Microplastic contamination in sewage sludge: Abundance, characteristics, and impacts on the environment and human health

This literature review addresses the presence of plastic in domestic wastewater, an increasingly important facet of the widespread use of plastic and its detrimental effects on the environment, with a focus on microplastics (MPs) in sewage sludge and their implications for a circular economy. Extensive research has been conducted on the occurrence of MPs in wastewater treatment plants. Sewage sludge is a byproduct of such plants that are widely used in the agricultural and other sectors but may contain emerging contaminants, including MPs, that can pose a significant risk to the environment. The review highlights the high concentrations of MPs in sewage sludge and underscores the need for appropriate disposal methods to prevent soil contamination. MPs can also detrimentally interact with other emerging contaminants, such as heavy metals and organophosphate esters. While extraction technologies exist to remove MPs from wastewater, their implementation is subject to technical and economic considerations. Future research should focus on the optimization and efficacy of these technologies to ensure safe sludge management. Given the high levels of MPs and other emerging contaminants found in sewage sludge, it is crucial to implement technologies that enable sustainable sludge disposal. By acknowledging these challenges and developing appropriate solutions, we can mitigate the environmental impacts of plastic and promote sustainable waste management practices.