From waste to compostable packaging: Addressing the environmental end-of-life impact of modified cellulosic films using biogeochemical analysis.

Over the next couple of decades more than a billion tonnes of oil-based plastic will be dumped into landfill and seep into our oceans, much of this from packaging. Many synthetic plastics do not biodegrade and will remain damaging our environmental ecosystem and enter our food chain. Most plastic products can be substituted for cellulosic alternatives that degrade without affecting the natural environment. The use of these biodegradable products is limited due to the high price and environmental concern of obtaining and processing wood cellulose. Moreover, PdVC resin coating (which contain chlorine and, as PVC, produce dioxin toxins through incineration) is required to provide barrier properties and heat sealability to cellulose.

In our lab, we are working with a cellulose company to produce cellulose pulps from agricultural waste and leftovers and to substitute resin coatings for a compostable aqueous coating technology. This PhD project will support this approach by understanding the biogeochemical cycle and biodegradability of this new range of packaging materials. You will evaluate how their disposal affects plant growth, the soil ecosystem and the ground water. The objectives are to: 1) determine the effect of films produced using agricultural waste and new aqueous coatings on soil properties, plant germination and the abundance and association of mutualistic fungi and bacteria; 2) determine the biodegradation of agricultural waste films and new coatings in water and identify its effects on water composition; 3) collaborate with industry to deliver the optimum combinations of waste/standard films and coatings aiming to minimize the environmental end-of-life impact of the materials and reduce carbon footprint. The project brings together academia and industry, to create a new partnership that bridge the efforts invested in the generation of natural and compostable flexible packaging with an understanding of the environmental physiological effects for a truly circular economy. At the end of the project, we will deliver crucial information on the environmental impact of using these novel water coatings and crop waste-based films in comparison to more traditional packaging material.

By analysing biodegradation, the project will deliver crucial information to support the development of these new bioplastics as an environmentally sustainable option. This knowledge will be used to influence the public and policy makers and create a new solution to reduce plastic pollution. This is interdisciplinary research split between environmental physiology (studying the physiological responses of plants to changes in the soil environment); pollution, waste and resources (by understanding the fate of waste materials); biochemical cycles (we are studying changes in the cycling of matter within the physical environment) and soil sciences (studying decomposition processes, water, nutrients and contaminants and their interactions with soil-borne symbionts). The project fits within few NERC remits: by studying the biogeochemical consequences of using these films, we are ‘monitoring the physical, chemical and biological processes on which our planet and life itself depends’. The project discoveries will help the development of strategies to ‘build resilience to environmental hazards (such as waste and producing alternative to plastic) and manage environmental change (changes in soil nutrition/conditioning and plant ecosystems)’.