Turning waste PPE into water and Vinegar; a revolutionary method developed at Auckland University

 

Corona pandemic has necessitated the widespread usage of Personal Protective Equipment like masks, gloves, PPE suits, and face shields worldwide. These single-use PPE kits are made out of polypropylene plastic which can take hundreds of years to degrade and are difficult to recycle this waste through conventional recycling systems as they cost more for local recyclers to collect and process than the eventual materials are worth. In such a situation, managing this generated biomedical garbage has become a global challenge.

Now, a team of researchers at the University of Auckland’s Faculty of Engineering have developed an unusual method to convert this non-recyclable PPE wastes into harmless byproducts such as water and vinegar which would prevent tons of PPE from ending up in landfills or dumped into the oceans. It could be an unquestioned revolutionary procedure to tackle the COVID-19 healthcare wastes problem.

The process to turn PPE waste into useful byproducts is….

Shredded PPE materials from gloves, masks, gowns and safety glasses are fed into a machine that applies pressurized hot water and compressed air are applied, water and acetic acid are the end-products.

The PPE-to-liquid process is carried out at a temperature of 300°C and takes about an hour in a small prototype machine in a laboratory in the faculty.

Gaseous by-products from the process are oxygen and low concentrations of carbon dioxide which can be safely discharged.

“This is a clean, chemical-free solution which will be a game changer internationally,” says Dr Saied Baroutian, an associate professor in the faculty’s Department of Chemical and Materials Engineering.

“The technology used is a hydrothermal deconstruction or valorization process and it destroys the waste completely. The liquid produced in the process is safe, inert and can be reused – the vinegar or acetic acid can be used for disinfecting and the water can be reused for the processing cycle therefore minimizing water consumption and helping with sustainability.”

“Other byproducts that are generated during the process include oxygen and reduced concentrations of CO2, which can be easily and safely extracted throughout. Furthermore, the waste is completely destroyed during the hydrothermal deconstruction/valorization process.”

A test tube of shredded  unrecyclable PPE that turns into a test tube of clean water 

The process has been developed at the university in collaboration with the Faculty of Medical and Health Sciences and the Universities of Otago and Waterloo (Canada).

Dr. Yvonne Anderson, a senior lecturer at the Department of Paediatrics, University of Auckland, is leading an another project that uses revolutionary technology to disinfect PPE so it can be reused or recycled safely.

Dr. Baroutian says: "By developing two technologies—one for reusable waste and the other for waste that cannot be reused or recycled—we are closing the loop on this ever-growing serious waste issue and providing a circular solution that truly is clean and green."

Baroutian and his team are now taking steps to develop the solutions into a larger scale pilot feasibility system to take one step closer towards producing a fully scalable proof-of-concept.

Read also: ‘Recycle man of India’ uses discarded PPE and face masks to make advanced eco-bricks

"That is the point where we can showcase the technology, ensure the designs will work with the flow of PPE waste and find funding or potential partnerships with commercial organizations so these technologies can be implemented in New Zealand and overseas," says Saeid.

The long-term goal is to produce a strategy that both answers the WHO’s call to ensure safe and rational use of PPE while partnering with the relevant organizations to take this innovative technology out of the lab and into practice on a global scale.

The team has also demonstrated that a widespread hydrothermal deconstruction system could have economic advantages as their evaluations assess that the method could process PPE waste streams at comparable costs to current autoclaving and waste disposal landfill methods.

The WHO has called for drastic changes to be made in how health care waste streams are managed as a fundamental requirement of climate-smart health care systems, there is an urgent need to improve waste management systems as Tonnes of COVID-19 healthcare waste may create major environmental issues in future.

It is one of two innovative solutions that link up to tackle the Covid-19 healthcare waste problem which has been described as “threatening human and environmental health” by the World Health Organization.