Establishing a reliable and secure water supply is still a significant challenge in many areas that need more infrastructure. Eliminating harmful bacteria from water systems is a critical obstacle to managing the spread of waterborne illnesses and protecting public health. This work focuses on enhancing the efficiency of using waste extracts, namely seaweed, by integrating them into aerogels based on Hydroxyethyl cellulose (HEC) and Polyvinylpolypyrrolidone (PVP). Four formulations were created with increasing concentrations of Padina extract (PE): PE-0, PE-1, PE-2, and PE-3 loaded HEC-PVP aerogels. PE-3 loaded HEC-PVP aerogel showed remarkable efficacy in completely deactivating several types of bacteria, including Escherichia coli, Salmonella enterica, Enterococcus faecalis, and Bacillus subtilis. This antibacterial impact was seen within a short time frame of 75 min after treatment, making it the most significant outcome. Significantly, it had the greatest level of inhibition against E. coli (IZD: 24 mm) and showed potent inhibitory effects against S. enterica, E. faecalis, and B. subtilis, with IZD values of 18, 15, and 14 mm, respectively. These results indicate that the aerogel's ability to kill microorganisms may be due to its surface qualities, which help release antimicrobial substances from the algal biomass contained in the aerogel.