Removal of Anionic Surfactants in Aqueous Solutions with Moringa Oleifera Seed Extract Coagulant

Amongst the multiple emerging pollutants in the modern world, perhaps surfactants may be considered one of the first importance group. They are ubiquitous contaminants that present a highly refractory nature and an extremely dangerous biopersistance, thus the interest of researchers in presenting new and more efficient methods for their removal from aqueous solutions. One of the most promising materials in the field of water remediation is Moringa oleifera seed extract. It acts as a coagulant and flocculant agent and its performance is high enough to consider it as a competitive treatment agent, compared even with classical metal salts such as alum of ferric chloride. In this work, Moringa oleifera seed extract was confirmed as a feasible coagulant in removing surfactants from aqueous effluents. Amongst them, long-chain anionic detergents such as Polyoxyethylene (3.5) sodium lauryl ether sulfate (SLES) was selected as a model compound for evaluating the coagulation response. The system coagulant-detergent was stable with different temperatures and pH, and the efficiency was very promising. Moringa oleifera was an effective coagulant since it was capable to reach up to 0.245 mg/mg coagulation capacity according to Gu-Zhu model. Design of experiments presented an optimum combination of coagulant dosage and initial surfactant concentration of 234 mg/L and 76 mg/L respectively. Therefore, this study adds a valuable characteristic to the well known Moringa oleifera coagulant and contributes to establish it as a real alternative to the traditional coagulants.