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Abstract

Catalase was immobilized on alumina carrier and crosslinked with glutaraldehyde. Storing stability, temperature and pH profiles of enzyme activity were studied in a column reactor with recirculation and in a batch stirred-tank reactor. The immobilized enzyme retained 44% of its activity at pH 11, 30 • C and 90% at 80 • C, pH 7. The half-life time of the immobilized catalase was increased to 2 h at pH 12, and 60 • C. Acceptable results were achieved when the residual water from the washing process of H 2 O 2 -bleached fabrics was treated with the immobilized enzyme and then reused for dyeing.

Scanning Electrochemical Microscopy #54. Application To The Study Of Heterogeneous Catalytic ReactionsHydrogen Peroxide Decomposition

“…Heterogeneous catalytic reactions at the liquid−solid interface are important in chemistry (e.g., in synthesis and electrode reactions). One important case is the heterogeneous decomposition of hydrogen peroxide into O 2 and OH - (eq 1) that occurs at a high rate on noble metals such as Pt and its alloys, − on oxides, − immobilized complexes , and enzymes such as catalase. − There is also interest in H 2 O 2 removal from final products and wastes − and in fundamental studies of the reaction mechanism in electrode reactions, like oxygen electroreduction or …”

A Millifluidic Device with Embedded Cross-Linked Enzyme Aggregates for Degradation of H2O2

“…From all of these results, it is obvious that this tubing can efficiently degrade residual H 2 O 2 from the wastewater samples even if the H 2 O 2 concentration is higher than 0.1 wt %. In the literature, the immobilized catalase was used to treat industrial wastewater only when the H 2 O 2 concentration was <0.1 wt %. , The capability of degrading higher concentrations of H 2 O 2 up to 2.0 wt % makes our process more suitable for industrial applications.…”

“…In the literature, the immobilized catalase was used to treat industrial wastewater only when the H 2 O 2 concentration was <0.1 wt %. 27,28 The capability of degrading higher concentrations of H 2 O 2 up to 2.0 wt % makes our process more suitable for industrial applications.…”

“…Both factors prevent the widespread use of catalase in large-scale industrial applications. To address this issue, catalase was immobilized covalently on a solid support for the continuous removal of H 2 O 2 in industrial processes. − For example, Costa et al prepared a packed column with catalase-immobilized alumina carriers and used it for continuous removal of H 2 O 2 from textile bleaching effluent stream; however, the reactor suffered from enzyme inhibition when the substrate (H 2 O 2 ) concentration exceeded 1 M . Similarly, Yoon et al entrapped catalase on chitosan beads and packed them inside a column for continuous removal of 10 mM of H 2 O 2 from an effluent stream for 24 h. However, H 2 O 2 removal efficiency reduced significantly after 15 h if the H 2 O 2 concentration reached 30 mM .…”

External Mass Transfer Model for Hydrogen Peroxide Decomposition by Terminox Ultra Catalase in a Packed-Bed Reactor

“…These enzymes can find many industrial applications, namely: 1) in the textile industry after textile blenching (Costa et al, 2002a), 2) in the food industry after cold pasteurization of milk (Farkye, 2004), 3) coupled with oxidases, prevention of the inactivation of the oxidases by the deleterious action of a high concentration of peroxide (Fernández-Lafuente et al, 1998) and 4) coupled with oxidases, prevention of side reactions caused by the H2O2 that can destroy the target product (Schoevaart and Kieboom, 2001). It is worth noting that application of catalase reduces 48% of the energy consumption, 83% of the chemical costs, 50% of the water consumption and 33% of the processing time (Eberhardt et al, 2004).…”