Bacterial cellulose hybrid membrane grafted with high ratio of adipic dihydrazide for highly efficient and selective recovery of gold from e-waste

•Bacterial cellulose hybrid membrane grafted with high ratio of adipic dihydrazide was fabricated.•Highly efficient and selective recovery of gold was achieved.•The effectiveness of gold recovery was verified in actual CPU leachate.•Recovery mechanism of Au(III) was systematically investigated. To solve metal resource shortage and alleviate environmental issues, it is in urgent need to explore cost-effective and environment-friendly adsorbents for sustainable recovery of valuable gold from e-waste. Herein, bacterial cellulose (BC) hybrid membrane grafted with adipic dihydrazide (ADH) has been fabricated via a facile schiff base reaction strategy for efficient and selective recovery of gold from complex aqueous media. The resulting ADH@BC hybrid membrane features high ratio of hydrazide groups (67% of ADH by mass content) and hierarchical porous structure, ensuring high adsorption capacity (1149 mg/g) and fast adsorption equilibrium time (20 min) toward gold. Meanwhile, the remarkable recovery selectivity of gold is achieved in the simulated e-waste leachate containing a large amount of interfering metal ions. Notably, the captured Au(III) species on ADH@BC hybrid membrane can be directly converted by redox-active hydrazide groups into Au(0) with no need of any external reductant. Furthermore, the developed ADH@BC membrane possesses superior recycling and reusability performance, as reflected by no obvious decrease in gold extraction capability after six cycles. More importantly, the ADH@BC hybrid membrane is capable of extracting almost 100% of gold from actual waste central processing unit (CPU) leachate, yielding high-purity gold (23.7 K) after pyrolysis.