Recent advances in layered double hydroxides for pharmaceutical wastewater treatment: A critical review

In recent decades, pharmaceuticals, lauded for saving millions of lives, have surfaced as a new class of environmental contaminants. These compounds, originating primarily from hospital and industrial settings, often resist traditional treatment technologies and can persist in the environment for extended periods. The scarcity of water resources underscores the urgent need for innovative strategies for the effective management of pharmaceutical wastewater. Recently, layered double hydroxides (LDHs) have garnered considerable attention for their application in the remediation of pharmaceutical wastewater. This review explores the recent advancements in LDH-based adsorbents and membranes for pharmaceutical wastewater treatment. LDHs demonstrate superior adsorption capabilities due to their intercalation properties and structural versatility, effectively removing pharmaceutical contaminants such as antibiotics and anti-inflammatory drugs. Moreover, LDH-modified membranes enhance separation efficiency by improving permeability, selectivity, and fouling resistance. Advanced analytical techniques, including machine learning and synchrotron radiation, have provided deeper insights into the LDH mechanisms. However, challenges such as metal leaching, low mechanical durability, and limited scalability remain critical hurdles. Future research should focus on optimizing LDH stability, integrating adsorption with membrane separation techniques, and exploring hybrid treatment strategies. The recovery of valuable pharmaceuticals through LDH-based systems also presents a sustainable approach to wastewater management. This review highlights the potential of LDHs in pharmaceutical wastewater treatment while identifying key points for further development to enhance their practicality and large-scale application.