A closed cycle of sustainable development: Effective removal and desorption of lead and dyes using an oxidized cellulose membrane

Abstract

Oxidized cotton linters, TOCell, were used as an adsorbent or derived membrane there from by linters cross-linking with citric acid. The adsorption/desorption study of Pb2+, methylene blue (MB), and crystal violet (CV) removal, was performed. Adsorption data fitting, obtained using the Langmuir model, gave 116 mg g−1 (Pb2+), 179 mg g−1 (MB) and 482 mg g−1 (CV) at 25 ℃ for TOCell linters, while 101 mg g−1 (Pb2+), 165 mg g−1 (MB) and 426 mg g−1 (CV) for TOCell membrane. After desorption dyes were subjected to photocatalytic degradation while lead was transformed into stable lead phthalate (LP), and further used as filler in composites based on unsaturated polyester resins (UPR). UPR was synthesized from waste polyethylene terephthalate (PET). Structural characterization was performed using FTIR, SEM, and NMR methods. Composites loaded with acryloyl modified kraft lignin (A-KfL) and/or LP was tested for tensile strength, Vickers microhardness, and fire resistance (UL-94 V method). The best mechanical and fireproofing properties were obtained at 15 wt.% A-KfL and 40 wt.% Al(OH)3 addition. The results of the toxicity leaching test (TCLP) confirmed the environmentally safe stabilization of desorbed pollutant in the UPR matrix. Application of environmentally friendly membranes, susceptible to easy biodegradation, had low negative effects to the environment.