Fine abstracts of chemistry:
First, the harmfulness of waste batteries
Second, the composition analysis and harm of waste batteries
Third, deep personal feelings have benefited a lot.
Keywords: waste batteries, environmental pollution, environmental protection, benefit mankind
Foreword:
In recent two years, the impact of waste batteries on the environment has become one of the hot topics in domestic media. It is reported that batteries seriously pollute the environment, and one battery can pollute hundreds of thousands of cubic meters of water. Some people even say that the disposal of waste batteries together with domestic garbage will cause harm such as Minamata disease in Japan. These reports have aroused great repercussions in the society, and many people and groups who love environmental protection have carried out or participated in the activities of recycling used batteries. As middle school students in the new century, we should also join in the activities to prevent waste battery pollution.
Text:
Waste batteries contain toxic substances such as mercury, cadmium, lead and zinc. If people are poisoned by mercury, it will damage the central nervous system and the mortality rate is as high as 40%. The main harm of cadmium is nephrotoxicity, and it can also cause "pain" (causing osteoporosis, rickets and fractures), and it is also a carcinogen; Eating lead-containing food will affect the synthesis of enzymes and normal heme, and affect the nervous system;
Within one month of landfill treatment, the metal shell of waste batteries will be corroded and perforated, and harmful substances in waste batteries will enter the soil and water, causing environmental pollution. According to environmental experts, if 6 tons of domestic waste is mixed with a mercury-containing battery, when the waste is buried, the mercury concentration in the soil will exceed the safety standard; If waste batteries are mixed with domestic garbage and enter the incineration plant, mercury, cadmium and other metals in them will be gasified and discharged into the atmosphere at high temperature, polluting the atmospheric environment and affecting human health.
Mercury and cadmium in the battery will not leak out and cause harm during normal use.
I. Harmfulness of (waste) batteries:
The hardest part is actually in the beginning In the face of such a big subject, where should we study it? We both thought of starting with the harmfulness of batteries. People say that waste batteries are harmful, so are all waste batteries harmful? What are the hazards of batteries? To this end, we consulted relevant information on the Internet and reached the following conclusions:
Not all waste batteries are dangerous and can't be touched. Different types of batteries have great differences in environmental pollution and should be treated differently. Some batteries, such as alkaline dry batteries and nickel-hydrogen batteries, will not cause serious harm to the environment, but some batteries, such as cadmium-nickel batteries, contain harmful substances, which may directly endanger people's health if they enter the environment for a long time.
(2) battery pollution has the characteristics of centralized production and decentralized pollution; Short-term use, long-term pollution characteristics, battery pollution is because the battery contains the following heavy metals:
Lead: diseases such as nervous system (neurasthenia, numbness of hands and feet), digestive system (dyspepsia, abdominal cramps) and blood poisoning.
Mercury: Mental state change is the main symptom of mercury poisoning. Rapid pulse, muscle tremor, oral and digestive diseases. Minamata disease in Japan is a typical example of mercury poisoning.
Cadmium and manganese: mainly harm the nervous system. After cadmium poisoning, the patient's hands and feet are painful, and the whole body is prone to fracture, commonly known as "pain"
(3) The ways of waste batteries polluting the environment:
As the saying goes: illness comes from the mouth, so does waste batteries. We have analyzed all kinds of battery pollution processes, including the following, and these elements are sealed inside the battery shell, which will not affect the environment. It is through long-term mechanical wear and corrosion that heavy metals, acids, alkalis, etc. The inside leaks out and enters the soil or water source, and then enters the human food chain through various channels, thus endangering human health.
These processes are briefly described as follows:
Battery → soil → microorganism → animal circulation
Dust → crops → food → human body → nerves → deposition.
Others: water source → plants → food → digestion.
Heavy metals absorbed by organisms from the environment can be accumulated step by step in thousands of higher organisms through the biomagnification of the food chain, and then enter people's bodies through food and accumulate in some organs, causing chronic poisoning.
④ Other manifestations of waste battery hazards:
So, how do waste batteries enter the environment? At present, there is no garbage sorting and recycling in China. At present, there are three main ways to treat domestic garbage: sanitary landfill, composting and incineration. The pollution effects of waste batteries mixed with domestic garbage in these three processes are as follows:
Landfill: Heavy metals in waste batteries pollute water and soil through infiltration. (mainly dry batteries)
Incineration: waste batteries corrode equipment at high temperature, and some heavy metals volatilize in the fly ash of the incinerator, causing air pollution, and heavy metals accumulate at the bottom of the incinerator, causing pollution to the generated ash.
Composting: The high content of heavy metals in waste batteries leads to the decline of compost quality.
Harm of waste battery to human body and its treatment
2 1 century is coming to us, but has people's awareness of environmental protection entered 2 1 century? Garbage can be seen everywhere, and spitting has become people's habit. Waste batteries are mixed with garbage, which pollutes the whole social environment and harms people's health. ...
Speaking of batteries, everyone is familiar with them and they are used in daily life. But how many people know that waste batteries pollute the social environment and do harm to human body? What should we do? As a contemporary young master, starting from the sense of responsibility and curiosity to the society, I want to know what elements are in the waste battery and why it is so powerful. During the discussion, the students put forward many reasons, which made us eager to understand the influence of waste batteries on human body and its countermeasures through our own exploration and dependence.
We started the first stage of research-discussing the implementation plan. First of all, I ask the first question: understand the harm of waste batteries. I think we should know the harm of waste batteries before we can dispose of them. Chen Feng proposed how to deal with waste batteries in the next step, and the students agreed. After XX finished speaking, XX couldn't wait to say: It is not enough to know the harm of waste batteries, but also need to be widely publicized in schools, families and society to attract the attention of the whole society. The students think her idea is very good. After brainstorming, we drafted a group plan:
First, understand the social demand for batteries within the limits of roads and bridges (one week)
Understand the social demand for batteries through market research.
Two, through the questionnaire survey, understand the pollution of waste batteries to the social environment and the harm to the human body (one week).
Understand the internal structure of the battery, and understand the harmfulness by checking the information and data.
Three, the disposal of waste batteries (one week and the second step at the same time)
After understanding the harm of the battery, the treatment method of the battery is discussed.
Fourth, widely publicize it to the society (for one week)
After understanding the hazards and treatment methods, conduct publicity.
Although we suffered a lot of setbacks and troubles in the questionnaire survey, we were able to successfully accomplish the expected goal. The survey results of knowledge about the harm of waste batteries show that 76.7% middle-aged cattle people know; 8.3% know very little; 15% people have no idea. Among the middle-aged and elderly people, 55.7% know, 24.3% know little and 20% don't know. Among young people (including students), 98% know the harm to the environment, and only 2% say they know very little, and everyone knows it.
What are the hazards of waste batteries to human beings? According to the data, if the battery is discarded in nature after use, the pollution to the environment is quite serious, and the harm to the human body can not be ignored. Because the battery contains mercury, after the outer metal rusts, mercury will slowly overflow from the battery, enter the soil or groundwater, and then enter the human body through crops or drinking water, which will damage people's kidneys. It is conceivable that a rotten battery can make a square meter of land lose its use value geographically, which is really terrible for people to hear. In addition, we have done experiments with the No.5 battery. We first put half a bottle of tap water in a washed plastic bottle, and then put a No.5 battery into the water. After a while, neither the water nor the battery changed. We took another empty bottle, washed it as before and filled it with water. We also took another used No.5 battery and tried to split it in half with a blade, but neither scissors nor a blade could separate them. Some students suggested knocking with an axe. The next day, a classmate brought an axe, and we took out a No.5 battery and knocked it on a battery with an axe. There were not many rooms, but some gray powder oozed metal, and we knocked on it intermittently, and the gray powder turned dark. After everyone's analysis and judgment, it is determined that these powders are prepared from mercury, cadmium, nickel and lead systems. Through the experiment, we realize that no matter what we do, we must work together with Qi Xin, and we can't back down when we encounter difficulties. Only by overcoming difficulties can we successfully complete the task. Then, we began to discuss the disposal of waste batteries. During the discussion, many good suggestions were put forward:
1. If you go to the store to buy batteries, you should take a waste battery with you, which can be cheap and discounted.
If you want to buy a battery, you can't buy it without wasting electricity.
Write a proposal to tell the residents about the dangers of used batteries, and then let them throw the remaining used batteries into the waste battery recycling box set up by the neighborhood Committee. ...
Second, the composition analysis and harm of waste batteries:
Composition of common batteries
A large number of elements or substances in the battery series are the main harmful substances.
Zinc-manganese battery
Alkaline zinc-manganese battery
nickel-cadmium/nicad battery
nickel-hydrogen battery
LiCo or NiMn organic electrolyte for lithium ion battery
There have been media reports that "a button cell can pollute nearly 600,000 liters of water, which is equivalent to a person's lifetime drinking water" and so on. For this statement, the author analyzes as follows. A survey by a research team at the University of Wisconsin-Madison shows that everyone's water demand varies greatly. Without dehydration, a person's daily intake can rise from the lowest 1.2 to the highest 7.7 liters, which has little to do with age difference. We can do our own calculations. Suppose a person drinks 2.3 liters of water every day on average, and if a natural person lives to 75 years old, the water consumption of a person's life is: 2.3× 365× 75 = 62,962.5 liters =62.9625 cubic meters =62.9625 tons.
Through the above analysis, we know that to understand the environmental pollution caused by heavy metals such as mercury, we should also refer to relevant environmental standards, such as the national standard "Environmental Quality Standard for Surface Water" (standard number: GB3838-2002).
According to the first and second drinking water standards, if each liter of water contains more than 0.00005 mg of mercury, it can be considered that it has broken through the national standards and caused environmental pollution. Therefore, it can be estimated that 5 mg of mercury dissolved in water can pollute 100000 liters of water, which is 10000 liters of water. Our button cell generally contains 3-4 mg of mercury, so even if all this mercury is dissolved in water, it can only cause pollution of 60,000 liters of water, which is equivalent to a person's drinking water for a lifetime. At this point, we have found the source of what the media said: "A button cell can pollute a person's drinking water for a lifetime". But as we said before, diffusion and dissolution take a long time, so this is just an image statement to arouse people's high awareness and everyone should look at it objectively.
Third, deep personal feelings have benefited a lot.
In this exploration activity, we have solved many reasons, learned about the pollution of waste batteries to the environment and the harm to human body, and learned that there are elements in batteries. Not only by looking up data, but also by doing experiments, I personally realized the internal structure of the battery. Now, we not only know the elements in waste batteries ourselves, but also tell the public about the danger of improper disposal of batteries after use. How meaningful! Through this activity, we enjoyed the joy of success after work and improved our social skills.
I hope our exploration and practice can arouse people's awareness of environmental protection and arouse the concern of the whole society for environmental protection and human health.