Environmental Chemistry Unit C Environmental Chemistry

Chemicals in the Environment 1.1 Chemicals in the Environment

A. The Environment everything in our environment is made up of chemicals many chemicals in the environment support life eg) CO2, H2O, O2, glucose etc. there are also many chemicals that do not support living things eg) CO2, sulphur dioxide, ash slide 1 of 13

these chemicals can come from natural sources eg) volcanoes, forest fires can also come from human activity eg) burning fossil fuels slide 2 of 13

B. The Nitrogen Cycle plants need nitrogen for growth & reproduction, but they can’t use “free nitrogen” (N2 gas) from the atmosphere during nitrogen fixation, bacteria combine free nitrogen with other elements such as oxygen plants then consume the fixed nitrogen through the water they take in slide 3 of 13

animals eat plants, and make complex nitrogen compounds like proteins microorganisms then break nitrogen compounds back down into free nitrogen, beginning the cycle again slide 4 of 13

C. Human Activities human activities can also change substances in the environment pollution is any change in an environment, to produce conditions harmful to living things slide 5 of 13

a fertilizer is a substance that enriches the soil so plants will grow Fertilizers a fertilizer is a substance that enriches the soil so plants will grow too much fertilizer can harm a plant, or leach into water systems and harm other organisms slide 6 of 13

pests are organisms that can harm humans, plants or structures Pesticides pests are organisms that can harm humans, plants or structures pesticides are chemicals designed to kill pests: herbicides, insecticides or fungicides pesticides that are incorrectly applied can cause damage to the environment eg) DDT kills mosquitoes but takes 2-15 years to break down slide 7 of 13

other waste is reused or recycled Solid Waste when we get rid of garbage, we can introduce chemicals into the environment some waste is incinerated at high temperatures, which can cause pollution other waste is reused or recycled slide 8 of 13

remaining waste is put into landfill sites, and buried to biodegrade (which can be slow!!) sanitary landfills use compacted clay and plastic liners to isolate hazardous chemicals slide 9 of 13

sewage treatment plants remove harmful substances from wastewater sewage is wastewater which contains dissolved and undissolved substances septic tanks use bacteria to break down organic molecules in wastewater sewage treatment plants remove harmful substances from wastewater slide 10 of 13

effluent is treated wastewater that is released into streams and lakes storm sewers are large pipes that take rainwater directly to rivers and lakes slide 11 of 13

many industrial processes, especially in Alberta, use fossil fuels eg) natural gas processing, electrical power generation fossil fuels are combustible substances made from dead plants and animals eg) coal, natural gas, oil slide 12 of 13

fossil fuels need oxygen to combust products are always carbon dioxide and water, which are both greenhouse gases natural gas is composed of fossil fuel gases when it contains deadly hydrogen sulphide, it is called “sour” gas slide 13 of 13