Crossflow filtration of iron(III), copper(II), and cadmium(II) aqueous solutions with alginic acid/cellulose composite membranes

Abstract

The removal of Fe(III), Cu(II), and Cd(II) ions from aqueous solutions was investigated with a crossflow filtration technique. Alginic acid (AA)/cellulose composite membranes were used for retention. In the filtration of Fe(III) solutions, the effects of the crossflow velocity, applied pressure, AA content of the membranes, and pH on the retention percentage and the permeate flux were examined. The maximum retention percentage was found to be 89% for a 1 Â 10 À4 M Fe(III) solution at the flow velocity of 100 mL/min and the pressure of 60 kPa with 0.50% (w/v) AA/cellulose composite membranes at pH 3. Aqueous solutions of Cu(II) and Cd(II) were filtered at the flow velocity of 100 mL/min and pressure of 10 kPa. The effects of the AA content of the membranes and pH of the waste medium on the retention percentage and the permeate flux were determined. For 1 Â 10 À4 M Cu(II) and Cd(II) solutions, the maximum retention percentages were found to be 94 and 75%, respectively, at pH 7 with 0.50% (w/v) AA/cellulose composite membranes. When metalion mixtures were used, the retention percentages of Fe(III), Cu(II), and Cd(II) were found to be 89, 48, and 10%, respectively, at pH 3 with 0.50% (w/v) AA/cellulose composite membranes.

Synthesis of poly(vinyl alcohol-co-ethylene)/cellulose composite membranes and their application in wastewater treatment

“…In this study, the maximum retention is achieved at pH 4. Similar results were obtained in the study of Çifci and Şanlı [21] Figure 10 shows the metal retention and flux at different initial concentrations for single Copper (II) ions. From this figure, the maximum retention of Copper (II) is achieved at a concentration of 0.5 × 10 −4 M. The high initial metal concentration accelerates collision between metal Copper (II) ion and membrane.…”

Poly(vinyl pyrrolidone)-enhanced crossflow filtration of Fe(III), Cu(II) and Cd(II) ions using alginic acid/cellulose composite membranes

“…AA/cellulose composite membranes were prepared as described previously [24]. Briefly, aqueous solutions with 0.25, 0.50, 0.75(w/v)% sodium alginate content were prepared.…”

“…Membranes were then immersed in 1 M HCl for 24 h. Membranes of 0.25 (w/v)% AA, 0.50 (w/v)% AA, 0.75 (w/v)% AA content were named as membrane I, membrane II, membrane III, respectively. Properties and the characterization of the membranes were given in our previous study [24].…”

“…pH adjustments were made using 0.1 M NH 3 and 0.1 M HCl solutions. The feed solutions were pumped through a crossflow filtration unit (Millipore) at a predetermined velocity (100 mL/min) and pressure (10 kPa) [24]. Membranes were placed into the filtration cell (area of 30 cm 2 ).…”

“…We have previously studied crossflow filtration removal of single of Fe(III), Cu(II) and Cd(II) metal ions from aqueous solutions using AA/cellulose composite membranes [24,25]. As a continuation of the studies, in this study we have used AA/cellulose composite membranes in the filtration using PVP as complexing agent.…”