Environment-Friendly Approach toward the Treatment of Raw Agricultural Wastewater and River Water via Flocculation Using Chitosan and Bean Straw Flour as Bioflocculants

Abstract

Currently, there is a growing concern regarding water remediation from agricultural and domestic wastewaters. Among water treatment methods, flocculation is a widely used approach. In this study, the bioflocculation of wastewaters from Sinaloa (Mexico) was examined using two bioflocculants: chitosan and bean straw flour (BSF). The jar-test results showed that chitosan exhibited high effectiveness in pollutant removal from different sampling zones (agricultural wastewater and river water). Additionally, this bioflocculant reduced remarkably the concentration of Mn and Fe. On the other hand, BSF showed high effectiveness in pollutant removal for a specific type of wastewater, being highly competitive as compared to chitosan. Besides, BSF led to 40% of Mn removal from highly contaminated river water samples. For both biomaterials, bioflocculation was driven by charge neutralization and sweep flocculation mechanisms. For a given agricultural wastewater sample, both bioflocculants performed better than the commercial poly(aluminum chloride) for pH regulation and Fe removal.