Activated carbon (AC) is widely acknowledged for its efficacy in purifying aqueous environments, playing a pivotal role in environmental remediation endeavors. However, the influence of AC particle size on contaminant sequestration and its impact on benthic communities remain subjects of ongoing interest and discourse in scientific circles. Despite extensive research on the effects of AC particle size, the quest for the optimal size that balances effective contaminant sequestration with the preservation of benthic organism health persists. This review delves into the contrasting impacts of powdered activated carbon (PAC) and granular activated carbon (GAC) on contaminant sequestration and the health of benthic organisms. Past studies have revealed divergent outcomes: ingestible PAC particles exhibit proficiency in contaminant remediation but pose risks to benthic organisms, whereas non-ingestible GAC demonstrates potential for effective remediation with minimal adverse effects. Through a comprehensive analysis of existing literature, this review aims to furnish existing and new valuable insights into evaluating the efficacy of different activated carbon particle sizes for contamination remediation and their effects on benthic organisms, ultimately aiming to pinpoint the optimal particle size that achieves superior performance in both areas.