Removal of Classical and Emerging Contaminants in Water Treatment Using Super-Bridging Fiber-Based Materials

New solutions are required to increase the capacity, robustness, and versatility of water treatment plants for both drinking water and wastewater applications. In this work, iron grafted cellulose fibers were designed and tested for the removal of classical and emerging contaminants in wastewater treatment. The synthesis of Fe-fibers was optimized to maximize the amount of positively charged iron (hydr)oxides grafted onto cellulose to improve the adsorption capacity for negatively charged contaminants such as phosphorus. Compared to conventional physicochemical treatment and ballast treatment, the fibers drastically increased floc size, hence allowing the replacement of settling by screening, a technology that is more compact than settling tanks. Fibers used in combination with coarse screens (mesh size of 1000 mu m) improved the removal of total suspended solids from 22% (conventional treatment) to 81% (fiber-based treatment). When fibers were used in combination with a coagulant and a flocculant, nanoplastics removal increased dramatically after separation via screening (1000 mu m mesh), from 20 to 71%. For benzene, toluene, ethylbenzene, and xylene (BTEX), cellulose fibers and Fe-grafted fibers removed, respectively, 88 and 80% of the contaminant load. Finally, fibers were proven to be washable and reusable more than five times, which shows potential for operational cost reduction and environmental benefits.