The Impact of Biodegradable and Compostable Plastic Products on the Occurrence and Contamination of Microplastics in Compost Leachate

The composting of organic and bio-waste is widely practised, and in some regions, it is even a mandatory waste management practice. A valuable by-product of this process is the nutrient-rich liquid known as compost leachate, which holds great potential for use in agriculture and horticulture. This investigation delves into the content, production methods, and impact of compost leachate on different crops while also emphasising its susceptibility to external factors. Compost leachate forms during composting and serves as an effective soil amendment material containing essential nutrients, microorganisms, and humic acids beneficial for plant growth. The quality of this by-product can be compromised by contamination from organic waste materials. Today, there has been widespread adoption of biodegradable or compostable plastic products in household composting systems due to misconceptions or public attitudes towards their usage. In-home composting, the process of decomposition might be slower, and there could be issues with the conventional waste management systems that are still commonly used. Additionally, not all degradable products are exclusively made from natural materials. Sometimes, synthetic polymer chains are utilised to accelerate degradation. This study aims to explore, through a simulated experiment, the possibility of microplastic contamination in composting environments, primarily due to the presence of biodegradable and compostable plastic items in these settings. The research findings indicate that the potential risks of microplastics to compost and compost leachate have been insufficiently explored, only recently becoming a focal point. The key conclusions suggest that the development of strategies to address these ecotoxicological factors is becoming increasingly pressing.