无投影片标题-EnvironmentalProtectionDepartment.ppt

保護臭氧層OZONE LAYER PROTECTION 臭氣層 OZONE LAYER 在離地面15至35 公里的平流層內，由臭氧氣體形成的一道屏障 A shield of ozone gas in the stratosphere between 15 to 35 km 它能吸收紫外光的輻射，因此可阻擋來自太陽有害光線的滲透 It absorbs ultraviolet (UV) radiation, thus inhibiting penetration of harmful UV rays from the sun 一九七五年，科學家己測到每年春季，南極洲上空豐厚的臭氧層呈現急 劇轉薄的現象 In 1975, scientists have detected a severe drop in ozone abundance in the layer over Antarctica each spring 臭氣層 OZONE LAYER 一九八七年， 發現南極洲上空的臭氧層消失了一半，出現一個大缺 口，面積相等於美國總面積的兩倍 In 1987, half of Antarctica’s ozone was found to have disappeared over a region twice the size of US, creating an enormous “hole” in the ozone layer 當地球表面受到更多紫外光的輻射時： With more UV radiation reaching the earth’s surface : 皮膚癌、白內障等發病率增加，人體免疫系統受損 Increased incidence of skin cancer, eye cataracts, damage to human immune system 地球生態系統受破壞 Damage to the ecology of the earth 臭氧層的損耗，乃由損耗臭氧層的物質所造成 Ozone depletion is caused by the ozone depleting substances 消耗臭氧層的物質OZONE DEPLETING SUBSTANCES (ODSs) 是人造化學化合物 - 鹵烴、其中包括碳和鹵素(氟、氯或溴)原子 A family of man-made chemical compounds- halocarbons, containing carbon and halogen (Fluorine, Chlorine or Bromine) atoms ODSs 性質極其穩定，延續長久，存在於大氣下層，可飄浮至離地 面16公里的平流層 Extremely stable and a long life span in the lower atmosphere allowing transport to the stratosphere situated 16 km above the ground level 在平流層內ODSs遭紫外光作用而分解，釋出氯原子與臭氧作用而產 生氧分子，因而降低平流層內臭氧濃度 In the stratosphere, ODSs are broken down by the action of ultraviolet light, releasing chlorine atoms, reacting with ozone to produce molecular oxygen, thus reducing the ozone concentration of the stratospheric ozone layer.  消耗臭氧層物質包括 ODSs include 含氯氟氫 ChloroFluoroCarbons (CFC) 鹵代碳氫化合物 (哈龍) HALogenated hydrocarbON (HALON) 甲基氯仿 (1,1,1-三氯乙烷) Methyl Chloroform (1,1,1-trichloroethane) 甲基溴 Methyl Bromide 四氯化碳 (四氯甲烷) Carbon tetrachloride (Tetrachloromethane) 含溴氟氫 HydroBromoFluoroCarbons (HBFC) 含氯氟氫 HydroChloroFluoroCarbons (HCFC) 消耗臭氧層物質的用途 APPLICATION OF ODS CFC, HCFC ： 供冷氣工程和製冷工業用作冷卻劑 (CFC-11, CFC-12