Unit C: Topic 6 NIMBY: Not In My Back Yard

Producing Wastes Since the industrial revolution, the amount of wastes being produced has been increasing. Since the industrial revolution, the amount of wastes being produced has been increasing. More wastes means more landfills but no one wants a landfill in their neighborhood. More wastes means more landfills but no one wants a landfill in their neighborhood.

The Movement of Pollution Pollution can be produced in one area but transported to other places in the world. Pollution can be produced in one area but transported to other places in the world. There are three stages of transport of pollutants: There are three stages of transport of pollutants: 1. Release of chemicals at the source. 2. Dispersion of the chemical into the atmosphere. 3. Deposition of the chemical in soil or water.

The direction and distance of airborne pollutants depends on various factors including: The direction and distance of airborne pollutants depends on various factors including: 1. The type of pollutant. 1. The type of pollutant. 2. The wind speed. 2. The wind speed. 3. The direction of the winds. 3. The direction of the winds. 4. The speed and direction of ocean currents. 4. The speed and direction of ocean currents.

Natural Vs. Man-Made Wastes Natural wastes include volcanic ash, forest fires, animal and plant wastes. Natural wastes include volcanic ash, forest fires, animal and plant wastes. Man-made wastes include toxic chemicals, airborne pollutants, etc. Man-made wastes include toxic chemicals, airborne pollutants, etc.

CFCs and the Ozone Layer CFCs = chlorofluorocarbons. They are produced by refrigerant coolants and aerosol cans as well as in Styrofoam. CFCs = chlorofluorocarbons. They are produced by refrigerant coolants and aerosol cans as well as in Styrofoam. One chlorine atom from a CFC molecule can break up 100’000 ozone molecules (O 3 ). One chlorine atom from a CFC molecule can break up 100’000 ozone molecules (O 3 ). International agreements have been signed to limit the production of CFCs. International agreements have been signed to limit the production of CFCs.

Surface Water Pollution Most comes from clothes washing which pollutes the water with nitrates and phosphates. Most comes from clothes washing which pollutes the water with nitrates and phosphates. Sewage treatment involves removing harmful levels of these chemicals. Sewage treatment involves removing harmful levels of these chemicals.

Septic Tank Underground tank that traps grease and solid wastes. Underground tank that traps grease and solid wastes. The remaining liquid waste are pumped into a field where bacteria can break down the waste products leaving water for irrigation and the waste as fertilizers. The remaining liquid waste are pumped into a field where bacteria can break down the waste products leaving water for irrigation and the waste as fertilizers.

Treating Sewage – A 3 Step Process Primary Treatment – Physically separating large solids and sediments Primary Treatment – Physically separating large solids and sediments Secondary Treatment – Removing organic compounds by bacterial decomposition. UV light or chlorine is used to kill germs. Secondary Treatment – Removing organic compounds by bacterial decomposition. UV light or chlorine is used to kill germs. Tertiary Treatment – Chemicals such as phosphates and nitrates are removed from water which is passed into soil as ground water. Tertiary Treatment – Chemicals such as phosphates and nitrates are removed from water which is passed into soil as ground water.

Ground Water Water that filters down through soil. It moves average 15 m/a. Water that filters down through soil. It moves average 15 m/a. The more permeable the soil, the faster the flow rate of ground water. The more permeable the soil, the faster the flow rate of ground water. Impermeable bedrock and clay prevent ground water from moving. Impermeable bedrock and clay prevent ground water from moving.

Aquifers Underwater pools which serve as supplies of spring water. Water here is filtered naturally and free from bacteria contamination. Underwater pools which serve as supplies of spring water. Water here is filtered naturally and free from bacteria contamination. However as ground water becomes polluted so do aquifers and water contamination here is nearly irreversible. However as ground water becomes polluted so do aquifers and water contamination here is nearly irreversible.

Biodegradable Organic substances which can be broken down naturally by organisms or common chemicals (eg. water, air). Organic substances which can be broken down naturally by organisms or common chemicals (eg. water, air). In order for biodegradation to occur, the waste must be mixed in with water, organisms, and air; conditions that aren’t met in most landfills. In order for biodegradation to occur, the waste must be mixed in with water, organisms, and air; conditions that aren’t met in most landfills.

Sanitary Landfills Most common Most common Waste is buried daily under dirt. Waste is buried daily under dirt. Clay lines the bottom to prevent contamination of groundwater. Liquid waste, Leachate, is sent to water treatment center. Clay lines the bottom to prevent contamination of groundwater. Liquid waste, Leachate, is sent to water treatment center. Hazardous by-products such as methane are produced anaerobically. Hazardous by-products such as methane are produced anaerobically.

Secure Landfills Used for toxic wastes. Used for toxic wastes. Clay lining is backed up with gravel, plastic layers and drain pipes to collect toxic seepage. Clay lining is backed up with gravel, plastic layers and drain pipes to collect toxic seepage. When filled, the waste are capped by layer of clay, plastic, and soil. When filled, the waste are capped by layer of clay, plastic, and soil. The landfill is forever monitored for toxic leaks through the drilling of wells. The landfill is forever monitored for toxic leaks through the drilling of wells.

The (Second) Last Slide Bioremediation – The use of living things instead of synthetics to fix a problem. Eg. Using plants to remove heavy metals from soils, and ladybugs as pesticides. Bioremediation – The use of living things instead of synthetics to fix a problem. Eg. Using plants to remove heavy metals from soils, and ladybugs as pesticides. Bioreactors – Using bacteria holding tanks as natural sanitary landfills. Bacteria break down organic wastes in the presence of air and water. Bioreactors – Using bacteria holding tanks as natural sanitary landfills. Bacteria break down organic wastes in the presence of air and water.

Phytoremediation and Phytoremediation: a technique that can be used to reduce the concentration of harmful chemicals in the soil or groundwater. Plants have been used to clean up metals and other pollutants. The plants are able to absorb and accumulate large amounts of these chemicals. When the plants have matured, they are harvested, burned or composted. Other plants can then be grown in the healthier soil.

Photolysis Photolysis is the breakdown of compounds by sunlight. The formation of ozone is an example of this process Another example is photodegradable plastic. This plastic is made of chemicals that react when exposed to sunlight. In 3 months, the plastic becomes a fine powder that is easier to dispose of. (This type of plastic will only degrade if it is exposed to sunlight – if it is buried, it will last in its original shape for hundreds of years.)