Topic 4 4 Water Pollution Types of Water

Topic 4. 4 - Water Pollution

Types of Water Pollution • Anthropogenic or natural Anthropogenic (human) pollution Red Tide Caused by algae bloom There a variety of freshwater and marine pollution sources

Types of Water Pollution • Point Source and Non-Point Source There a variety of freshwater and marine pollution sources

Types of Water Pollution • Organic or Inorganic Human and animal waste Gulf of Mexico animalradio. com There a variety of freshwater and marine pollution sources

Types of Water Pollution • Direct or Indirect Dumping toxins into waterways Excess nitrates entering waterways blogs. ntu. edu. sg There a variety of freshwater and marine pollution sources

Possible Sources of Water Pollution • Sewage (human & animal) • Oil spills • http: //www. winnipegsun. com/2016/09/08/city • Heat (thermal pollution downplays-recurring-fecal-coliform-problem from electrical stations) • Pesticides • Radioactive waste • Industry • Solid domestic waste • Pathogens (trash debris) • Nitrates (fertilizers) • Phosphates (detergents) • Suspended particles (from erosion) • Heavy metals (industry) • 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)

Possible Effects of Water Pollution • Eutrophication • Loss of biodiversity (species & habitat) • Increase in disease from pathogens • Bioaccumulation and biomagnification • https: //www. youtube. com/watch? v=J 9 i 6 a_NRahg • Disruption of breeding grounds, nesting sites • https: //www. youtube. com/watch? v=s. YAz. TYm. XMB g • Damage to coral reefs • Damage to organisms (ingesting plastics) • https: //www. youtube. com/watch? v=1 I 7 on 22 j. A 48 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)

Measuring Water Pollution Direct Methods Performed by monitoring the level of the pollutant itself • p. H • Nitrates or ammonia • Dissolved oxygen (DO) • Conductivity (may indicate dissolved pollutants or heavy metals) • Turbidity • Fecal coliform test A wide range of parameters can be used to directly test the quality of aquatic ecosystems, including p. H, temperature, suspended solids (turbidity), metals, nitrates and phosphates

Measuring Water Pollution Indirect Method - BOD • Biochemical 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 microorganisms • If enough oxygen is present, aerobic decomposers will continue until all waste is consumed Biochemical 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

Measuring Water Pollution Indirect Method - BOD • Biodegradation 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).

Measuring Water Pollution Indirect Method - BOD • Biochemical Oxygen Demand (BOD) • DO should be measured for the initial amount of oxygen in the sample • Sample should be sealed and placed in the dark (…why? ) • After 5 days a second DO reading should be recorded • Calculate the change in oxygen level • Unpolluted, natural water has a BOD less that 5 mg/L

Measuring Water Pollution Indirect Method - Indicator Species • Organisms that show something about their environment by their abundance or scarcity • These species are sensitive to changes in an environmental factor Some species can be indicative of polluted waters and be used as indicator species

Measuring Water Pollution Indicator Species • In Freshwater Ecosystems the following are often indicators of the water quality • Frogs and Toads have permeable skin so are affected by water pollutants and are only present in clean water • Mayfly larva indicate clean water • Water louse indicate polluted water • Sludgeworms indicate very polluted water Some species can be indicative of polluted waters and be used as indicator species

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

• 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 it • The Trent Biotic index is based on the fact that certain species disappear and the species diversity decreases as the organic pollution increases • The 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

Measuring Water Pollution - Biotic Indices • Indirect measure of pollution • Often used in conjunction with BOD as invertebrates are sensitive to decreases in oxygen demand • Often used to compare 2 ecosystems or point source pollutants using Simpson’s diversity index • Measures the effect of pollutants on biodiversity

Eutrophication • Occurs when excess nutrients enter an aquatic ecosystem • Drastic increase in algae growth • May happen in freshwater or oceans (red tide) • Natural or anthropogenic • Human 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

Eutrophication • https: //www. youtube. com/ watch? v=6 LAT 1 g. LMPu 4 virtual school eutrophication • https: //www. youtube. com/ watch? v=g. Mw. Qa. Ht. K 904 Lake Erie Explain the process and impacts of eutrophication 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

Dead Zones https: //www. youtube. com/watch? v=r. SF 7 feo. J 6 ho • In 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

Red tides • Algal bloom of red species of phytoplankton • Produce toxins that kill fish and accumulate in shell fish – can make humans seriously ill

Dealing With Pollution

Dealing with pollution • Research 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