What we do with our waste and how that waste affects our fresh clean water supplies are thoughts that don’t often cross our minds, but they should.
While we may not give it much thought, several scientists based at the Unversity College Cork (UCC) Environmental Research Institute (ERI) certainly do. In fact, many of them are spending their life’s work trying to solve the one-way system of waste that could potentially threaten our lives as well as affecting a vast array of flora and fauna.
UCC waste expert Niall O’Leary said the real problem arises with what happens to 141 million tonnes that enter the waste management system globally.
“According to European parliament figures, 30% of European plastic waste is recycled, with the remainder treated via incineration for energy recovery (40%) and landfilling (30%). “ Dr O’Leary said that in recent years landfilling has reduced in popularity and as well as that there is a growing concern that incineration can produce toxic gaseous by-products and supports a linear, unsustainable consumption of plastics.
Because of this, recycling has become the go-to solution.
“The 2018 European Plastics Strategy seeks all consumer plastics to be recyclable by 2030,” Dr O’Leary said, “however, it is worth noting that while this strategy envisages an environmental impact as an outcome, the primary focus of any strategy in Europe is growth, job creation and global economic competitiveness.
While a shift to recycling introduces resource efficiency and economic advantage it does not tackle the growing problem of plastic consumption.
The European plastics industry reported a turnover of 360 billion euros in 2018, while employing 1.6 million people, and the development of recycling infrastructure will contribute significant sector growth.
So what happens when we “recycle” our plastic waste?
Dr O’Leary explained the process.
“In Ireland, we lack the large scale industrial recycling capacity necessary to process waste plastics into polymer flakes/pellets for sale back to the industry.
“In addition, not all plastics are valuable from a recycling perspective.” As most people know, hard plastic containers can be recycled while soft plastic and films cannot. As well as this, plastics with leftover food on them render them useless.
Dr O’Leary said that this ongoing issue of mixed waste being passed off as recyclables has been dealt with by shipping them to countries across the globe willing to pick out the valuable material and incinerate or landfill the remainder.
In 2016 approximately 90% of Irish plastic recyclate was shipped to China on this basis However, in 2017, China, which received 51% of global plastic waste, banned the import of such low-value material causing a major upset to world plastic recyclate markets and resulted in plastic waste backups across the globe with Ireland, Germany and the UK most affected in Europe.
In response, countries redirect their recyclable waster to new destinations such as Turkey, Malaysia, Indonesia, Bangladesh, Senegal, Vietnam and a variety of others.
Unfortunately, these countries do not have the infrastructure to effectively manage this waste and the ultimate result is contamination of land, freshwater and marine systems with plastic debris.
Current estimates suggest that between 8-15 million tonnes of plastic debris enter global marine environments, with Asian countries seen as the largest contributors. They have become the world’s plastic landfill.
“While the Irish government may applaud our high national plastic recycling rates in relation to EU targets, our environmental impact is still shameful and worse still we impose it on those living on the other side of the world,” Dr O’Leary said.
Ultimately, we need to reduce our consumption to make a difference in the ongoing issue of pollution by plastic.
Unfortunately plastic is not the only problem we have to deal with and ensuring we have clean, freshwater is a growing battle.
Dr Jean O’Dwyer holds a BSc in Environmental Science and a PhD in Environmental Health Science from the University of Limerick. She is a permanent lecturer in the School of Biological, Earth and Environmental Sciences (UCC) and a principal investigator in UCC’s ERI with a focus on contaminants in water.
Speaking about the issue, Dr O’Dwyer said, from a health perspective, safeguarding our water resources in relation to agricultural impacts such as fertiliser runoff, wastewater and industrial effluents such as chemicals or plastic particles, is a national priority.
An expert in her field, Dr O’Dwyer said: “while we can reduce contamination, we cannot eliminate it, and as such, significant investments need to be made to improve our national drinking water infrastructure.
There are several simple things people can do to safeguard their water supplies from turning off the tap while brushing your teeth, to having quick showers and cutting out half loads of washing.
At a higher level, Dr O’Dwyer said that the Government needs to invest heavily and urgently in the water infrastructure to reduce leakages and improve water quality.
UCC’s Ecophysiology expert Professor Marcel Jansen has been focusing on wastewater for many years and said while waste is a problem for society, there are ways to capitalise on the substance.
“There are copious examples of how wastewater has negatively impacted on water quality, natural ecosystems, and ultimately us human beings.
“However, increasingly, we are considering wastewater as a resource, an opportunity, rather than as a problem. If we consider the case of wastewater with high levels of plant nutrients such as nitrogen and phosphorus, we are talking about key resources for plant growth and hence agriculture.” One major wastewater problem is the water from our washing machines which may contain 1000’s of plastic microfibers that are released when we wash our synthetic fleeces and other clothes made using synthetic polymers.
“Such micro-sized fibres are difficult to remove in conventional wastewater treatment plants, and hence these fibres are among the most common type of microplastics found in lakes and streams.
“Fibres may stick to aquatic plants and algae, and subsequently, enter the food chain. Indeed, plastic microfibers have been found in a variety of food products.” Another type of wastewater is water enriched in plant nutrients such as nitrogen or phosphorus.
Such wastewater may boost the growth of algae in rivers and lakes, to such an extent that these waters become unsuitable for invertebrates, and especially fish.
Again, this impacts directly on us humans, as we rely on clean freshwater sources as drinking water, as a resource for fisheries and agriculture, and for its amenity value such as swimming, boating and fishing.
Here at UCC, the EPA-funded Newtrients project is working to get value out of one of the biggest waste streams in Europe, the wastewater generated by the dairy industry when making products such as yoghurt, cheese and milk powder.
“On average, for every litre of milk used to make dairy products, at least one litre of wastewater is produced,” Professor Jansen said.
“Rather than accepting that this is waste, the industry has worked hard to extract valuable components, which would otherwise be contaminants that would negatively impact on the environment.
“For example, protein is extracted from dairy processing wastewater and sold as a nutritional supplement.” Other organic material is fermented to produce biofuel.
“UCC scientists, Niall O’Leary and David Wall, are working hard to produce bioplastic from dairy processing waste. The produced plastics are not only made from waste, they are also biodegradable, thus avoiding future waste.
“Thus, the wastewater from one of the largest, native industries in Ireland, is becoming a valuable resource.” Following production of bioplastics, the wastewater is still enriched in nitrogen and phosphorus and here a second innovative process is being developed by Professor Hansen.
“An aquatic plant is used to extract nitrogen and phosphorus from the wastewater. The used plant is simultaneously very ordinary and very special. It is duckweed that can be found on many of our lakes and channels, however, this plant has a very interesting characteristic. Duckweed produces large amounts of high-quality protein which is a desirable component of feed.
“The plant can also be used to replace commonly used soybean. Thus, by growing duckweed on dairy processing wastewater, we not only prevent the pollution of our streams and lakes with nutrients, but we also require less soybean imported from, for example, non-sustainable sources in South America.
“This example emphasises that there can be real value in waste and that taking advantage of waste as a resource will make life on planet Earth a step more sustainable.”