Types & Waste Management Waste

Types of Waste

Biodegradable vs. Nonbiodegradable Biodegradable: can be broken down by bacteria and other biological processes Can be broken down and absorbed by the environment Biodegradable materials- plant and animal matter Biodegradable products- newspaper, paper bags, cotton fibers Nonbiodegradable: can’t be broken down by biological processes Typically synthetic materials  made by combining chemicals to form compounds that do not form naturally Examples- polyester, nylon, plastic

Biodegradable Materials Nonbiodegradable Materials

Solid Waste Definition of waste: material that is not wanted or unusable remains of something Synonyms for waste- garbage, rubbish, trash, litter, debris Solid waste can be classified into different categories depending on their source: Household waste  municipal waste Industrial waste  hazardous waste Biomedical/hospital waste  infectious waste

Municipal Solid Waste Consists of: Household waste Construction and demolition debris Sanitation residue Sanitation- making sure something is clean and free of harmful germs Waste from streets Generated mainly from residential and commercial places

4 broad categories of garbage: Organic waste- kitchen waste, vegetables, flowers, leaves, fruits Toxic waste- old medicines, paints, chemicals, bulbs, spray cans, fertilizer and pesticide containers, batteries, shoe polish Recyclable- paper, glass, metals, plastics Soiled- hospital waste such as cloth dirtied with blood and other body fluids

Rising urbanization rates has increased the amount of municipal solid wastes Urbanization: increasing number of people living in suburbs and cities Changes in life style and food habits have also increased amount of municipal solid wastes Also changes the make up of the waste Products packed in cans, aluminum foils, plastics, and Styrofoam  products don’t break down naturally

Type of Municipal Waste Time it Takes to Break Down Organic waste- vegetable and fruit peels, leftover food 1-2 weeks Paper10-30 days Cotton Cloth2-5 months Wood10-15 years Woolen items1 year Tin, aluminum, and other metals such as cans years Plastic bagsUndetermined Glass bottles Undetermined

Industrial Waste Definition: waste that is produced from manufacturing processes in factories, mills, and mines Considered to be a hazardous waste since it can be toxic to humans, animals, and plants Corrosive- can wear away or burn Highly flammable or explosive Can react when exposed to certain gases Examples- old batteries, paint tins, old medicines, metal, chemical paper, pesticides, dye, rubber

Medical Waste Definition: waste generated during the diagnosis, treatment, or immunization of human beings or animals Also known as hospital or infectious waste Biohazardous-highly infectious Can cause serious threats to humans

Can include: Sharps- medical needles used to give shots or medicine, or draw blood Dirty swabs and bandages Beds, sheets, and clothing soiled with body fluids Biohazardous waste must be kept in separate containers and thrown away at a special treatment center

Waste Issues Most products today are used once and then thrown away Many towns are running out of space to dispose of the waste that people create As the amount of waste we produce grows larger  amount of land available per person becomes smaller Thousands of years ago waste was mostly animal and vegetable matter Today’s waste contains metals, materials that don’t break down, or are toxic Not enough land to dispose of waste in landfills

Ways to Get Ride of Garbage Waste Management

Landfill Definition: a carefully designed structure built into or on top of the ground which trash is isolated from the environment Most municipal waste ends up in a landfill Provides a place for garbage that can’t be recycled, composted, or reused Compost- broken down organic matter that is used as plant fertilizer

Parts of a Landfill Compacted clay- prevents rainwater and leachate from entering the groundwater below Leachate: water in a landfill that is contaminated with byproduct of decomposition Bottom liner system- puncture-resistant plastic layer that prevents the trash from coming in contact with the outside soil and groundwater Cells (old and new)- where trash is stored in a landfill Trash is compacted (squeezed) to become smaller to take up less space to allow for more air space in landfill for trash to decompose

Parts of a Landfill cont. Storm water drainage system- collects rain water that falls on the landfill and empties it into a ditch that surrounds the landfill Landfill needs to be kept as dry as possible to reduce amount of leachate Leachate collection system- collects leachate that has percolated through and removes it from the landfill Water is then pumped into a leachate pond where it is then sent to a wastewater treatment plant

Parts of a Landfill cont. Methane collection system- collects methane gas that is formed during the breakdown of trash Methane gas can either be: Collected in a pipe and then burned Used as a fuel source to generate electricity Covering or cap- seals off the top of the landfill Old cell is covered with 6 inches of soil Prevents animals from getting into the trash Grass can be planted on top to keep soil in place

Issues with Landfills Groundwater contamination- leachate can leak into the soil and groundwater below Leachate contains chemicals that are harmful to both the environment and animals Methane gas is highly flammable Methane “flare” used to burn excess methane build-up in a landfill

Incineration Definition: burning of waste in an incineration plant Remaining ash after trash is burnt is either buried in a landfill or mixed into concrete

Pros and Cons of Incineration Benefits- Volume/amount of waste is reduced Can be used to generate energy  can help reduce dependence on fossil fuels Disadvantages- Not all material can be burnt  heavy metals Harmful emissions can be released into the air