Topic of Research Seminar: Silica Monoliths Immobilized with Enzymes for degradation of Micropollutants in Wastewater

Abstract: In this research work, silica monoliths with high porosity (83 %), double pore size distribution (20 μm and 20 nm macro- and mesopores diameters, respectively) and high surface area (370 m2 g-1) have been used as solid supports to immobilize a laccase from Trametes versicolor by covalent grafting with glutaraldehyde. Enzymatic monoliths were applied to degrade tetracycline (TC) in aqueous solutions in a tubular “Flow Through Reactor” configuration with recycling. During the first 5h of reaction at pH 7, 40–50% of TC was degraded, and then a threshold was reached. One of the hypotheses explaining this behaviour is a possible co-substrate lack (oxygen) near catalytic sites. Enzymatic monoliths were used during 75 h of sequential operation without losing activity. A mathematical model built coupling the Michaelis-Menten reaction kinetics with a dynamic mass balance allowed computing TC degradation efficiency. Simulation results revealed that the global process is controlled by the enzymatic kinetics but the monolith size could be adapted to degrade 100 % TC in a single pass.

Subject Field of Topic: Enzymatic degradation of micropollutants in wastewater

Name of Speaker: Dr. Sher Ahmad

Professorial Rank of Speaker: Assistant Professor

University Email of Speaker: [email protected]

Affiliation of Speaker: School of Chemical & Materials Engineering (SCME), National University of Sciences and Technology (NUST)

Date of Seminar: March 28, 2022, at 1400 hours

Venue: SCME Seminar Hall, NUST H-12 Campus, Islamabad