Plastic bags can make people who use them get the greatest convenience;

The widespread use of plastic bags is cheaper and more affordable than other similar products;

Plastic bags can be used by many people because of their light weight;

The new "degradable" plastic bag can make it more environmentally friendly;

Color artists of plastic bags can also make it into works of art;

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As one of the great inventions in the 20th century, plastic has greatly facilitated people's lives, and plastic bags made of it are closely related to people's lives. The benefits of plastic bags are obvious. Nowadays, plastic bags have quietly entered the university cafeteria because of their convenience. In the past, the scene of people queuing to buy food with lunch boxes has "disappeared" and stood at the gate of the school cafeteria. What I saw was this scene: the people who went in were empty-handed, but when they came out, they were full of plastic bags, which contained everything: rice, cooking, porridge steamed bread, casserole noodles and so on. It can be said that everything can be taken back except the rice seller who can't take it back to the dormitory in plastic bags.

After our preliminary understanding, this phenomenon exists in many colleges and universities in Xi. Plastic bags are frequently used in colleges and universities, and a large number of them are discarded. If a school has 10000 people and each person uses a plastic bag every day, then the school will throw away 10000 every day, which is about 3 meters high; Based on the calculation of 39 universities in Xi 'an, 390,000 universities will be thrown away every day, which is about 1 17m high. These figures are still very conservative estimates. In the actual investigation of our investigation team, it is found that the number of plastic bags used in Xi university canteens is far more than these. What is the situation of colleges and universities in Shaanxi Province and even the whole country? This number must be very large. It is out of the responsibility of protecting the environment that our investigation team conducted a questionnaire survey on some universities in Xi.

Through this investigation and interview, I hope that the data analyzed by all members of the investigation team can give you an inspiration and an incentive-please use sterilized tableware or bring your own tableware, stay away from plastic bags in the canteen, do your part to reduce "white pollution" and love our hometown!

Investigation situation

1. 1 scope of investigation

The 10 institutions of higher learning surveyed are: Northwest University, xi Jiaotong University, Northwestern Polytechnical University, xidian university, Shaanxi Normal University, Xi International Studies University, Xi Polytechnic University, Xi Youshi University, Xi Institute of Engineering and Technology, and Xi Institute of Physical Education.

1.2 investigation time

March 2005

1.3 means of investigation

In the form of questionnaire survey, questionnaires are distributed to students in the above universities. * * * A total of 450 questionnaires were sent out, and 359 were actually valid. Among them, in the first part of the survey, because the canteens of Xi Jiaotong University and Xi University of Technology did not use dining plastic bags, the actual effective number was 306.

The students in the surveyed universities filled in carefully and put forward many good suggestions and solutions. At the same time, the investigators also focused on Northwest University, and visited the staff of Northwest University canteen management center, Xinyuan canteen office and the master of individual windows in the first canteen of Northwest University, and got their strong support and help, which provided more detailed data for the investigators' investigation, so the credibility of these questionnaires was very high and the accuracy of the data was very reliable.

2 Survey results and analysis

2. 1 Xi Current situation of plastic bags used in some university canteens

Among the eight effective universities surveyed, 45.8% students in Northwest University use at least 1 ~ 3 plastic bags every day, 37.5% students use at least 4 ~ 6 plastic bags every day, and 15.3% students use more than 6 plastic bags every day, accounting for the highest proportion among all the universities surveyed. 48.6% students in Xi 'an International Studies University use1~ 3 at least every day. 45.7% students use it at least 4 ~ 6 times a day on average; 66.7% students in Northwestern Polytechnical University use at least1~ 3 every day on average; 82% students in Xi 'an Institute of Engineering and Technology use1~ 3 at least every day; 82.4% students in Xi 'an Anyou University use at least1~ 3 every day; 82.6% students in xidian university use at least1~ 3 every day on average; 88.9% students in Xi Institute of Physical Education use1~ 3 at least every day; 95.8% students in Shaanxi Normal University use 1 ~ 3 at least every day.

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It can be seen that the unscrupulous use of plastic bags in colleges and universities is not "nonsense". Among them, the use of plastic bags in the canteens of Northwest University and Xi International Studies University is the most serious, while students of Xi Jiaotong University use tableware or bring their own tableware in the canteen. Xi University of Technology uses degradable plastic lunch boxes instead of plastic bags. These two universities set a good example for other universities in this respect.

2.2 Phenomenon analysis

What is the reason for the large use of plastic bags in university canteens? Our investigation team conducted a rigorous data analysis and collation.

Among 306 valid questionnaires from 8 universities that use plastic bags, 69.3% students think it is convenient to pack rice in plastic bags, and they can buy rice directly after class. There are also students who live on high floors who think it is too much trouble to take tableware back to the dormitory. Using plastic bags directly can save a lot of time. 1 1.8% students use plastic bags because they are too lazy to wash dishes; 10. 1% Because other people use it, they think it should be safe and clean, so they can use it with confidence. See figure 1 for details.

Figure 1 Proportion chart of reasons why students use plastic bags

As can be seen from the data in the picture, plastic bags really greatly facilitate students' lives; However, I believe that as long as students are diligent and use sterilized tableware or bring their own tableware, plastic bags in the canteen can be greatly reduced or even not used, thus alleviating the pressure of some plastic products on the environment.

For the serious phenomenon of using plastic bags in university canteens, our investigation team made a hypothesis, that is, assuming that the school forces the use of plastic bags, how will the students react? Through data analysis and summary, it is found that 7.5% people feel that it will cause great inconvenience to their lives; 37.6% people feel a little inconvenient; 22.2% people think it doesn't matter; 30. 1% people agree that schools should do this, which is beneficial to environmental protection; 2.6% chose other. As can be seen from this set of data, plastic bags do occupy a certain position in our lives. Fortunately, 30. 1% students are still willing to give up this convenience and join the ranks of environmental protection.

In eight schools that use plastic bags, we summarized and analyzed the students' reactions, especially in Northwest University. Among them, 9.7% students find it extremely inconvenient, 18. 1% students find it a little inconvenient, 22.2% students think it doesn't matter, and 50% students think it's a good move. It can be seen that half of the students in Northwest University are in favor of this move, because plastic bags are not used in the canteen.

In addition, our investigation team also set up such a survey topic: If you walk in the school cafeteria and find that almost everyone carries 4-6 plastic bags for meals, how do you feel? 52.7% of the students chose "it doesn't matter", 32.8% chose "disgust" and 14.6% chose "other". More than half of the students choose ". This is precisely because the popularity of plastic bags in colleges and universities is very high, which inevitably makes people feel that it is normal for students who go in and out of the cafeteria to pack their meals in plastic bags. Obviously, we should start with environmental protection publicity and education to completely reduce plastic bags in canteens and reduce "white pollution".

Figure 2 Xi college students' reaction to the requirement of "compulsory ban on plastic bags in schools"

2.3 college students' understanding of white pollution

The survey results show that the environmental protection concept of college students has reached a worrying level, especially as high as 52.7% of college students are indifferent to the serious use of plastic bags in canteens, which has aroused our investigation team's deep thinking and further launched a survey on the knowledge of "white pollution" among college students.

Here, first of all, what is "white pollution"? This should start with plastic, which is a polymer material. Petroleum can produce ethylene, propylene, butadiene, vinyl chloride, styrene, etc. Under certain conditions, small molecular substances can be polymerized to produce a series of high molecular polymers such as polyethylene, polypropylene and polyvinyl chloride. Polypropylene. The plastic bags we often use are blow-molded from the above polymer materials. Since the 1960s, plastics have entered a wide practical stage. Because of its many advantages, easily available raw materials, low price, convenient processing and light texture, it was welcomed by all countries in the world as soon as it came out and immediately entered all aspects of social life. Plastic is made into bowls, cups, bags, pots, barrels, pipes and building materials, so it is called plastic.

Disposable plastic products (including foamed plastic lunch boxes, plastic tableware, plastic packaging materials and thin plastic bags, plastic films, plastic agricultural mulch films, etc.). Due to the lack of effective recycling value, it is discarded in the environment, which not only destroys the landscape, but also causes "visual pollution". And because it is difficult to degrade in nature, it also causes direct and indirect damage to the natural ecological environment.

Through investigation, 54.6% of students probably know the knowledge of "white pollution"; 27.9% students know the knowledge of "white pollution"; 16.7% students don't know much about it, that is, they just know it; 0.8% of the students know nothing about this, and the detailed proportion is shown in Figure 3.

Regarding whether the use of plastic bags in the canteen will cause pollution, 64.3% of the students think it will cause pollution; 27.9% students think it will cause pollution, but it is not serious; 7.2% students think it will not cause pollution.

There are 5 1.0% students who know nothing about the treatment of plastic waste. 39.8% know a little; Only 9.2% of the students know.

Figure 4 Xi University Students' Knowledge of White Pollution.

As can be seen from the above data, there are still quite a few college students who don't understand the knowledge about "white pollution". What's more, they think that plastic bags will not pollute the environment, which shows that the problem is serious. Therefore, it is urgent to strengthen environmental publicity and education!

Some suggestions on investigating college students in three universities

It can be seen that the phenomenon of using plastic bags in university canteens is very serious. According to the investigation, almost all these plastic bags were transported to the landfill site in Anjiangcungou, Xi 'an for landfill treatment, and the landfill site would slowly degrade the plastic bags themselves. In this process, harmful gases such as chlorine and sulfur dioxide decomposed in plastic bags will bring immeasurable harm to our living environment.

In our questionnaire survey, we also collected a lot of reasonable suggestions on how to avoid using plastic bags in catering, which are summarized as follows:

(1) The school explicitly prohibits the use of plastic bags for catering, and eliminates all possible sources;

(2) Schools should publicize "white pollution" to improve college students' environmental awareness;

(3) Expand the dining hall, increase dining seats, ensure the cleanliness and hygiene of tableware in the dining hall, and encourage students to use sterilized tableware in the dining hall;

(4) Encourage students to bring their own tableware, and distribute stainless steel tableware when freshmen enter school;

(5) The canteen is equipped with tableware places, and the dormitory can be equipped with students' dishwashing places and detergents;

(6) The canteen uses degradable environmental protection bags instead of plastic bags.

It can be seen that students are eager to do everything possible to avoid using plastic bags.

4 survey results

As far as the dining hall of Northwest University is concerned, some windows use as many as 3,600 plastic bags a day, and a window selling porridge only costs 70 yuan RMB to buy plastic bags a week (the unit price of plastic bags is about 0.0 1 yuan/bag). For such a cheap plastic bag, these figures are huge.

All the canteens in Northwest University use an average of 5.88 million plastic bags a year, which means it costs 50,000 yuan to buy plastic bags for meals. Imagine that if this money is used to improve the quality of food in the canteen, both the canteen and the students will benefit more.

According to the analysis of this series of survey data, the plastic bags used in the canteen of Northwest University are about 16, 1 10 every day, weighing about 32.2kg and covering an area of about 644.4㎡. It can be inferred that there are 39 universities in Xi 'an, so the universities in Xi 'an use about 628,000 plastic bags every day, weighing about 60. There are 62 colleges and universities in Shaanxi Province, so there are about 999,000 plastic bags used by colleges and universities in Shaanxi Province every day, weighing about 2t and covering an area of about 39,960m2. There are 2 103 universities in China, so there are about 33.879 million plastic bags used by universities in China every day, weighing about 68t, with an area of about 1.355 160 m2.

These figures are enough to reflect the seriousness of using plastic bags in colleges and universities, and how do these plastic bags deal with the aftermath? It is understood that almost all of them are transported to landfills for landfill. According to the reports of the United States and Japan, the time of degradation and differentiation of waste plastics buried in soil or seawater is 200-300 years, which will also dissolve harmful substances in the soil and cause more serious secondary pollution. This shows the seriousness of the consequences of "white pollution". This is beyond human imagination. Think about it. If this situation continues to develop without treatment, we will soon be submerged in the stinking "white terror".

Plastic bags in colleges and universities are devouring the natural ecological environment! The earth is breathing! It is urgent to control "white pollution"!

5 waste plastic treatment methods

Recently, the State Economic and Trade Commission issued the "Tenth Five-Year Plan" for the development of renewable resources recovery. By 2005, it is estimated that the annual recovery of major renewable resources in China is: 36 million tons to 37 million tons of waste steel, 2 million tons of waste non-ferrous metals, and 0/70,000 tons of waste paper; 800,000 scrapped cars, 6,543,800 light tons of scrapped ships and 7.9 million tires were recovered and dismantled. The recycling amount of discarded household appliances and computers reaches more than 80% of the total, while the amount of discarded plastic products is as high as 5 million to 6 million tons.

5. 1 plastic recycling technology

At present, many scientific research departments in the world have developed many feasible technologies to deal with waste plastic products, which have alleviated and effectively controlled the rapid spread of "white pollution" on the earth in a certain range. The main methods are as follows:

(1) Landfill is the worst way to treat waste plastic products, but compared with irresponsible garbage discharge, it is still a positive way, and the depth of landfill should at least not affect the growth of ground plants.

(2) Recovery of incineration heat energy of waste plastics The combustion heat of waste plastics is generally higher than that of wood, so there is great potential for recovery of heat energy. However, the combustion furnace of waste plastic products needs special design, otherwise it will cause secondary pollution to the atmosphere.

(3) Thermal decomposition technology of waste plastics The basic principle of thermal decomposition technology is to completely decompose the original resin polymer in waste plastic products and return it to a low molecular weight state. The main advantages of thermal decomposition technology of waste plastics are: high utilization value of decomposition products; There is no limit to the number of repeated treatments of waste plastics, that is, waste plastics are decomposed into monomers and then polymerized into polymers, and their products can be decomposed again after being discarded, and so on.

(4) Recycling of waste plastics Recycling of waste plastics can be divided into direct recycling and modified recycling. At present, direct recycling is the main method, and modified recycling is the development direction. The direct recycling of waste plastics refers to the direct processing and molding of waste plastics after cleaning, crushing and plasticizing, or the processing and molding of products after granulation. Its advantages are simple process and low cost of recovered products. The disadvantage is that the mechanical properties of recycled materials are greatly reduced and are not suitable for high-grade products. In order to improve the basic mechanical properties of recycled materials and meet the quality requirements of special products, various modification methods should be adopted. Some mechanical properties of modified waste plastics reach or exceed those of resin products. Therefore, the modification and reuse of waste plastics is a promising way. There are two methods to modify waste plastics, physical modification and chemical modification. The physical modification method is mainly prepared by mixing process. Chemical modification includes cross-linking, grafting and chlorination. The mechanical properties of modified recycled products have been improved and improved, and they can be used as high-grade recycled products.

5.2 Comparison of various new materials and technologies

(1) degradable plastic technology degradable plastic technology is to add a certain amount of additives, such as photosensitizer, starch and other raw materials, in the process of plastic production, so that degradable plastic products can be decomposed into pieces from a complete shape after being used up and abandoned in nature for three months, thus at least improving the environment visually. But the biggest disadvantage of this technology is that these fragments can no longer be degraded, and can only be changed from large pieces to small pieces of plastic.

(2) Hot pressing process of adding amine to plant fiber powder. This technology uses plant fibers, such as rice straw, rice straw, bagasse, etc., to obtain fiber powder, and then mixes a large amount of glue or resin, and then injects it into the mold for molding at high pressure and high temperature. The products produced by this technology have good biodegradability, but the disposable tableware produced by this technology has not removed the fiber pigment in production (chemical bleaching is necessary to remove the pigment, which will inevitably lead to water pollution), and the appearance color of the products is not satisfactory. In addition, it is difficult to remove pesticide residues on the surface of plant fibers in the production process, so it is not necessarily safe to make food containers. Moreover, due to the limitation of technology, it is difficult to realize industrial mass production.

(3) Using paper instead of plastic technology, that is, using paper pulp as raw material, molding and drying in a mold to produce disposable tableware. Tableware made by this method has the advantages of non-toxicity, easy recovery, renewable utilization and degradation, and is called "environmental protection product", which is a good alternative technology for comprehensive evaluation at present. However, from the whole process of paper production and use, this technology also has some shortcomings. First of all, the production of pulp needs a lot of forest resources. On the other hand, pulp will cause serious water pollution in production, and in some cases the pollution degree even exceeds that of plastic. Therefore, from a macro perspective, using paper instead of plastic can not completely eliminate environmental pollution, but only advance the environmental pollution of tableware when making lunch boxes. Moreover, the production cost of pulp is high, which makes the price of paper tableware produced with pulp higher, so it is not a perfect scheme to replace plastic with paper.

(4) Biodegradable technology This technology mainly uses starch as the main raw material, adds annual plant fiber powder and special additives, and makes biodegradable fast food boxes by chemical and physical methods. Because starch is a biodegradable natural polymer, it will be decomposed into glucose and finally into water and carbon dioxide under the action of biological agents, which has no pollution to the environment. In addition, the materials mixed with it are also biodegradable materials. Therefore, the snack box made of this material has excellent degradation performance. According to the detection of the relevant state departments, the samples began to be moldy in the composting state for five days, and the tested samples were integrated with the compost ten days later. Before the test, the sample will lose its shape and color, and all will become water and carbon dioxide within 40 days. In addition, its raw materials are widely available, such as corn, beans, sweet potatoes, cassava and so on. And the price is low, and the cost of each biodegradable snack box produced by this material is only 0. 18-0.20 yuan; No pollution in the production process; The additive is non-toxic and harmless edible bio-gum, which can be further developed as feed after use and has the effect of recycling.

The lunch box made by this technology not only has excellent degradation performance, but also all other performance indexes have passed the detection of relevant technical supervision departments and are in line with relevant national technical standards. At the appraisal meeting of scientific and technological achievements sponsored by Beijing Science and Technology Commission, relevant experts agreed that this product has advanced international level compared with similar products and is an ideal advanced material to replace plastic foamed tableware. What is particularly gratifying is that in order to realize its industrial production, R&D has also developed a fully automatic production line for producing biodegradable fast food boxes, which provides a solid industrial foundation for it to completely replace plastic foamed tableware and completely eradicate "white pollution". We wish the main rookie in environmental protection products-degradable fast food boxes to make continuous progress and make due contributions to improving and improving China's environmental protection level.

6 conclusion

Through the investigation and analysis of a small unit such as university canteen for several months, our investigation team deeply realized the seriousness and harmfulness of using plastic bags in universities. After the statistics of the survey data came out, every member of our science and technology investigation team was very shocked. The consumption of plastic products is so large and the scope is beyond our expectation. As far as colleges and universities in China are concerned, the daily usage of canteens alone is as high as 33.879 million, weighing about 67.8 tons.

In the era of growing population, plastic waste occupies almost every corner of the city and competes with human beings for every inch of land. It is urgent to control "white pollution", and everyone is responsible.

(1) Colleges and universities should do a good job in environmental protection education, earnestly strengthen awareness quality education and publicity activities in this regard, and make everyone realize that this kind of indiscriminate use of plastic bags should be put an end to;

(2) Relevant departments of colleges and universities should strengthen management measures and provide a series of effective measures to facilitate students;

(3) Students in our colleges and universities should set an example. In the absence of effective enforcement of the existing ban, they should try not to use or use less plastic bags for catering. They can bring their own plastic bags when they visit the supermarket. They should not throw white garbage, improve the utilization rate of plastic products, and try their best to make others use less disposable plastic products.

(4) China lags far behind advanced countries in terms of actual benefits of recycling. In the future, it is necessary to further improve the system, establish and improve a feasible recycling mechanism, manage and utilize laws and regulations, strengthen the pace of scientific research departments, do a good job in promoting the recycling of waste plastics, and learn from foreign advanced technologies to make today's "white pollution" a hero for the benefit of mankind;

(5) Actively promote the research on low-cost and high-quality degradable plastics, and gradually eliminate "white pollution" from the source.

Finally, I wish more people of insight to embark on the long journey of eliminating "white pollution" and jointly draw a clean and beautiful new world.

7 references

(1) Environment, "Three Ways to Control White Pollution", Luo Guishan, 2004+02.47.

(2) Green Life and Future, edited by Jingling Liu, Chemical Industry Press, April 68, 2002 (3) Environmental Network.

On the use of plastic bags in student canteens of universities in Xi.

Ask questions and check

It is more serious to use plastic bags in university canteens now. To this end, we hope to conduct a questionnaire survey among students. The questionnaire is divided into two parts. I hope the students will actively cooperate with our survey and fill in the questionnaire carefully!

I. About plastic bags for dining in colleges and universities:

1. Your university is:

2. Do you use dining plastic bags () in the canteen of your school?

A. yes; B. No. (If not, please continue with the second part of the selection.)

3. What food is packed in plastic bags in your school canteen (multiple choices are allowed) ()

A. rice, stir-fry; B. porridge, porridge; C. steamed bread, steamed buns and cakes; D. casserole and noodles;

E. Others

4. How many plastic bags do you use every day?

a . 1 ~ 3； b . 4 ~ 6； C. more than 6.

5. Do you think the plastic bags used in the canteen are safe and clean ()

A. yes; B. no; C.i don't know

6. Why do you pack food in plastic bags ()

A. convenience; B. I am too lazy to wash the dishes; C. everyone uses it; other

7. If the school forbids the use of plastic bags, you will feel ()

A. extremely inconvenient; B. it's a little inconvenient; C.it doesn't matter; D. very good; other

Second, about "white pollution":

1. Do you think the plastic bags used in school canteens will cause white pollution?

A. no; B. there is pollution, but it is not serious; C. yes; other

Do you know anything about "white pollution"

A. understanding; B. I probably know; C. I don't know much; D. I don't know.

3. Do you know the way to deal with plastic garbage?

A. know; I don't know.

4. If you walk in the school cafeteria and find that almost everyone carries at least 2 ~ 4 plastic bags for rice, how will you feel ()

A. disgust; B. it doesn't matter; other

Are there any good suggestions and effective measures to ban the use of plastic bags for meals in colleges and universities?

Northwest university chemical engineering college science and technology investigation team