The efficacy study of enhanced coagulation using activated silica in water treatment and removal of humic acids
Journal of Behdasht dar Arseh (i.e., Health in the Field),
Vol. 13 No. 3 (1404),
10 June 2026
,
Page 28-36
https://doi.org/10.22037/jhf.v13i3.47232
Abstract
Background and Aims: Turbidity and natural organic matter (NOM) are among the most significant contaminants affecting water quality and can reduce the efficiency of water treatment processes. The present study was conducted to evaluate the performance of an enhanced coagulation process using ferric chloride in combination with activated silica for water treatment and humic acid removal.
Materials and Methods: In this study, Response Surface Methodology (RSM) with a Central Composite Design (CCD) and jar test experiments were applied to evaluate the effects of initial turbidity, initial TOC, alkalinity, and the concentrations of ferric chloride and activated silica on the coagulation process. Synthetic water samples with an initial turbidity of 5–45 NTU and an initial TOC of 2–12 mg/L were used. Ferric chloride was applied at concentrations of 5–25 mg/L and activated silica at concentrations of 2–10 mg/L as SiO2. Ethical principles were observed throughout the study and in the use of all resources.
Results: The findings indicated that the proposed quadratic model adequately predicted the process performance, with a coefficient of determination of R2=0.9909 for turbidity removal efficiency and R2=0.9800 for TOC removal efficiency. Under the optimal conditions of initial turbidity of 10 NTU, TOC of 8 mg/L, alkalinity of 140 mg/L as CaCO3, ferric chloride concentration of 25 mg/L, and activated silica concentration of 10 mg/L as SiO2, the removal efficiencies of turbidity and TOC were 81% and 83.75%, respectively.
Conclusion: The findings of the study indicate that the simultaneous application of ferric chloride and activated silica leads to a significant increase in the removal efficiency of turbidity and TOC and demonstrates higher performance compared with the conventional coagulation process using ferric chloride alone.
- Enhanced coagulation
- Activated Silica
- Turbidity
- Natural organic matter (NOM)
- Disinfection by-products (DBPs)
How to Cite
References
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