A cationic curdlan derivative as an efficient flocculant for removal of metal oxides from model wastewater

Abstract Wastewater treatment is currently one of the main priorities for researchers, whose goal is to protect water resources that are still decreasing due to climate change, overuse in the industrial field, pollution from different causes, etc. With this in mind, the purpose of the present paper is to evaluate the capacity to decrease the content of some metal oxides (Cr 2 O 3 , FeO and TiO 2 ) from synthetic wastewater using a curdlan-based polysaccharide derivative which contains quaternary ammonium salt groups ([ N -(3-chloro-2-hydroxypropyl)-trimetylammonium] chloride)— TMAP 0.4 -C by the flocculation method. The impact of polymer dosage and the initial concentration of the polymer solution, as well as pollutant content, dispersion composition, and pH on the removal efficacy has been investigated. The UV–Vis spectroscopy measurements data have revealed that the removal efficiency exceeds 71% for all metal oxides at optimum polymer doses ranging between 0.13 and 1.5 mg∙L −1 . In addition, the zeta potential and particle size distribution measurements indicate that electrostatic attraction interactions play an important role in the separation of these pollutants. Moreover, the FeO or kaolin—curdlan derivative flocs have been further applied for the reduction of Bordeaux Mixture fungicide from model wastewater with a removal efficiency of more than 90%. Kinetic analysis revealed that the adsorption process was best described by pseudo-second-order and Elovich models.