Work

Occurrence, spatiotemporal trends, fate, and treatment technologies for microplastics and organic contaminants in biosolids: A review

Year: 2024

Type: review

Abstract: This review provides a comprehensive overview of the occurrence, fate, treatment and multi-criteria analysis of microplastics (MPs) and organic contaminants (OCs) in biosolids. A meta-analysis was complementarily analysed through the literature to map out the occurrence and fate of MPs and 10 different groups of OCs. The data demonstrate that MPs (54.7% occurrence rate) and linear alkylbenzene sulfonate surfactants (44.2% occurrence rate) account for the highest prevalence of contaminants in biosolids. In turn, dioxin, polychlorinated biphenyls (PCBs) and phosphorus flame retardants (PFRs) have the lowest rates (<0.01%). The occurrence of several OCs (e.g., dioxin, per- and polyfluoroalkyl substances, polycyclic aromatic hydrocarbons, pharmaceutical and personal care products, ultraviolet filters, phosphate flame retardants) in Europe appear at higher rates than in Asia and the Americas. However, MP concentrations in biosolids from Australia are reported to be 10 times higher than in America and Europe, which required more measurement data for in-depth analysis. Amongst the OC groups, brominated flame retardants exhibited exceptional sorption to biosolids with partitioning coefficients (log Kd) higher than 4. To remove these contaminants from biosolids, a wide range of technologies have been developed. Our multicriteria analysis shows that anaerobic digestion is the most mature and practical. Thermal treatment is a viable option; however, it still requires additional improvements in infrastructure, legislation, and public acceptance. Biosolids, by-products of wastewater treatment, are increasingly used in agriculture and other land-based applications. They however contain various organic contaminants (OCs), posing potential risks to human health and ecosystems. Based on the past 30 years of scientific literature, this study presents a systematic review and a meta-analysis of 11 OC groups with regards to the occurrence and spatiotemporal trends, fate, treatment technologies, and multicriteria analysis of the treatment technologies. Our findings will provide valuable insights into the management and treatment of OCs in biosolids, contributing to safer and more sustainable practices.

Source: Journal of Hazardous Materials

DOI: 10.1016/j.jhazmat.2024.133471