Phytoremediation of Co-Contaminated Environments: A Review of Microplastic and Heavy Metal/Organic Pollutant Interactions and Plant-Based Removal Approaches

The increasing presence of microplastics (MPs) in terrestrial ecosystems, particularly when combined with organic pollutants and heavy metals, presents a considerable environmental challenge. This review examines the intricate interactions between MPs, co-contaminants (both organic and inorganic), and plants involved in phytoremediation processes. A literature search was performed across the databases Scopus, ScienceDirect, and Google Scholar, covering the timeframe from 2015 to 2025. The studies selected specifically addressed the synergistic and antagonistic effects of microplastics in conjunction with heavy metals or organic pollutants (such as PAHs and pesticides) within plant–soil systems. The findings reveal that MPs influence pollutant mobility, bioavailability, and toxicity through adsorption and desorption mechanisms, leading to varied implications for plant growth, microbial communities, and contaminant uptake. Depending on the physicochemical characteristics of MPs and co-pollutants, the effects can range from increased phytotoxicity to diminished contaminant accumulation in plants. Additionally, physiological and molecular disruptions, including oxidative stress, hormonal imbalances, and impaired enzymatic activity, were frequently noted in co-contamination scenarios. Recent developments, such as the creation of genetically modified hyperaccumulator plants and the use of nanotechnology and microbial consortia, demonstrate potential to enhance phytoremediation efficiency in complex polluted soils. This review underscores the pressing need for integrated, multidisciplinary strategies to overcome the limitations of existing phytoremediation methods in co-contaminated environments. Future research should focus on standardized methodologies, a mechanistic understanding, and the safe implementation of emerging biotechnologies for sustainable soil remediation.