D. Shell, SMHS 2012

#1 solid

waste

4

layers

2

layers

Obsolete technology just thrown away:

in developed countries the avg. COMPUTER thrown away after 2 YEARS

they’re not broken, just replaced with newer

big waste of plastics & metals (some heavy metals are toxic Pb, Cd, Hg)

some things can be recycled (plastic into park benches or asphalt road repair patches) – 11% parts recycled in US

in western Europe & Japan laws require computer makers to take back old computers & remove most toxic chemicals (they will pass on this expense by making new computers more expensive, though)

The SOLID WASTE PROBLEM Trash that is generated by organisms

2 Types of Solid Waste o Municipal Solid Waste = our garbage 1.5% of solid waste

U.S. average 1500 lbs./person/yr or 4.4 lbs/person/day Organic: kitchen waste, flowers, leaves, etc. (days – weeks to decompose) Recyclable: paper (decomposes in days), plastics (thousands – millions of years),

Metals (thousands of years), glass (never). o Nonmunicipal Solid Waste = mining waste (#1 solid waste), agriculture, & industrial waste

Radioactive: spent fuel rods, smoke detectors, CFLs (compact fluorescent lights)

take thousands of years to decompose Medical / Soiled: hospital waste – syringes, gowns, cotton balls, etc (months – years) Toxic: paints, chemicals, pesticides (take hundreds of years to decompose) Municipal Solid Waste

Disposal of Municipal Solid Waste 1. Open Dumps – dump trash in pile

Banned in the US – illegal dumping is a problem.

Used in some LDCs

Cheap & easy

Provides easy income for those who sort through the trash to find recyclables

bad odors, diseased vermin

liquid that oozed through pile made its way into creeks & groundwater = called leachate

2. Sanitary Landfills (55.4% of trash disposed of using this method) Non-Municipal Solid Waste

waste place in hole w/ rubber & clay liner, compacted & covered each day (no smell or vermin)

leachate & methane collected. methane used for electricity production

when filled can be made into a park, parking lot, playground, golf courses, etc (no buildings)

charge a “tipping fee” to garbage trucks to accept trash. Some states are cheap & some are expensive. Avg. = $50/ton Paid for by your taxes or garbage fees.

ideal location for SL is away from groundwater, lots of clay in soil, but not too far from city (keep transport costs down)

Waste is covered each day to encourage decomposition & to keep vermin out. Problems w/ SLs

many SLs don’t have modern features, groundwater can be contaminated by leachate

SLs must be monitored for 30 years after closing & treat leachate (NY Fresh Kills Landfill, closed 2002, still makes 1,000,000 gal of leachate/day)

hard to find new locations for landfills NIMBY (“not in my back yard”)

plastics (50% from packaging) do not decompose

decomposition in the absences of oxygen = anaerobic respiration – CH4 is explosive

tires must be ground up before going in or are banned (lots of them) o water collects in the tires & encourages pests

like mosquitoes & vermin that carry disease

D. Shell, SMHS 2012

3. Incinerators (14.5%)

reduces volume of waste by 90%, produces heat for electricity production (less CO2 emitted than coal power)

paper, plastic, rubber = best to burn

Japan burns approximately 90% of their waste (take up less space than landfills.)

Waste-to-Energy: burning trash creates the heat necessary to create steam which in turn is used to produce electricity.

Problems w/ Incineration o air pollution: need expensive air scrubbers to remove

acidic gases & fly ash (contains dioxin & heavy metals) o ash must be put in expensive hazardous waste site or, if in SL, must be monitored o incinerators are VERY expensive to set up compared to SLs o Sorting out batteries, plastics & other toxic substances is expensive

4. WASTE PREVENTION (3 R’s)

In order of PRIORITY is 1) REDUCE 2) REUSE 3) RECYCLE a. REDUCE waste

decrease consumption (do we really need it?)

redesign to make it as good but with less material

manufacture products that don’t pollute as much

eliminate unnecessary packaging

trash taxes to encourage reuse & recycling (pay-as-you-throw)

Pollution Prevention Act (1990) – 1st US law that focuses on reducing generation of pollutants at point of origin rather than cleaning up afterwards b. REUSE waste

keeps high quality resources from turning into low quality waste

BETTER than RECYCLING (which needs energy to restore old to new) o ex. refillable glass bottles (must be thicker than single-use bottle = heavier more expensive to

transport, so soda more $$)

many European countries & Japan have laws that encourage refillable glass bottle use

11 US states have deposit laws on bottles

ex. metal or plastic lunch boxes & Tupperware o no plastic wrap or foil that ends up in dump

ex. cloth grocery bag instead paper or plastic

note: cloth diapers reusable, but wastes lots of water & energy to clean. Overall disposable less polluting, but expensive. c. RECYCLE waste (30% of waste)

conserves natural resources (in some cases), but takes more energy (in some cases)

creates jobs to separate materials (some argue that this is a weak reason for “job growth”)

US #1 recycling country in world

Product Stewardship Laws require the manufacturer to take back their packaging or the product once it is obsolete (company will raise $$)

Reduces need for landfills

Reduces dependency on foreign oil.

Reduces air & water pollution (in some instances) by reducing mining waste Paper recycling: (45% gets recycled) saves trees??, more pollution than incineration though (de-inking leaves chemical sludge) & more energy to produce paper from recycled paper fiber than virgin wood pulp. Most fiber in recycled paper is pre-consumer (scraps from paper factory) & NOT post-consumer (garbage that we throw away) Glass recycling: (26.3%) separated colors can be made into new glass cheaper than from raw materials, but labor cost to separate make it more expensive Aluminum recycling: (55%) recycling aluminum cans save energy, mining requires over 90% more energy & produces greater than 90% more pollution than recycling. 5% of the energy used in the US is to extract Al from its ore Plastic recycling: (< 20%) less expensive to make plastic from raw materials (oil) because there are so many types of plastic & many things have several types together (can’t separate)

$

D. Shell, SMHS 2012

5. Ocean Dumping a. Banned in the US according to the Ocean Dumping Ban Act of 198 b. Hard to regulate c. Debris gets eaten by animals & deposits itself on beaches

6. Exporting a. Pros: Quick & easy; provides $ for LDCs (MDCs give their trash along with $ to LDCs) b. Cons: expensive to transport; LDCs may not be using proper disposal methods (i.e. open

dumps or ocean dumping) 7. Composting

a. Allowing organic material to decompose naturally b. Different types:

i. Backyard: using barrels , piles, or chicken wired areas 1. Vermicomposting: adding worms to help speed up the decomposition

process. ii. Municipal: cities collect yard waste & take it to a facility

c. Pros: creates nutrient-rich soil; aids in water retention of soil; slows down erosion; no toxic materials d. Cons: public reaction to odor, vermin, insects; takes time

HAZARDOUS WASTE (1% of Solid Waste = discarded solid or liquid that:

has carcinogenic chemicals (dioxins, PCBs, solvents, pesticides)

catches fire easily (gasoline, paints, solvents)

releases toxic fumes (acids, bases, ammonia, chlorine bleach)

is corrosive (cleaning agents & drain cleaners)

are endocrine disruptors (lead, cadmium, mercury)

radioactive wastes (Hanford Nuclear Reservation p.559)

*household (municipal) hazardous wastes not regulated Case Study: Love Canal, NY (elementary school built over a hazardous waste landfill. Leaked, causing students to get sick Dioxins: formed during combustion (burning) of chlorine compounds

from incinerators, iron ore mills, copper smelters, cement kilns, metal recycling, coal combustion, & paper plants that bleach with chlorine

Japan has 10x more dioxins than other parts of the world b/c of incineration of trash (burn 75%)

Dioxins settle on things from smoke, are persistent, & get bioaccumulated & biomagnified in food chain

we all have some in our bodies, just worried that too much is bad

not certain that they cause cancer, but highly suspected. Also may affect immune, reproductive, & nervous system PCBs: C, H, Cl containing compounds used from 1929-1979 for electronic coolants, lubricants, hydraulics, etc.

Are chemically stable and persistent in the environment. Often get into humans by contaminated food (rice contamination in Asia).

often get into aquatic food chains by settling in sludge at bottom. people that eat a lot of fish more susceptible

store in fats like dioxins so they bioaccumulate & biomagnify

harm skin, eyes, reproductive, gastrointestinal, endocrine disruptor, nervous system, & may be carcinogenic

High Temp incineration can DESTROY PCBs (can’t help w/ PCBs already in soils), but new bacteria can biodegrade them in soil (under study)

Management of Hazardous Wastes (very expensive)

Principal of Inherent Safety: redesign industrial processes to use less toxic materials (source reduction) o Recycle waste (as is done with motor oil in your vehicles) o Reduce or eliminate toxicity w/ improved technology (ex: using Puron in place of Freon)

Resource Conservation & Recovery Act: 1976, tells EPA to identify which chemicals are hazardous & provide standards to states on how to handle hazardous waste management programs. RCRA bans these wastes in sanitary landfills w/o proper detoxification treatment.

o Known as “Cradle-to-Grave” law – monitors waste from the time of its creation, through its use & to its disposal

Toxic Substances Control Act (1976) – TOSCA o Gives the EPA the ability to track chemicals currently produced or imported into the US

D. Shell, SMHS 2012

Nuclear Waste Policy Act (1982) o Established a study to find a suitable disposal site for nuclear waste (Yucca Mountain)

Comprehensive Environmental Response, Compensation & Liability Act (CERCLA or Superfund) o 1980 program to clean up OLD abandoned & illegal haz. waste sites. o Greatest threat from haz waste is seeping thru soil into groundwater o at some sites it was never recorded what chemicals are stored there o federal government supplies funds to help companies that either ran or dumped wastes at sites

to clean up the worst ones o Hazardous waste disposal companies pay into this fund - $ given to the government who pays for

the cleanup Hazardous Waste Disposal

Hazardous Waste Landfills: similar to sanitary landfills but with more strict requirements on liners (requires 3 instead of 2). o Barrel the waste before placing in the landfill

Biological treatment: slower, but less expensive o Bioremediation: use bacteria to “eat” the chemicals out of polluted soil. o Phytoremediation: use plants to absorb chemicals out of polluted soil

Incineration: o Burning the waste – may lead to toxins in the air or toxic ash

Thermal Treatment: o Plasma Arcs (using electrical energy to melt or decompose the waste) o Pros: small, mobile, little ash o Cons: expensive, can release particulates, Cl2, toxic metals or radioactive

waste

Underground Injection: o Pros: low cost, wastes can be retrieved, simple o Cons: leaks, may cause earthquakes (b/c of drilling in the earth),

groundwater contamination Integrated Waste Management Using many different methods to get rid of waste