Plastic waste is a major global issue with plastics recycling an emerging industry to combat this environmental challenge. It is estimated that only a fraction of the world’s plastics is captured for reuse, despite there being many uses for recycled plastic material.
In late 2015, Aerofloat was contacted by Australian Recycled Plastics (ARP) to consult on its wastewater challenge at its plastics recycling plant in Narrabri, North West NSW. Narrabri has an average mean rainfall of 650mm per year and water supply is limited in the area. As such, water conservation is imperative for ARP.
When building the greenfield plastics recycling plant, ARP installed a half million litre water capture facility from the roof of the 4000m2 building, as well as a water recycling system to treat the process wastewater. This system consisted of fine screens followed by ultrafiltration.
Upon commencement of production, ARP found that a major odour problem arose at the plant as the water recycling design did not address any soluble contaminants in the water. These contaminants were being generated primarily from the degrading soluble protein and lactose from residual dairy products in the plastic. The odours were causing occupational health and safety issues for the workers and were also contaminating the final product – a pelletised plastic form of PE and PET. The PE and PET pellets are used for products demanding high quality specifications, namely the manufacture of food meat trays and as a component in composite plastic decking material.
To resolve the odour and contamination problems, ARP was forced to regularly dispose of wastewater and refill with fresh water, as well as limit the production hours, thereby causing major interruptions to operations. The operational down time and cost of replacing the water was not a viable long-term option for the company. ARP needed a swift solution to continue operations which is where Aerofloat stepped in.
The Aerofloat solution
In order to begin the recycling process, plastic must enter a large tank of water to essentially clean and separate the different types of plastic. In the tank, Polyethylene (PE) floats and Polyethylene Terephthalate (PET) sinks. This process requires large volumes of recirculating water. As this water becomes contaminated, often with residual dairy components from ice-cream, yoghurt and milk containers, it must be regularly replaced. This can be a costly exercise, making it desirable to treat and recycle the process wastewater.
Aerofloat provided a wastewater treatment system which included its patented AeroMBBR and AeroDAF products. The system needed to have the following features:
- easy to install
- low maintenance
- cost effective
- sealed and vented
- easily cleaned with minimal downtime
Within one week of Aerofloat installing the system the odour in the production facility and products was eliminated. Shortly thereafter, ARP was operating at full capacity. The Aerofloat system has been fully operational since March 2016, making ARP a very satisfied client.