ADSORBENTS BASED ON MODIFIED NANOCELLULOSE: WATER PURIFICATION FROM ORGANIC AND INORGANIC POLLUTANTS
Abstract
Against the backdrop of rapid industrial growth, water pollution has become a pressing global environmental issue. This review provides a systematic analysis of the efficiency of functionalized nanocellulose- based adsorbents for the removal of organic (synthetic dyes, phenols, antibiotics, pesticides) and inorganic (Pb 2+ , Cd 2+ , Hg 2+ , Cr(VI), Cu 2+ , As) pollutants from water. Key findings: the highest sorption capacities are achieved by TEMPO-oxidized nanocellulose and amine-functionalized composites – up to 2500 mg/g for methylene blue and up to 2270 mg/g for lead ions. Nanocellulose-based molecularly imprinted polymers (MIPs) selectively adsorb phenols with efficiencies of up to 97% even in the presence of structurally similar competitors. Most adsorbents reviewed retain 80+90% of their capacity after 20 regeneration cycles. The paper examines three main types of nanocellulose (CNC, NFC, BNC), their preparation methods (acid hydrolysis, TEMPO-oxidation, mechanical and enzymatic treatment), and surface functionalization strategies (isocyanate-based, amine- and thiol-functionalization). The alignment of nanocellulose production from agricultural waste (rice husks, soybean hulls) with sustainable development principles is emphasized. Key unresolved challenges – scale-up, stability in real wastewater matrices, and cost-effectiveness – and future research directions are also identified.