Biotreatment strategies for the removal of microplastics from freshwater systems. A review

Research on plastic pollution has recently evidenced the ubiquitous presence of tiny plastic particles called microplastics. Microplastics alter organisms because microplastics tend to bioaccumulate, they contain hazardous additives, and they carry other contaminants and pathogens adsorbed on their surface. Here, we review the biodegradation of the five most common microplastics: polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polystyrene. Despite the fact that most plastics are hardly biodegradable, biodegradation is still a popular remediation techniques because it is highly economical and environmentally friendly. Biodegradation can be done applying single or combined bio-cultures such as bacteria, mold, yeast, and algae. We present analytical and microbiological methods used for monitoring microplastic biodegradation. Actually, no microbial method removes completely microplastics from the environment within a reasonable time interval. As a consequence, the last developments combine biodegradation with other methods such as membrane filtration.