環(huán)境生態(tài)學(xué)---第二十三章空氣、水和土壤污染物-文庫(kù)吧在線文庫(kù)
【正文】 n (W3) Air, water and soil pollutants (W1) 溫室效應(yīng) “溫室效應(yīng)”（ greenhouse effect）是這樣一種理論，它假設(shè)二氧化碳和甲烷這樣的普通人為污染物造成的污染會(huì)導(dǎo)致全球氣溫的上升。低空（對(duì)流層）的臭氧是有毒的，可由化石燃料釋放的光化學(xué)煙霧生成。據(jù)估計(jì)，單個(gè)氯原子能破壞 100000個(gè)臭氧分子。相對(duì)少量的增加紫外輻射會(huì)引起復(fù)制過(guò)程中的突變，從而導(dǎo)致癌細(xì)胞的生成。如果將大氣中的二氧化碳濃度在已有水平上翻倍，預(yù)計(jì)氣溫將上升 ℃ 左右。存在于巖石圈的化石燃料（煤、石油和天然氣）直到最近幾個(gè)世紀(jì)才被挖掘出來(lái)。砒霜是最常見的 砷化物，口服 50mg即可引起急性中毒， 60600mg(一般 200mg)可致死，兒童的最低致死量為 1mg／ kg體重。生物除污是利用微生物凈化污染土壤的一項(xiàng)技術(shù)。 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 group of stable chlorinated pounds, that are highly toxic to vertebrates. Water pollutants 水體污染物 水污染分為四類：（ i）生物試劑，（ ii）溶解的化學(xué)物質(zhì)，（ iii）不溶的化學(xué)物質(zhì)和（ iv）熱。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）?；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）。 水污染 A range of chemical cause soil pollution problems, of which halogens (primarily solvents and pesticides) constitute the largest group. These chemicals are manufactured. The most plex group of pounds which are found polluting soils include polymers such as nylon, plastics and rubber. Bioremediation is a technique of utilizing microanisms for the decontamination of polluted soils. S
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1