Hybrid layered double hydroxide-bacteria systems for wastewater treatment: Toward tunable bio-inorganic interfaces...

Hybrid Layered Double Hydroxide (LDH)-bacterial composites are emerging as a promising solution for next-generation wastewater treatment, combining the advantages of inorganic sorbents and biological catalysts. This review explores recent advances in the design, synthesis, and application of LDH-bacteria hybrids, with particular emphasis on surface functionalization strategies, composite stability, environmental interactions, and process integration. LDHs offer high surface area, tunable interlayer chemistry, and strong anion exchange capabilities, making them excellent platforms for supporting microbial colonization. Complementarily, bacteria enhance pollutant removal through enzymatic degradation, redox transformations, and in situ regeneration of sorption sites. The synergy between LDHs and bacteria results in multifunctional systems capable of removing a wide range of contaminants, including heavy metals, dyes, nutrients, and emerging organic pollutants. Key developments include the use of biomimetic coatings, nanomaterial doping, and biodegradable polymers to improve the compatibility, selectivity, and sustainability of these composites. However, challenges remain regarding long-term stability, potential toxicity, scalability, and environmental risk. This review critically examines current research and identifies future directions for optimizing bio-composite design, improving biocompatibility, and enabling circular resource recovery. Hybrid LDH-bacterial systems hold significant promise in redefining wastewater treatment as a multifunctional, adaptive, and sustainable process. With continued interdisciplinary innovation, these materials could advance the evolution of a more robust and circular water management solution.