Chap. 21 & 22: Solid & Hazardous Waste

Describe the regulation of hazardous waste in the United States under the Superfund Act.

right to know what toxic chemicals are being stored or released in their communities.

Distinguish among the 3 Rs—to reduce, reuse, and recycle—in dealing with the wastes we produce.

• Reduce: consume less and live a simpler lifestyle. • Reuse: rely more on items that we can use repeatedly instead of on throwaway items, and buy necessary items secondhand or borrow or rent them. • Recycle: separate and recycle materials and other items, and buy products made from recycled materials.

List three ways to reduce your output of hazardous waste.

■ Avoid using pesticides and other hazardous chemicals ■ Use less harmful and usually cheaper substances instead of commercial chemicals for most household cleaners. ■ Do not dispose of pesticides, paints, solvents, oil, antifreeze, in any method. Instead, use hazardous waste disposal services available in many cities.

List five other ways to reuse various items.

■ Use rechargeable batteries and recycle them when their useful life is over ■ When eating out, bring your own reusable silverware and napkin ■ Bring your own reusable container for takeout food or restaurant meal leftovers ■ Carry groceries and other items in a reusable basket or cloth bag ■ Buy used furniture, computers, cars, and other items instead of buying new

What are the major advantages and disadvantages of incinerating hazardous wastes?

- Advantage: breaks them down and convert them to harmless or less harmful chemicals such as carbon dioxide and water. - Disadvantage: incinerating hazardous waste can release air pollutants such as highly toxic dioxins, and it produces a highly toxic ash that must be safely and permanently stored in a landfill or vault especially designed for this hazardous end product.

What are the major advantages and disadvantages of burying solid waste in sanitary landfills?

- Advantages: 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 - Disadvantages: Noise, traffic, and dust, Releases greenhouse gases (methane and CO2) unless they are collected, Output approach that encourages waste production, Eventually leaks and can contaminate groundwater

What are the major advantages and disadvantages of using a plasma arc torch to detoxify hazardous wastes?

- Advantages: Small, Mobile, Produces no toxic ash - Disadvantage: High cost, Produces CO2 and CO, Can release particulates and chlorine gas, Can vaporize and release toxic metals and radioactive elements

What is bioremediation & phytoremediation?

- Bioremediation: bacteria and enzymes help to destroy toxic or hazardous substances, or convert them to harmless compounds. - Phytoremediation: using natural or genetically engineered plants to absorb, filter, and remove contaminants from polluted soil and water

1. Review the Key Questions and Concepts for this chapter on p. 558. Describe the problems associated with electronic waste (e-waste) (Core Case Study).

- E-waste is the fastest-growing solid waste in the world. - Most e-waste ends up in landfills and incinerators, even though 80% of the components in these devices contain materials that can be recycled or reused. - It is also a source of toxic and hazardous pollutants and chemicals, including PVC, lead, and mercury that can contaminate air, water, and soil, and cause serious health problems.

Describe two approaches to recycling household solid wastes and evaluate each approach.

- Materials-recovery facilities (MRFs): there, machines or workers separate the mixed waste to recover valuable materials for sale to manufacturers as raw materials - Source separation: separating trash into recyclable categories

Explain the connection between cell phones and African lowland gorillas.

- Most cell phones contain coltan, a mineral extracted from the deep forests of Congo in centralAfrica, which is the home to the last remaining endangered lowland gorillas. - Coltan is a metallic ore that is refined to produce metallic tantalum, which can hold an electrical charge. -In recent years, rapid expansion of both legal and illegal coltan mining in the Congo—which holds about 80% of the world's coltan reserves—has dramatically reduced the habitat of lowland gorillas and other species. It has also contributed to the killing of lowland gorillas for bush meat to feed the miners.

Distinguish between open dumps and sanitary landfills.

- Open dumps are essentially fields or holes in the ground where garbage is deposited and sometimes burned. - Sanitary landfills are newer landfills where solid wastes are spread out in thin layers, compacted, and covered daily with a fresh layer of clay or plastic foam, which helps to keep the material dry and reduces leakage of contaminated water (leachate) from the landfill.

Describe three ways to detoxify hazardous wastes.

- Physical methods for detoxifying hazardous wastes include using charcoal or resins to filter out harmful solids, distilling liquid wastes to separate out harmful chemicals, and precipitating, or allowing natural processes to separate, such chemicals from solution. - Chemical methods are used to convert hazardous chemicals to harmless or less harmful chemicals through chemical reactions e.g. cyclodextrin remove toxic materials such as solvents and pesticides from contaminated soil and groundwater. - Use of nanomagnets magnetic nanoparticles coated with certain compounds that can remove various pollutants from water. - Biochemical methods e.g. bioremediation, in which bacteria and enzymes help to destroy toxic or hazardous substances, or convert them to harmless compounds.

Distinguish between primary (closed-loop) and secondary recycling, and give an example of each.

- Primary, or closedloop, recycling, materials such as aluminum cans are recycled into new products of the same type. - Secondary recycling, waste materials are converted into different products. For example, we can shred used tires and turn them into rubberized road surfacing material.

Describe the importance of using refillable containers,

- Reusing these containers saves energy while reducing CO2 emissions, air pollution, water pollution, and solid wastes, - It also stimulates local economies by creating local jobs related to the containers' collection and refilling.

Distinguish among waste management, waste reduction, and integrated waste management.

- Waste management: attempt to control wastes in ways that reduce their environmental harm without seriously trying to reduce the amount of waste produced. - Waste reduction: producing much less waste and pollution, and also finding ways to reuse, recycle, or compost them - Integrated waste management: a variety of coordinated strategies for both waste disposal and waste reduction

Distinguish among solid waste, industrial solid waste, municipal solid waste (MSW), and hazardous (toxic) waste, and give an example of each.

- solid waste: any solid unwanted or discarded material we produce - municipal solid waste: garbage or trash, which consists of the combined solid waste produced by homes and workplaces - industrial solid waste produced by mines, farms, and industries that supply people with goods and services. - hazardous waste: waste that threatens human health or the environment because it is poisonous, dangerously chemically reactive, corrosive, or flammable.

Give two reasons for sharply reducing the amount of solid and hazardous waste we produce.

1. At least three-fourths of these materials represent an unnecessary consumption of the earth's resources and thus violate the chemical cycling 2. Studies show that we could reuse and recycle up to 90% of the MSW we produce and thus reduce our resource use dramatically

Describe six ways in which industries and communities can reduce resource use, waste, and pollution.

1. Redesign manufacturing processes and products to use less material and energy. 2. Develop products that are easy to repair, reuse, remanufacture, compost, or recycle. 3. Eliminate or reduce unnecessary packaging. 4. Use fee-per-bag waste collection systems 5. Establish cradle-to-grave responsibility laws 6. Restructure urban transportation systems

What is a brownfield?

Abandoned industrial and commercial sites such as factories, junkyards, older landfills, and gas stations

What are the major advantages and disadvantages of disposing of liquid hazardous wastes in (a) deep underground wells and (b) surface impoundments?

DEEP WELL DISPOSAL: - Advantages: Safe if sites are chosen carefully, Wastes can often be retrieved, Low cost - Disadvantages: Leaks from corrosion of well casing, Emits CO2 and other air pollutants, Output approach that encourages waste production SURFACE IMPOUNDMENT: - Advantages: Low cost, Wastes can often be retrieved, Can store wastes indefinitely with secure double liners - Disadvantages: Groundwater contamination from leaking liners (and overflow from flooding), Air pollution from volatile organic compounds, Output approach that encourages waste production

What are the major advantages and disadvantages of using incinerators to burn solid and hazardous waste?

- Advantages: Reduces trash volume, Produces energy, Concentrates hazardous substances into ash for burial, Sale of energy reduces cost - Expensive to build, Produces hazardous waste, Emits some CO2 and other air pollutants, Encourages waste production

What are the priorities that scientists believe we should use in dealing with hazardous waste?

A sustainable approach to hazardous waste is first to produce less of it, then to reuse or recycle it, then to convert it to less hazardous materials, and finally to safely store what is left.

Explain why reusing and recycling materials are so important and give two examples of each.

Reusing items decreases the consumption of matter and energy resources, and reduces pollution and natural capital degradation; recycling does soto a lesser degree.