pollution of air and water

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POLLUTION OF AIR AND WATER

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gives a detailed account on the varying causes of pollution-air and water (as guided by the oxford science text of class 8).

TRANSCRIPT

  • PERCENTAGE OF AIR IN ATMOSPHERE :- NITROGEN-78.08%,OXYGEN-20.95% & others -0.97%
  • AIR POLLUTION- THE PRESENCE OF CHEMICALS IN THE AIR IN QUANTITIES HARMFULL TO HUMAN HEALTH AND THE ENVIRONMENT IN WHICH THEY LIVE IS KNOWN AS AIR- POLLUTION. NOW WE MOVE ONTO THE COMMON AIR-POLLUTANTS AND THEIR MAJOR SOURCES ON THE NEXT SLIDE COMING UP:- -PARTICULATE MATTER -OXIDES OF SULPHUR AND NITROGEN -CLOROFLUROCARBONS -CO2&CARBON MON OXIDE
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  • AN INCREASE IN THE AMOUNT OF CO2 AND CERTAIN OTHER GASES IS RESPONSIBLE FOR A PHENOMENON KNOWN AS GLOBAL WARMING. GREEN HOUSE-EFFECT IS THE PHENOMENONWHEREBY THE EARTHS ATMOSPHERE TRAPS THE SOLAR RADIA TION BECAUSE OF THE PRESCENCE OF GASES SUCH AS CO2,WATER VAPOUR, METHANE ETC.
  • 2.THE EARTHS SURFACE RADIATES HEAT TO THE ATMOSPHERE SOME OF WHICH ESCAPES INTO THE SPACE.GREENHOUSE GASES SUCH AS CO2 & METHANE ABSORB SOME OF THE HEAT & SEND IT BACK TO EARTH. 1.SUNLIGHT PENET - RATES THE ATMOS PHERE & WARMS THE EARTHS SURFACE. 3.WHEN THE CONCENTRATION OF GREEN HOUSES INCREASES IN THE ATMOSPHERE ,MORE HEAT IS TRAPPED NEAR THE EARTHS SURFACE.THIS RESULTS IN A RISE IN THE EARTHS SURFACE TEMPERATURE.
  • CAUSES POSSIBLE EFFECTS *DEFORESTATION. *INCREASE IN EARTHS SURFACE TEMPERATURE *BURNING OF FOSSIL FUELS. *MELTING OF POLAR ICE CAPS *RELEASE OF METHANE DUE TO THE BREAK DOWN OF ORGANIC MATTER. *RISE IN GLOBAL SEA-LEVEL RESULTING IN THE FLOODING OF LOW LYING COASTAL REGIONS
  • AIR POLLUTANTS SUCH AS OXIDS OF SULPHUR & NITROGEN REACT WITH O2 & WATER VAPOUR OF THE ATMOSPHERE ,THEY EVANTUALLY FORM DILUTE SOLUTIONS OF H2SO4, &HNO3.THESE ACIDS MIX WITH RAIN WATER & COME DOWN IN THE FORM OF RAIN WATER .
  • -PHOTOCHEMCALSMOG IS SAID TO HAVE AN ADVERSE IMPACTON PLANT GROWTH BECAUSE IT FORMS A LAYER ON LEAVES &,ALONG WITH DUST ,BLOCKS SUNLIGHT FROM BEING ABSORBED BY THR LEAF SURFACE.THIS LAYER BLOCKS THE ABSORPTION OF CO2 BY THE LEAVES AND ALSO AFFECTS THE FUNCTIONING OF THE STOMATA ,THEREBY REDUCING THE RATE OF PHOTSYNTHESIS. -ACID RAIN DAMAGES PLANTS AND CAN ALSO CAUSE PREMATURE LEAF FALL.
  • -CARBON MONOXIDE IN THE AIR EASILY COMBINES WITH THE HAEMOGOBLIN IN THE BLOOD AND HAMPERS THE TRANSPORT OF OXYGEN WITHIN OUR BODY,WHICH CAN LEAD TO DROWSINESS,HEADACHE,DIZZINESS & NAUSEA. -EXPOSURE TO HIGH LEVELS OF SUSPENDED PARTICULATE MATTER ,SULPHUR DIOXDE,OXIDES OF N2O,AND OTHER AIR POLLUTANTS IRRITATES THE EYES ,NOSE ,THROAT & LUNGS.YEARS OF EXPOSURE TO THESE CHEMICALS CAN LEAD TO RESPIRATORY DISEASES SUCH AS LUNG CANCER ,ASTHMA & BRONCHITES.
  • -USE OF UNLEADED PETROL SHOULD BE ENCOURAGED -THE EXHAUST GASES IN VEHICLES SHOULD MADE TO PASS THROUGH THE CATALYTIC CONVERTER WHICH CON VERTS HARMFULL CARBON MONOXIDE & NITROGEN OXIDES TO HARMLESS CO2,NITROGEN OXIDE & H2O,BEFORE RELEASING THE EXHAUST INTO THE AIR.
  • -LESS POLLUTING SUBSTANCE SUCH AS CNG SHOULD BE USED -REGULAR POLLUTION CHECK SHOULD BE MADE MANDATORY FOR ALL VEHICLES -COAL SHOULD BE MADE FREE OF SULPHUR BEFORE BEING BURNT IN POWER PLANTS.ONLY LOW-SULPHUR COAL SHOULD BE USED FOR BURNING.
  • -LESS POLLUTING ENERGY RESOURCES SUCH AS HYDROELECTRICITY,NUCLEAR ENREGY SHOULD BE USED. -USE OF PUBLIC TRANSPORT SHOULD BE ENCOURAGED
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  • -INDUSTRIAL WASTES DISCHARGED INTO THE WATERS CONTAIN A LOT OF TOXIC SUBSTANCES THAT MAKE WATER UNFIT FOR DRINKING & BATHING. -UNTREATED DOMESTIC SEWAGE WHEN DISCHARGED INTO WATER BODIES ,BECOMES A BREEDING GROUND FOR A NO. ORGANISMS THAT CAUSE WATER BORNE DSEASES.
  • -OIL SPILLS ARE VERY HARMFUL TO AQUATIC ANIMALS , WHICH LEAD TO DESTRUCTION OF MARINE LIFE. MOREOVER, THE CLEANING UP PROCESS ALSO TAKE A LOT OF DAMAGE TO THE MARINE LIFE. -IGNITION OF ARMS AND MERCURY RELEASE A LARGE AMOUNT OF MERCURY.WHEN WATER CONTAMINATED WITH MERCURY IS USED FOR DRINKING BY ANIMALS AND HUMAN BEINGS IT CAN CAUSE NUMBNESS TO LIMBS,LIPS & TONGUE. IT CAN ALSO LEAD TO BLURRED VISION & MENTAL DISORDERS. -THE WASTE WATERS RELEASED BY FACTORIES & INDUSTRIES AND THE FERTILIZER RICH RUN-OFFS FROM THE AGRICULTUREFIELDS IS RICH IN ORGANIC-MATTER.
  • THE ENTRY OF NUTRIENT-RICH WATERRESULTS IN A THICK GROWTH OF ALGAE,CALLED ALGAL BLOOM,AND MANY OTHER WEEDS.SOON THESE PLANTS COVER THE ENTIRE SURFACE OF WATER .THIS IS CALLED EUTROPHICATION MAY BE DEFINED AS THE THE ALGAE USE UP A LOT OF OXYGEN THAT THE OTHER AQUATIC ANIMALS DIE DUE TO LACK OF IT. ALGAL BLOOMS SHUTS OUT THE SUNLIGHT. LIMIT OF LIGHT PENETRA -TION DEAD WATER NO LIVING AQUATIC PLANT OR ANIMAL LIFE.
  • -BATHING AND WASHING CLOTHS IN WATER BODIES SHOULD 0BE AVOIDED. -DOMESTICS AND INDUSTRIAL SEWAGES SHOULD BE TREATED TO REMOVE TOXIC SUBSTANCES BEFORE BEING RELEASED INTO WATER BODIES
  • -POLLUTION CONTROL RULES ENFORCED BY THE GOVERMENTSHOULD BE FOLLOWED STRICTLY -USE OF ECO-FRIENDY FERTILIZERS & HERBICIDES SHOULD BE ENCOURAGED
  • THE WATER SUITABLE FOR DRINKING BY HUMAN BEINGS IS KNOWN AS -BE TRANSPARENT,COLOURLESS AND ODOURLESS. -CONTAIN SUFFICIENT AMOUNTS OF SALTS & OXYGEN -BE FREE FROM HARMFUL CHEMICALS AND MICRO- ORGANISMS
  • 1.WATER COLLECTED FROM THE RIVER IS MADE FREE OF LARGE PIECES OF DIRT & PUMPED INTO RESORVOIRS. 2.WATER IS ALLOWED TO STAND IN LARGE TANKS SO THAT SUSPENDED IMPURITIES SETTLE DOWN.THIS IS CALLED SEDIMENTATION. 3.WATER IS PASSED THROUGH FILTER BEDS TO REMOVE ALL OTHER INSOLUBLE IMPURITIES.THIS IS CALLED FILTRATION. 4.WATER IS CHLORINATED TO KILL ANY HARMFULL MICRO ORGANISM THATIS PRESENT AT THIS STAGE. 5.WATER IS SUPPLIED TO HOMES & FACTORIES BY HUGE WATER MAINS
  • BOILING-BOILING WATER IS ONE OF THE EASIEST WAY OF PURIFYING WATER.IT IS, HOWEVER VERY IMPORTANT THAT WATER IS BOILED AT 100C FOR AT LEAST 10-15 MINUTES TO KILL HARMFULL MICRORGANISMS. ADDITION OF CHEMICAL TABLETS-CHEMICALS LIKE CHLORINE TABLETS AND POTTASIUM PERMAGNATE CAN BE ADDED TO WATER FROM WELLS AND WATER TANKS TO KILL HARMFULL MICRO ORGANISMS & GERMS.
  • USE OF ELECTRIC WATER FILTERS-THEY HAVE A MICRO POROUS FILTERS, CARBON & A SOURCE OF ULTRAVIOLET RADIATION. THE MICRO PORUS FILTER STRAINS OUT PHYSICAL IMPURITIES PRESENT IN THE WATER SUCH AS DUST, RUST etc. CARBON ABSORBS ORGANIC IMPURITIES & REMOVES UNWANTED TASTE & ODOUR. ULTRA VIOLET RADIATION KILLS MICRO ORGANISMS.
  • BOTANISTS AND MANY COMMERC -IAL PLANT GROWERS USE GREEN HOUSE GASES FOR GROWING PLA -NTS IN COLD CLIMATE CONDTION -S THE TEMPRATURE INSIDE A GRE -EN HOUSE IS HIGHER THAN THE TEMPRATURE OUTSIDE BECAUSE THE SOLAR INTERIORS OF THE GREENHOUSE IS REMMITED INTO THE GREEM HOUSE, THUS KEEPING IT WARM.THIS IS WHAT HELPS PLANT GROW. ALTHOUGH 75% OF EARTHS SURFACE IS COVERED WITH WATER, A MERE 0.01% OF THIS WATER IS AVAILABLE FOR HUMAN CONSUMPTION .THIS IS BECAUSE THE WATER PRESENT IN THE OCEANS & SEAS ARE SALTY AND, HENCE CANNOT BE USED FOR DRINKING. IN ADDITION, MOST OF THE FRESH WATER IS FROZENIN THE GLACIERS & POLAR ICE CAPS AND IS,THEREFORE NOT ACCESABLE. WORD HELP
  • WATER POLLUTION WAYS TO REDUCE POLLUTION AIR POLLUTION