China "membrane method" to solve the problem of lack of water
Walking in the saline land on the Bohai Sea, endless desolation. Without clean water, nothing can be done. Today, thin filters solve the water shortage problem.
In the 12th Five-Year Plan for Water Pollution Control and Management, the project team of "Industrialization of PVDF Membrane Components and Equipment for Drinking Water Treatment" supported by Ministry of Housing and Urban-Rural Development has set up 30 in all parts of the Yangtze River, Yellow River, Huaihe River and Haihe River Basin Several "membrane method" water plant, filtered out nearly a million tons of purified water a day.
Membrane filtration, safe and efficient
In mid-August, the reporter went to Tianjin Port Nangang Industrial Zone Water Distribution Center to visit. Nangang Industrial Zone built on saline soil. The ground is the salt of white flowers, no deep water and fresh water. Covers an area of nearly 100,000 square meters, producing 50,000 tons of tap water daily distribution center, is the only source of water in Nangang Industrial Zone. Tianjin Membrane company provides the core technology for the water plant - ultrafiltration membrane purification equipment.
Reporters here have seen tap water production process. Raw water from the Luan River water plant, reservoir water pressure through the pump station, via a polyester water main line. Raw water after adding flocculant, in a dozens of grid tie devious circuit, a large number of flocs, and then into the inclined plate sedimentation tank to remove floc. After entering the "ultrafiltration system", intimate contact with the membrane.
The so-called film, is a root "film wire" made in parallel. Membrane is up to 1.8 meters, such as Lanzhou noodle thickness of a tube, 0.7 mm in diameter, diameter 1.2 mm. Seemingly smooth membrane surface covered with tiny nano-scale holes, water flow through the outer surface of the membrane filament, penetrated into the membrane through the hole, the size of the particles and microorganisms are intercepted.
One hundred to the root membrane silk, bundled into a tube ultrafiltration membrane module. There are 1,200 such components in the Nangang waterworks. Raw water pressurized into the membrane module, the crystal clear filtered water flow out continuously, that is, to drink clean water. Bacteria, algae, colloids and fine particles are blocked outside the membrane.
Dirty particles attach to the membrane, affecting its work, so the membrane also needs to be cleaned daily. The most common is the reverse cleaning, clean water from the membrane filament pressure to the membrane, the dirty particles washed away, you can also send compressed air to enhance the backwash effect. The cleaned sewage is drained from the outlet of the membrane module. To a certain time, the need for chemical cleaning, so that the membrane recovery filtering ability. If properly maintained, the life of the membrane can exceed six years.
Tianjin Membrane membrane company responsible for the water project, since May 2013 formally run; so after the completion of the second phase, its water supply capacity will be doubled. UF membrane system is stable and efficient. Its operating cost is less than a dime a ton of water. Unit production costs less than 300 yuan per ton. Tianjin Membrane membrane company before the main sewage treatment, water-specific support, successfully entered the drinking water market, a special highlight of water. Shandong Tai'an Sanhe 80,000 tons of water plants and other home projects, have applied their technology.
Film manufacturing, domestic force
In 2011, it started to finance the industrialization of water-specific drinking water. In response to the instability and weak competitiveness of domestically produced ultrafiltration membranes, the Group conducted research on the key technologies of large-scale production of membrane separation equipment and developed low-cost and high-performance Series and complete sets of ultrafiltration membrane equipment for ultrafiltration membrane technology in urban waterworks and rural drinking water in large-scale application to provide protection to enhance the competitiveness of domestic membrane companies. This project is presided over by Tianjin Membrane Company, Shandong Zhaojin Meidian Company and Suzhou Membrane Company which are sub-project undertakers.
Zhaojin Meidian company in Shandong, the reporter saw the film production process, the polymer raw material extracted from the spinning machine long a thin tube, forming a film in the liquid silk. One hundred to the root of film, in the "chopping board" tied into a bunch of artificial, and then into a special liquid soaked, slowly from beige to ivory.
The membrane is made of polymer material PVDF (polyvinylidene fluoride). Its cross-section is seen under a scanning microscope with perforations, with an average pore size of less than 0.03 microns, which is equivalent to one-thirtieth of that of hair. Yang Min by the Chinese Academy of Sciences, "Popular Science", the reporter learned: The process is to "pore-forming agent" mixed with PVDF, made of tubular filaments, and then dissolved into the pore-forming agent, leaving the same hole network of frozen tofu structure. Various enterprises pore forming agent formulations, and processing technology are different.
Staff invited visitors to pick up a film, force tearing, but never pull. Zhaojin membrane days the company said they have developed a large flux, anti-pollution wet PVDF hollow fiber ultrafiltration membrane of industrial preparation technology. Researchers using PVDF modified materials and non-toxic soluble oligomers made pore, also introduced some new technology to create a performance of drinking water membrane. With the company's laboratory microscope can be seen that the membrane cross-section of the pores are uniform.
Zhaojin days will be the development of new high-quality film, successfully applied to the Yuanzhuang water plant in Huainan City, Cangzhou Luyuan Water Treatment Project, Altay drinking water projects throughout the country a dozen water plants, and dozens of rural drinking water in Shandong project.
The above three sub-topics bear the units of ultrafiltration membrane components and equipment are more than 95% of the localization rate, the cost of similar products abroad to reduce more than 30%.
According to a statistical data from China Water Network, the water treatment scale completed by the research group of PDVF Membrane Components and Equipment Industrialization for Drinking Water Treatment accounted for over 40% of the newly-built drinking water engineering market.
Membrane water plant, Fengsheng "water" from
Ultrafiltration membranes are not the cheapest water treatment solution, but they are favored by today's water utilities because of their "idiot-like" nature, small footprint, and their water quality. In the economic strength of the premise, the membrane processing project construction is the most convenient.
For example, funded by the Ministry of Housing project Suzhou film company, its membrane products are not only used in the Taihu Lake area, to solve the problem of cyanobacteria water quality problems, but also for the Yellow River sediment-rich reservoir water treatment, but also used in Shanxi Coal Chemical Industry Park 90,000 tons of water plants. The combination of column-type and curtain-type membranes, working in concert with other processing equipment, shows considerable flexibility and the water plant is neat and compact with a modern factory feel.
Membrane equipment is not only more flexible, but also more environmentally friendly. Compared with the traditional process, the use of better pharmaceuticals, the secondary pollution caused by less.
Because of this, only 20 years of history of the film industry growth alarming. In 1987, the world's first membrane technology waterworks was built in Colorado, USA, capable of handling 105 tons of water per day. Today, this small-scale membrane water plant can not be counted. Some membrane water plants have reached 300,000 tons Nissan level. The world is currently increasing the proportion of ultrafiltration membrane waterworks.
In recent years, with the emphasis on water quality in China, China has surpassed the EU and the United States to become the largest membrane market in the world. Membrane water plant, as well as household, commercial membrane filters, have become the field of domestic and foreign enterprises snatch. The construction of Beijing Guo Gongzhuang water plant is expected to daily output of 500,000 tons, is the world's largest membrane project. It is estimated that in 2015, the output value of China's membrane industry will reach 100 billion yuan.
In the national water projects funded, the rapid rise of China's membrane business in recent years. According to experts, five years ago, foreign brands such as Dow and GE have an absolute advantage in the domestic market. Now that domestic brands have made breakthroughs in technology, the price per square meter of membrane is only 1/2 to 2/3 of that of foreign ones, and the quality is different Getting smaller and smaller. A group of well-known manufacturers, such as Hainan Lisheng, Tianjin Membrane, Shandong Membrane Membrane, Suzhou Membrane have accounted for half of the country, and rival foreign giants.