A comprehensive review of layered double hydroxide/magnetite-biochar for chromium removal from wastewater

Chromium contamination in wastewater poses significant environmental and health risks due to its toxicity and persistence. Traditional remediation methods often lack efficiency, are costly, and have limited scalability, leading to interest in advanced materials for Cr removal. Layered Double Hydroxide (LDH) and magnetite-biochar composites show promise as adsorbents, offering high surface area, magnetic properties, and anion exchange capabilities. This review presents the first comprehensive analysis of LDH/magnetite-biochar composites for Cr(VI) remediation, covering synthesis, modification, and application. Key findings emphasize their superior adsorption capacity and ease of regeneration, attributed to the combined effects of LDH's ion-exchange properties and biochar's porosity. Additionally, the use of biochar from agricultural waste supports a circular economy, providing a cost-effective approach to heavy metal removal. Future research should focus on optimizing synthesis methods and exploring large-scale applications, positioning these composites as viable materials for sustainable wastewater treatment.