Bioinspired double-chain lignin aerogel enabled by one-pot crosslinking: Pb(II) adsorption and antibacterial...

The development of sustainable, multifunctional adsorbents capable of simultaneously removing heavy metals and suppressing harmful bacteria in wastewater remains a significant challenge. Inspired by DNA structure, a novel double-chain aerogel adsorbent (SPL) was synthesized from sodium lignosulfonate (SL) and ε-polylysine (ε-PL) via a one-pot Mannich crosslinking reaction. The optimized SPL-2.5 exhibited a high Pb (II) adsorption capacity of 196.35 mg/g, with the process following the Langmuir isotherm and pseudo-second-order kinetics, indicating monolayer chemisorption. The aerogel also demonstrated excellent reusability, retaining over 60% efficiency after six consecutive cycles, and potent antibacterial activity against Staphylococcus aureus (inhibition zone >60 mm). Spectroscopic and DFT analyses identified synergistic complexation by -SO₃H, -COOH, and -NH₂ groups as the key mechanism. The sulfonic acid group (-SO₃H) was the strongest binding site. A preliminary economic evaluation indicated a competitive production cost of approximately USD 13.67 per kilogram. This work presents a cost-effective, eco-friendly, and multifunctional bioinspired aerogel, offering a promising strategy for the comprehensive remediation of heavy-metal-laden wastewater.