Comparative Assessment of Alum, Guar Gum,and Xanthan Gum for the Coagulation-Flocculation Removal of Cellulose Fibres from Wastewater

Coagulation–flocculation remains the cornerstone of suspended solids removal in water treatment, yet reliance on synthetic coagulants such as alum poses environmental and health concerns. This study conducts a comparative assessment of alum, guar gum, and xanthan gum—alone and in hybrid combinations—for the removal of cellulose fibers from synthetic wastewater. Systematic jar tests were performed using cellulose suspensions derived from toilet, kitchen, and unbleached papers, with dosages of alum (0.1–0.5 mg/L) and biopolymer flocculants (1–5 mg/L) optimised under controlled pH conditions. Alum achieved up to 98.9% turbidity reduction at 0.5 mg/L, while guar gum outperformed alum in low-to-moderate turbidity matrices with 99.7% removal at 3 mg/L, and xanthan gum reached 98.2% removal at 5 mg/L. Hybrid alum–guar protocols attained ≥ 98% reduction at minimal chemical loads (0.1 mg/L alum + 1 mg/L guar), with optimal performance near neutral pH. These findings highlight the potential of plant-based flocculants as sustainable alternatives to synthetic coagulants.