Selective and efficient lithium extraction from shale gas produced water via H1.33M1.67O4/MXene/Chitosan composite granules

Lithium is a critical strategic resource in the transition to clean energy, and developing efficient, sustainable recycling technologies is essential to achieving carbon neutrality goals. The study addresses challenges such as low lithium-ion concentrations and the presence of competing cations in shale gas produced water (SGPW). An innovative composite adsorbent enhanced by a hydrogen bond network, consisting of H 1.33 Mn 1.67 O 4 (HMO), MXene, and chitosan (CTS), is introduced. Directional bonding among MXene, CTS, and HMO forms an interpenetrating structure that stabilizes the HMO lattice, with only 0.005 % Mn loss after ten cycles. Adsorption tests with actual SGPW demonstrated that the material adsorbs lithium-ion capacity at 11.80 mg/g, exhibiting higher lithium selectivity compared to other cations. A laboratory-scale experiment was conducted using a fixed-bed filtration system, the most effective adsorbent reached saturation close to 52 h under a near approach velocity of 0.13 cm/min (hydraulic loading) with a full bed volume of 7.7 cm 3 , containing around 4.92 g of adsorbent. A novel material design paradigm for lithium extraction from neutral to alkaline wastewater is presented, combining high selectivity with long cycle life.