CONTRIBUTION OF THE ASSOCIATION OF NATURAL HIGH-MOLECULAR COMPOUNDS IN IMPROVING THE EFFICIENCY OF FLOCCULATION PROCESSES

Abstract

Natural flocculants as chitosan and sodium alginate has a complex of environmental and physic-chemical properties: biodegradability, playback of the raw material base, reaction and complexing ability. Researches had shown that natural polymers can be used for flocculation of suspensions. Association has a specific role in the flocculation process. Association determined by the nature and charge density of the flocculants. It is necessary to understand the mechanism of processes in these systems in order to select an effective flocculants. The mechanism of action of compositions natural flocculants is different from synthetic. The state of biopolymers depends on the pH of the solution. The aim of our researches was to study the flocculation ability of the compositions natural flocculants. It was studied sedimentation stability of suspensions containing macromolecular substances (flocculants) of different nature. We used an aqueous suspension of kaolin and bentonite. Kaolin and bentonite were dried to constant weight. The concentration of the dispersed phase in suspensions was 1–3%. It was shown that the sedimentation stability defines as flocculants characteristics such as molecular weight, concentration, nature of flocculants, polyelectrolyte’s charge density and nature of the suspensions. It was found that compositions of natural flocculants chitosan and sodium alginate are more effective of individual flocculants. The degree of separation suspensions reaches 90–98%. The findings suggest that the studied natural flocculants have significant potential for use, thanks to a number of advantages: the efficiency of their actions, low reagent consumption, environmental safety.