Presentation on theme: "Waste Generation and Waste Disposal"— Presentation transcript:
1Waste Generation and Waste Disposal Chapter 16Waste Generation and Waste Disposal
2The Throw Away SocietyUntil a society becomes relatively wealthy, it generates little waste.Every object that no longer serves it original purpose becomes useful for something else.1900s US – Junk dealers or scrap metal dealers – no one called it recycling back thenAfter World War II – rapid population growth in US led to increased consumption patternsIncreasing industrialization and wealth, as well as cultural changes, made it possible for people to purchase household conveniences that could be used and thrown away.Planned Obsolescence – the design of a product so that it will need to be replaced within a few yearsEverything from toasters to carsTV dinners, throw-away napkins, disposable plates and forksUnited States became the leader of what came to be known as a “throw-away society.”Planned obsolescence – most significant contributor to this.
3Municipal Solid WasteMunicipal Solid Waste (MSW) - Refuse collected by municipalities from households, small businesses, and institutions such as schools, prisons, municipal buildings and hospitals.Residences – 60%Commercial – 40%Waste generation varies by season of the year, socioeconomic status of the individual, and geographic location within the country.
4Containers and packaging comprise the greatest amount of MSW
5E-WasteElectronic waste (E-waste) televisions, computers, cell phones that contain toxic metals.Older cathode-ray tube (CRT) television or computer monitors contains 1-2 kg ( lbs) of the heavy metal lead as well as other toxic metals such as mercury and cadmium.Costs more to recycle a computer than put it in a landfillIn US, most electronic devices are not designed to be easily dismantled after they are discarded.Much E-waste from US is exported to China where adults and children separate valuable metals using fire and acids with no protective clothing or respiratory gear.
6Reduce, Reuse, Recycle Reduce- waste minimization or prevention Source reduction – seeks to reduce waste by reducing, in the early stages of design and manufacture, the use of materials – toxic and otherwise – destined to become MSW.A company that produces laundry detergent switches from distributing its product in plastic bottles to instead using flexible pouches that require 84% less packaging.Reuse- reusing something like a disposable cup more than onceFlea markets, eBay, Craigslist, and Freecycle
7Reduce, Reuse, RecycleRecycle- materials are collected and converted into raw materials and then used to produce new objectsClosed-loop recycling – recycling of a product into the same productAluminum cansOpen-loop recycling – one product (plastic soda bottles) Is recycled into another product (polar fleece jackets).Avoids sending materials to the landfill, but does not reduce demand for raw materials (ex. Petroleum), to make new bottlesSingle stream or zero-sort recycling – allow residents to mix all types of recyclables in one container.Sorting facility workers sort materials in categories that are in the greatest demand at a given time and offer greatest economic return.Pine Grove Area School District - The recycling collected at your school goes to a transfer station in Coal Township. There it is loaded into a 53 foot trailer and transported to a facility in Philadelphia.One of the greatest problems with recycling – there is not always a market for recycled goods
10CompostingCompost- organic material that has decomposed under controlled conditions to produce an organic-rich material.Roughly 33% of current MSW could be compostedBenefits of Composting:reduced volume of material ending up in a landfillgeneration of rich organic fertilizerreduced amount of methane generated in landfillsreduced amount of energy needed to transport material to a landfill
11LandfillsSanitary landfills- engineered ground facilities designed to hold MSW with as little contamination of the surrounding environment as possible.Primary method of disposal for MSW in USConstructed with clay or plastic lining at the bottomClay used because it can stop water flow and retain positively charged ions, like metals.Pipes constructed to collect leachate and methaneMethane could be extracted and used as fuel or burned offLeachate- the water that leaches through the solid waste and removes various chemical compounds with which it comes into contact.Could be extracted and transported to a wastewater treatment facilityCover of soil and slay, called a cap, installed when landfill reaches capacity.MSW periodically compacted into cells – reduces the volume of solid waste – increases capacity of landfill.Closed landfill can be reclaimed – planted with shallow-rooted plants – parks, playgrounds, golf coursesTipping fees – each truck put on a scale, and after MSW is weighed it is tipped into the landfillReimburses construction fee of landfill
13Choosing a Sanitary Landfill Site Should be located in a soil rich in clay to reduce the migration of contaminants.Located away from rivers, streams, and other bodies of water and drinking water supplies.Far from population centers, however, as distance increases so does amount of energy requiredRegional landfills becoming more common – greatest economic advantageSiting – designation of a location – always controversial and sometimes politically chargedUnsightliness and odorHave been the source of considerable environmental injusticeNIMBY – “Not-in-my-backyard” attitude – People with financial resources or political influenceA site may be chosen not because it meets safety criteria but because its neighbors lack the resources to mount a convincing opposition.
14Problems with Landfills Always a possibility that leachate will contaminate waterways.EPA estimates that virtually all landfills in the US have some leaching.When waste is compacted into cells and covered with soil, all the oxygen is used up. Anaerobic decomposition begins, which generates methane and CO2 – both greenhouse gases.Methane also creates an explosion hazard – landfills are vented so methane does not accumulateProfessor William Rathje – University of Arizona – used bucket auger to obtain information on the decomposition rates of MSW in landfills.Found newspapers with headlines still legible 40 years after being deposited in landfills.Decomposition only takes place where correct mixture of air, moisture, and organic matter are present – most landfills do not contain this and will probably remain the sizes they were when capped.
16IncinerationIncineration- the process of burning waste materials to reduce its volume and mass and sometimes to generate electricity and heat.Waste heat and fly ash formed as byproducts of incineration.Ash – residual nonorganic material that does not combust during incinerationBottom ash – collected underneath the furnaceFly ash – residue collected beyond the furnaceDisposal of the ash is determined by concentration of toxic metals – lead and cadmiumIf deemed safe could be used as fill in road construction or as an ingredient in cement blocks and cement flooringIncineration of certain materials (plastic) could release acidic gases such as hydrogen chloride (HCl), which are recovered in a scrubber, neutralized and disposed of in a landfill.Waste heat – when heat generated by incineration is used rather than released to the atmosphere it is called a waste-to-energy system.
17Incineration Problems High tipping fees to cover construction and operation.Raises NIMBY and environmental justice issuesMay release pollutants, such as organic compounds from incomplete combustion of plastics and metals.Expensive to build so they require large quantities of daily MSW to be profitable.May not completely burn all wastePlant operators can monitor oxygen and temperature of the burn – everything lumped together – difficult for uniform burn
19Hazardous WasteHazardous waste- liquid, solid, gaseous, or sludge waste material that is harmful to humans or ecosystems.According to EPA, over 20,000 hazardous waste generators in the US produce about 40 million tons of hazardous waste/year.By-product of industrial processes such as textile production, machinery cleaning, computer manufacturing, small businesses (dry cleaners), automobile service stations, and small farms.Collection sites for hazardous waste must be staffed with specially trained personnel.Hazardous waste must be treated before disposal.
20LawsResource Conservation and Recovery Act (RCRA)- designed to reduce or eliminate hazardous waste. Also know as “cradle-to-grave” tracking.RCRA ensures that hazardous waste is tracked and properly disposed of.Main goal is to protect human health and the natural environment by reducing or eliminating the generation of hazardous waste.
21LawsComprehensive Environmental Response, Compensation, and Liability Act (CERCLA)- also know as “Superfund”.Puts a tax on the chemical and petroleum industries. This revenue is used to cleanup abandoned and nonoperating hazardous waste sites where a responsible party cannot be found.Requires the federal government to respond directly to the release of substance that may pose a threat to human health or the environmentEPA maintains the National Priorities List (NPL) of contaminated site eligible for cleanup funds.October 2010 – 1,282 Superfund sites – one in every state except North DakotaNJ has 114 followed by CA and PA with the next highest number.Love Canal, NY
22BrownfieldsContaminated industrial or commercial sites that may require environmental cleanup before they can be redeveloped or expanded.Old factories, industrial areas and waterfronts, dry cleaners, gas stations, landfills, and rail yards are some examples.Seattle’s Gasworks Park – previously used as a coal and oil gasification plant – purchased by the city in 1962 to rehabilitate the site into a park.Underwent chemical abatement and environmental cleanup – now distinctive landmark for the cityCriticized as an inadequate solution – managed entirely by state and local governments – varies widely between regionsLacks legal liability controls to compel polluters to rehabilitate their propertiesWithout legal recourse many brownfields sites remain unused and contaminated
23International Consequences Difficult to dispose of – hazardous waste often sent to countries with less stringent regulationsGarbage and ash barges travel the oceans looking for a developing country willing to accept hazardous waste from the US in exchange for cash payment.Khian Sea – cargo vessel that left Philadelphia in 1986 with almost 13,000 metric tons of hazardous ash from an incinerator.Traveled to a number of countries in the Caribbean – some ash dumped in Haiti, some dumped in the oceanIn 1996, US ordered that the ash be retrieved and removed from Haiti and returned to the USHeld at a dock in FL – ash was deemed nonhazardous by the EPA and in 2002 was placed in a landfill in Franklin County, PA – not far from its source of origin.
24Life Cycle AnalysisLife-cycle Analysis – an important systems tool that looks at the materials used and released throughout the lifetime of a product – from the procurement of raw materials through their manufacture, use, and disposal.Often called cradle-to-grave analysisPaper vs. Styrofoam cup in opening story
25Integrated Waste Management A method that seeks to develop as many options as possible, to reduce environmental harm and cost.Reduction, recycling, composting, landfills, and incineration are some ways IWM is utilized.Behavior related to use and disposal is considered and possibly altered in order to obtain the desired outcome – LESS GENERATION OF MSW.Volkswagen – manufactures some of its cars so that they can be easily taken apart and materials of different composition easily separated to allow recycling.