Contaminated wastewater is a common by-product of recycling plants, especially when it comes to recycling plastic materials such as post-consumer films, agricultural films, HDPE rigids, PET bottles and PP plastics, LDPE bottles, or co-mingled waste streams. These materials are widely used in the manufacturing of various products, including plastic bags, shrink wrap, and bottles, among others.
Recovering and recycling plastic is crucial for achieving sustainability goals. During the recycling process, these materials are washed, shredded, and melted down to be repurposed into new products. However, this process creates its own environmental problems in the form of contaminated wastewater which needs to be treated before being released back into the environment.
During the washing and recycling processes, food residue, paper fibre, cleaning agents and many other pollutants are released into the wash water. For the wash water to be circulated and reused, these contaminates need to be continually removed from the wash water circuit. If left untreated, the suspended solids and COD concentrations in the wastewater can continue to increase, until eventually the wash water circuit will become so contaminated it will need to be dumped.
To address this issue, recycling plants use various treatment methods to remove the contaminants from the wastewater. These methods can include mechanical screening, chemical or physical, and biological processes, depending on the nature of the contaminants.
At Water Tecnik, we design and manufacture proven wash water reuse systems to recycle the wash water. This enables our customers in the recycling industry to grow their business, improve their product quality and reduce their operational costs. There are proven benefits to washing in clean process wash water:
- It improves end product quality.
- It reduces costs associated with wastewater disposal.
- It reduces time associated with wash water system drain down.
- There are reduced costs associated with clean water into site.
- It improves plant availability and therefore throughput.
There are several key process stages employed when removing contaminants from wastewater:
MECHANICAL SCREENING
Shredders and friction washers cut plastic into small pieces, along with foils, caps, paper fibres etc. Water Tecnik screening machines are designed to remove these larger particles and are ideal at this stage.