Ultrahigh Efficiency Hybrid Biomass-Inorganic Coagulation Strategy for Water Treatment

Coagulation is a vital water treatment process for removing colloids, natural organic matter, and microorganisms, such as bacteria and algae. While aluminum and iron salts are highly effective conventional coagulants, their use raises concerns including health risks linked to aluminum exposure, altered water taste, and secondary contamination from exceeding the amount of iron residues. Biomass-derived coagulants, obtained from renewable resources such as plant extracts and agricultural residues, have emerged as sustainable alternatives due to their biodegradability and minimal sludge production. However, their lower coagulation efficiency, particularly in treating complex or highly turbid water, limits widespread application. This study investigates a hybrid coagulation strategy combining cellulose-derived materials dual polymer-grafted cellulose nanocrystals with reduced doses of iron salts to enhance performance and overcome limitations. This synergistic approach significantly enhances coagulation efficiency, achieving 90% turbidity reduction in soluble humic substances in water with minimal coagulant dosage. In addition, this method is a competitive alternative to the use of synthetic flocculant polyacrylamide, offering environmental benefits. In this way, the potential hybrid coagulation mechanism is studied as well. Additionally, the strategy provides a universal framework for integrating various modified biomass-derived coagulants with metallic salts, optimizing dissolved organic matter removal. By advancing this hybrid methodology, the research bridges performance gaps in biomass-based systems. This work not only highlights the potential of hybrid coagulants for natural organic matter removal but also demonstrates their adaptability across diverse environmental conditions.