This article is from: Science Popularization in China

On the afternoon of March 30, 2022, China Biodiversity Conservation and Green Development Foundation (China Green Development Association) Working Committee on Air Governance and Low Carbon Development jointly held an online green and low carbon technology promotion conference on "Iron and Steel Enterprises Implementing the Double Carbon Target". Hu Qunhui, engineer of Hunan Aowei Environmental Protection Technology Co., Ltd. introduced and shared the technology with the title of "reverse osmosis membrane material industrialization and its application in industrial wastewater treatment". Now the content of the speech is arranged as follows for readers' reference:

Good afternoon, experts and leaders. The topic of my report today is "Reverse osmosis membrane material industrialization and its application in industrial wastewater treatment". As we know, our country's water resources and water quality in the distribution of a profile is the shortage of fresh water resources and uneven distribution, drinking water security problem increasingly highlight, regional water quality is uneven, the northern and western regions of the water quality good, the eastern region water pollution was very serious, surface water and groundwater water quality safety of insecurity.

So, drinking water security and the application of membrane water treatment technology is about the same, that is to say, the sewage is generally through the MBR can recycle to a water level, and then by ultrafiltration and reverse osmosis filter, can achieve a water purification and in addition to salt water respectively, further through EDI can to a ultrapure water level.

As people pay more attention to health, the problem of drinking water safety is becoming more and more intense. The increasing awareness of ecological protection has become a powerful driving force for the rapid development of water treatment membrane technology.

So, reverse osmosis membrane and the membrane filter is one of the key technology to solve the problem of drinking water safety, composition and membrane separation technology from the market share of a part, is currently the water desalination industry, give priority to with seawater and brackish water and river water and sewage, the status quo of industrialization of reverse osmosis membrane materials industry is that by 2021, The global production of reverse osmosis and pulled-filtration membrane is about 240 million square meters, among which foreign brands account for 2/3 of the global share and domestic brands account for 1/3 share. So far, in the industrial film market is 8 inches of an industrial reverse osmosis film, the stock market is about 6 million, among which the Dupont film components account for more than half, and then the domestic film total account for less than 15%. In 2021, the increase of domestic impermeable film is about 1.1 million, the total proportion is less than 20%.

Chinese market eight inches industrial film market forecasts, its application distribution mainly in the desalination of water and pure water, and then printing and dyeing, paper making, petroleum, chemical, steel, metallurgy, coal chemical, so in the process of industrialization, the outbreak of the new champions league in 2021 and the influence of related policies, domestic 8 inches of reverse osmosis membrane incremental in 100-1.1 million, It was roughly flat compared with the previous year.

In this piece of pure water film, the amount will gradually become less, because in the coal chemical industry, steel and petrochemical and so on some industries of wastewater advanced treatment, it is an application of gradual development and growth.

Then, a key problem in the development and industrialization of membrane materials is mainly in three aspects. First, how to improve the balance between selectivity and permeability in the molecular structure design of functional layer of membrane materials; The second is the structural design and development of the pollution resistant layer in the broad spectrum of the applicable environment and to enhance the product life; The third is a production design for defect-free controlled mass production and performance normalization. So, through the strategy of improving the anti-pollution performance of the membrane material, AUwei Technology realized the construction of the membrane material's clear hydration anti-soft coating, and realized the improvement of its clear water and reduce the surface roughness, and optimized the charge performance of the membrane material.

So, this membrane material in different pollutants in a pollution and cleaning recovery situation, we can see, that is, through an improvement of our modified coating, it in a variety of pollutants in a pollution situation and cleaning recovery performance have been greatly improved.

So, industrial membrane, reverse osmosis membrane product series, we are mainly four product series, one is ultra-low pressure composite reverse osmosis membrane, mainly in a very low operating pressure, can achieve a high water yield and high desalination rate and conventional membrane, greatly reducing the operation cost.

The second series is a low-pressure composite reverse osmosis membrane, which is the desalting of brackish water, mainly running at low pressure. It is characterized by high water yield and better desalting performance. It is mainly used in a device of some pure water and ultrapure water.

The third series is anti-pollution reverse osmosis membrane element series, mainly used in some water reuse and inlet water for some highly polluted water sources. Designed for poor water quality, it has strong anti-pollution performance and reduces the frequency of chemical cleaning.

The fourth series is seawater desalination series and high pressure membrane series, suitable for desalination and sub-seawater, with a high concentration of brackish water treatment, can be used for desalination of high concentration of brackish water, power plant boiler feed water and waste water reuse landfill leachate and other application fields.

So in the anti-pollution series, is the use of a special process on the surface of the film. And then through the membrane element structure design, so that the membrane element has better anti-pollution ability and better cleaning recovery.

So, desalination membrane, mainly used in wastewater reuse and landfill leachate and zero discharge field, the amount is very large.

In the industrial nanofiltration membrane element this piece, we are mainly divided into four series by the throttle rate of the monovalent salt, NF10, 30, 60, 90 respectively is the corresponding sodium chloride in ten percent, thirty, sixty, ninety or so of the removal rate, its divalent ion removal rate in more than ninety percent.

So, in the field of nanofiltration membrane, its interception molecular weight in 150~300Da, and then there are several series, mainly to do some special material separation.

In an application scenario of industrial membrane products, Australia d technology products currently in the semiconductor industry, electric power, chemical industry, automobile, metallurgy, textile and steel, coal chemical industry, printing and dyeing, industrial wastewater and garbage leachate, aquaculture and other industries are used, its water production purposes, from the electronic ultrapure water, in addition to salt water reuse and boiler water, as well as some special process water, There are a large number of application cases for water reuse and so on.

Here are a few typical cases of application sharing, the first is the boiler water, is in the shandong weiqiao aluminum electric self-provided power plant boiler water, the application of it in the water is water, through the integration of the feed water, ultrafiltration, and then into the two-stage reverse osmosis, again into the mixed bed, so in the end as a boiler water, the system run in two years, The desalting rate was kept above 98%.

The second is coal chemical water, coal chemical industry in a water reuse project, in the coal Yulin energy chemical industry, its production sewage after deepening atomization treatment, and then into ultrafiltration, and then directly into the reverse osmosis water, as its process water. This is the actual data of the project site and the membrane system operation of the membrane product. Its influent conductance is about 1800, and its water yield is about 50.

Finally, I briefly introduce AOWI Technology, the company is currently mainly four core technologies, the first is the membrane product design and development capabilities, is our reverse osmosis membrane, nanofiltration membrane and ultrafiltration membrane of a membrane material development capabilities.

The second block is the ability to detect characterization analysis, which is a table characterization analysis ability including water quality and other aspects in our membrane product development process and membrane product application process.

The third is the independent design ability of key equipment, because reverse osmosis technology is still monopolized by foreign countries, and there is no standardized membrane material production equipment in China, so we independently designed this key production equipment according to our membrane material formulation process.

The fourth part is the application design ability of membrane products. We also have a technical team, including our own development of a membrane system design software.

In the acid recovery, alkali recovery and solvent recovery and container separation, we are also doing some pre-research work. That's all for my report today. Thank you for your listening. Please criticize and correct me.