Pollution of WaterAshish Kumar SinghRoll no.11Guided by Dr. Laxmikant L.
DEFINITIONA change in the chemical, physical,biological and radiological quality ofwater that is injurious to its existing,intended or potential use
Where do Water pollutants come from? Point Sources – A single definable sourceof the pollution, e.g. a factory, a sewageplant, etc. Point-source pollution is usuallymonitored and regulated.
Non-point sources – is not a single source,but a wide range of sources, e.g. runoff fromurban areas, or farmland. Non-pointsources are much more difficult to monitorand controlWhere do Waterpollutants come from?
Water pollutants Industrial EffluentsThis waste water may contain acids, alkalis, salts, poisons,oils and in some cases harmful bacteria. Mining and Agricultural WastesMines, especially gold and coal mines, are responsible forlarge quantities of acid water. Agricultural pesticides, fertilizers and herbicidesmay wash into rivers and stagnant water bodies. Sewage Disposal and Domestic WastesSewage as well as domestic and farm wastes often polluterivers and dams.
Non-persistent (degradable)water pollutants These compounds can be broken downby chemical reactions or by naturalbacteria into simple, non-pollutingsubstances such as carbon dioxide andnitrogen. if the pollution load is high, this processcan lead to low oxygen levels andeutrophication. This damage is reversible.
Non-persistent (degradable)Water pollutants Domestic sewage Fertilizers Some industrial wastes
Persistent Water pollutants This is the most rapidly growing type ofpollution This includes substances that degrade veryslowly or cannot be broken down at all; They may remain in the aquatic environmentfor years or longer periods of time. The damage they cause is either irreversibleor repairable only over decades or centuries
Persistent Water pollutants some pesticides (e.g., DDT, dieldrin) petroleum and petroleum products PCBs, dioxins, polyaromatic hydrocarbons(PAHs) radioactive materials such as strontium-90,cesium-137, radium-226, and uranium metals such as lead, mercury, cadmium
Other water quality pollutants warm water from cooling towers(thermal pollution) floating debris garbage foam
1. Classes of WaterpollutantsPathogens Bacteria, Viruses, Protozoa,Parasitic Worms, Colliform Bacteria Used AsIndicators Of Water QualityOxygen Demanding Wastes Organics That AreDecomposed By Bacteria And That Use A Lot OfO2, Dissolved Oxygen (DO) Decreases, And BODIncreasesWater Soluble Inorganic Chemicals Acids,Salts, Toxic Metal Compounds Like Mercury, AndLead.Inorganic Plant Nutrients Water SolublePhosphates, Nitrates => Algal Blooms, DecreasedDissolved O2, Increased BOD.
2. Classes of Waterpollutants Organic Chemicals Oil, Gas, Plastics, Pesticides, CleaningSolvents, Detergents, Etc. Radioactive Isotopes Are Biologically Amplified To HigherConcentrations In The Food Chain.Ionizing Radiation cause Birth Defects, Cancer. Warmed Water From Power Plants.Decreases DO And Increases Susceptibility To Diseases.
Industrial Waterpollution Industries discharge a variety ofpollutants in their wastewater includingheavy metals , resin pellets, organictoxins, oils, nutrients, and solids.
Over 1 billion people lack access tosafe water supplies, while 2.6 billionpeople lack adequate sanitation. Thishas led to widespread microbialcontamination of drinking water. Water-associated infectious diseasesclaim up to 3.2 million lives each year,approximately 6% of all deathsglobally.Microbial contaminationMicrobial contamination of water
Acid rain Acid rain is formed when moisture in theclouds mixes with sulfur or nitrogen in theair. The sulfur and nitrogen get into the air bythe burning of fossil fuels such as coaland gasoline. The average pH of rainfall is4.3.
Disease burden from water pollution Water-associated infectious diseasesclaim up to 3.2 million lives each year,approximately 6% of all deathsglobally. The burden of disease frominadequate water, sanitation, andhygiene totals 1.8 million deaths andthe loss of greater than 75 millionhealthy life years.
Oil Pollution of water Both Point and Nonpoint Sources Largest source of oil pollution is pipelineleaks and runoff–61% ocean oil pollution river & urbanrunoff–30% intentional discharges fromtankers–5% accidental spills from tankers
CONTROL OF WATERPOLLUTION Nonpoint Pollution Sources and LandManagement–Reduce nutrient loading through landuse regulations–Source reduction is cheapest andmost effective way to reducepollution. Banning phosphate detergents Soil Conservation Sewage Treatment Remediation
MUNICIPAL SEWAGETREATMENT Primary Treatment - Physical separation of largesolids from the waste stream. Secondary Treatment - Biological degradation ofdissolved organic compounds.– Effluent from primary treatment transferred intotrickling bed, or aeration tank Effluent from secondary treatment is usually disinfected(chlorinated) before release into nearby waterway. Tertiary Treatment - Removal of plant nutrients(nitrates and phosphates) from secondary effluent.– Chemicals, or natural wetlands.
Water Remediation Extraction techniques are used to pumpout polluted water for treatment.–Oxidation, reduction, neutralization,or precipitation. Living organisms can also be usedeffectively to break down pollutedwaters.
Solutions on Water Pollution•Prevent groundwater contamination•Greatly reduce nonpoint runoff•Reuse treated wastewater for irrigation•Find substitutes for toxic pollutants•Reduce resource waste•Reduce air pollution•Reduce poverty
Referance PARK’S TEXTBOOK OF PSM WWW.WATERWORLD.COMWWW.WATERWORLD.COM WWW.WIKIPEDIA.ORG WWW.SLIDESHARE.COM