3. pollution detection
- 1. "The word sustainable has been reduced to being the Praise, Jesus! of the eco-earnest. It's a word where corporate marketers, with their mediated up-swell of green sentiment, mesh perfectly with the relentless denial of the privileged. It's a word I can barely stand to use because it's been so exsanguinated by the morally limp, the personally smug, the cheerleaders for the technotopic, consumer kingdom come. To doubt the vague promise now firmly embedded in the word - that we can have our cars, our corporations, our consumption and our planet, too - is both treason and heresy to the emotional well-being of most progressives. But here's the question: Do we want to feel better or do we want to be effective? Are we sentimentalists or are we warriors?" -- Lierre Keith
- 2. 5.2 Pollution Detection and Management J. Voytilla
- 3. Pollution Detection Pollution can be measured both DIRECTLY and INDIRECTLY 1. Direct methods involve taking measurements directly from air, soil, or water. - e.g. acidity of rainwater, amount of a gas present, amount of nitrates and phosphates, etc 2. Indirect methods involve measuring changes in biotic and abiotic factors which occur as a result of pollutants. - e.g. measuring O2 content of water, presence/absence of indicator species
- 4. Research! Please find 2 DIRECT methods of monitoring pollution for each of a) Water b) Air c) Soil
- 5. Indirect Methods: B.O.D. The BIOCHEMICAL OXYGEN DEMAND is a measure of dissolved O2 required to break down the organic material in a given volume of water through aerobic biological activity. Broken down by whom? The BOD can thus be used as an indirect method of estimating pollution levels in water, and in fact it is considered a standard test to detect the polluting capacity of effluent.
- 6. BOD How does it work? - The greater the quantity of organic pollutant, the greater the amount of O2 consuming microbes - More microbes means that more O2 is used - Thus the more organic pollutant present, the higher the BOD The BOD test measures the mass (in mg) of dissolved O2 CONSUMED per litre of water when a water sample is incubated in a dark chamber at 20 C for five days.
- 7. Examples of BOD Values Source BOD (mg/L) Unpolluted river < 5 Treated sewage 20 – 60 Raw domestic sewage 350 Cattle slurry 10,000 Paper pulp mill 25,000
- 8. Calculate BOD Volume O2 BOD Probable Location 120 L 48 g 3000 L 45 kg 23000 L 184000 mg
- 9. Indirect Methods: Biotic Indicators Indicator species are those that demonstrate the relative health of an area or ecosystem by their presence or absence or abundance or their scarcity. These species are particularly vulnerable or sensitive to changes in the environment. A Biotic Index is a scale or range (1-10) that provides a measure of the quality of an ecosystem by the presence and abundance of the species living in it.
- 10. Indicator Species Thus, if an ecosystem polluted a particular indicator species could be a) Absent b) Reduced in number c) Present d) Present in abundance This is due to the species’ particular tolerance for a pollutant: some dig it, some can’t abide it
- 11. Research Research 10 indicator species that are used to monitor pollution / ecosystem health. Include whether its the presence/absence/abundance/index of the species that is used. Include what problem each species is used to indicate.