| In this research, technical and economical viability of a "Polymer Supported Ultrafiltration" (PSU) process is studied, in order to recover metal ions (copper, nickel, cadmium and lead) from aqueous effluents. PSU consists of two stages. The first reactive stage is complex formation between 1 or more kinds of metal ions with polymeric ligands, and the second stage is retention of macromolecular complexes previously formed by membrane technology.;Firstly, acid-base properties and complex stabilities with metal ions of different polymers based on poly(acrylic acid) (PAA) are studied. The measurement of this constants was important since they are used as parameters in further modelization of PSU process.;Next, 2 different lab-scale OF installations with ceramic tubular membranes (one of them with reduced hydraulic diameter) were designed, set up and adjusted. Hydrodynamics of both installations were studied to improve permeate fluxes and polymer rejection coefficients at different pH values, ionic strengths, feed flow rates and solute concentrations.;After previous experiments in total recirculation mode, pH values were optimized for reactive stages of metal retention and further polymer regeneration with experiments in batch mode (permeate and rejected streams are sent to separated reservoirs).;Continuous operations is the most used mode at industrial scale (feed stream and permeate stream flows are equal in order to maintain constant system volume). Operation in continuous mode was analysed with poly(acrylic acid), Cd and Pb, in solutions with a single metal ion and binary mixtures of metal ions. All stages comprising this process were mathematically modelled.;Finally, scale-up of process was tackled with an industrial polymer (Colloid 208), much cheaper than PAA, and Cd as pollutant metal ion.;By means of an economic analysis, we came to the conclusion that proposed process is co1mpetitive with regard to traditional procedures, and its approximate cost is 6.34[Euro]/m3. |
