環(huán)境生態(tài)學(xué)---第二十三章空氣、水和土壤污染物(已修改)
2024-10-28 14:30 本頁(yè)面
【正文】 W1 空氣、水和土壤污染物 要 點(diǎn) 空氣污染 空氣污染是由人類活動(dòng)引起的天然與合成的有害物質(zhì)向大氣中的排放。污染物可直接進(jìn)入大氣（初級(jí)污染物），或在太陽(yáng)輻射的影響下于大氣中產(chǎn)生（次級(jí)污染物）。已表明會(huì)給環(huán)境和健康帶來(lái)威脅的主要空氣污染物包括氧化氮類、二氧化硫、臭氧和固體顆粒?？諝馕廴疽材芨淖儦夂蛞约巴寥?、湖泊和河流的化學(xué)性質(zhì)。 籠罩著空氣污染的城市 Water bodies in northern temperate regions of Europe and North America have suffered form acidification due to ‘a(chǎn)cid rain is a result of fossil fuel burning, which produces sulfur oxides (SOx) and nitric oxide (NO) which may bine with atmospheric water to form sulfuric acid (H2SO4) and nitric acid (HCO3), respectively, The term ‘a(chǎn)cid deposition’ is more accurate as acid may also be deposited from the air in the form of snow, sleet and fog. Acid rain reduces the pH of soil and lakes, while acidification can also cause the death of trees and allow toxic metals (. aluminium and mercury) to be leached from soils and sediments. Acid rain 酸 雨 歐洲和北美的北溫帶地區(qū)的水體已經(jīng)遭受到酸雨帶來(lái)的酸化。酸雨是化石燃燒的結(jié)果?；剂系娜紵龝?huì)產(chǎn)生氧化硫類物質(zhì)（ SOx）和一氧化氮（ NO），它們能分別和大氣中的水分結(jié)合而形成硫酸（ H2SO4）和硝酸（ HNO3）。這種現(xiàn)象稱為“酸降”更恰當(dāng)，因?yàn)樗嵋矔?huì)以雪、雨和霧的形式從空氣中沉降下來(lái)。酸雨降低土壤和湖泊的 pH，同時(shí)酸化也能導(dǎo)致樹木的死亡，并使得有毒金屬（如鋁和汞）從土壤和沉積物中釋放出來(lái)。 酸雨形成 因酸雨致死的樹木 Water pollution can be divided into one of four categories: (i) biological agents, (ii) dissolved chemicals, (iii) nondissolved chemicals, and (iv) heat. The eutrophication of aquatic ecosystems occurs due to an excess of inanic nutrients. Organic matter in the water is broken down by microanisms that deplete the oxygen levels, which may be quantified by the ‘biochemical oxygen demand’ (BOD). A particularly important class of anic water pollutants is the family of polychlorinated biphenyls (PCBs), a g
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1