Such a huge number of batteries exposes a big problem, that is, how to make so many batteries not destroy and pollute our living environment. According to our investigation, waste batteries contain a lot of heavy metals and electrolyte solutions such as waste acid and waste alkali. If discarded at will, corrupt batteries will destroy our water source, erode the crops and land on which we depend, and our living environment is facing great threats. If a 1 battery rot in the ground, its toxic substances can make one square meter of land lose its use value; Throw a grain of button cell into the water, and the toxic substances it contains will pollute 600,000 liters of water, which is equivalent to a person's lifetime water consumption; Waste batteries contain heavy metals such as cadmium, lead, mercury, nickel, zinc and manganese, among which cadmium, lead and mercury are harmful to human body. However, although metals such as nickel and zinc are beneficial substances in a certain concentration range, exceeding the limit in the environment will also cause harm to the human body. Heavy metals oozing from waste batteries will pollute rivers, lakes, oceans and other water bodies, endanger the survival of aquatic organisms and the utilization of water resources, and indirectly threaten human health. Waste acid, waste alkali and other electrolyte solutions may pollute the land, acidifying and salinizing the land, just like a time bomb buried around us. Therefore, the collection and disposal of waste batteries is very important. If it is not handled properly, it may cause serious harm to the ecological environment and human health. Discarding waste batteries at will not only pollutes the environment, but also wastes resources. Someone has calculated an account. Based on the annual production of 654.38+000 billion batteries in China, the annual consumption is 654.38+056 million tons of zinc, 226,000 tons of manganese dioxide, 2080 tons of copper, 27,000 tons of zinc chloride, 79,000 tons of ammonium chloride and 43,000 tons of carbon rods. Although advanced technology has given us the right direction, the battery pollution situation in China is still not optimistic. At present, most of the waste batteries in China are mixed with domestic garbage and buried underground. Over time, after transformation, the batteries rot and heavy metals dissolve, which may pollute groundwater and soil and eventually enter the human food chain through various channels. Heavy metals ingested by organisms from the environment are gradually enriched thousands of times in higher organisms through the biomagnification of the food chain, and then enter the human body through the food chain and accumulate in some organs, leading to chronic poisoning. Minamata disease in Japan is a typical case of mercury poisoning.
Batteries are generally divided into disposable batteries and rechargeable batteries. The main disposable batteries are zinc-manganese battery (containing zinc and manganese dioxide), zinc-mercury battery (containing zinc and mercury oxide) and lithium battery. The main rechargeable batteries include Cd-Ni battery, Fe-Ni battery, Zn-Ag battery, Zn-air battery, lithium iron sulfide battery and lead-acid battery. Zinc-manganese battery and zinc-mercury battery are the most commonly used batteries in our daily life, and mercury (Hg) and cadmium (Cd) are the main pollutants that pollute the batteries.
Toxicity of mercury
Mercury, commonly known as "mercury", is a liquid substance at room temperature, which can prevent the oxidation of cathode metal zinc in the battery and improve the storage life of the battery. So as early as before, almost all batteries with zinc as the negative electrode had a certain amount of mercury as a preservative. However, the combination of mercury and mercury is neurotoxic and has adverse effects on endocrine system and immune system. It will lead to slurred speech, unsteady gait, quadriplegia, and finally lead to general spasm and mental disorder and death.
For a long time, when producing dry batteries in China, a toxic substance-mercury or mercury compounds has to be added. The mercury content of alkaline dry batteries in China is 1%~5%, and that of neutral dry batteries is 0.025%. The mercury used in the production of dry batteries in China reaches dozens of tons every year. With the progress of science and technology, the battery began to gradually implement low mercury and mercury-free, and the fluoropolymer Forafac, which replaced mercury, achieved good results in preventing zinc corrosion.
Toxicity of cadmium
Cadmium is not an essential trace element for human body. There is no cadmium in newborn babies, but it will gradually accumulate with age. Cadmium has nephrotoxicity, and the damage of cadmium to kidney is irreversible. At the same time, osteoporosis, chondrosis, fracture and so on can occur after kidney injury. In 1993, the International Union for Cancer Control designated cadmium as a carcinogen of IA. For the above reasons, many developed countries suggested that the use of cadmium-nickel batteries should be banned, and nickel-hydrogen batteries replaced cadmium-nickel batteries, thus avoiding the use of cadmium. However, most battery manufacturers in China still use cadmium as raw material to produce batteries, which further increases the harm of batteries.
Mercury
Mercury discarded in natural batteries will slowly overflow from the batteries and enter the soil or water source. Under the action of microorganisms, inorganic mercury can be converted into methyl mercury, which will gather in fish. After eating this fish, methylmercury will enter human brain cells, causing serious damage to human nervous system, and even people will go crazy and die. The famous Minamata disease in Japan is caused by methylmercury.
manganese
Excessive accumulation of manganese in the body can cause neurological dysfunction, and the early manifestations are comprehensive dysfunction, monotonous speech, dull expression, apathy and mental symptoms.
cadmium (Cd)
Long-term consumption of water and food contaminated by cadmium will lead to bone diseases. After cadmium enters the human body, it will cause osteomalacia and bone deformation, and in severe cases, it will form natural fractures and lead to death.
lead to
Lead mainly acts on nervous system, hematopoietic system, digestive system, liver, kidney and other organs, which can inhibit the anabolism of hemoglobin, and can also directly act on mature red blood cells, which is very harmful to infants. Chronic lead poisoning will lead to physical retardation and mental retardation of children.
nickel
Nickel powder is soluble in blood, participates in internal circulation, and has strong toxicity, which can damage the central nervous system, cause vascular variation, and even lead to cancer in severe cases.
Recycling of waste batteries
Although the waste battery is small, it is very harmful. However, because the pollution of waste batteries can not be felt by the senses like garbage, air and water pollution, it has great concealment, so it has not been paid due attention. At present, China has become a big country in battery production and consumption, and waste battery pollution is a major environmental problem that needs to be solved urgently.
According to environmental experts, for every 65,438+0,000 grams of metal recovered from waste batteries, there are 82 grams of mercury and 88 grams of cadmium. It can be said that recycling waste batteries not only controls pollution sources, but also realizes the recycling of resources. Foreign developed countries attach great importance to the recycling of used batteries. Many countries in western Europe have special waste battery recycling bins not only in shops, but also in the streets. 95% materials in waste batteries can be recycled, especially heavy metals. For example, the foreign recycled lead industry has developed rapidly, and 55% of the existing lead production comes from recycled lead. In the lead recovery industry, the recovery of waste lead batteries accounts for a large proportion. 100 kg waste lead battery can recover 50 ~ 60 kg lead. There are mature technologies abroad for the regeneration of waste batteries containing cadmium. About 20 kilograms of cadmium can be recovered by treating 100 kilograms of cadmium-containing waste batteries. Environmental protection treatment is mainly adopted for mercury-containing batteries to prevent them from polluting the environment. However, China's current management in this area is quite weak.
Note: Do not connect the two ends of the battery, otherwise the battery will be damaged by short circuit.
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The harm of heavy metals can be derived from the harm of waste batteries. Some examples are given below.
Minamata disease in Japan /view/ 1670239.htm