do no harm on environment, all the toxic heavy metal would be removed.
Sewage Teatment Plant Visiting
We visited sewage treatment plant for managing to the know the whole treatment process well. People in plant showed us that the technique in commercial sewage treatment is mature enough. Illegal disposal by dishonest companies are out of control, it all depends on self-discipline.
This inspired us to design a biosynthesis process to produce QDs which is more eco-friendly and not only could be used in manufacturing but also could recycle cadmium in water, and make it valuable to enter market again. These eco-friendly QDs decrease the waste of cadmium and pollution via producing process, and help company improving their corporate image for getting more costumers.