Chapter 16 Waste Generation and Waste Disposal Humans

Chapter 16 Waste Generation and Waste Disposal

Humans generate waste that other organisms cannot • In 1900 in the U. S. virtuallyuse all metal, wood, and glass materials were recycled. • After World War II, industrialization brought wealth to many Americans, which made it possible for people to purchase household conveniences that could be used and thrown away. • Municipal Solid Waste (MSW)- refuse collected by municipalities from households, small businesses, and institutions such as schools, prisons, municipal buildings, and hospitals.

Approaches to Waste Management • Waste – any unwanted material or substances that results from a human activity or process. • Municipal Solid Waste – non-liguid waste that comes from homes, institutions, and small businesses. • Industrial Solid waste – includes waste from production of consumer goods, mining, agriculture, and petroleum extraction and refining. • Hazardous Waste – refers to solid or liquid waste that is toxic, chemically reactive, flammable, or corrosive. (paint, household cleaners, medical waste, industrial solvents)

Aims for Managing Waste • Waste can degrade – Water – Soil – Human health – Environment • Waste Stream – the flow of waste as it moves from its sources toward disposal destinations. Can be recycled, incinerated, placed in a solid waste landfill or disposed of in another way.

• A large dump in Manila, Philippines. Throughout the world, impoverished people scavenge dumps.

• MSW composition in the United States in 2008 by category.

E-Waste • Electronic waste or e-waste, is one component of MSW that is small by weight but very important and rapidly increasing. • E-waste includes televisions, computers, portable music players, and cell phones. • E-waste often has heavy metals such as lead, mercury and cadmium.

• Lots of e-waste is being recycled and in doing so, the people who are taking them apart are at risk of working with hazardous substances • Much of our e-waste gets shipped over-seas and the disassembly is done by poor workers with minimal safety regulations. • “Environmental Justice Concern” • The cathode ray tubes in TV’s and computers represent the second largest source of lead in landfills.

• E-waste being recycled in China. Much of the recycling is done without protective gear and respirators that would typically be used in the U. S.

Three Components of Waste Management • Minimizing the amount of waste we generate • Recovering waste materials and finding ways to recycle them • Disposing of waste safely

The three Rs Reduce, Reuse, Recycle • Reduce- waste minimization or prevention • Reuse- reusing something like a disposable cup more than once • Recycle- materials are collected and converted into raw materials and then used to produce new objects

The three Rs Reduce, Reuse, Recycle • Closed-loop recycling is the recycling of product into the same product. An example is an aluminum can. This process is called closed loop because in theory, it is possible to keep making aluminum cans from only old aluminum cans. • Open –loop recycling is the recycling of one product such as plastic soda bottles into another product, such as a polar fleece jacket.

Minimizing – Source reduction – Manufactures could use materials more efficiently – Consumers can buy fewer goods, less packaging and use goods longer – Reuse goods, buy used and donate used

Reducing Waste is a Better Option • Reducing is the best way to avoid cost of disposal and all the environmental issues that go along with disposal. • Source Reduction – preventing waste generation • Much of waste comes from package – Buy unwrapped fruit and vegetables – Buy in bulk – Use recycled goods – Use re-usable bags to shop with instead of plastic

Recovering Waste Materials • Recovery – recycling and composting is viewed as the next best strategy in management. • Recycling – sending goods to facilities that extract and reprocess raw materials to manufacture new goods. (newspapers, white paper, cardboard, glass, metal cans, appliances and some plastic containers. • Today about 30% of waste is recycled • New technologies have been developed for recycling.

Recycling Consists of Three Steps • Recycling – consists of collecting materials that can be broken down and reprocessed to manufacture new items. • Step 1 – collecting and processing the materials. Materials are taken to a Materials Recovery Facility (MRF’s) • Step 2 – Sorting, cleaning and preparing for reprocessing • Step 3 – Manufacturing new goods and purchasing by the public

Recycling

United States Recycling Rates

Recycling has grown rapidly and can expand further • Thousands of curbside recycling programs exist today • More then 500 MRF’s are in operation. • In the United Sates recycling has risen from 6. 4% to 23. 8%.

Reuse is the major strategy for waste reduction • • • Substitute disposal goods for durable goods Bring your own coffee mug Bring your own shopping bags Buy used clothes Buy used cars

Canadian City Showcases Reduction and Recycling • Edmonton, Alberta has created one of the worlds most advanced waste management programs • 85% of the city’s waste was being landfilled and space was running out. • Today, 35% goes to landfills, 50% is composted and 15% is recycled. • 81% of the cities citizens participate in curbside recycling.

State of the Art Recycling and Refuse Center

Composting • Biological decomposition – the recovery of organic waste. Organic material that has decomposed under controlled conditions to produce an organic-rich material

Composting • Composting is the conversion of organic waste into mulch or humus through natural biological process of decomposition. • Compost can be used to enrich soil. • Compost can be in underground pits, pile or constructed containers • Things that can be composted – non meat foods, coffee grounds, grass clippings, leaves and many other items.

Composting • Municipal composting facility. A typical facility collects almost 100, 000 metric tons of food scraps and paper year and turns it into usable compost.

Financial incentives can help address waste • Economic incentives to reduce such as “pay-asyou-throw” approach to garbage collection, uses financial incentive to change consumer behavior. • “Bottle bills” 11 states have these laws to allow return for cash of bottles. • Bottle bills – designed to cut down on litter. • Challenges - (1) amendments to the bottle laws needs to include newer type of containers. Such as colored bottles (2) adjust refunds on bottles for inflation

Waste Disposal Methods • Burying waste in landfills • Burning waste in incinerators

Currently, most solid waste is buried in landfills or incinerated

• Sanitary landfills- engineered ground facilities designed to hold MSW with as little contamination of the surrounding environment as possible. • Leachate- the water that leaches through the solid waste and removes various chemical compounds with which it comes into contact.

Municipal Solid Waste • Municipal waste varies from place to place. – In the United States, paper, yard debris food scraps and plastics are components of municipal solid waste (71%). • Most solid waste comes from packaging and nondurable goods. • U. S leads the world in solid waste followed by – Canada and the Netherlands.

Municipal Waste

Waste generations is rising in all nations • Waste generations has been increasing since 1960. • Per capita waste has risen 69%. • More and more developing nations are increasing their solid waste. • Over the past 3 decades, per capita waste generation rates have more than doubled.

Open dumping of the past has given way to improved disposal methods • There use to be open dumping and burning of waste. This still exists in some areas of the world. • Some people scavenge on dumps and then sell trash to make money.

• Many nations have improved their methods of waste disposal. • Most industrial nations now bury waste in a lined and covered landfill. • Dump – is unlined • Sanitary Landfill – are capped after they have reached there permitted level.

Unlined Dump

Lined Landfill

Modern Sanitary Landfill • Landfill constructed today has many features to keep components of the solid waste from entering soil, water table or nearby streams.

Sanitary landfills are regulated by health and environmental guidelines • Designed to prevent waste from contaminating the environment and threatening public health. • Landfills in the United States are regulated locally and by the State but also must meet national standards set by the U. S. Environmental Protection Agency (EPA)

Modern Sanitary Landfill • A municipality or private enterprise constructs a landfill at a tremendous cost. These costs are recovered by charging a fee, called a tipping fee. • Tipping fees at solid waste landfills average $35 per ton in the U. S. , although in certain regions, such as the Northeast, fees can be twice as much. • These fees create an economic incentive to reduce the amount of waste that goes to the landfill.

• The EPA regulates landfills under the Resource Conservation and Recovery Act (RCRA). • RCRA enacted in 1976 and amended in 1984. How Landfills Work • Waste is partially decomposed by bacteria and compresses under its own weight. • Waste is layered along with soil, this limits odor • Limiting infiltrations allows for biodegradation by aerobic and anaerobic bacteria.

How Landfills Work “Continued” • Landfills are required to be located away from wetlands and earth-quake-prone faults and 6 feet above the water table. • Bottoms and sides must be lined with heavy plastic and up to 4 ft of impermeable clay to help prevent contaminants from seeping into aquifers. • A system of pipes are used to gather leachate – liquid that results when substances from the trash dissolves in water as rainwater percolates down.

Landfill layers

Landfill Closure • After a landfill is closed, it is capped with an engineered cover that must be maintained. • The cap is a hydraulic barrier of plastic that prevents water from seeping down and from gas seeping up. • Methane gas is produced by the decompositions that takes place in the landfill. • This gas can be extracted and used as a source of energy when burned.

Landfill Cap

Methane Collection System

Landfills can Produce Gas for Energy • Anaerobic decomposition that takes in landfills produces Methane as a by-product. • This can be used collected, processed and used the same way as natural gas.

Landfill Transformation After Closure • • • Some get converted to public parks Shea Stadium Queens Museum of Art New York Hall of Science Queens Botanical Gardens Playgrounds

Some Problems with Landfills • Liners can be punctured and leachate collection systems are not maintained. • Problems with decomposition • Finding suitable areas to locate landfills because many communities do not want them (NIMBY). • Disproportionate amount of landfills are located in poor and minority communities. • Landfills produce methane and it can be explosive if not handled correctly

Incinerating Trash Reduces Pressure on Landfills • Incinerators are specially constructed facilities that may be an improvement over open –air burning of trash. • Incineration – is the combustion or burning waste materials to reduce its volume and mass and sometimes to generate electricity and heat • Waste is sorted and metals are removed. • Emissions from incineration can be a health threat. • Scrubbers – chemically treat the gasses produced in combustion to treat the hazardous components. • Neutralize acidic gases such as sulfur dioxide and hydrochloric acid turning them into water and salt.

Incineration basics • Ash – is the residual nonorganic material that does not combust during incineration. • Residue collected underneath the furnace is known as bottom ash and residue collected beyond the furnace is called fly ash. • Disposal of this ash is determined by its concentration of toxic metals. • When heat generated by incineration is used rather than released to the atmosphere, it is known as a waste-toenergy system.

How Scrubbers Work • A liquid containing a solution to neutralize the gases is sprayed or the gases are passed through dry lime.

Trash to Steam Plant

Particulate Removal • Particulate matter is physically removed from incinerator emissions in a system of huge filters known as a Baghouse. • The particles called fly ash often contain some of the worst dioxin and heavy metal pollutants.

• Burning garbage at very high temperatures can destroy pollutants such as PCB’s. • However, you can not fully eliminate toxic emissions. Many incinerators burn waste to generate energy. Waste-to energy or Trash to Steam - using the heat produced to boil water, creating steam that drives electricity generation or that fuels heating systems.

Some Problems with Incineration • Tipping fees for incinerating trash • Releases air pollutants such as organic compounds from incomplete combustion of plastics and metals. • Ash is often toxic and must be disposed of properly. • Incinerators may not completely burn all the waste deposited in them.

Industrial Solid Waste • Regulation and economics influence industrial waste generation. – 7. 6 billion tons of industrial waste is generated each year, 97% is wastewater – Strategies for industrial waste are the same for municipal – Regulations vary greatly State by State – Raising cost of disposal enhances the finacial incentive to reduce.

Hazardous Waste • Hazardous waste are diverse in their chemical composition and may be liquid, solid, or gaseous that are harmful to humans and ecosystems. • EPA definition – Hazardous is waste that is one of following: – Ignitable – substances that easily catch fire – Corrosive – substances that corrode metals in storage tanks or equipment – Reactive – substances that chemically unstable and readily react with other compounds, often explosive or by producing noxious fumes – Toxic – substances that harm human health when they are inhaled, are ingested, or contact human skin

Hazardous waste have diverse sources • Industry, mining, household, small businesses, agriculture, utilities, and building demolition all create hazardous waste. • Industry produces the largest amounts of hazardous waste, but in most developed nations industrial waste generation and disposal is highly regulated. • Organic compounds and heavy metals are the two most hazardous groups of industrial chemicals.

Organic Compounds and Heavy Metals • We use a lot of synthetic organic compounds and petroleum products. • Plastic containers, rubber tires, pesticides, solvents and wood preservatives resist decomposition. • Many synthetic compounds are toxic because they can be absorbed through the skin. • Many act as mutagens, carcinogens, teratogens and endocrine disruptors.

Heavy Metals • Lead, chromium, mercury, arsenic, cadmium, tin and copper are widely used in industry especially in electronics fabrication. • Heavy metals enter the environment when batteries, paints, electronic devices and other materials are disposed of. • Heavy metals are fat soluble, break down slowly and can bioaccumulate in our food web system.

Several Steps Precede the Disposal of Hazardous Waste • Under the Resource Conservation and Recovery Act, the EPA sets standards for states to manage hazardous waste. • Large generators of hazardous waste to obtain permits and mandates the hazardous materials be tracked from “cradle to Grave” • This means at each step of transportation and disposal facility, a report must be sent to the EPA listing the amount and type of material generated • This is intended to stop illegal dumping

• Because of the cost to dump hazardous waste, sometimes companies dump illegally. • Good thing is the high cost of dumping has made more businesses to invest in reducing their hazardous waste. Three Disposal Methods for Hazardous Waste • Landfills • Surface Impoundments • Injection Wells

• The three methods do not lesson the hazards but it does isolate it from people. • Landfills that take hazardous waste have much stricter design and constructions standards then regular landfills. – Several impervious liners – Leachate removal systems must be located far from aquifers • Liquid hazardous waste goes to surface impoundment – shallow depressions lined with plastic and impervious material such as clay

Surface Impoundment

• Water containing dilute hazardous waste is put into the ponds and then it evaporates, leaving the residue of the solid hazardous waste on the bottom. • The dry material then get landfilled • Deep-well injection – this is a well that is drilled deep beneath the water table into porous rock, and wastes are injected into it. • The waste is supposed to stay deep underground away from groundwater and human contact. • Problem – wells corrode and leak waste into soil, and then into aquifers.

Deep Injection Well

Radioactive Waste is Especially Hazardous • In New Mexico is the first underground repository for nuclear waste • The caverns are 655 meters below the surface in a huge salt formation which is thought to be geologically stable

Laws • Resource Conservation and Recovery Act (RCRA)- designed to reduce or eliminate hazardous waste. Also known as “cradle-tograve” tracking. • RCRA ensures that hazardous waste is tracked and properly disposed of. • In 1976, the RCRA’s main goal was to protect human health and the environment by reducing or eliminating the generation of hazardous waste.

Laws • Comprehensive 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 non-operating 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 environment.

Contaminated Site are Being Cleaned Up slowly • Thousands of former military and industrial sites remain contaminated with hazardous waste. • Comprehensive Environmental Response Compensation and Liability Act (CERCLA) – 1980. This was created to clean up sites polluted with hazardous waste from past sites. • EPA administers the clean program called Superfund.

Superfund • Under the EPA, sites are identified in order to protect groundwater near these sites and clean up pollution. • EPA is also in charge of cleaning up Brownfields – these are land whose reuse or development are complicated by the presence of hazardous materials.

Brownfields • Contaminated industrial or commercial sites that may require environmental cleanup before they can be redeveloped or expanded. • Many brownfields include old factories, industrial areas and waterfronts, dry cleaners, gas stations, landfills, and rail yards.

Laws • Map showing distribution of NPL (Superfund) sites in the U. S. The EPA maintains the NPL of contaminated sites that are eligible for cleanup funds. • National Priorities List (NPL) has more than 1, 200 sites throughout the U. S. Most well known NPL site could be Love Canal, New York.

Two Publicized Cases Spurred the Creation of Superfund • Love Canal – a residential neighborhood in Niagara Falls where toxic chemicals were buried by a company decades before. • Times Beach – In Missouri, was an area contaminated with dioxin from buried waste oil.

Love Canal Superfund Site

Integrated 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. • The book Cradle to Cradle argues that it is first necessary to assess existing practices in order to minimize waste generation before, during, and after manufacturing.