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Water
Chapter 19
Term | Definition |
---|---|
Hard Water | water that will not easily latther with soap, caused by the presence of Ca & Mg ions |
Treatment - Screening | passing the water through a wire mesh to remove floating debris |
Treatment - Flocculation | Aluminium sulfate is added and suspended solid to stick together to form larger particles |
Treatment - Settlement | water flows from the bottom of large tanks and very slowly rises to the top; as a result the 90% of the particles are removed. |
Treatment - Filtration | The water is passed through large beds of sand, this removes remaining solids. the water is now clear |
Treatment - Chlorination | Chlorine is added to water to sterilise it. |
Treatment - Flourination | Sodium flouride is added to prevent tooth decay |
Treatment - pH adjustment | Calcium Hydroxide/ Sulfuric acid are added if needed to maintain a pH of 7-9 |
Biochemical Oxygen Demand | The amount of dissolved oxeygen consumed by a biological action when a sample of water is kept at 20' in the dark for 5 days |
Eutrophication | The enrichment of water with nutrients, which leads to excessive algae growth |