China's Textile Industry Actively Develops New Technologies And Strives To Produce Environmentally Friendly Products.

In recent one or two years, some environmental protection organizations have published reports on environmental pollution in China. Spin The printing and dyeing industry is a key point. It seems that the textile and dyeing industry is the biggest "evil person" who pollutes the environment. Everyone loves their homes. Our printing and dyeing industry is taking actions to reduce pollution emissions, fulfill social responsibilities and protect the blue sky and blue sky.

Facts speak louder than words. It is understood that in 11th Five-Year, the year of the start of 2006, the total industrial output value of textile industry was 2 trillion and 500 billion yuan, accounting for 11.56% of the gross domestic product, and the amount of waste water discharged accounted for 9.6% of the total industrial wastewater discharge. In 2010, the total industrial gross value of textile industry reached 4 trillion and 770 billion yuan, accounting for 11.89% of the gross domestic product. The amount of waste water discharged accounted for 11.6%. of the total industrial wastewater discharge and compared with the total industrial output value created by the textile industry.

In the printing and dyeing industry, due to the general enhancement of scientific and technological progress and the awareness of energy saving and emission reduction, the resource consumption and pollutant emission intensity of the unit products in printing and dyeing process have been greatly reduced in recent years. In 2003, the discharge of tonnage wastewater was 81 tons, 68.3 tons in 2006 and 66.6 tons in 2010. Chemical oxygen demand (COD) emissions were 13.1 kilograms, 10.9 kilograms and 8.6 kilograms respectively. In 2006, the ammonia nitrogen emissions from tons of fiber were 0.69 kg and 0.47 kg in 2010. The data show that the emission reduction effect of China's "printing and dyeing industry" during the "11th Five-Year" period is very obvious.

The national "12th Five-Year plan" has reduced the water consumption per unit of industrial added value by 30%, reducing the chemical oxygen demand and sulfur dioxide emissions by 8%, and reducing ammonia nitrogen and nitrogen oxides emissions by 10% respectively. This is the main constraint index for China's "12th Five-Year" period. As a pillar industry of the national economy, the textile industry also regards energy saving and emission reduction as the main task of sustainable development. In the framework of building up a textile power program (2011~2020), it has implemented the "cleaner production and large-scale implementation of clean production, and basically established a low carbon, green and circular economy system" on the basis of "energy saving and emission reduction to meet the national mandatory standards and achieve the national energy saving and emission reduction tasks". As one of the six goals of the "12th Five-Year" development of the textile industry, it has clearly put forward "developing new technologies for water and anhydrous dyeing and finishing, and developing energy saving and emission reduction textile machinery".

In 12th Five-Year, the Ministry of environmental protection and the State Administration of quality supervision, inspection and Quarantine jointly issued the "discharge standard for water pollutants in textile dyeing and finishing industry" and "water pollutants in silk reeling industry" in October 2012. emission standard "Standards for discharge of water pollutants in wool textile industry" and "discharge standard for water pollutants in linen textile industry" were formally implemented in January 1st this year. The new standard has determined the limits of discharge of water pollutants, monitoring and monitoring requirements in the production process of silk, wool, linen and textile dyeing and finishing enterprises, as well as the relevant regulations for the implementation and supervision of standards.

The effluent discharge standard of the new regulation is higher than that of Europe, America and Japan. Take cod as an example: the emission limits of existing enterprises in China are 100mg/L, the newly built enterprises are 80mg/L, the existing and newly established enterprises in special areas are 60mg/L. America (BPT standard), the limit value of COD in scouring effluent is 140mg/L, the waste water is 160mg/L, the waste water in textile finishing is 60mg/L., the EU limits the chemical oxygen demand to 125mg/L., and the limit of chemical oxygen demand is 120mg/L. in Japanese national standard.

This proves that China's textile industry and enterprises need to bear more financial and material costs in order to achieve emission standards higher than that of developed countries and regions in the world.

According to Zheng Yongcan, general manager of Shaoxing new Sanjiang dyeing and printing company, after the implementation of the new standard, the cost per ton of sewage treatment will increase by 2 yuan, that is, the current sewage treatment fee per ton 2.5~3 yuan will increase to 4.5~5 yuan, and the cost of the increase will be borne by the enterprise. He said: "in order to realize the dream of" beautiful China ", our printing and dyeing enterprises must bear the cost of increasing pollution control equipment and technology.

According to industry experts, now the printing and dyeing industry has replaced and eliminated backward equipment with high energy consumption, high water consumption and poor stability through large-scale technological transformation and equipment with large energy saving, water saving, energy saving and environmental protection. Especially in the eastern coastal areas, the weight ratio of the world's advanced dyeing and printing equipment has been greatly improved. With the continuous improvement of automatic control level, the on-line detection technology including moisture content, hot air humidity, door width, roll diameter, edge position, length, humidity, speed difference, pre shrinkage, working fluid concentration, liquid level, detection and control has been gradually applied in printing and dyeing enterprises. The application of on-line temperature and humidity detection technology has achieved remarkable technological results and energy saving and emission reduction effects.

At present, there are large quantities of textile dyeing and printing in China. enterprise Like the new Sanjiang company, we are making fruitful efforts to further reduce emissions. I believe that the dream of "beautiful China" with blue sky and blue sky is not far away. {page_break}

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China's advanced energy saving and emission reduction technologies are being applied in every aspect of the textile industry.

Source reduction - cleaner production

The printing and dyeing wastewater is produced in the production process. Although the wastewater treatment is important, it belongs to the terminal treatment. In order to protect the environment, it is more important to cut down from the source, that is, the cleaner production process is adopted in the production process to reduce the pollution coefficient. The new technologies that have been developed and are being gradually promoted are:

Pretreatment process

It includes low alkali pretreatment, enzyme pretreatment, low temperature pre-treatment, such as cold pad batch pretreatment process, high efficiency short flow pre-treatment, such as one-step, one-step, half step, two step treatment process: "green" refining agent and auxiliaries pretreatment, chlorine free bleaching and cryogenic plasma treatment process under development, ultrasonic and laser processing technology.

Dyeing and printing process

High fixation rate or high dye uptake, dyestuff dyeing, high dyeing fastness dyeing, one bath, one-step and short flow dyeing, low bath ratio, low liquid dyeing, low salt dyeing, controlled dyeing by computer, non-aqueous and anhydrous dyeing, gas-phase or sublimation dyeing, new pigment dyeing, cold transfer printing, inkjet printing, etc.

These new processes can greatly save energy and reduce emissions, and many of them have qualitative products, such as air flow dyeing machines, whose bath ratio can be as small as 1: 3.5; the ratio of uniform dyeing machine to 1: 4.5; the quality of cold transfer printing equipment and inkjet printing equipment is continuously improving, the price is gradually decreasing, and the market share is gradually improving.

Wastewater treatment technology

Wastewater treatment includes conventional treatment technology and advanced treatment technology.

In order to achieve discharge standard, conventional treatment technology is usually combined with biochemical and physicochemical methods.

The advanced treatment technology is aimed at reusing or high emission requirements. Advanced treatment and reuse technologies have been applied mainly in the following aspects: biological aerated filter, diatomite technology, activated carbon technology, membrane technology, macroporous ion exchange resin, catalytic oxidation technology, inorganic mineral water treatment agent and compound mineral water treatment agent.

Biological aerated filter

Biological aerated filter (BAF) is developed on the basis of traditional water treatment technology. Using ceramsite or activated carbon as filter material, deep treatment of low concentration effluent after two stage treatment can basically achieve the goal of COD60mg/l.

Diatomite Technology

As a natural adsorbent, diatomite has a certain effect on the treatment of low concentration organic wastewater, but the biggest problem is the large amount of sludge.

Activated carbon technology

Activated carbon is a material with large surface area and strong molecular adsorption capacity. Developed countries used this technology for advanced treatment. However, activated carbon for water treatment is currently available.
The cost is relatively high, about 10 thousand yuan / ton, and the capacity of 1 grams of activated carbon to adsorb COD is about 8~11 milligram. In this way, 10 mg COD per ton of water is about 8~10 yuan, and the cost is too high. It can only be used for special occasions or for final checks.

Biochar filter

Biochar filter is activated carbon or activated carbon as filter material, as a deep processing technology.

Membrane technology and macroporous ion exchange resin

Membrane technology and macroporous ion exchange resin are mature technologies in the world, but in essence, they are separation technology, not treatment technology. They are only two parts of separating waste water into fresh water and concentrated water. Fresh water can completely meet the requirement of reuse, and the theoretical utilization rate can reach 80% or even higher. At present, membrane technology, macroporous ion exchange resin ester in wastewater treatment and reuse of the bottleneck is that the price of materials and equipment is high, after separation of liquid treatment is difficult to meet the standard.

Natural mineral processing

Many natural minerals can be used as sorbent, ion exchanger, flocculant and so on, such as zeolite, diatomite, bentonite, manganese sand, montmorillonite, tourmaline, medical stone and so on. For low concentration wastewater treatment and reuse, it has a certain effect. Its drawback is low efficiency and high dosage. However, "inorganic minerals" can be reused after being used. This recycling mode is worth promoting, and technology needs to be researched and developed.

Catalytic oxidation technology

Catalytic oxidation technology for the treatment of high concentration organic wastewater has started very early, such as iron carbon method, but the condition is required under acidic conditions (pH=3). Rare earth elements have good catalytic, adsorption and reaction functions. At present, this technology is mainly applied in France, Japan, Germany, Israel and other countries. Using the rare earth resources in China, the same effect can be obtained by using tailings and waste materials.

As China's printing and dyeing industry wastewater discharge standards have reached the world's most stringent level, from the analysis of wastewater treatment technology, the space to further improve the emission standard value is minimal. Therefore, in the future, the research direction is to explore how to achieve the new emission standards and improve the reuse rate.

The construction of printing and dyeing industrial park is an effective way to enhance management. Although printing and dyeing wastewater is divided into many kinds, it is generally similar to high concentration organic wastewater. Centralized treatment is not only convenient for management, but also concentrated on technical strength. The specific methods are total control, annual reduction, centralized management, and traffic monitoring. {page_break}

　 Example

A few days ago, the two project of "Tencel / wool / cotton blended high quality fabric dyeing and finishing technology and industrialization development" and "research and industrialization development of new fiber fabrics with temperature self-adjusting" were completed by Shandong Binzhou Binzhou textile Limited by Share Ltd. The appraisal meeting was held by Binzhou science and Technology Bureau. The experts agree that the two technologies have reached the international advanced level.

"Tencel / wool / cotton blended fabric dyeing and finishing new technology and industrial development" project, aiming at the characteristics of three kinds of fibers, Tencel cold, bleaching and low-temperature oxygen bleaching pretreatment, and by optimizing dyeing and finishing technology, the damage of wool is effectively reduced. By optimizing dyes and auxiliaries, the dyestuff of dyes on three kinds of fibers is solved. Using mechanical and chemical finishing, the fabric has elastic fluffy handle and waterproof, anti oil, easy to clean and ironing effect. Through low temperature pretreatment, air flow dyeing / cold pad batch dyeing, energy consumption and wastewater discharge can be reduced, and cleaner production is achieved, with remarkable economic and social benefits.

Aiming at the problems existing in the pretreatment and dyeing of new fibers with temperature self-adjusting, a new type of environmental friendly compound enzyme combined with hydrogen peroxide is introduced to optimize the selection of dyestuffs, auxiliaries and processes. The problems such as uneven dyeing and easy scratching are solved. Through the enzyme treatment and functional finishing of fabrics, the fabric has the characteristics of clear grain, smooth cloth, natural cool, moisture absorption, sweat perspiration, good drapability and elasticity. The new self-adjusting fabric has a unique style and is well received by consumers both at home and abroad.