Macroporous Wood-Waste-Derived Activated Carbon-Loaded Carboxymethyl Cellulose Sponge as a Reusable Disinfection Platform for Wastewater Management

The design of simple, safe, and low-cost point-of-use (POU) water disinfection technologies remains a major challenge, particularly in decentralized and resource-limited areas. To achieve this goal, we developed a sustainable composite sponge using wood-waste-derived activated carbon (AC) embedded in a carboxymethyl cellulose (CMC) sponge matrix. Structural characterization revealed the formation of an interconnected macroporous network, with larger pores and improved surface properties after AC incorporation. The antibacterial activity of the pure CMC sponge was negligible, while incorporating AC significantly improved the antibacterial efficacy against representative strains of waterborne pathogens, including Escherichia coli, Salmonella enterica, Staphylococcus aureus, and Enterococcus faecalis . The inhibition zones of AC@CMC sponge at a range from 16.7 to 22.4 mm are observed, and ≥ 6 log₁₀ CFU/mL bacterial reduction is achieved under optimal conditions with the voided arrangement in microbe-sponge contact reactions. The results of time-dependent inactivation tests indicated that all bacterial strains were eliminated within 45–75 min. Likewise, the protein leakage from the bacterial cytoplasm gradually increased after treatment (up to 69.8 µg/mL). It way observed from the obtained Data that the prepared sponge Matrix inhibited the biofilm formation over 14 days. Further, the Microtox ® assay results stated that all sponge materials were biocompatible and environmentally safe. As a result, the AC@CMC sponge delivered complete bacterial inactivation within 25–40 min and sustainable high disinfecting efficiency under secondary-treated wastewater reuse systems over five-cycles. In conclusion, the AC@CMC sponge is a sustainable, easily recoverable and efficient disinfection platform providing great promise for decentralized/point-of-use wastewater treatment applications.