Factors Influencing the Performance of Natural and Synthetic Additives as Iron Oxide Dispersants

Abstract

Abstract This paper deals with studies on the evaluation of natural additives and synthetic polymers as iron oxide dispersants in aqueous solution. The natural additives tested include lignosulfonate, fulvic acid, tannic acid, sodium alginate, starch, and green tea extract. It has been found that additives containing phenolic, carboxyl, and sulfonic acid groups i. e., lignosulfonate, fulvic acid, tannic acid, and green tea extract exhibit superior performance as iron oxide dispersants over alginate and starch. Among various synthetic polymers tested the results indicate that co- and ter-polymers containing carboxyl and sulfonic acid groups are better dispersants than the carboxyl group containing homo-polymers. The results on the influence of impurities i. e., Fe3+, Al3+, cationic flocculant, and biocides show that these impurities when present at low concentrations exhibit antagonistic effect on the dispersant performance. Results also show that dispersant performance decreases with increasing calcium ions concentration.