UNIT 14 - Waste Management
Municipal solid waste
non-liquid waste that comes from homes, institutions, and small businesses
Describe examples of how you can reduce waste in your own home
Follow the four R's of resource use: Refuse, Reduce, Reuse, and Recycle. Ask yourself whether you really need a particular item. Rent, borrow, or barter goods and services when you can. Buy things that are reusable, recyclable, or compostable, and be sure to reuse, recycle, and compost them. Do not use throwaway paper and plastic plates, cups, and eating utensils, and other disposable items when reusable or refillable versions are available. Use e-mail in place of conventional paper mail. Read newspapers and magazines online. Buy products in a concentrated form whenever possible.
Incineration
Involves burning of waste. Heat can be reused as energy Ashes must be disposed of in hazardous waste landfills. Scrubbers: chemically treat the gases produced in combustion to remove hazardous components and neutralize acidic gases Huge filters physically remove particulate matter. Mostly practiced by smaller countries with less available land/space.
Sanitary landfill
Involves burying non-hazardous waste underground Waste is buried and covered over with dirt or in more modern landfills covered with an impermeable liner When it rains - rainwater percolates downward and collect toxic compounds. This is called leachate. If the bottom layer is made out of dirt or if it is made permeable, then groundwater contamination can occur Older landfills were not lined. Leachate containing toxic compounds contaminated groundwater Modern landfills contain a liner to prevent leakage Methane and CO2 are byproducts of the breakdown of organic wastes. Breakdown is slow because of lack of oxygen
Composting
Reduces a large amount of biological waste going to landfills. Can be reused as fertilizer, potting soil and amend and enhance soil. Promotes healthier and more fertile plants. Enriches soil , reduces erosion and encourages biodiversity Reduces need for chemical fertilizers Part of natural carbon, nitrogen and phosphorous cycle. Detritivores and decomposers aid in process of decomposition to add nutrients back to soil Can be done at home/neighborhood or through the city's recycling program.
Describe examples of how you can reuse products in your own home.
To save waste, items can be used again or durable goods can be used instead of disposable ones. - Refill or reuse containers instead of buying new ones.- Glass bottles can be reused - Use reusable plastic or metal lunchboxes. - Reuse bags for grocery shopping - Carry groceries and other items in a reusable basket, a canvas or string bag, or a small cart. - Use reusable sponges and washable cloth napkins, dishtowels, and handkerchiefs instead of throwaway paper ones. People can donate items to resale centers such as Goodwill Industries and the Salvation Army. Bring your own cup to coffee shops. Rent or borrow items instead of buying them - such as library books.
Describe the 4 R's of Waste Reduction and give examples of each.
A. Refuse Avoid purchasing items you do not need Avoid buying products made with non-reusable/recyclable containers Refuse to buy goods that have wasteful packaging Example - canvas tote bags for groceries instead of using store's plastic bags B. Reduce Conserve resources Decrease use of virgin products where we can Buying recycle goods over virgin products stimulates market for recycled goods. C. Reuse Design products/processes where products or services can be reused. Reuse containers like Tupperware instead of disposable containers. Reuse bags instead of throwing them away D. Recycle Reduce use of virgin materials Reduce waste going to landfills Yard waste can be composted at home or by the city
Identify and describe the pros and cons of sanitary landfills.
Advantages No open burning compared to burning trash as seen in many developing countries. Little odor Low groundwater pollution if sited properly Can be built quickly Low operating costs Can handle large amounts of waste Filled land can be used for other purposes No shortage of landfill space in many areas Methane gas from decomposing trash can be burned for electricity. Disadvantages Noise and traffic Dust Air pollution from toxic gases and volatile organic compounds Releases greenhouse gases (methane and CO2) unless they are collected Groundwater contamination Slow decomposition of wastes Discourages recycling waste reduction May leak and can contaminate groundwater Problems with finding sites. Nobody wants one where they live (Not in my Back Yard = NIMBY)
Describe the pros and cons of incineration?
Advantages Reduced trash volume Less need for landfills Low water pollution Quick and easy Heat and electricity are useful by-products from burning. Disadvantages High cost especially with the use of pollution control devices Air pollution (especially toxic dioxins). Need pollution control devices. Produces a highly toxic ash as a waste product that must be buried. Encourages waste production rather than waste reduction Discourages Recycling and waste reduction
Primary or closed-loop recycling
Waste discarded is recycled into the same products Ex - newspaper, aluminum cans, glass Reduces amount of using new materials by 20-90%
Secondary or open-loop recycling
Waste materials are converted into a different product Example -resins from used tires can be converted to trashcans Reduces use of virgin materials by only 25%
Hazardous waste
solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive defined as anything that is: Ignitable: substances that easily catch fire (natural gas, alcohol) Corrosive: substances that corrode metals in storage tanks or equipment Reactive: substances that are chemically unstable and readily react with other compounds (i.e., explosively or by producing noxious fumes) Toxic: substances that harm human health when they are inhaled, ingested, or contact human skin. This includes substances that are carcinogenic or mutagenic.
Waste water
water used in a household, business, or industry, as well as polluted runoff from our streets and storm drains