Waste Classification WASTE MANAGEMENT
Brainstorm Think about the daily wastes you produce and your home produces. Where do your wastes go? Do you recycle? Compost? Reuse?
From the earliest of times, humans have produced wastes; however, at the turn of the 20th century, the type and quantity of wastes produced has changed from the small amounts of organic waste which could be buried in small dumps and allowed to decompose over time. The industrial revolution and urbanization brought many challenges for waste management.
Toxic wastes produced by the industrial sector, and manufactured products (batteries, obsolete phones, computers, broken toys, packaging, etc.) along with the clumping of wastes in large urban centres, have posed the biggest problems. In Ontario, more than 90% of wastes are produced by residential and commercial activities. Ontario residents produce approximately 4.5 million tonnes of waste, with the commercial sector producing 6.5 million tonnes and the construction industry another 2 million tonnes.
Types of Waste Waste can be defined as materials that are unwanted by the producer, or they can be by-products from a production process, for example, carbon dioxide produced from the burning of fossil fuels. The waste may have also been a consumed product, for example a newspaper that has been read or the packaging from a product (e.g., an empty cereal box). Wastes may be hazardous or non-hazardous and they can be solid, liquid, or gaseous.
Hazardous Waste Perhaps the biggest challenge of waste management is dealing with hazardous wastes, which pose a threat to ecosystems, wildlife, and human health. Nuclear, chemical, human, and hospital wastes are four different types of hazardous waste.
Nuclear waste any material that comes into contact (and therefore may be contaminated) with the nuclear generating process; these materials may be contaminated for thousands of centuries. Nuclear waste is disposed of deep underground where it can remain undisturbed and where radioactive decay will have no impact on life. Chemical waste may be one of thousands of chemicals used in industry, pest control, by-products of mining and manufacturing, or many other activities. The chemicals are often collected, reused (e.g. motor oil), and recycled.
Human wastes that get flushed into the sewage, contain bacteria. Treatment plants and septic systems help to treat the waste. Hospital wastes may include obsolete drugs, contaminated fluids, diseased flesh/cultures, and used needles (some of which may also be household hazardous waste). In most cases these hazardous wastes are incinerated.
What should you do with your household hazardous waste? Some common household hazardous wastes include: batteries, used car oil, pesticides, fertilizers, cleaning solutions, medications, used needles, paint thinners, varnishes, and any other product with a label that states it is explosive, poisonous, or flammable. Cell phones and computers, along with many other electronic devices, are classified as hazardous waste because of the small amounts of heavy metals, including mercury and lead, that are used in their production. Almost all communities across Ontario have household hazardous waste collection days where you can drop off items free of charge. In some communities a "Toxic Taxi" program has been set up where your household hazardous wastes can be picked up.
Plastics Although not considered hazardous, waste plastics can be a nuisance in the environment because they are synthetic products that do not occur naturally in the environment. Plastics are not biodegradable and may persist for hundreds of years in the environment before being broken down. A new technology in treating plastics is by recycling them into plastic lumber that can be substituted for wood lumber; it is made from recovered plastics and can be mixed with other substances (e.g., sawdust) to alter its physical characteristics.
Advantages of recycled plastic over wood include: moisture, insect, bacteria and chemical resistant; splinter free; no sealants or preservatives are needed; coloured throughout and do not require paint; and flexible and can be easily shaped.
Non-Hazardous Waste Non-hazardous wastes are unwanted products with no hazardous (flammable, toxic, and explosive) properties. These wastes may be organic, which can be used in composting to produce nutrient rich product and is applied to soils to enhance their physical and chemical characteristics. Many of the inorganic wastes produced could be recycled and reused including metals, water, paper, and plastic.
Discussion Think about and investigate the wastes produced throughout the lifecycle of a product (e.g., computer, cell phone, running shoe, cosmetics, etc.), from production, to the market, and finally the disposal of the product. Write a paragraph (5-7 sentences) describing the wastes produced for your chosen product.