Waste Treatment Science 9 PDF

Waste Treatment Science 9 Wastewater Treatment Goal is to take water that has been “used” and return it to the environment with minimal pollutants Primary Treatment – physical separation of large solids and sediments Secondary Treatment – bacteria decompose organic matter and, once...

Waste Treatment Science 9 Wastewater Treatment Goal is to take water that has been “used” and return it to the environment with minimal pollutants Primary Treatment – physical separation of large solids and sediments Secondary Treatment – bacteria decompose organic matter and, once removed (BIOSOLIDS), the remaining water is treated with chlorine, ozone or UV light Tertiary Treatment – percolation of water through plant bed to remove phosphates or nitrates Sewage includes: dissolved and un-dissolved materials from your kitchen, bathroom and laundry. Septic tank (rural areas) - A septic tank is a large underground container that traps grease and large solids. The remaining liquid waste is distributed through pipes with holes; the pipes lead into a drainage area containing gravel. ∙ Bacteria and other microorganisms as well as soil break down the organic waste and use it as a source of food energy. This system mimics the way in which decomposers normally recycle biodegradable wastes. 5 Sanitary Landfills Used for normal household and industrial waste Garbage is compacted and covered daily with earth and sometimes clay. Clay liner at bottom prevents leachate from reaching groundwater supplies. Methane gas – a product of anaerobic biodegradation of waste – is piped off before it becomes a hazard Secure Landfills where hazardous waste is placed in or on land and that is designed, constructed and operated to prevent any pollution from being caused by the facility outside the area of the facility  Fuel Combustion The burning of∙ hydrocarbons (fossil fuels –including coal, oil and natural gas - from dead plants and animals) produces large amounts of carbon dioxide and water vapor.Sulfur dioxides and Nitrogen oxides , traces of mercury and lead are also produced. hydrocarbon + oxygen carbon dioxide + water + energy 8  Industrial Process The generation of electrical energy , mineral processing and fertilizer production can release harmful chemicals ( sulfur dioxides and nitrogen oxides ) into the air. Natural gas contains compounds such as methane, ethane, propane, and butane. If natural gas contains hydrogen sulfide (H 2S) it is called ' sour gas '. If it doesn't it is called ' sweet '. When hydrogen sulfide is removed, sulfur dioxide is produced There are over 6,000 sour gas wells and 18,000 kilometres of operating sour gas pipelines in Alberta. Sour gas is processed at approximately 250 plants in Alberta,