Xiaojun Wang（The right two）Examining and receiving the engineering at the scene

　　Journal of Chinese Academy of Sciences reported on September 5^th（Reporter Chunlei Shen） “Our school has received the prepayment of the company.” Recently, Doctor Xiaojun Wang, who comes from the College of Environment and Energy in SCUT, had been in relief. No long ago, South China University of Technology had signed a cooperation agreement with Hutai (Panyu) textile printing and dyeing company, and would contribute a reuse engineering which can deal with 3,000t thick wastewater.

　　“The payment of this technological corporation is up to 11,180,000yuan, which is also our first contract worth 10 million depending on the engineering about which printing and dyeing wastewater can be reused and reaches near zero emission.” Xiaojun Wang had a reported in Journal of Chinese Academy of Sciences, “The new technology is not easy from research to promotion, especially the promotion.”

　　A method that achieves zero emission of printing and dyeing wastewater

　　Printing and dyeing industry need a lot of water, with the increasing tension of water, we shall increase the reusing rate of wastewater to decrease the resume of water and the emission of wastewater.

　　Xiaojun Wang introduced to reporters that the common method of wastewater treatment can remove the most organic pollutants, SS and chroma. Moreover, the dealt wastewater receives the standard of emission. If we want to increase the reusing rate of wastewater, we can depend on the process of Reverse Osm (RO), which separates the dealt wastewater to thin and thick water through reverse osmosis membrane. The thin water is high-quality reused water which is near to pure water, while the thick one concentrates all of the impurity or contaminant in wastewater.

　　Printing and dyeing wastewater only contains salt, and the concentration is not low. The reason why the wastewater contains salt is related to one of the processes. Xiaojun Wang makes an example that we need to add salt to water in the process of dyeing to make the cloth easier to color. The concentration should be controlled from 3% to 4%. After mixing this part of wastewater and others, the concentration becomes about from 0.7% to 0.8%. Through the solution of RO, all of the salt is resolved in the thick water, and the concentration of salt increase to 1.5%~2%.

　　Since the process of dyeing needs salt, can we recycle both water and salt in the thick water which is dealt through RO? For this reason, Xiaojun Wang leaded his team and tried a lot of experiment, in the end, they found that organic pollutants and hardness are both the key factor affecting the quality of reusing water.

　　Xiaojun Wang made an explanation that chemical oxidation can remove the organic pollutants in the wastewater and decrease color differences formed by being dyed. Otherwise, the method of softening can remove the hardness to avoid dyeing unevenness formed by hardness.

　　For these reasons, the team replaced tap water and salt by reusing water removed organic pollutant. According to the demand of dyeing, they added suitable salt and founded the two results are almost the same. The color difference is between 1%. The method not only achieves the national standard, but also recycles both water and salt.

　　This method had a try in the lad and then had been verified in the small dyeing test machine in the factory. In the end of 2013, the team applied a patent “A method that achieves zero emission of printing and dyeing wastewater”, and was authorized in 2014. “This patent spends the shortest time from application to be authorized in recent years.” Xiaojun Wang said proudly.

　　It’s difficult to market.

　　“Recycling soft salt water through this patent not only improves the utilization rate of salt and wastewater, but also has some economic benefits.” Xiaojun Wang indicated, after calculation, he founded that when conversing the thick RO water to soft salt water, the payment to deal with per ton water needs about 7yuan. Moreover, one-ton soft salt water contains 16kg salt which worth 500yuan when assuming one-ton salt worth 500yuan. In addition, one-ton water can save 11yuan water when assuming one-ton water worth 8yuan, which is not contained the payment of wastewater emission.

　　Generally speaking, it’s easy for the patent to promote for which can both decrease wastewater emission and create economic benefits. However, it’s difficult to do it in reality.

　　“Every year I participate in the meetings about printing and dyeing and promote our technology, many companies think it’s good technology, but they have no motion to improve the factory with this technology.”

Xiaojun Wang cannot understand why it’s so difficult to promote this good technology?

　　After communicating with factories, the team of Xiaojun Wang had founded that it’s related to the economy. Generally speaking, a big textile printing and dyeing enterprises are built by river for enough water. The payment for conversing one-ton river water to industrial top water needs 0.3 ~ 0.5yuan. If using RO, one-ton RO pure water is up to 3yuan, which only contains reusing pure water. Besides, we shall think about relevant engineering, processes, the adjustment of processes and so on.

　　As a technology about water treatment, it’s different to some product development technology. A new product can make profits to enterprises, while water-treatment technology mainly protects the environment. The direct profits for enterprises are so limited that it cannot be sold a high pride.

　　The profit of printing and dyeing enterprise is low compare with others so that the corporate have to control the cost of production carefully. The relevant technological principal of Guangdong Esque Textile Company, which is the other partner of the team of Xiaojun Wang, indicated that conversing river water to industrial tap water is the most convenient and saving method for enterprise. If using new method, we shall run the system of RO and then deal with the thick water of ROfurther. In the production workshop, we need dedicatedpipeline to recycle salt water, add new pipeline for materials and some operating procedures. Therefore, it’s difficult to transform the old factory.

　　Thisprincipal still indicated that the patent of the team of Xiaojun Wang is more suitable for new factory. And Xiaojun Wang had found that on the one hand the promotion of new technology is in need of government and economy, on the other hand the technology is more suitable for water shortage area.

　　Technology has come into play.

　　In recent years, with the increase in environmental law enforcement, the demand of water withdrawal and emission of some factory or industrial area has been carried out strictly. Moreover, the environmental protecting sense of enterprise keeps improving. The patent of the team of Xiaojun Wang has come into play, which not only recycles water but also salt.

　　He told reporter that his team had corporations with many textile printing and dyeing enterprises in Guangzhou, Foshan and Dongguan, including Hutai (Panyu) Textile Printing and Dyeing Company. Ten years ago, we developed Ozone-aeration biological filter deep treatment process, which has been run in Hutai factory many years.

　　Xiaojun Wang recalled that the doctor and master of my research group verified the reliability of recycling water through a small dyeing machine of Hutai Company, all of which is just to develop the technology of recycling thick water. Therefore, Hutai Company understood our technology.

　　This year, Hutai Company had a corporation with the team of Xiaojun Wang on this patented technology in order to improve the clean production level of the enterprise, decrease the resume of water and increase the reusing rate, which signed a contract for the 3,000-ton concentrated water reuse project.

　　Xiaojun Wang told reporters that in this project, they provided not only patented technology but also relevant engineering design, engineering construction, key device and technical services. And this is the largest horizontal technology development project about patented-technology promotion in SCUT in recent year.

　　In the textile printing and dyeing industry, we often hear the slogan of zero-emission technology. It’s feasible to steamed all of the water and reuse the condensate but high cost has a limit to the promotion of the technology, especially the industry with low profits.

　　Xiaojun Wang said that the advantage of the technology is that reusing both water and salt with minimal price so that improving water reusing rate economically, which has great significance to decrease wastewater pollution in the printing and dyeing industry for Pearl River Delta and ** Delta Economically Developed Area.

　　All beginnings are hard. Xiaojun Wang wishes that this patented technology could come into much play.