A STUDY OF CONFIGURATIONS OF CLAY-GLASS BEADS MIXTURE TO DETERMINE THE INFLUENCE OF COMPOSITION AND COMPACTION PRESSURE ON THE RETENTION OF NITRATE

摘要

In compacted Na-montmorillonite membranes, the pore size and surface charge will influence filtration processes of solutes. A dead-end hyperfiltration setup was utilized to (1) study the intrinsic retention, membrane filtration coefficient, and solution flux of different membrane configurations and (2) model nitrate breakthrough effluent concentrations through the membrane. Scanning electron microscopy and solute analytical techniques were employed to assess what critical components at micrometer scale would prevail in a non-bio-stimulated remediation of simulated agricultural wastewater. The results reveal hyperfiltration of nitrate ions is a function of the compaction pressure and composition of bentonite in the mixed soils. Although high-content bentonite membrane configurations (5 g clay at 2500 psi) offered better solute rejections with a 30% increase in the cell concentration, the compaction of the membrane had the most deterministic influence on the solution flux. We can adduce that for permselective membranes, it is more probable that a size exclusion mechanism predominates ion exclusion in solute sieving.