Recycling Plastics Australia Case Study

Aerofloat’s award-winning plastics recycling wastewater treatment system successfully installed at Recycling Plastics Australia.

Aerofloat was engaged by Recycling Plastics Australia (RPA) to design and install a plastics recycling wastewater treatment plant that would remove odour from the finished product whilst significantly reducing the factory’s water use.

Aerofloat completed the design in-house and offered 3D models of the design prior to installation, giving RPA the confidence that the system would fit the space.

In plastics recycling, the initial cleaning and separating process requires large volumes of recirculating washwater. This water can become contaminated (such as with dairy components from yoghurt, ice-cream, and milk containers), requiring regular replacement to avoid contamination and odours of the final recycled product.

Prior to Aerofloat’s solution, 70,000 litres of washwater was being replaced weekly. The end of each week, dirty washwater had impacted machinery and most crucially, the recycled plastic result.

Aerofloat efficiently designed and installed an effective wastewater treatment plant that provided RPA with a continuous supply of clean water.

Aerofloat’s unique design incorporated its patented aeration system to treat the washwater to a standard suitable for reuse in the washwater tank, thereby saving significant water usage and costs for Recycling Plastics Australia.

Aerofloat installed its fully automated recycled wastewater treatment system with remote monitoring to ensure RPA operators had access to its wastewater treatment system around the clock. This advanced remote monitoring access also allowed staff to call on Aerofloat’s engineers for expert advice as required.

Aerofloat’s patented AeroMBBR ensured a low-maintenance solution for RPA. Wastewater entered the AeroMBBR where the biomass attached to the surface of the media; organic matter was then degraded, resulting in BOD removal.

• In the AeroMBBR, biomass growth on the surface of the floating plastic media created a thin film.
• This high-density population of bacteria achieved high-rate bio degradation.

Organic carbon was converted to carbon dioxide while the ammonia and nitrogen in the organics were converted to nitrates through a nitrification process.

Oxygen required for the process was provided through the roots blower installed via patented Aerofloat removal lances. The Dissolved Oxygen (DO) levels in AeroMBBR was monitored by an Intelligent DO monitoring system that automatically drives the blowers to maintain desired DO levels.

The treated wastewater flowed back to the balance tank for reuse. Any excess biomass and solids leaving the AeroMBBR were continuously removed in the AeroDAF M400: the system included an automated flocculation dosing system designed to treat flows up to 24m3/hr.

The solids removed by AeroDAF M400 were stored in a 15m3 sludge tank which was thickened and dewatered using a bag-dewatering process – reducing on trade-waste trucking costs.

Aerofloat was able to treat the wastewater to meet local discharge requirements, while using minimal space.

Despite COVID-19 restrictions, Aerofloat’s engineers were able to safely install the system at the South Australian site, within the agreed schedule.

Aerofloat efficiently designed and installed an effective plastics recycling wastewater treatment plant that provides RPA with a continuous supply of clean water.

The clean water has been both chemically and biologically treated (resulting in zero downtime for RPA’s operations) and ensures its recycled plastic products are odourless.