Synthesis of Sustainable Dual-Function Aerogels from Water Hyacinth Cellulose and Shrimp Shell Nano-Chitosan for Heavy Metal Removal and Coliform Bacteria Filtration in Polluted Water

¹ Department of Aquatic Product Technology, Faculty of Fisheries and Marine Sciences, IPB University, Bogor, West Java, 16680, Indonesia
² Department of Biochemistry, Faculty of Mathematics and Natural Science, IPB University, Bogor, West Java, 16680, Indonesia
³ Department of Chemistry, Faculty of Mathematics and Natural Science, IPB University, Bogor, West Java, 16680, Indonesia
⁴ Department of Agricultural Industrial Engineering, Faculty of Agricultural Engineering and Technology, IPB University, Bogor, West Java, 16680, Indonesia
⁵ Center for Coastal and Marine Resources Studies (PKSPL), International Research Institute for Maritime, Ocean and Fisheries (i-MAR), IPB University, 16127, Bogor, Indonesia

^* Corresponding author: wahyu.ramadhan@apps.ipb.ac.id

Abstract

Rivers are essential water sources but are increasingly polluted by urban waste containing heavy metals and harmful bacteria. An effective solution is optimizing an eco-friendly water hyacinth cellulose aerogel and shrimp shell nano-chitosan for heavy metal adsorption and coliform bacteria filtration. This study extracted cellulose from water hyacinth (S-EG) and chitosan from shrimp shells, followed by nano-chitosan synthesis and aerogel formulation with three cellulose-to-nano-chitosan ratios: F1 (2:1), F2 (1:1), and F3 (1:2). Gel precursors were characterized, and adsorption and filtration capacities were tested to identify the optimal formula. Results showed yields of 12.46% for S-EG, 11.23% for chitosan, and 80% for nano-chitosan. Among the formulas, F3 had the best properties, including 80.16% gel content, 143.41% swelling ratio, and 3630 cPs viscosity. The F3 aerogel achieved 97% porosity, a surface area of 243.5 m²/g, and a low density of 0.07 g/cm³. Adsorption capacities were significant, reaching 99.5% for Cu, 88.68% for Zn, and 7.33% for Pb, along with a 30% reduction in E. coli. These findings indicate that the 1:2 cellulose-to-nano-chitosan aerogel formulation is highly promising as a sustainable solution for heavy metal adsorption and bacterial filtration in polluted water systems.