Recycling and recovering waste materials is an important way to reduce the environmental impact of garbage and trash. There are many different categories of waste that can potentially be recycled or recovered in some way. The main types of recoverable waste include paper, plastic, glass, metals, electronics, batteries, and organic materials like food scraps and yard trimmings.
Paper
Paper makes up a large percentage of recoverable waste. Many types of paper can be recycled, including newspapers, magazines, cardboard, office paper, and junk mail. Recycling paper reduces the need to cut down trees and produces less pollution than creating new paper from scratch. Around 65% of paper in the US is currently recycled.
What kinds of paper can be recycled?
Most paper and cardboard products can be recycled, including:
- Newspaper
- Magazines and catalogs
- Office paper
- Envelopes
- Paper grocery bags
- Cardboard boxes
- Cartons
- Paper towel tubes
Shredded paper can also be recycled but needs to be kept separate from other paper. Paper that has been soiled with food or other waste may not be recyclable.
How is paper recycled?
Paper goes through the following recycling process:
- Collection – Paper is collected from recycling bins and trucks pick it up from the curb.
- Sorting – Materials are sorted at a recycling facility to separate paper from other recyclables.
- Shredding – Paper is shredded into small pieces.
- Pulping – The shredded paper is mixed with water and turned into pulp.
- Cleaning – The pulp is cleaned to remove contaminants like tape, staples and glue.
- De-inking – Ink is removed from the pulp.
- Refining – The pulp is mechanically and chemically processed to improve fiber strength.
- Papermaking – The recycled pulp is turned into new paper products.
Plastic
Plastic recycling recovers waste plastic material and reprocesses it into useful products. Recycling plastic reduces the need for new plastic production. Around 8-9% of plastic waste in the US is currently recycled.
What kinds of plastic can be recycled?
The most commonly recycled plastic items include:
- Plastic bottles and jugs
- Food containers like yogurt cups
- Detergent and soap bottles
- Bags
- Packaging materials
Plastics are marked with numbers 1-7 to identify the type of resin. Typically plastics numbered 1 (PET), 2 (HDPE) and 5 (PP) are most frequently recycled.
How is plastic recycled?
Plastic recycling involves the following steps:
- Collection – Plastic is collected at curbside or at drop off locations.
- Sorting – Plastics are sorted by resin codes and separated by color and transparency.
- Shredding – The plastic is shredded into flakes.
- Washing – Flakes are washed to remove contaminants.
- Melting – The flakes are melted into a liquid state.
- Refining – Impurities are removed from the melted plastic.
- Pelletizing – The liquid plastic is made into pellets.
- Reuse – The pellets are then used to make new plastic products.
Glass
Glass recycling helps recover waste glass from things like food jars, beverage bottles, windows, and other sources. Recycled glass reduces the need to mine raw materials. In the US around 27% of glass containers are currently recycled.
What kinds of glass can be recycled?
Types of glass that are commonly recycled include:
- Glass bottles and jars from food, drinks, beer, wine, sauces and condiments.
- Glass from windows and decorative pieces.
- Ceramics and porcelain.
Lids and caps from bottles should be removed. Certain glass products like light bulbs, dishes, and pyrex are often not recyclable.
How is glass recycled?
The glass recycling process includes:
- Collection – Glass is collected from recycling bins or drop-off centers.
- Sorting – Glass is sorted by color and separated from contaminants.
- Crushing – Glass is crushed into small cullet pieces.
- Screening – Cullet is sifted to remove residues and impurities.
- Decontaminating – Further cleaning removes remaining contaminants.
- Melting – Cullet is melted down at high temperatures.
- Manufacturing – Molten glass is made into new glass products.
Metals
Metal recycling recovers metal waste like steel, aluminum, copper, silver, brass and lead. It reduces the energy costs of mining new metals. Around 34% of steel and 42% of aluminum is recycled in the US.
What kinds of metals can be recycled?
Some common recyclable metals include:
- Aluminum – Beverage cans, foil, components, siding.
- Steel – Food cans, appliances, scrap metal.
- Copper – Piping, wiring, cookware, computer parts.
- Brass – Musical instruments, plumbing pieces, bullet casings.
- Lead – Batteries, radiation shielding, weights, ammunition.
Precious metals like gold, silver and platinum found in jewelry and electronics are also recyclable.
How are metals recycled?
Metal recycling typically involves:
- Collection – Metals are collected at recycling centers, scrap yards or curbside.
- Sorting – Metals are sorted by type through magnets, eddy currents, density separations.
- Shredding – Scrap metal is shredded into small pieces.
- Melting – Metal scraps are melted in furnaces according to specific metallurgical processes.
- Purification – Impurities are removed from the molten metal.
- Manufacturing – The molten metal is made into new metal materials or products.
Electronics
E-waste or electronic waste recycling recovers materials like metals, plastics and glass from electronics. Recycling electronics reduces environmental contamination and minimizes the need for mining raw materials. Currently around 40% of e-waste in the US is recycled.
What kinds of electronics can be recycled?
Many types of electronics can be recycled or reclaimed, including:
- Computers – desktops, laptops, tablets
- Monitors and displays
- Televisions
- Mobile phones
- Stereos, radios, DVD players
- Microwaves
- Video game systems
Electronics contain recoverable materials like steel, copper, aluminum, gold, silver, plastics and glass.
How are electronics recycled?
Electronic recycling involves:
- Collection – Electronics are collected from trash bins, drop-off centers, retailers, schools and businesses.
- Sorting – Items are manually sorted by product type.
- Dismantling – Products are taken apart by hand or machinery.
- Separation – Components like metals and plastics are separated using magnetic and density techniques.
- Shredding – Separated materials are shredded into raw commodities.
- Refining – The shredded materials are further refined through various metallurgical and recycling processes.
Batteries
Battery recycling recovers heavy metals, plastics and corrosive materials from used batteries. This keeps hazardous wastes out of landfills. Around 14% of lead-acid batteries are recycled in the US, along with 14% of rechargeable nickel-metal hydride batteries.
What kinds of batteries can be recycled?
Many common battery types are recyclable, like:
- Lead-acid car batteries
- Nickel-cadmium (Ni-Cd) batteries
- Nickel-metal hydride (Ni-MH) rechargeable batteries
- Lithium-ion (Li-ion) rechargeable batteries
- Alkaline batteries (household batteries)
- Button cell batteries
Carbon-zinc and zinc-air batteries are not usually recyclable. Damaged or leaking batteries may not be accepted.
How are batteries recycled?
Battery recycling typically follows these steps:
- Collection – Batteries are collected through retailers, local programs or household hazardous waste sites.
- Sorting – Batteries are sorted by chemistry type through automated or manual methods.
- Shredding – Batteries are shredded mechanically in hammer mills or shredders.
- Separation – Metals, plastics and acids are separated using density, magnetics, screening and filtration.
- Treatment – Acids and electrolytes may be neutralized.
- Refining – Plastics and metals go through additional processes to purify them.
Organic Materials
Organic recycling takes waste materials like food scraps, yard trimmings and wood waste and recycles them into useful products like compost, fertilizer, biogas and biofuels. Currently around 35% of yard trimmings and food scraps are composted in the US.
What kinds of organic waste can be recycled?
Many organic materials can be recycled or composted, such as:
- Food scraps and food processing waste from homes and restaurants
- Yard trimmings like leaves, grass clippings and tree branches
- Wood waste including sawdust, wood chips and scrap lumber
- Agricultural crop wastes like fruit and vegetable peels, husks and stalks
- Livestock manure and bedding
- Biosolids from wastewater treatment
Most organic waste materials are suitable for composting or anaerobic digestion processes.
How are organic materials recycled?
Organic recycling involves:
- Collection – Organics are collected from households, businesses, farms or waste facilities.
- Sorting – Materials may be sorted to remove contaminants and separate types of organics.
- Shredding – Large pieces are broken down for composting.
- Composting – Organics are composted aerobically to produce fertilizer and soil amendments.
- Anaerobic digestion – Bacteria break down organics without oxygen to produce biogas and digestate.
- Refinement – Compost and digestate are refined to produce marketable products.
Conclusion
Many different categories of waste can be recycled or recovered, including paper, plastics, glass, metals, electronics, batteries and organic materials. Each material goes through a series of steps including collection, sorting, processing and manufacturing to produce new products or materials. Recycling and recovering waste reduces the amount of virgin resources needed and the environmental impacts of waste disposal.