In recent years, a large number of discarded packaging plastic films, plastic bags and disposable non-degradable plastic tableware have been used rapidly and discarded at will, which has generally caused serious white pollution in large and medium-sized cities. Together with automobile exhaust and phosphorus-containing detergent, it is listed as the three key points of environmental protection in China this year.
Plastic is a kind of domestic garbage that is difficult to treat. When it is mixed into soil, it will affect the absorption of water and nutrients by crops, resulting in crop yield reduction. Landfill it, occupy land and degrade it for hundreds of years. A large number of scattered plastics are also easy to cause animal manslaughter. Elk in Nanyuan, Beijing died after eating plastic bags from nearby garbage dumps. Plastics are easy to agglomerate into bundles, and even block the water flow, leading to the failure of water conservancy facilities and urban facilities, leading to disasters.
The production and use of foamed tableware in China are huge, and the use of plastic bags for food packaging and shopping is also amazing. According to a rough estimate, there are about 8 million tons of white garbage in China this century. Plastic products are one of the most difficult parts of all domestic garbage, and have always been a worldwide problem. Generally speaking, garbage disposal can be reduced, recycled and harmless by sanitary landfill, high-temperature composting and incineration. However, the situation in China is not optimistic, and garbage collection and disposal is far from an orderly system. Take Beijing as an example, garbage collection has not been completed in bags, let alone classified collection.
Although incineration can destroy plastic bags, building a garbage incineration plant is 20 times the investment of a landfill of the same size. As for the method of producing organic oil by artificial degradation, high-purity plastic products are needed, and large-scale treatment is unrealistic. Therefore, sanitary landfill has become the main way to collect plastics at present. Beijing has built three sanitary landfills: Asuwei, Beishenshu and Anding. A thick impermeable layer is laid at the bottom of the landfill, which is continuously covered by soil with the accumulation of garbage, and then vegetation is regenerated to ensure that the garbage is in a closed space and will not pollute groundwater, soil and surrounding air. However, taking Anding landfill as an example, a piece of land of 300 mu is only enough for a Xuanwu district in Beijing 14 years.
Not long ago, some shopping malls responded by boycotting the use of non-degradable plastics. They tried to sell degradable garbage bags, but few buyers, because the price of this kind of garbage bags is above 1 yuan, which can't bear a lot of weight. Wankelong advocates the use of cloth bags, and the effect is not satisfactory.
Treating both the symptoms and the root causes is the best way to solve the problem. Experts believe that on the one hand, it is necessary to deal with existing garbage in a timely and effective manner, and on the other hand, it is necessary to replace plastics with degradable and easily degradable products. 1998165438+1October, a disposable tableware made of straw was put on the fast food table of Beijing Parkson Shopping Center for the first time. This kind of tableware is not only safe and hygienic, but also can be used as fertilizer once put underground and fish feed when put into water. It will be abandoned on the side of the road and will be in blowing in the wind in a few days. On June 5438+0998+February 13, more than 100 enterprises displayed their tableware made of rice husk, pulp and starch. A biodegradable disposable snack box has been studied by more than 30 researchers in Beijing Yiqing Research Institute for nearly 3 years, and recently passed the test. The test confirmed that the lunch box was exposed to nature after use and turned into water and carbon dioxide within 40 days. This lunch box takes starch (corn and cassava starch) as raw materials, adds annual plant fiber powder and bio-waterproof glue, and sprays it into a mold for heating and foaming. All kinds of new substitute products are in the initial stage, but they have not reached the level of mass production and promotion.
In addition; People's awareness of environmental protection is still relatively backward, which is actually an important factor hindering the control of white pollution. The first step to control white garbage is garbage sub-packaging, which is expected to be realized after most people's conscious awareness of environmental protection is established. Therefore, the most important thing to control white pollution is to raise everyone's awareness of environmental protection. Because it takes more than 100 years for white garbage to degrade naturally in nature, solving its pollution problem can really be called a century-old problem.
I learned from Suizhou that the local government not only effectively solved the "white pollution", but also dug up "gold mines" from these wastes.
In the Plastic Weaving Industrial Park in Huan Tan Town, Suizhou City, there are 23 enterprises engaged in the processing and granulation of waste plastics, the stretching and weaving of granular materials and the production of finished products. In the production workshop of the industrial park, you can see the whole process of the machine "eating white and producing gold": the waste plastic waste such as plastic film, woven bag, oil pot and plastic cup has become colorful plastic particles after crushing, cleaning, finishing rolling, coloring and processing. After drawing, knitting and sewing, it is finally made into woven bags and sent to the market for sale.
According to the deputy secretary of Huan Tan Town Committee, the annual "white consumption" of the industrial park is more than 30,000 tons, and the white garbage such as bag film and agricultural film produced by local mushrooms can't make the industrial park "full". The "white garbage" of some counties and cities adjacent to Hunan, Henan and Hubei can also be eaten. At present, the annual output of semi-finished products in the industrial park can reach 20,000 tons, with an annual output value of 250 million yuan and profits and taxes of 25 million yuan. But also does not cause secondary pollution in the production process, and the recovery rate can reach more than 95%. Moreover, after these products are used in the market, they can always be recycled, reprocessed, reused and reused.
The treatment methods of white garbage include raw material reuse, chemical reuse and incineration heat energy reuse.
1. In Japan, there are white garbage disposal trucks every day to collect white garbage such as foam plastic from major shopping malls and retail stores for disposal. They burn orange juice to 200 degrees, turn white garbage into iron, turn it into fiber after special treatment, and then weave the fiber into clothes and buy it in the market, so that the waste can be reused. They have brought nothing to nature.
The "white garbage" that gives us a headache is actually a treasure. Cracked and refined monomers can be used as recycled raw materials; Granulating, which can be degraded as a renewable raw material; Adding chemical reagents to adjust synthetic coatings and adhesives; Used for refining gasoline and diesel oil, the oil yield is as high as 70%-75%, and it does not contain lead.
3. Du Yuanhao, chairman of Honghu Technology Wuhan Co., Ltd., a black plastic pipe manufacturer, introduced that recycling discarded woven bags, white plastic cups and plastic bags to make drainage pipes can eat tens of thousands of tons of "white garbage" every year.
This enterprise recycled polypropylene plastic bags, which were cleaned, toughened, strengthened and modified to make special materials for granular pipes, and then used patented technology and special molds to press a series of drainage pipes with a diameter of 1.2 meters.
4. A device for producing combustible gas by using white garbage, which has a retort (1), a heating chamber (5) is installed at the lower part of retort (1), the upper part of retort is closed with a closing cover (2), and retort (3) is inside. It can properly treat white garbage without secondary pollution to the environment, and its gas can be reused. Its structure is particularly simple and the processing cost is particularly economical. This is a breakthrough in garbage disposal and has wide application value.
Xinhui City has a southern textile raw material factory, which uses plastic waste to refine gasoline and diesel oil.
Recently, we went into the factory for an interview and saw the workers put plastic garbage into the "pot", where gasoline and diesel oil flowed out. According to Zhou, the boss of the factory, the raw material they use is the plastic waste left after pulping in the paper mill, which can process more than 20 tons every day and produce more than 20 tons of fuel oil 10.
Manager Zhou bought the patented technology of changing garbage into fuel oil from the State Environmental Protection Bureau two years ago. The plastics synthesized from petroleum will be sent to the thermal cracking reactor, and the waste plastics of high polymers will be cracked and reduced to low molecular gasoline and diesel oil by chemical methods. The process of changing garbage into oil in this factory has also achieved harmlessness and no secondary pollution.
How to solve these white rubbish? Fortunately, with the development of science and technology, people have thought of the best way at present, that is, waste reuse, that is, turning waste plastics into products for daily use through this machine in front of them.
These waste plastics can be directly put into the equipment without any cleaning and sorting treatment. After installation, the equipment will be heated, and these plastics will undergo automatic dust removal and cracking reaction. You see, it is incredible that the dirty and broken waste plastic will soon become a watery liquid. These aqueous liquids can be polymerized into excellent leak-proof plugging agent without any additives.
Seeing this, everyone may be thinking, can this leak-proof and plugging agent be effective? What a coincidence, this roof was waterproof last summer, just poured a little waterproof agent and smoothed it down, which is much simpler than the previous three-felt and four-oil. Now, after checking in summer and winter, the owner of the house is full of praise for the effect of this waterproof agent.
With this technology, the situation of waste plastics is very different from before. They are called white pollution, and now they have their own values and uses. They really make the best use of everything from the perspective of protecting the environment and rationally developing and utilizing resources.