Waste management trash, recyclables, hazardous waste, nuclear waste, e-waste, biological waste, . . .

Once upon a time Any waste just thrown into a pit, covered once in a while with soil

Dump became a ``landfill’’                                                                                                                              Sanitary landfill Lined, to prevent leachate from reaching groundwater Often, escaping gas collected (methane) Dust and noise control Once covered, ``restoration’’ with native plants.

Fresh Kills landfill

What kinds of ``waste’’ are there? ``trash’’ Paper, cardboard, books Metals Glass Plastics Organics: food, yard, bodily waste, wood Rubber, textiles, leather = MSW Electronic waste Large manufactured goods (e.g. refrigerator) Toxic waste—chemicals Mining waste 75% Biological waste Nuclear waste MSW = ~3% of all waste

MSW U.S. produces most About 4-5 lbs/person How much do you produce? How can you produce less?

Incineration Some: refuse-derived fuel Non-combustibles removed first Some: Mass burn Burn the material ``as is’’ Reduces volume Problems? Ash Metals Wet waste May use heat from combustion to generate electricity Some: refuse-derived fuel Non-combustibles removed first Stuff remaining, inc. paper, plastic, is shredded and burned Why?

The 3 R’s REDUCE REUSE RECYCLE Recycle is the third option, not the first

How reduce amount of waste produced? Ideas? Eliminate packaging Change formulation of a product Avoid excess purchases Repair

How reuse? Ideas? Bring own bags when shopping Wash containers (Chinese food) Back of printed paper for scrap

Recycling Is it worth it? Costs and benefits Environmental and economic Material Energy savings Air poll decrease Aluminum 95% Carboard 24 Glass 5-30 20 Paper 40 73 Plastics 70 steel 60

Recovery rates Material % that is recycled or composted Paper 52% Plastic soft drink bottles 31 Aluminum cans 45 Steel 63 Major appliances 67

Hazardous waste What is it? Ignitable, corrosive, toxic, reactive Includes waste from large producers such as chemical plants, petroleum refineries, electroplating industry, large paint shops. But also: dry cleaners, hospitals, car-repair shops, university labs

How much? More than 40 million tons a year in the U.S.

What to do with it? Produce less recycle Engineers in many industriesdevelop new processess that use less materials and produce less waste recycle

How regulated? Resource Conservation and Recovery Act = RCRA, pronounced ``rikrah’’ Objectives: "to promote the protection of health and the environment and to conserve valuable material and energy resources.“ Only 5% of haz waste. Doesn’t include: Radioactive waste, mining waste, waste from very small generators (< 100 kg/month)

Types of hazardous waste Toxic chemicals Metals (e.g., lead) Infectious waste (hospitals) Radioactive waste Organic compounds

What can be done about hazardous waste? Some is recycled Solvents can be recovered Lead can be recovered Small % now about 5% is recycled

What can be done about hazardous waste? Incineration Destroy the toxic compound Sometimes, recover part (metals) Air emissions are regulated by Clean Air Act One issue: dioxins produced when plastics not burned at high enough temperatures

What can be done about hazardous waste? If liquid (e.g., paint thinner, solvents, etc) Most hazardous liquids are injected into the ground Deep Into porous rock (often) Sometimes into previously drilled holes Regulated in part by: Safe Drinking Water Act