Aquatic and Terrestrial Pollution Notes - 8.9 to 8.11

Solid Waste Types

MSW (Municipal Solid Waste) - Solid waste from cities, which includes households, businesses, schools, etc.

• Only 2% of MSW is considered hazardous

E Waste - discarded electrical or electronic devices, including items like computers, televisions, and smartphones

• contain heavy metals that can leach into soil and groundwater if disposed of in landfills

• can be recycled and reused to create new electronic devices

Both E and MSW can leach endocrine-disrupting chemicals into landfills

Waste Stream

the flow of solid waste to recycling centers, landfills, or incinerators

Sanitary Landfills

Where developed nations dispose of trash; different than dumps which are just areas where trash is dumped without features such as

• clay/plastic bottom liner - prevents pollutants from leaking into groundwater

• Leachate collection System

• Methane Recovery Sys

• Clay Clap

Landfill contents and Decomposition

Landfills have very low rates of decomposition due to the low amount of O2, moisture, and organic material combination

• causes them to remain the same size

Things that shouldn’t be landfilled

hazardous waste, metals like copper and aluminum, and old tires

Things that should be landfilled

cardboard food wrappers, rubber, plastic films/wraps, styrofoam

• food, yard waste, and paper can and do go in landfills but should be recycled or composted

Landfill issues

groundwater contamination and release of GHG’s

• gw - contaminated with heavy metals like lead and mercury, acids, medications, and bacteria if leachate through lining into soil/gw beneath

• GHG’s. - CO2 and methane are released from landfills due to decomposition

NIMBY (Not In My BackYard)

The idea that communities don’t want landfills near them for a number of reason such as smell, sight, and the attraction of animals such as rats and crows

Waste Incineration

Waste can be burned to reduce volume that needs to be landfilled since most waste can easily combust in high temps

• can reduce volume by 90% but also releases CO2 and air pollutants (PM, SOx, NOx)

• can be burned to generate electricity

Ocean Dumping

illegal ocean dumping occurs in some countries with few environmental regulation of lack of enforcement

• plastic especially collects into large floating garbage patches in the ocean

• can suffocate animals if they ingest t of entangle them so that can’t fly are swim, eventually causing them to starve

The Three R’s

Reduce - Reduce consumption to decrease the amount of natural resources used to create, package, and ship goods

• metal/reusable water bottles to reduce plastic water bottle use

• riding a bike, working from home, or walking to reduce gas emissions/use

Reuse - Doesn’t require additional energy to create a product

• buying second-hand, using old wooden pallets from furniture, and washing plastic takeout containers to reuse

Recycle - least sustainable of the three, but it converts solid waste material into new products

• glass being turned into glass again, or plastic being turned into fabric

Recycling Pros and Cons

Can reduce demand for new materials, especially metals and wood which causes habitat destruction and soil erosion when harvested

costly and still requires significant energy

Composting

Organic matter (food scraps, paper, yard waste) being decomposed under controlled conditions

• reduces landfill volume and produces rich organic matter that can enhance water holding capacity and nutrient levels of agricultural or garden soil

• reduces methane release from anaerobic decomposition

• can release a foul smell

Primary Treatment

First in sewage treatment; the physical removal of large debris like leaves, plastic, and sediment with a screen or grate,

Secondary Treatment

Second in sewage treatment; the biological breakdown of organic matter (feces) by bacteria (aerobic process)

Tertiary Treatment

Ecological or chemical treatments to reduce pollutants left after primary & secondary (N, P, bacteria)

• uses chemical filters to remove more of the nitrates & phosphates from secondary treatment discharge

• Critical step because effluent that is discharged into surface waters with elevated nitrate/phosphate levels leads to eutrophication

• $$ Expensive and not always used

Disinfectant

UV light, ozone, or chlorine is used to kill bacteria or other pathogens, such as e. Coli (considered part of Tertiary)

Effluent

the liquid waste or sewage that is discharged from a treatment facility, such as a wastewater treatment plant.

Sludge

Sludge refers to the thick, semi-solid material that accumulates at the bottom of wastewater treatment systems like septic tanks in the primary and secondary treatment process. It contains a mixture of organic and inorganic matter.

• water is spun and pumped off to concentrate it further

• the dry remaining physical waste is collected to put into landfills to be burned or turned into fertilizer pellets

Sewage Treatment Issues

Combined sewage and stormwater runoff systems can cause wastewater treatment plants to flood during heavy rains, releasing raw sewage into surface waters

Raw sewage release contaminates surface waters with:

• E. coli

• Ammonia

• Nitrates

• Phosphates

• Endocrine disruptors (medications)

Even treated wastewater effluent released into surface water often has elevated N/P levels and endocrine disruptors (medications passed through the body)