Presentation on theme: "Chapter 12: Waste “Nothing can be forgotten, only left behind.” Jon Harjo, Native American Poet."— Presentation transcript:
Chapter 12: Waste “Nothing can be forgotten, only left behind.” Jon Harjo, Native American Poet
12.1 Solid Waste: The Throwaway Society You have lunch, throw away the garbage…but what happens to it after you ‘toss it away’? It is picked up by a collection service and taken to a landfill where it will be dumped with thousands of tons of other trash and then covered with a thin layer of dirt at the end of the day What happens when it is full, or water runs down into the landfill, dissolving harmful chemicals (paint thinner, nail polish remover) and that seeps into the groundwater?
The Generation of Waste Imagine multiplying the waste disposal problems associated with your trash plus all the trash everyone else throws away in a day; most is used once and then thrown away US generates more than 10 billion metric tons of solid waste (any discarded solid material) in a year; this includes junk mail to coffee grounds to cars Waste generated by Americans has doubled since the 1960’s
Space and Waste Many towns are running out of space to dispose of the amounts of trash people are producing Ex: In 1987, a huge barge full of trash sailed up and down the East Coast for more than 5 months in search of a place to dump the garbage; it contained 3200 tons of garbage; eventually, it returned to Islip, New York, burned the garbage and finally buried 430 tons of ash
Population and Waste Thousands of years ago, hunter-gatherers had a smaller population and most of the waste created was animal and vegetable matter (biodegradable material); larger amounts of land per person and disposal of waste was easier Earth’s population and the waste we produce is getting larger; amount of land available per person is becoming smaller; therefore, it is getting harder to find space to dispose of all the waste we are creating
Not All Wastes are Equal The amount of waste is a concern; however, the kinds of waste are just as important Two basic kinds: biodegradable (can be broken down by living things) and non-biodegradable (cannot be broken down) Examples of biodegradable products: plant and animal matter, newspaper, paper bags, cotton fibers, leather; examples of non-biodegradable waste are materials created by combining chemicals to form compounds – polyester, nylon
Plastic Problems Plastics illustrate how non-biodegradable materials can cause problems. Made from petroleum or natural gas; these consists mostly of carbon and hydrogen (same elements which make up most molecules in living things); however, in plastics, when put together in molecular chains, are not found in nature. Microorganisms have evolved the ability to break down nearly all biological molecules, but have yet to develop a way to break down the molecular structure of most plastics Some plastics we throw away may accumulate and last for hundreds of years.
Types of Solid Waste Most of what we throw away on a day-to- day basis is called municipal solid waste However, 70% of the other solid waste comes from manufacturing and mining; 6% is considered hazardous
Municipal Solid Waste About 2% of the total solid waste in the US is made up of municipal solid waste (produced by households and businesses 210 million metric tons of municipal waste produced per yr. in US; enough waste to fill a convoy of garbage trucks that would stretch around the Earth 6 times! growing faster than manufacturing and mining waste
Solid Waste from Manufacturing, Mining and Agriculture Waste from manufacturing, mining and agriculture make up the rest of the total solid waste produced in the US, about 56% of the total Includes items like: scrap metal, plastics, paper, sludge and ash Consumers do not directly produce manufacturing waste but the indirectly contribute to it by buying products that have been manufactured Mining waste consists of rock and minerals that are left over from excavation and processing; left exposed in large heaps, dumped in oceans or rivers, or disposed of by refilling and landscaping abandoned mines Agricultural waste makes up 9% of the total solid waste; includes crop waste and manure Agricultural waste is biodegradable, can be broken down and then returned to the soil; however, with the increase use of fertilizers and pesticides, agricultural waste is becoming more difficult to dispose of (harmful to the soil)
Section 12.2: Landfills Solid Waste Management Most trash goes to the landfill but some is incinerated and 25% is recycled In 1970, we recycled only 6.6%
Landfills More than 50% of our waste ends up in a landfill; modern day landfills are much safer than the open dumps of the past (obnoxious smells and breeding grounds for rats and insects) Landfills are permanent waste disposal facilities; wastes are put in the ground and covered each day with a layer of soil, plastic or both. Function of a landfill: to contain waste that is buried inside, to keep waste from causing environmental problems, and most importantly, to prevent the waste inside the landfill to come in contact with the soil and groundwater that surrounds it.
Problems with Landfills Leachate (water containing toxic chemicals; formed when water seeps down through the garbage picking up the poisonous chemicals along the way) continues to be a problem area for landfills; forms when water seeps down through a landfill and combines with the dissolved chemicals from decomposing garbage (ex: paints, pesticides, cleaners, cans, batteries, appliances) Landfills typically have monitoring wells and storage tanks to measure and store leachate, which can then be treated as wastewater. However, if not monitored well, leachate can flow into groundwater supplies making area water unsafe to drink Methane is another problem. Organic waste decomposes (without oxygen) producing methane, a highly flammable gas Methane is usually pumped out of landfills and used as fuel. However, if it is not monitored safely, it can seep through the ground and into basements of homes up to 300 meters from a landfill, causing dangerous explosions if ignited by a spark
Safeguarding Landfills The Resource Conservation and Recovery Act (passed in 1976, updated in 1984) requires that new landfills have to be built with safeguards to reduce pollution problems; must be lined, have systems to treat leachate and vent pipes to carry methane out of the landfill (released into air or captured and burned to produce electricity) Adding these safeguards increases the cost of building them and finding acceptable places to build them is difficult; must be close to the city producing the waste but far enough away from the residents Any solution is likely to be expensive: legal fees to fight local residents’ objections or cost of transporting garbage to distant sites
Building More Landfills We can build safer landfills, but we are currently running out of space we are willing to develop for the new landfills Materials are not decomposing as fast as we can fill landfills; biodegradable materials (ex: newspaper) takes several years to decompose Total number of active landfills in US in 1988 was 8000; by 1999, the total number decreased by 2300 because they had been filled to capacity Most existing landfills are scheduled to fill up and close within the next 10 years; EPA estimates 20 states will be out of space for additional landfills
12.3 Reducing Solid Waste Incinerators One option for reducing the amount of solid waste sent to landfills is to burn it. In 1999, the US had 102 operational incinerators that were capable of burning up to 94,000 metric tons of municipal solid waster per day; solid waste does not disappear, it’s just reduced by 75%, taking up less space in landfills Incinerators cannot separate the hazardous from the non hazardous waste: therefore, incinerating the solid waste usually results in dangerous toxic ash; air is polluted from the gases produced by incineration Places with incinerators tend to recycle less because it requires a certain amount of solid waste to keep them operating
Reducing Solid Waste If incinerators and landfills are expensive and polluting, what are some other options? Producing less waste, Recycling, Changing the materials used in products These methods of reducing solid is known as source reduction By producing less waste, we will reduce the expense and difficulty of collecting and disposing of it. Ex: use both sides of paper; don’t use unneeded bags, napkins or utensils at restaurants and stores; don’t buy products with unnecessary packaging; using washable diapers instead of disposable ones; use refillable bottles; redesigning products to use less material; return to using sturdy products that last longer and can be repaired rather than disposed of
Buying less You can influence manufacturers to reduce solid waste by buying products that have less packaging, products that last longer or products that can be used more than once Manufacturers will be more likely to make more of these products because the demand for them is greater ex: dishtowels instead of paper towels, rechargeable batteries instead of regular batteries Until 1965, nearly all bottled drinks were in containers designed to be returned to stores when they were empty; they were collected, washed and refilled at bottling companies. Today, the demand is for disposable rather than refillable bottles If people were to use more refillable bottles, manufacturers would start producing them again
Lasting Longer Manufacturers could also reduce waste and conserve resources by redesigning products to use less material; thus, saving resources and reduce waste disposal problems.
Recycling Recycle as much as possible Besides reducing waste, we need to find ways to make the best possible use of all the materials we discard Making products from recycled materials usually saves energy, water and other resources Ex: Takes 95% less energy to produce aluminum from recycled aluminum than from ore; 75% less energy to make steel from scrap ore; 70% less energy to make paper from recycled paper than from trees Most people think only to recycle bottles, cans and newspaper
Recycling: A Series of Steps Most people think about recycling as taking their bottles, cans and newspapers to a recycling center or putting these things at the curb in specially marked containers; however, recycling involves a series of steps in order for recycling to work. First: discarded materials must be collected and sorted by type Second: each type is taken to a facility where it is cleaned and made ready for use again ex: glass – sorted by color and then crushed; paper – sorted by type and made into pulp with water Finally: materials are used to manufacture new products to be sold to consumers If more people would buy recycled, demand would increase for these products causing manufacturers to build more facilities to make recycled products. Thus, making it easier for communities to sell the materials they collect from residents for recycling
Composting Yard waste makes up more than 15% of a communities municipal solid waste; doesn’t really need to go to a landfill because it is biodegradable Can be put in a compost pile and it will break down naturally Adding fruit and vegetable trimmings and table scraps will encourage bacteria to grow and break down the waste rapidly (warm, moist and dark conditions) Creates compost which can be used in gardens because of the rich nutrients Some cities provided facilities to take yard waste and compost it at a large, central facility Composting can also be an effective way of handling waste from food processing plants and restaurants, manure from animal feedlots and municipal sewage sludge. If all biodegradable wastes were composted, the amount of solid waste going to landfills could be reduced.
Changing the Materials we Use Much waste could be eliminated by changing the materials used to package products Ex: drink boxes are make of a combination of foil, cardboard and plastic and are hard to recycle because there is no good way to separate the three different components: could be recycled if they were eliminated and all drinks came in recyclable glass or aluminum containers Recycling other common household products can help eliminate solid waste, for example, newspapers can be made into cardboard, egg cartons, and building materials; used aluminum cans can be recycled to make new cans, lawn chairs, aluminum siding for homes and cookware; glass bottles and jars can be made into new glass bottles and jars; plastic beverage containers to be made into nonfood containers, insulation, carpet yarn, textiles, fiberfill, scouring pads, toys, plastic lumber and crates.
Degradable Plastics Most plastics are not biodegradable, some companies have developed new kinds of plastics that they say are degradable One type is called photodegradable plastic: when left in the sun for many weeks, it becomes weak and brittle and eventually breaks into pieces Another type is called green plastic: made by blending the sugars in plants with a special chemical agent to make plastic; labeled as green because they are made from living things; requires 20-50% less fossil fuel to produce, engineered to degrade within 45 days of being thrown away When green plastic is buried, bacteria in the soil eat the sugars and leave the plastic weakened and full of microscopic holes; chemical agents in the plastic break the longer molecules into shorter ones until it eventually falls apart into small pieces
Problems with Degradable Plastics The biggest problem with the degradable plastic is that the organic parts degrade and the plastic parts are only reduced to smaller pieces; helps the animals in the environment because they cannot choke on the plastic pieces, but those pieces do not completely disappear
12.4 Hazardous Waste Many products we use today (laundry soap to computers) are produced in factories using thousands of chemicals; some in the processing, some as cleansers, some used to generate electricity for the factories Large quantities are oftentimes leftover as waste; many are classified as hazardous waste which may cause health risks to humans or other living things
Types of Hazardous Waste Can be a solid, liquid or gas; oftentimes contain toxic, corrosive or explosive materials, ex: cleansers to disinfect surfaces, lubricants to help machines run Methods of disposing these materials are not always carefully planned out, ex: Love Canal, in Niagara Falls, NY. Homes and a school were built on land that a chemical company used as a site to dump toxic waste; problems started when toxic waste began to leak from the site. Love Canal prompted people to pay more attention to how hazardous wastes were being stored and disposed of; federal laws were passed to clean up old waste sites and regulate future waste disposal.
Resource Conservation and Recovery Act RCRA (Resource Conservation and Recovery Act) requires producers of hazardous waste to keep records of how their waste were handled from the time they were made to the time they are disposed of They are legally responsible even if a problem arises in the future; all sites must be built and operated according to standards designed to prevent environmental pollution
The Superfund Act Sa fe disposal of hazardous waste is expensive so illegal dumping of hazardous waste is tempting In 1980, the Comprehensive Environmental Response, Compensation and Liability Act, aka Superfund Act was passed; gave the EPA the right to sue owners of hazardous waste sites and force owners to pay for cleanup Also, created a fund of money to pay for cleaning up abandoned sites; difficult and extremely expensive Love Canal alone cost $275 million (put a clay cap on the site, installed a drainage system and treatment plant to handle the leaking waste, relocated the residents); 20 years later, the site was evacuated Many Superfund sites will need to be cleaned; 75 of the 1200 approved sites have been completed
Hazardous Waste Management Every year, US produces about 252 million metric tons of hazardous waste; growing every year No guarantee that the methods used today to dispose of hazardous waste will be safe for the environment in the future
Preventing Hazardous Waste One way to prevent hazardous waste is to produce less of it; some manufactures have discovered ways to produce less or no hazardous waste. Ex: instead of cleaning metal parts with chemicals, some companies found they can use tiny plastic beads (act like a sandblaster) which can reused several times and are not hazardous when disposed of Another way it to find a way to reuse it; in US more than 50 programs have been set up for companies to give what they would normally throw away to another company, who can use it, ex: cleaning solvents, after one use, can be sold to another company whose produce would not be harmed by using the small amount of contaminant in the solvent
Conversion into Nonhazardous Substances Some wastes can be treated with chemicals to make the waste less hazardous, ex: lime, which is a base, can be added to acids to neutralize them; a base compound can react with acids to convert acids into salts; cyanides, can be combined with oxygen to form carbon dioxide and nitrogen Wastes can be treated biologically. ex: sludge from petroleum refineries may be converted by soil bacteria into less harmful substances.
Land Disposal Most hazardous waste produced in US is disposed of on land Deep well injection pumps waste deep into the ground where they are absorbed into a dry layer of rock below the groundwater level; wastes are covered with cement to prevent contamination Surface impoundment is another common land disposal facility. It is basically a pond with a sealed bottom; wastes accumulate and settle to the bottom, water evaporated and leaves room to add more waste Hazardous waste in concentrated or solid form are put in barrels and buried in landfills; hazardous landfills are similar to regular landfills only have extra safety precautions to prevent leakage
Biologically Treating Hazardous Waste Biological and chemical agents can oftentimes absorb, break down or reduce toxicity of hazardous waste; bacteria grown in labs can be used to clean up contaminated areas, ex: mercury, arsenic and cyanide Some plants and trees that absorb heavy metals can be planted; chemicals to neutralize and absorb hazardous can be applied
Incinerating Hazardous Waste B urning hazardous waste in specially designed incinerators is another method of disposal They can be safe but also have several problems; generally the most expensive form because they require a lot of energy; must have pollution control devices; need to be monitored carefully so hazardous gases and particles are not released into the air; leftover ash needs to be buried
Exporting Hazardous Waste Until recently, local laws regulated the waste disposal; many companies would try to get rid of their hazardous waste by sending them to landfills in other states, usually less populated southern states. In 1980’s, southern populations grew, and these states started to refuse taking the waste Hazardous waste are also exported to other countries because there might be a facility there that specializes in the treating, disposing of or recycling of particular substances.
Hazardous Waste At Home Hazardous waste disposal is not only a big industry problem, it is also an issue in the home Everyday household products can be hazardous (ex: paint, pesticides, batteries, computers, fertilizers, cleaners, antifreeze, cell phones) Many household products are poured down the drain or put in the trash to go to landfills
Disposing of Household Hazardous Waste To make sure more hazardous materials are be disposed of properly, many cities are creating collection sites for hazardous waste; some cities collect only once or twice a year; others have permanent facilities Trained workers sort hazardous materials and send some materials for recycling and pack other material into barrels for disposal Used batteries and motor oil are recycled, paint may be blended and used for city park maintenance or used to clean up graffiti
Motor Oil When you change your oil at home, do you ever wonder what to do with the old, dirty oil? Many people illegally pour it on the ground or throw it in the trash; about 700 million liters/185 million gallons are thrown away by people every year (not including the oil from service stations and auto repair shops!) What can you do with your oil? Take it to an automobile service station where it is turned in for recycling, take it to an oil collection receptacle if your city has one or call the local city government to find out where it can be taken