The Chemical Dictionary introduces you to the hazards o […]
The Chemical Dictionary introduces you to the hazards of sulfur dioxide and preventive measures. Sulfur dioxide is the most common sulfur oxide and one of the major pollutants in the atmosphere. Sulfur dioxide is a colorless, transparent gas with a pungent odor. Soluble in water, ethanol and ether. Liquid sulfur dioxide is relatively stable and inactive. Gaseous sulfur dioxide is heated to 2000 ° C without decomposition. Does not burn, and does not form an explosive mixture with air.
1. The harm of SO2 to human health
SO2 is a colorless gas with strong pungent odor. It is easily soluble in body fluids and other viscous fluids. Long-term effects can cause various diseases such as upper respiratory tract infection, chronic bronchitis, emphysema, etc. , endangering human health. Under the action of oxidant and light, SO2 will produce sulfate aerosols that cause human disease and even increase the mortality of patients. According to relevant research, when the annual concentration of sulfate is about 10μg/m3, the concentration is reduced by 10%. Can reduce mortality by 0.5%;
2. The harm of SO2 to plants
Studies have shown that under the influence of high concentration of SO2, plants produce acute damage, necrotic spots on the surface of the leaves, or directly cause the leaves of plants to wither and fall off; under the influence of low concentration of SO2, the growth function of plants is affected, resulting in a decrease in yield. The quality is getting worse. According to the statistics of 25 factories and enterprises in 13 provinces and cities in China in 1983, the damage area caused by SO2 reached 23,300 hectares, the grain was reduced by 18,500 tons, and the vegetables were reduced by 500 tons. The damage was quite serious.
3. Corrosion of metal by SO2
The corrosion of metals by SO2 in the atmosphere is mainly the corrosion of steel structures. According to statistics, the direct economic losses caused by metal corrosion in developed countries account for 2% to 4% of the total output value of the national economy. The direct loss due to metal corrosion is much greater than the sum of losses caused by floods, windstorms, fires and earthquakes. And metal corrosion directly threatens the safety of industrial facilities, living facilities and transportation facilities.
4. Impact on the ecological environment
The acid rain and acid mist damage caused by SO2 is also quite large, mainly due to the corrosion of lakes, groundwater, buildings, forests, ancient artifacts and human clothing. At the same time, long-term acid rain will also cause immeasurable losses to soil and water quality.
Sulfur dioxide prevention measures
Personal protection: First of all, education on labor protection and safe production should be strengthened. The operator can wet several layers of gauze with saturated sodium carbonate solution and glycerin and then clamp it in the gauze mask to absorb SO2. Before and after work, rinse with 2% sodium carbonate solution.
Conventional treatment of SO2: While paying attention to workers' personal protection, effective measures should be taken to treat SO2 fumes. Since the 1950s, China has carried out a series of experimental research work on the recycling of low-concentration SO2 in non-ferrous smelting flue gas, and has made certain progress.
Ammonium method: Treatment of SO2 by ammonium imide method is to absorb SO2 with ammonia water and by-product ammonium. Although the ammonium imide technology is more mature, the by-product produced is a sub-ammonium in a liquid state. The storage and transportation of the product are difficult, and it is only suitable for a small smelter with an ammonia source.
Sodium sulfite method: Small and medium smelters can use the sodium sulfite method for flue gas desulfurization. The sodium sulfite method utilizes caustic soda or soda ash to absorb SO2 while producing by-product sodium sulfite. For example, the Shanghai smelter uses this method to treat smoke. The sodium sulfite process is simple in process, convenient in operation, low in system resistance, and low in investment and operating costs. The desulfurization efficiency is as high as 95%. The sulphate is 0. 8 t, caustic soda 0. 1 t. The by-product sodium sulfite is of limited use and therefore cannot be universally used.