Unit 24 - Solid and Hazardous Waste

converting to less hazardous or non-hazardous substances...

- natural decomposition - incineration - thermal treatment - chemical, physical, and biological treatment - dilution in air or water

sanitary landfills disadvantages

- noise, traffic, and dust - releases greenhouse gases (methane and CO2) unless they are collected - output approach that encourages waste production - eventually leaks can contaminate groundwater

classes of hazardous waste

- organic compounds - toxic heavy metals - radioactive waste

paper recycling

- paper is the world's fifth consumer of energy use - high water use - pollution - recycled paper uses 64% less energy, produces 35% less water pollution, and produces 74% less air pollution

collect and then detoxify hazardous wastes

- physical methods - chemical methods - use nanomagnets - bioremediation - phytoremediation - incineration - using a plasma arc torch

plastic recycling

- plastics are composed of resins created from oil and natural gas - currently only 7% is recycled in the US -> there are many types of plastic resins and they are difficult to separate

types of wastes that can be recycled:

- pre-consumer, internal waste generated in manufacturing process - post-consumer, external waste generated by product use - with incentives, the US could recycle and compost 80% of its MSW

integrated management of hazardous wastes

- produce less - convert to less hazardous substances - rest in long-term safe storage - increased use for postconsumer hazardous waste

recycling advantages

- reduces energy and mineral use and air and water pollution - reduces greenhouse gas emissions - reduces solid waste - net economic health

waste-to-energy incineration advantages

- reduces trash volume - produces energy - concentrates hazardous substances into ash for burial - sale of energy reduces cost

waste reduction is based on:

- refuse -> don't use it - reduce -> use less - reuse -> use it over and over - recycle

where does waste end up?

- rivers - lakes - ocean - natural landscapes

deep-well disposal advantages

- safe if sites are chosen carefully - wastes can often be retrieved - low cost

source separation

- separation of products from MSW for recycling at their source of generation, often a household - pay-as-you-throw - fee-per-bag

what are solid and hazardous wastes? why are they problematic?

- solid waste contributes to pollution and includes valuable resources that could be reused or recycled - hazardous waste contributes to pollution, as well as to natural capital degradation, health problems, and premature deaths - (toxic waste) threatens human health and the environment

burning/burying solid waste advantages

- technologies for burning and burying solid wastes are well developed - waste-to-energy incinerators are used to heat water or produce electricity - landfills emit more air pollutants than modern waste-to-energy incinerators

composting

- using bacteria to decompose biodegradable waste - mimics nature's recycling of nutrients - resulting organic matter can be used to (1) supply plant nutrients (2) slow soil erosion (3) retain water (4) improve crop yield

surface impoundments disadvantages

- water pollution from leaking liners and overflows - air pollution from VOCs - output approach that encourages waste production

throwaway economy alternatives

- we increasingly substitute throwaway items for reusable ones - in general, reuse is on the rise - one solution is to tax plastic shopping bags they way Ireland, Taiwan, and the Netherlands have done

open dumps

- widely used in less-developed countries; rare in developed countries - large pit where sometimes garbage is burned

materials-recovery facilities (MRFs)

can encourage increased trash production

quiz question #5 one characteristic of waste-to-energy incineration is that it [BLANK].

concentrates hazardous substances into ash

single-pickup system

no separation needed

waste management

reduce harm, but not amounts

quiz question #2 according to integrated waste management experts, the most desirable among the following activities is [BLANK].

reducing

quiz question #1 what is a disadvantage of sanitary landfills?

release of greenhouse gases

cradle-to-grave approach

requires manufacturers to take back electronic products at the end of their useful lives and repair, remanufacture, or recycle them

putting it (hazardous waste) in perpetual storage...

- landfill - underground injection wells - surface impoundments - underground salt formations

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

case study: solid waste in the US

- leader in solid waste problem in trash production, by weight, by person - 98.5% of all solid waste is industrial waste - most wastes break down very slowly, if at all

case study: recycling e-waste

- 70% goes to china where there are child workers and hazardous working conditions - US produces roughly 50% of the world's e-waste, but only recycles 14%

deep-well disposal disadvantages

- leaks from corrosion of well casing - emits CO2 and other air pollutants - output approach that encourages waste production

surface impoundments advantages

- low cost - wastes can often be retrieved - can store wastes indefinitely with secure double liners

international basel convention

bans transferring hazardous wastes from developed countries to developing countries

case study: e-waste

- an exploding problem - electronic waste (e-waste) is the fastest growing solid waste problem - most ends up in landfills and incinerators - composition includes high-quality plastics, valuable metals, toxic and hazardous pollutants - shipped to other countries - international basel convention - european union -> cradle-to-grave approach

what can be done about hazardous waste?

- avoid using pesticides and other hazardous chemicals, or use them in the smallest amounts possible - use less harmful substances instead of commercial household cleaners - do not dump pesticides, paints, solvents, oil, antifreeze, or other hazardous chemicals down the toilet, down the drain, into the ground, into the garbage, or down storm drains; free hazardous waste disposal services are available in many cities) - do not throw old fluorescent light bulbs, which contain mercury, into regular trash (many communities and home product retailers offer free recycling of these bulbs)

hazardous waste storage

- burial on land or long-term storage -> last resort only - deep-well disposal -> 64% of hazardous liquid wastes in the US - surface impoundments -> lined pools for evaporation - secure hazardous waste landfills -> expensive

burning/burying solid waste disadvantages

- burning contributes to air and water pollution; greenhouse gas emissions - buried wastes eventually contribute to the pollution and degradation of land and water resources - toxic chemicals that are filtered must be disposed of or stored

ways to reuse:

- buy beverages in refillable glass containers - use reusable lunch containers - store refrigerated food in reusable containers - use rechargeable batteries and recycle them when their useful life is over - when eating out, bring your own reusable container for leftovers - carry groceries and other items in a reusable basket or cloth bag - buy used furniture, cars, and other items whenever possible

recycling disadvantages

- can cost more than burying in areas with ample landfill space - reduces profits for landfill and incinerator owners - inconvenient for some

producing less hazardous waste...

- change industrial processes to reduce or eliminate hazardous waste production - recycle and reuse hazardous waste

sanitary landfills

- compacted layers of waste between clay or foam - bottom liners; containment systems

by refusing and reducing resource use and by reusing and recycling what we use we:

- decrease our consumption of matter and energy resources - reduce pollution and natural capital degradation - save money

waste-to-energy incineration disadvantages

- expensive to build - produces a hazardous waste - emits some CO2 and other air pollutants - encourages waste production

sustainable approach to solid waste:

- first reduce it - then reuse or recycle it - finally to safely dispose of what is left

sustainable approach to hazardous waste:

- first, produce less of it - then, reuse or recycle it - then, convert it to less-hazardous materials - finally, safely store what is left

solid waste

- industrial solid waste -> mines, farms, industries - municipal solid waste (MSW) -> trash

six strategies:

1. change industrial processes to eliminate harmful chemicals 2. redesign manufacturing process to use less material and energy 3. develop products that are easy to recycle 4. eliminate unnecessary packaging 5. use fee-per-bag waste collection systems 6. establish cradle-to-grave responsibility

quiz question #4 municipal solid waste (MSW) is [BLANK].

from homes, businesses, and some industries

quiz question #3 recycling of MSW in the USA [BLANK].

has been successful in reducing some waste materials that would otherwise go to landfills

primary, closed-loop recycling

materials recycled into same type

secondary recycling

materias converted to other products: tires

BIG IDEA #2

the order of priorities for dealing with (hazardous) waste should be to (1) produce less of it (2) reuse and recycle as much of it as possible and (3) convert it to less hazardous material (4) safely store what is left

BIG IDEA #1

the order of priorities for dealing with (solid) waste should be to (1) produce less of it (2) reuse and recycle as much of it as possible and (3) safely burn or bury what is left

waste reduction

use less and focus on reuse, recycle, compost

integrated waste management

uses a variety of strategies for both waste disposal and waste reduction

BIG IDEA #3

view solid wastes as wasted resources, and hazardous wastes as materials that we should not be producing in the first place