Effect of Applied Pressure on the Separation of Succinate and Acetate in Dead-End Nanofiltration

Abstract

The objective of this work is to study the removal of acetate from succinate in an aqueous solution by dead-end nanofiltration. The effect of applied pressure under 40, 50 and 60 psi on the separation between both solutes was investigated. Experiments with a HL4040FM membrane were evaluated using various synthetic solutions, i.e. single-solute solutions of potassium acetate and potassium succinate and mixed-solute solutions containing both solutes. In single-solute solution, the retentions of acetate and succinate salts increase with increasing in applied pressures. At each applied pressure the retention of acetate salt decreases with time while the retention of succinate salt declines to a constant. In mixed-solute solutions, in presence of succinate anion, the retention of acetate anion is significantly lower than those observed in single-solute solution even showing negative value. The lower retention of acetate can be well described by the facilitated transport of the monovalent anion due to pumping effect and electroneutrality in the presence of a divalent anion. It was expected that removal of acetate by-product from succinate solution with HL4040FM in dead end filtration was possible.