Topic 4.4 - Water Pollution - PowerPoint Presentation

1. Topic 4.4 - Water Pollution

2. Types of Water Pollution Anthropogenic or naturalAnthropogenic (human) pollutionRed Tide Caused by algae bloomThere are a variety of freshwater and marine pollution sources

3. Types of Water Pollution Point Source and Non-Point SourceThere are a variety of freshwater and marine pollution sources

4. Types of Water Pollution Organic or InorganicGulf of Mexico animalradio.comHuman and animal wasteThere are a variety of freshwater and marine pollution sources

5. Types of Water Pollution Direct or IndirectDumping toxins into waterwaysblogs.ntu.edu.sgExcess nitrates entering waterwaysThere are a variety of freshwater and marine pollution sources

6. Possible Sources of Water PollutionSewage (human & animal)http://www.winnipegsun.com/2016/09/08/city-downplays-recurring-fecal-coliform-problem PesticidesIndustryPathogensNitrates (fertilizers)Phosphates (detergents)Heavy metals (industry)Oil spillsHeat (thermal pollution from electrical stations)Radioactive wasteSolid domestic waste (trash debris)Suspended particles (from erosion)Invasive species`Types of aquatic pollutants include organic material, inorganic plant nutrients (nitrates and phosphates), toxic metals, synthetic compounds, suspended solids, hot water, oil, radioactive pollution, pathogens, light, noise, and biological (invasive species)

7. Possible Effects of Water PollutionEutrophicationLoss of biodiversity (species & habitat)Increase in disease from pathogensBioaccumulation and biomagnificationhttps://www.youtube.com/watch?v=J9i6a_NRahg Disruption of breeding grounds, nesting sites https://www.youtube.com/watch?v=sYAzTYmXMBg Damage to coral reefsDamage to organisms (ingesting plastics)https://www.youtube.com/watch?v=1I7on22jA48 Types of aquatic pollutants include organic material, inorganic plant nutrients (nitrates and phosphates), toxic metals, synthetic compounds, suspended solids, hot water, oil, radioactive pollution, pathogens, light, noise, and biological (invasive species)

8. Measuring Water PollutionDirect MethodsPerformed by monitoring the level of the pollutant itselfpHNitrates or ammoniaDissolved oxygen (DO)Conductivity (may indicate dissolved pollutants or heavy metals)TurbidityFecal coliform testA wide range of parameters can be used to directly test the quality of aquatic ecosystems, including pH, temperature, suspended solids (turbidity), metals, nitrates and phosphates

9. Measuring Water PollutionIndirect Method - BODBiochemical Oxygen Demand (BOD)= a measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity by microorganismsIf enough oxygen is present, aerobic decomposers will continue until all waste is consumedBiochemical oxygen demand (BOD) is a measure of the amount of dissolved oxygen required to break down the organic material in a given volume of water through aerobic biological activity. BOD is sued to indirectly measure the amount of organic matter within a sample

10. Measuring Water PollutionIndirect Method - BODBiodegradation of organic material utilizes oxygen.There is a finite source of oxygen, and once it is used the water becomes anoxic.This leads to anaerobic decomposition which leads to the formation of methane, hydrogen sulphide and ammonia (toxic).

11. Measuring Water PollutionIndirect Method - BODBiochemical Oxygen Demand (BOD)DO should be measured for the initial amount of oxygen in the sampleSample should be sealed and placed in the dark (…why?)After 5 days a second DO reading should be recordedCalculate the change in oxygen levelUnpolluted, natural water has a BOD less that 5mg/L

12. Measuring Water PollutionIndirect Method - Indicator SpeciesOrganisms that show something about their environment by their abundance or scarcityThese species are sensitive to changes in an environmental factorSome species can be indicative of polluted waters and be used as indicator species

13. Measuring Water PollutionIndicator SpeciesIn Freshwater Ecosystems the following are often indicators of the water qualityFrogs and Toads have permeable skin so are affected by water pollutants and are only present in clean waterMayfly larva indicate clean waterWater louse indicate polluted waterSludgeworms indicate very polluted waterSome species can be indicative of polluted waters and be used as indicator species

14. Indicator species and biotic indexIndicator species indicate whether there is pollution present or not.A Biotic index works by assigning different levels of tolerance to pollution to the different types of organisms

15. This Biotic index (Trent Scale) is a scale of 1-10 that gives a measure of the quality of an ecosystem by presence/abundance of species in itThe Trent Biotic index is based on the fact that certain species disappear and the species diversity decreases as the organic pollution increasesThe scale corresponds to 4 basic water quality (Excellent, good, fair, poor)A biotic index indirectly measures pollution by assaying the impact on species within the community according to their tolerance, diversity and relative abundance

16. Measuring Water Pollution - Biotic Indices Indirect measure of pollutionOften used in conjunction with BOD as invertebrates are sensitive to decreases in oxygen demandOften used to compare 2 ecosystems or point source pollutants using Simpson’s diversity indexMeasures the effect of pollutants on biodiversity

17. EutrophicationOccurs when excess nutrients enter an aquatic ecosystemDrastic increase in algae growthMay happen in freshwater or oceans (red tide)Natural or anthropogenicHuman influence by using fertilizers or detergents. The resulting increase of nitrate and phosphorous encourages algal growth.This prevents sunlight from penetrating so the water plants die Bacteria break down the dead plants and use up all the oxygen leaving the water lifeless`Biodegradation of organic material utilizes oxygen which can lead to anoxic conditions and subsequent anaerobic decomposition which leads to formation of methane, hydrogen sulphide and ammonia (toxic gases)Eutrophication can occur when lakes, estuaries and coastal waters receive inputs of nutrients (nitrates and phosphates) which result in an excess growth of plants and phytoplankton

18. Eutrophication https://www.youtube.com/watch?v=6LAT1gLMPu4 virtual school eutrophication https://www.youtube.com/watch?v=gMwQaHtK904 Lake Erie Explain the process and impacts of eutrophicationEutrophication can occur when lakes, estuaries and coastal waters receive inputs of nutrients (nitrates and phosphates) which result in an excess growth of plants and phytoplankton

19. Dead ZonesIn costal marine environments, dead zones are regions where oxygen concentrations are very low (hypoxia)Dead zones in both oceans and freshwater can occur when there is not enough oxygen to support marine life https://www.youtube.com/watch?v=rSF7feoJ6ho

20. Red tidesAlgal bloom of red species of phytoplanktonProduce toxins that kill fish and accumulate in shell fish – can make humans seriously ill

21. Dealing With Pollution

22. Dealing with pollutionResearch methods aimed at mitigating the effects of eutrophication and place them in one of the above categories.Then evaluate 3 of your methods.E.g.Ban or limit detergents with phosphate (phosphate are only needed in hard water areas).This could be difficult as you would have to get companies to agree to making two products, and would people accept their washing powder being not as effective.