Biochar as a Potential Tool for Addressing Microplastic Pollution: A Review

Microplastic (MP) pollution has emerged as a critical environmental issue, impacting ecosystems and human health worldwide. This review investigates the impact of biochar (BC) as an innovative and sustainable solution to combat MP contamination. BC possesses unique physicochemical properties that enhance its ability to adsorb and immobilize MPs from various environmental media. Recent findings highlighted in this review demonstrate that BC significantly increases the adsorption capacity for MPs, effectively reducing their mobility and bioavailability. Key factors influencing BC's adsorption efficiency include its surface charge, surface area, morphology, and porosity. However, using BC poses ecological risks due to toxic components like polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), polychlorinated dibenzo-dioxins (PCDDs), polyfluorinated compounds (PFRs), and heavy metals, which can leach into the environment and harm aquatic life and soil biota. Additionally, BC's strong adsorption capacity may inadvertently remove essential nutrients from ecosystems, impacting plant and aquatic health. Thus, careful management and further research are necessary to mitigate potential negative impacts. The bibliometric analysis of this paper reveals a significant increase in research activity, particularly since 2021, highlighting the growing academic interest and international collaboration in this field. Key findings from the analysis include the dominant contributions from countries like China, the USA, and Australia, and the pivotal role of key researchers in advancing this area of study. Potential gaps in the current research on BC's impact on MPs include a scarcity of long-term studies, variability in BC types, limited assessment of ecological and health impacts, insufficient consideration of the scalability of BC application, and the disposal of BC after treatment.