Removal of Saponins From Sugar Factory Wastewater Using Aluminum Sulfate, Ferric Chloride, and Natural Zeolite Coagulants Publisher



Rahpeima S ; Honarvar M ; Khorasgani FC
Source: International Journal of Energy and Water Resources Published:2026

Abstract

Wastewater from sugar beet processing plants is often rich in surface-active organic compounds, such as saponins, and high levels of suspended solids and organic pollutants, which makes treatment particularly challenging. While biological methods are widely used, there is limited data are available on the effectiveness of chemical and natural coagulants for treating such wastewater, especially under different operational conditions. This study aimed to evaluate the performance of aluminum sulfate, ferric chloride, and natural zeolite (N.Z.) in treating sugar beet processing wastewater, focusing on reducing saponin levels and improving other quality parameters, including turbidity, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), and pH. The central hypothesis was that coagulants, when used at optimal pH and dosage, would outperform other methods in reducing pollutants and saponin from this specific type of wastewater. The methodology included laboratory-scale coagulation–flocculation experiments, testing coagulant concentrations of 10,000, 20,000, and 30,000 mg/L at three pH levels (5, 7, and 9). Results showed that ferric chloride at pH 7 and 750 mg/L, as well as aluminum sulfate at pH 9 and 2000 mg/L, achieved the highest saponin removal efficiency, up to 99%. Increasing pH significantly enhanced coagulant performance. Conversely, whereas natural zeolite demonstrated lower efficiency. These findings suggest that coagulants—particularly ferric chloride—offer a fast, cost-effective, and efficient method for removing saponins and improving wastewater quality, especially where biological treatments are not feasible. Additionally, the results underscore the importance of pH control and dosage optimization in designing effective coagulation-based treatment systems. © 2025 Elsevier B.V., All rights reserved.