Stable and antibacterial tannic acid-based covalent polymeric hydrogel for highly selective Pb2+ recovery from lead-acid battery industrial wastewater

The resource of trace lead (Pb 2+ ) from wastewater bearing intricate components is imperative for sustainable progression of the lead-acid battery industry. Herein, we fabricated a tannic acid-based covalent polymeric hydrogel (TA@PMAM) with antimicrobial properties and stability via facile Michael addition reaction. The incorporation of tannic acid (TA) through robust covalent bond leads to a stable porous 3D covalent polymer network with almost no loss of mechanical properties even after 20 compression cycles. Batch adsorption experiments of TA@PMAM revealed an extraordinary adsorption capacity of Pb 2+ (Qe =196.6 mg/g), achieving 87.2 % of Pb 2+ adsorption within the first 5 min owing to porous structure, numerous adsorption sites and good hydrophilicity. Moreover, TA@PMAM demonstrated a strong affinity for Pb 2+ in the presence of the interfere metal ions (Cu 2+ , Co 2+ , Mn 2+ etc .) due to the carbonyl and phenolic hydroxyl that can specifically pair with Pb 2+ . Stable adsorption properties of TA@PMAM were confirmed in fixed bed column adsorption experiment using lead-acid batteries wastewater, retaining 79.56 % of initial adsorption capacity even after 10 times’ reuse. Besides, TA@PMAM possesses a broad spectrum of antimicrobial properties. This study sheds novel light on the design and fabrication of adsorbent, which holds great potential for commercialization in recovering lead from battery industrial wastewater.