Activated Nanomagnetic Biochar for Dye Adsorption: A Recent Systematic Review

Abstract

The increasing demand for efficient and sustainable water treatment technologies has driven significant interest in the development of Activated Nanomagnetic Biochar (ANBC) for dye adsorption. However, despite the growing body of research, a comprehensive synthesis of current advancements remains limited. This Systematic Literature Review (SLR) aims to consolidate and critically analyze the existing studies on this emerging material. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, an extensive search was conducted across two major databases, Web of Science and Scopus, resulting in 26 Primary Studies (PS) that met the inclusion criteria. The selected studies were systematically categorized into three major research themes: (1) synthesis and characterization of magnetic nanocomposites, focusing on the methods and techniques used to fabricate and analyze ANBC; (2) adsorption and removal of dyes, which examines the performance metrics and mechanisms of dye adsorption under various environmental conditions; and (3) environmental and sustainable applications, highlighting the role of ANBC in promoting eco-friendly and scalable wastewater treatment solutions. The findings reveal that advances in synthesis techniques and surface modifications have significantly enhanced the adsorption capacities and reusability of these materials. The integration of magnetic properties facilitates separation and recovery from aqueous systems, though scalability and long-term stability under field conditions require further investigation. Nevertheless, challenges related to large-scale production, long-term stability, and environmental safety persist. This review identifies current research gaps and provides insights into future directions for the development of next-generation biochar-based materials for sustainable water remediation.