Free and Ca-Alginate Beads Immobilized Horseradish Peroxidase for the Removal of Reactive Dyes: an Experimental and Modeling Study

Abstract

The aim of this work was to remove the dyes Reactive Blue 221 (RB 221) and Reactive Blue 198 (RB 198) of synthetic effluent using the immobilized enzyme horseradish peroxidase (HRP) in Ca-alginate beads. Experimental parameters affecting the dye removal process such as the effect of pH, temperature, hydrogen peroxide concentration, mass capsules, and reuse were evaluated, and a numerical model of mass transfer was developed. A maximum removal of 93 and 75%, respectively, for the dyes RB 221 and RB 198, at pH 5.5 and temperature of 30 °C, concentration of hydrogen peroxide of 43.75 μM for dye RB 221 and 37.5 μM for the dye of RB 198 was obtained. A removal reaction of 180 min for RB 221 and 240 min for RB 198 was observed. Three reuse cycles of use of immobilized enzyme were achieved for both dyes. The numerical model proposed led to a good fit compared to experimental data. The HRP enzyme immobilized in Ca-alginate capsules showed a great potential for biotechnological applications, especially for the removal of reactive dyes.

Alginate-Based Applications in Biotechnology with a Special Mention to Biosensors

“…Additionally, this technology addressed the low level of dissolved oxygen limitation associated with the aerobic treatment of phenol-polluted groundwater by encapsulating oxygen-releasing nanoparticles within the core to ensure a continuous in situ supply of hydrogen peroxide needed for the HRP reaction. Farias et al also immobilised HRP on calcium alginate beads to remove reactive dyes [98]. A one-step chitosan/alginate core-shell matrix has also been reported, taking advantage of chitosan's pH-responsive sol-gel transition property and the calcium-responsive solgel transition property of alginate [99].…”

Soybean peroxidase immobilised on cellulose-alginate hydrogels for removal of recalcitrant organic pollutants in water

“…Three different kinds of hydrogels containing alginate were prepared, namely HY-A (alginate hydrogels), HY-AC (alginate hydrogels with dispersed cellulose), HY-AC-SBP (alginate hydrogels with dispersed cellulose functionalised with SBP). To synthesise HY-A, 75 mg of alginate were dissolved in 3 ml of distilled water under stirring and then dripped in a CaCl 2 solution (0.2 M) [27][28][29] . The obtained spherical hydrogels were left in the gelling solution for around 30 min and then filtered and washed.…”

“…To synthesise HY-A, 75 mg of alginate were dissolved in 3 ml of distilled water under stirring and then dripped in a CaCl 2 solution (0.2 M). [27][28][29] The obtained spherical hydrogels were left in the gelling solution for around 30 min and then filtered and washed. To synthesise the other types of hydrogels, 75 mg of alginate were dissolved into 3 ml of distilled water, and then 200 mg of cellulose (with or without loaded enzyme) were dispersed in the viscous solution by…”

Oxidoreductases as a versatile biocatalytic tool to tackle pollutants for clean environment – a review

“…160 Besides, the immobilization of enzymes appears as an alternative to promote operational stability, ease of storage, handling, reusability, recycling, and continuous processing. [161][162][163][164][165][166][167] Therefore, these new possibilities for catalyst combinations open promising prospects for new technologies in the field of green chemistry and should become the focus of future research and advances in protein engineering.…”