Raw broad bean (Vicia faba L.) flour as a natural coagulant and flocculant agent for turbidity removal in water

Abstract

Water, an essential resource for life, requires appropriate treatment to eliminate suspended particles, pathogenic microorganisms, and heavy metals, which affect human health and water quality. Turbidity, an indicator of the presence of particles, demands removal processes. This study evaluated the effectiveness of raw broad bean (Vicia faba L.) flour as a natural coagulant in reducing water turbidity. The research was experimental, explanatory, quantitative, and cross-sectional, manipulating independent variables such as coagulant concentration and rapid and slow mixing speeds to analyze their impact on the dependent variable, turbidity. Six tests were conducted using water from the Tenerías River in Cusco, applying a 1% solution of broad bean flour. The results showed a turbidity reduction greater than 98% in samples with initial values ranging from 281 to 455 NTU, and over 92% in waters with turbidity between 88.2 and 114 NTU, demonstrating the high effectiveness of the coagulant. Moreover, no significant changes in pH and electrical conductivity were observed, indicating that the treatment does not significantly alter these properties. Statistical analysis determined that the quadratic model is the most suitable for estimating the optimal dosage, with correlation and determination coefficients above 0.90 and 90%, respectively, and a p-value lower than 0.05, confirming the significance of the results. In conclusion, raw broad bean flour represents a renewable, biodegradable, and effective alternative to aluminum sulfate in water treatment processes, promoting the sustainability and safety of water resources.