water pollutants and their sources(水污染及污染源).docx

Ppt1 Here Id show the water pollutants and their sources.Ppt2 The wide range of pollutants discharged to surface waters can be grouped into broad classes, as shown in Table . Domestic sewage and industrial wastes are called point sources. Urban and agricultural runoff are called non-point sources. dmestk su：d生活污水城市和农业径流Ppt3 Here I list some contaminants kntminnt The Oxygen-demanding material 需氧物质Nutrients nju:trint 营养物质Pathogens Organisms pdns 病原微生物Suspended solids or sediments sdmnt 沉积物Salts Toxic metals tksk 有毒金属And we will discuss them later.Ppt4 Point sources First the point sources. Domestic sewage and industrial wastes are called point sources because they are generally collected by a network of pipes or channels and conveyed to a single point of discharge into the receiving water. As is shown in the picture.Channels tnlz 通道，水槽Domestic sewage consists of wastes from homes, schools, office buildings, and stores. The term municipal sewage is used to mean domestic sewage into which industrial wastes are also discharged.municipal sewagemjnsp()l城市污水In general, point source pollution can be reduced or eliminated through waste minimization and proper wastewater treatment prior to discharge to a natural water body.eliminatedlmnetd消除minimization,mnmzen最小Priorpra在前Under the Federal Water Pollution Control Act of 1972 some animal feeding operations (AFOs) may be designated as a point source. AFOs are designated point sources if the feeding operation may be classified as a concentrated animal feeding operation (CAFO). AFOsis an organophosphorus pesticidesFedaral 联邦AFOs 灭蚜磷Designated dzg,netd指定的organophosphorus,g()nfsf()rs有机磷pesticidespestsadz杀虫剂Ppt5 Non-point sources Urban and agricultural runoff are characterized by multiple discharge points. These are called non-point sources. mltpl多个城市和农业径流具有多个放电点。Often the polluted water flows over the surface of the land or along natural drainage channels to the nearest water body. Even when urban or agricultural runoff waters are collected in pipes or channels, they are generally transported the shortest possible distance for discharge, so that wastewater treatment at each outlet is not economically feasible.drainage channelsdrend排水沟feasible可行的 And we have a picture about Analysis and usage of urban rainfall and flood current Non-point pollution from urban storm water and, in particular, storm water collected in combined sewers that carry both storm water and municipal sewage requires major engineering work to correct. As the picture shows.sewersu; sju下水道，结合管道 flood current洪流Ppt6 Agricultural runoffRunoff from agricultural land is a significant non-point source. Fertilizer, whether in the form of manure or commercial fertilizer, contributes nutrients. manuremnj肥料，粪便commercial fertilizer商业肥料And from the photo we can see the Agricultural runoff of The loess plateau Agricultural runoff carries nutrients and toxic organic compounds.Soil erosion contributes suspended solids. loess plateauls; ls plt黄土高原Ppt7 the oxygen-demanding materialThe definition: Anything that can be oxidized in the receiving water with the consumption of dissolved molecular oxygen is termed oxygen-demanding material. Consumption:knsm(p)()n 消耗molecularmlekjl分子This material is usually biodegradable organic matter but also includes certain inorganic compounds.Biodegradable ,ba()dgredb()l 可生物降解The consumption of dissolved oxygen, DO (pronounced “dee oh”), poses a threat to fish and other higher forms of aquatic life that must have oxygen to live. poses a threat to 威胁Then we have an extension.(图片)The critical level of DO varies greatly among species.For example, brook trout may require about7.5 mg/L of DO, while carp may survive at 3 mg/L. So in pond farming we have DO controller.as the picture. extension 扩展critical临界mg/L: Milligrams per literBrook trout brk trat溪红点鲑carp鲤鱼Next, their sources.Oxygen-demanding materials in domestic sewage come primarily from human waste and food residue.Particularly noteworthy among the many industries that produce oxygen-demanding wastes are the food processing and paper industries.domestic sewage生活污水Human waste 人类粪便Food residue rezdju食物残渣Ppt8 NutrientsNitrogen and phosphorus, two nutrients of primary concern, are considered pollutants because they are too much of a good thing.Nitrogennatrd()n氮Phosphorus fsf()rs 磷 All living things require these nutrients for growth. Thus, they must be present in rivers and lakes to support thenatural food chain. And problems arise when nutrient levels become excessive and the food web is grossly disturbed, which causes some organisms to proliferate.Chain 链Excessive ksesv 过量Grossly严重的Proliferate prlfret 增殖Excessive nutrients often lead to large growths of algae, which in turn become oxygen-demanding material when they die and settle to the bottom. So I choose a photo of eutrophication.algae藻类eutrophication富营养化Some major sources of nutrients are phosphorus-based detergents, fertilizers, and food-processing wastes.detergentdtd()nt洗涤剂化肥，食品加工废弃物Ppt9 Pathogenic OrganismsMicroorganisms found in wastewater include bacteria, viruses, and protozoa excreted by diseased persons or animalsMicro/organisms 微生物viruses病毒protozoa,protzo原生生物excrete排泄When discharged into surface waters, they make the water unfit for drinking Bacteria that have developed immunity to antibiotics are now being found in natural waters . The resistance of the bacteria appearing in natural waters is an ominous prelude to the future effectiveness of antibiotics.Immunity mju：nt免疫力Antibiotics,ntbatks抗生素resistance 阻力ominous mns预兆的，不吉利的prelude prelju：d前奏Cholera and typhoid are endemic diseases in the world with over 384,000 cases of cholera and 16 million cases of typhoid per year.Here we have photo of Vibrio cholerae.Cholera 霍乱Vibrio cholerae霍乱弧菌typhoid tafd伤寒的endemic endemk地方性的Ppt10 Suspended SolidsOrganic and inorganic particles that are carried by the wastewater into a receiving water are termed suspended solids (SS).When the speed of the water is reduced by flowing into a pool or a lake, many of these particles settle to the bottom as sediment.In common usage, the word sediment also includes eroded soil particles that are being carried by water even if they have not yet settled.Sedimentsedm()nt沉积物ero