2. Water Pollution Sewage is a rich source of organic waste. Organic waste provides food for microorganisms. Bacteria feed on organic waste and multiply. The bacteria use up the oxygen from the water. Other aquatic organisms suffocate due to lack of oxygen in the water.
3. Add the following labels to your copy of the polluted river: Overloaded sewage works Sewage containing organic materials and bacteria Bacteria feed on organic waste and use up oxygen Water organisms die from lack of oxygen. Organic waste sinks and is decomposed by bacteria (gases formed) Methane gas is released to surface
5. Treatment of Sewage Raw sewage consists of water containing organic waste, soap, food fragments, rags, grit and other materials. Sewage treatment involves the conversion of harmful materials to harmless products by the use of special microbes. Notes
6. Activated Sludge Tank Bacteria + oxygen convert sludge to harmless liquid Aerobic Sludge Digestion Tank Bacteria feed on sludge. Produces methane that can be used as a fuel. Sludge: land or sea disposal Anaerobic Sedimentation Tank Liquid (effluent) on top. Sludge forms at bottom. Grit Tank Heavy solids sink to bottom Treated waste emptied into river Screening Grids strain out large objects Biological Filter Tank Fluid sprayed over stones coated with microbes Aerobic
7. Complete your copy using the Success Guides p88 Activated Sludge Tank Aerobic Sludge Digestion Tank Sludge: land or sea disposal Anaerobic Sedimentation Tank Grit Tank Treated waste emptied into river Screening Biological Filter Tank Aerobic
8.
9. To stay balanced an ecosystem has to recycle many chemical elements. Both the nitrogen and carbon cycle are dependent upon bacteria. In your groups try and draw a quick diagram of the nitrogen cycle in the back of a jotter (think back to Biosphere?). How many stages rely on bacteria? Recycling of Chemical Elements Notes
10. Nitrogen gas in air Mmm Waste ! Decomposition by bacteria and fungus Denitrification by bacteria Nitrogen in plants (Protein) Nitrogen fixation by bacteria Absorption by roots Nitrogen fixation by bacteria Further nitrification by bacteria Nitrogen in NITR ATES in soil Nitrogen in animals (Protein) Nitrogen in dead plant/animal bodies and waste Nitrogen in NITR I TES in soil Nitrification by bacteria Ooh, Ammonia! Nitrogen in ammonium compounds in soil
11. The Carbon Cycle On your copy of the diagram add the following labels to each arrow: Respiration by microbes, animal respiration, plant respiration, death, death, fossilisation, photosynthesis, nutrition, burning. Coal Carbon in dead organic matter carbon dioxide gas Carbon in animals Carbon in green plants
12. Upgrading Waste Many industrial processes produce organic waste products. These can be fed to microbes and converted to useful products. FUEL Using the Success Guides (p89): -describe how fuel can be obtained from waste manure, and from sugar. -how would these fuels be an advantage over fossil fuels? Notes
13. Protein-rich Food Explain how bacteria and fungus can produce protein-rich foods. What are they used for? Success Guides
14. Working with Microbes Produce a safety poster that could be displayed in a microbiology lab. Things to include: -Contamination and the need for precautions. -Work surfaces, clothing. -Preventing contamination of agar. -Disposing of microbes -A completed diagram of sterile techniques Success Guides p86 Torrance p215-217
