What Happens to Mixed Recycling?

Recycling is an essential part of reducing waste and conserving resources. Many of us participate in curbside recycling programs, carefully separating our recyclables from our trash, hoping that our efforts are making a positive impact. But what really happens after those blue bins are collected, especially when the contents are mixed recyclables?

In this post, we’ll explore what happens to mixed recycling once it’s picked up and processed, and why it’s important to get it right.

The Journey Begins: Collection

The first step in the recycling process is the collection of mixed recyclables. These materials often include things like paper, plastic containers, glass bottles, and metal cans. In many municipalities, the recycling is collected in a single bin, which is known as “single-stream recycling.” This means that different types of recyclables—such as paper, plastic, and metal—are all mixed together.

Once the materials are collected, they’re taken to a Materials Recovery Facility (MRF), where the real sorting begins.

Sorting at the MRF: The Magic of Technology (and Human Hands)

At the MRF, recyclables go through a multi-step process to be sorted into their respective categories. There’s no such thing as "one-size-fits-all" recycling, so each material has to be processed differently. Here’s how it typically works:

1. Initial Screening: The mixed recyclables are dumped onto a large conveyor belt and passed through an initial screening process. Larger items like cardboard are separated out first.

2. Mechanical Sorting: Next, machines with various sensors and mechanical arms work to further break down the materials. For example, magnetic belts remove steel cans, while air classifiers use blasts of air to separate lightweight materials, such as plastic bottles, from heavier items.

3. Optical Sorters: These high-tech machines use lasers to identify different types of plastics. This allows them to sort various types of plastic by resin type (e.g., PET, HDPE), ensuring that the correct plastics are sent to their appropriate recycling stream.

4. Human Intervention: While machines do a lot of the sorting, human workers are still an essential part of the process. They monitor the system, pull out contaminants (like non-recyclable items), and help ensure that everything is processed correctly.

The Trouble with Contamination

One of the biggest challenges in mixed recycling is contamination. When non-recyclable or dirty materials make their way into the bin, it can ruin an entire batch of recyclables. Contamination can include items like greasy pizza boxes, plastic bags, or even food waste.

In a facility, if a large portion of materials is contaminated, the whole batch may need to be sent to a landfill or incinerator. This highlights the importance of knowing what can and cannot be recycled and properly preparing materials (for example, rinsing out food containers).

Processing Recyclables: Turning Waste into Resources

Once the recyclables are properly sorted and cleaned, they’re ready to be processed into new materials. Here’s how some common recyclables are turned into new products:

• Paper: Paper is pulped, cleaned of any contaminants, and then reformed into new paper products, such as newspapers, cardboard, or even new printing paper.

• Plastic: Plastic is melted down and reformed into pellets, which can be used to create new plastic products, from bottles to textiles like fleece jackets.

• Glass: Glass is cleaned and melted down to be used again in glass containers, reducing the need for new raw materials like sand.

• Metal: Metals like aluminum and steel are melted down and can be turned into new cans, cars, or even new building materials.

These recycled materials are then sent to manufacturers who turn them into new products, closing the loop in the recycling cycle.

The Challenges of Mixed Recycling

While recycling is an important tool for reducing waste and conserving resources, mixed recycling does face challenges. One major issue is the inefficiency of sorting materials when they are mixed. Though sorting technology has greatly advanced, it’s still more difficult to process mixed recyclables compared to source-separated recyclables (where each material type is sorted by the consumer before collection).

Additionally, not all materials are easily recyclable, and some require more specialized processes. For instance, electronics, batteries, and certain types of plastics can be tricky to recycle and may require separate handling.

What You Can Do to Help

To make recycling even more effective, here are a few things you can do:

1. Avoid Contamination: Make sure to rinse containers before placing them in the recycling bin to avoid contamination. Do not throw items like plastic bags, food waste, or non-recyclable plastics in the recycling bin.

2. Know What to Recycle: Familiarize yourself with your local recycling guidelines. Not everything with the recycling symbol is recyclable, and some items may need to be taken to special drop-off locations.

3. Reduce and Reuse: Recycling is important, but reducing your consumption and reusing items is even better. The less waste you create in the first place, the less that has to be recycled.

Conclusion

Mixed recycling is an integral part of reducing waste and conserving resources. While the process is complex and there are challenges in sorting and processing, the journey from your recycling bin to a new product is crucial for creating a more sustainable future. By understanding how mixed recycling works and being mindful of what we put in our bins, we can ensure that our efforts are making the most positive impact.

So next time you toss a plastic bottle into the recycling bin, you’ll have a better idea of how that bottle might end up as something new—and perhaps how you can make the process even more effective!