Chapter 9 water pollution
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Water pollution occurs when chemicals, physical materials, or biological materials are discharged into water bodies and negatively impact organisms. Many rivers in Malaysia become polluted due to waste dumping from industries like paper mills. Pollution threatens aquatic life and indigenous communities that rely on rivers for food and water. Major sources of water pollution include domestic waste, industrial effluents containing toxins, and agricultural runoff containing fertilizers and pesticides. Pollution leads to issues like eutrophication, hypoxia, disease outbreaks, and the bioaccumulation of toxins in the food chain, harming both the environment and human health. Solutions include better enforcement of laws, controlled development, stopping deforestation, and preventing oil spills and emissions
Chapter 9 water pollution
- 1. ENVIRONMENTAL TOXICOLOGYChapter 9Water PollutionMohd Amir Bin Arshad1
- 2. IntroductionWater pollution is any chemical, physical or biological change in the quality of water that has a harmful effect on any living thing that drinks or uses or lives (in) it.2
- 5. Many rivers become polluted due to the wastes that have been poured out.Example: Paper making industry, requires chemicals in its production. The rivers are used as an outlet for the chemicals to drain away.
- 7. There are some of ethnic aboriginal groups that still exist in Malaysia and they depend on the rivers and streams to survive. They depend on the river for food, water supply for drinking, bathing and for their crops.
- 9. Due to tourism purpose, forests surrounding the river areas have been chopped down. The surrounding soils have no roots to hold on to and soon erode when the rains come. The soil runs into the rivers and soon become murky.Threaten an aquatic life.
- 10. A good example is the construction of a new golf course near the waterfall at tourist attraction Fraser’s Hill in the state of Pahang.The impact, become extremely murky and dirty due to the silt and sand that comes from the construction. The waterfall has now lost all its attraction.
- 11. Tasik Chini & Pollution?Gambartasikchini11
- 12. The lake water choked with coliform bacteria to levels “beyond imagination”.Also found in the well waters used by the orangasli in the surrounding area.Lake become 'blocked' sink. The water is stagnant.Sewage pipes from the camp lead straight into the lake.12
- 13. 13Main factor-built TasikChini National Service Camp.
- 14. Sources of PollutionsPoint SourceNon-Point Source14
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- 16. Point Sources?Point sources discharge pollutants at specific locations (direct) through pipelines or sewers into the surface water.Examples of point sources are: factories, sewage treatment plants, underground mines, oil wells, oil tankers and agriculture.16
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- 18. Non-point sources?Non-point sources are sources that cannot be traced (indirect) to a single site of discharge.Examples of non-point sources are: acid deposition from the air, traffic, pollutants that are spread through rivers and pollutants that enter the water through groundwater.Non-point pollution is hard to control because the perpetrators cannot be traced.18
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- 22. Domestic pollutantsWastewater generated from the household activities. It contains organic and inorganic materials such as phosphates and nitrates. Organic materials are food and vegetable waste, whereas inorganic materials come from soaps and detergents. 22
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- 24. Domestic pollutantsSources of Domestic Pollutantshousehold product
- 25. public underground sewerage systems
- 26. septic tanks
- 27. pesticides
- 30. washing machines, sinks, and baths.24
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- 32. Industrial PollutantsCaused by the discharged of industrial effluents.The industrial effluents contain organic pollutants and other toxic chemicals. Some of the pollutants from industrial source include lead, mercury, asbestos, nitrates, phosphates, oils, etc.
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- 34. Agricultural PollutantsCaused by agricultural wastes:Fertilizers
- 35. Pesticides
- 36. Soil additives
- 38. Animal wastesWashed off from the land to the aquatic system through irrigation, rainfall and leaching.28
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- 41. Accident or disasterOil spill is a major problem in the oceans and seas. The oil tankers and offshore petroleum refineries cause oil leakage into the waters. Oil floats on the water surface and prevents the atmospheric oxygen from mixing in the water.The oil enters the body of the organisms. It also coats the body of the aquatic animals and birds which may also kill them.31
- 43. Effect to humanSeveral type of disease/poisoning due to consumed of contaminated water. 33
- 45. Heavy metal poisoningExposed to Arsenic, Lead, mercury, cadmium etc.35
- 46. EutrophicationEutrophication means natural nutrient enrichment of stream and lake water.Mainly caused by an increase in nitrate and phosphate levels in water. Due to the enrichment, water plants such as algae will grow extensively.36
- 47. Eutrophication37
- 48. EutrophicationEutrophication also results in overgrowth of plants like Eicchornia that covers the entire surface of water. This reduces the light reaching the lower layers in water. As a result the water will absorb less light and certain anaerobic bacteria will become more active. 38
- 49. Eutrophication39
- 50. Hypoxia (Oxygen depletion)Eutrophication leads to hypoxia. Enrich of nutrients promoting algae growth.Thus, water might turns into green.40
- 51. Hypoxia (Oxygen depletion)Rich algal growth leads to great increase in the number of the decomposers. All these life forms-decomposers, algae, other plants, fishes and other aquatic animals, use the oxygen in the water for respiration. This causes great demand for oxygen and results in depletion of oxygen.41
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- 53. Bad Smell of WaterWhen water enriched with nutrients, eventually anaerobic bacteria will become highly active. These bacteria produce certain gasses during their activities. Example is hydrogen sulphide. This compounds smells like rotten eggs. When water smells like rotten eggs we can conclude that there is hydrogen present, due to a shortage of oxygen in the specific water.43
- 54. Heat pollutionCertain industries such as power plants, refineries, nuclear reactors release a lot of hot water from their cooling plants. Release hot water to water bodies without reduce the temperature. The warmer water decreases the solubility of oxygen in the water and it also causes water organisms to breathe faster. Organisms will die from oxygen shortages.44
- 55. Acidification Industry emits great amounts of acidifying gasses, such as sulphuric oxides and carbon monoxide. These gasses also dissolve in rainwater. This causes a change in pH of the precipitation-the pH of rain will fall to a value of or below 4.The lower the pH, the more acid the substance. 45
- 57. BiomagnificationsPesticide (DDT) not bio-degradable. These accumulate in the organisms.These organisms are fed upon by aquatic life (fish) to the man. These contaminants remain in the fats and are not degraded in the body. Over the years the amount of DDT increases in the body.47
- 58. BiomagnificationsThus, pollutant reaches the body of man. At each step in the food chain, the contaminant increases in quantity.48
- 59. Pollution is measured by knowing the biological oxygen demand (BOD). Low BOD = Little Pollution High BOD = Higher Pollution49
- 60. Water Pollutants & Effects50
- 61. Water Pollutants & Effects51
- 63. Charity begins at home53
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