Solid and Hazardous Waste

E-waste—An Exploding Problem 1. Electronic waste, e- waste: fastest growing solid waste problem 2. Most ends up in landfills & incinerators 3. Composition includes  High-quality plastics  Valuable metals  Toxic & hazardous pollutants All of these items are examples of e-waste

How is e-waste Regulated? 1. Shipped to other countries  What happens in China and India? 2. International Basel Convention  Bans transferring hazardous wastes from developed countries to developing countries  172 countries signed this treaty; the U.S. did NOT sign this treaty 3. European Union  Cradle-to-grave approach Separating materials from e-waste

Huge Amounts of Materials are Thrown Away 1. Solid waste  Industrial solid waste Mines, farms, industries  Municipal solid waste (MSW) Paper, food scraps, cans, bottles, yard waste, glass, wood, etc  Hazardous waste (toxic waste) Threatens human health of the environment Organic compounds Toxic heavy metals Radioactive waste – spent fuel rods & nuclear medicine –high level stored at nuclear reactor sites

Huge Amounts of Materials are Thrown Away 1. 80–90% of hazardous wastes produced by developed countries  U.S. is the largest producer 2. Why reduce solid wastes?  ¾ of the materials are an unnecessary waste of the earth's resources  Generates huge amounts of air pollution, greenhouse gases (CH 4 ), & water pollution The darker the color, the more waste that is produced by that country

What Harmful Chemicals Are in Your Home? Cleaning Disinfectants Drain, toilet, and window cleaners Spot removers Septic tank cleaners Paint Products Paints, stains, varnishes, and lacquers Paint thinners, solvents, and strippers Wood preservatives Artist paints and inks Gardening Pesticides Weed killers Ant and rodent killers Flea powders General Dry-cell batteries (mercury and cadmium) Glues and cements Automotive Gasoline Used motor oil Antifreeze Battery acid Brake and transmission fluid Stepped Art Fig. 21-2, p. 559

Solid Wastes Polluting a River in Indonesia Fig. 21-3, p. 560 Less developed countries do not have the money to enforce regulations of solid waste

Total and Per Capita Production of Municipal Solid Waste in the U.S. Recycling has helped to decrease the trend

We Can Burn or Bury Solid Waste or Produce Less of It 1. Waste Management  Reduce harm, but not amounts 2. Waste Reduction  Use less & focus on reduce, reuse, & recycle 3. Integrated waste management  Uses a variety of strategies such as:  Use refillable containers, shopping bags, coffee cups, etc  Use cloth diapers instead of disposable  Recycling tires into road materials and coral reefs  Designing vehicles with ultra strong & ultra light materials  Reduce, Reuse, and Recycle  Most important: REDUCE

Integrated Waste Management Fig. 21-6, p. 562 Integrated waste management: Wastes are reduced through reuse, recycling, and composting

Integrated Waste Management: Priorities for Dealing with Solid Waste Fig. 21-7, p. 562

Cut Solid Wastes by Reducing, Reusing, & Recycling Six strategies: 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:  manufactures accept old computers, appliances, cell phones for trade in 6.Restructure urban transportation systems  Public transportation (subway, train, bus) instead of everyone driving

Two Types of Recycling 1. Primary, closed-loop recycling  Materials recycled into same type: aluminum cans 2. Secondary recycling  Materials converted to other products: plastic water bottle turned in to shirts and pens 3. Types of wastes that can be recycled  Pre-consumer: internal waste  Post-consumer: external waste (more sustainable than pre- consumer waste) 4. Why should we recycle materials?  Uses less energy & water than virgin materials  Causes less environmental degradation than virgin materials  Decompose very slowly  Frees up landfill space

We Can Mix or Separate Household Solid Wastes for Recycling 1. Materials-recovery facilities (MRFs)  Can encourage increased trash production  Can also encourage recycling 2. Source separation  Pay-as-you-throw  Fee-per-bag  Friendlier to the environment (more sustainable) MRFs can create local jobs

Backyard Composter Drum: Bacteria Convert Kitchen Waste into Compost Fig , p. 566 When compost is ready, it can be used in flower beds and vegetable gardens. Do NOT put meat scraps or eggs in it (do not need to add pathogenic bacteria to the environment)

Fig , p. 569 Advantages and Disadvantages of Recycling AdvantagesDisadvantages Reduces energy and mineral use and air and water pollution Can cost more than burying in areas with ample landfill space Reduces greenhouse gas emissions Reduces profits for landfill and incinerator owners Reduces solid waste Source separation inconvenient for some Can save landfill space

Encourage Reuse & Recycling 1. Obstacles to reuse and recycling:  Market prices don’t include harmful costs associated with production, use, discarding  Recycling industries get less favorable government treatment than large industries do (no subsidies)  Prices for recycled materials fluctuate 2. Encourage reuse and recycling  Government Decrease taxes on recycled materials Decrease subsidies and tax breaks for making items from virgin resources  Fee-per-bag collection  New laws  Citizen pressure

A Waste-to-Energy Incinerator with Pollution Controls  Burns waste and recovers some of the heat energy to produce steam for heating & generating electricity.  To be economical, they must be “fed” huge volumes of trash each day; encourage trash production and discourages reduce, reuse, & recycling  There is a potential to release toxic emissions into the atmosphere

Fig , p. 571 AdvantagesDisadvantages Produces energyProduces a hazardous waste Concentrates hazardous substances into ash for burial Emits some CO 2 and other air pollutants Sale of energy reduces costEncourages waste production Reduces trash volume Advantages & Disadvantages of Waste-to- Energy Incineration Expensive to build

Burying Solid Waste Has Advantages & Disadvantages 1. Open dumps  Widely used in less-developed countries  Rare in developed countries 2. Sanitary landfills: Most common method of disposing of MSW in the U.S.  Since 1997, only modern sanitary landfills have been permitted in the United States  Many small, older landfills have been closed & replaced with larger local or regional landfills The most serious threat is leachate from the landfill leaking into groundwater (Remember Love Canal!)  Can produce methane gas

Fig , p. 572 When landfill is full, layers of soil and clay seal in trash Topsoil Sand Electricity generator building Clay Garbage Methane storage and compressor building Leachate treatment system Probes to detect methane leaks Pipes collect explosive methane for use as fuel to generate electricity Methane gas recovery well Leachate storage tank Compacted solid waste Garbage Leachate pipes Leachate pumped up to storage tank for safe disposal Groundwater monitoring well Synthetic liner Leachate monitoring well Sand Groundwater Clay Clay and plastic lining to prevent leaks; pipes collect leachate from bottom of landfill Subsoil Sand

Fig , p. 572 Advantages & Disadvantages of Sanitary Landfills AdvantagesDisadvantages Releases greenhouse gases (methane and CO 2 ) unless they are collected Can handle large amounts of waste Filled land can be used for other purposes Output approach that encourages waste production No shortage of landfill space in many areas Eventually leachate leaks and can contaminate groundwater Low operating costsNoise, traffic, and dust

Integrated Hazardous Waste Management Fig , p. 573

Detoxify Hazardous Wastes 1. Collect and then detoxify  Physical methods  Chemical treatment: used to neutralize acidic components  Use nanomagnets  Bioremediation: using micro-organisms to solve an environmental problem such as contaminated soil or groundwater (Also called Biological treatment)  Phytoremediation: direct use of green plants and their associated microorganisms to stabilize or reduce contamination in soils, sludges, sediments, surface water, or ground water.

Detoxify Hazardous Wastes 1. Collect and then detoxify  Physical methods  Chemical methods  Use nanomagnets  Bioremediation  Phytoremediation 2. Incineration 3. Using a plasma arc torch

Phytoremediation Fig , p. 575

We Can Store Some Forms of Hazardous Waste 1. Burial on land or long-term storage  Last resort only 2. Deep-well disposal  64% of hazardous liquid wastes in the U.S. 3. Surface impoundments  Lined ponds or pits 4. Secure hazardous landfills

Fig , p. 577 Bulk waste Gas vent Plastic cover Impervious clay Impervious clay cap Clay cap Sand Water table Leak detection system Earth Groundwater Double leachate collection system Plastic double liner Reactive wastes in drums Groundwater monitoring well Earth Topsoil

Hazardous Waste Regulation in the United States : Resource Conservation and Recovery Act (RCRA)  EPA sets standards and gives permits  Cradle-to-grave  Covers only 5% of hazardous wastes : Comprehensive Environmental, Compensation, and Liability Act (CERCLA) -- Superfund  Deals with the cleanup of abandoned hazardous waste sites such as Love Canal  National Priorities List  2010: 1300 sites, 340 sites cleaned so far  Pace of cleanup has slowed; Superfund is broke 3. Laws encouraging the cleanup of brownfields

Three Big Ideas 1.The order of priorities for dealing with solid waste should be to produce less of it, reuse and recycle as much of it as possible, and safely dispose of what is left. 2.The order of priorities for dealing with hazardous waste should be to produce less of it, reuse or recycle it, convert it to less hazardous material, and safely store what is left. 3.We need to view solid wastes as wasted resources and hazardous wastes as materials that we should not be producing in the first place.