Pharmaceutical products (PPs) are considered as emerging micropollutans in wastewaters, river and seawaters, and sediments. The biodegradation of PPs, such as ciprofloxacin, amoxicillin, sulfamethoxazole, and tetracycline by enzymes in aqueous solution was investigated. Laccase from Trametes versicolor was immobilized on silica monoliths with hierarchical meso-/macropores. Different methods of enzyme immobilization were experienced. The most efficient process was the enzyme covalent bonding through glutaraldehyde coupling on amino-grafted silica monoliths. Silica monoliths with different macropore and mesopore diameters were studied. The best support was the monolith featuring the largest macropore diameter (20 µm) leading to the highest permeability and the lowest pressure drop and the largest mesopore diameter (20 nm) ensuring high enzyme accessibility. The optimized enzymatic reactor (150 mg) was used for the degradation of a PP mixture (20 ppm each in 30 ml) in a continuous recycling configuration at a flow rate of 1 ml/min. The PP elimination efficiency after 24 h was as high as 100% for amoxicillin, 60% for sulfamethoxazole, 55% for tetracycline, and 30% for ciprofloxacin.

In this work, the laccase from Trametes versicolor was immobilized in highly porous silica monoliths (0.6 cm diameter, 0.5 cm length). These monoliths feature a unique homogeneous network of interconnected macropores (20 μm) with mesopores (20 nm) in the skeleton and a high specific surface area (330 m 2 /g). The enzymatic monoliths were applied to degrade tetracycline (TC) in model aqueous solutions (20 ppm). For this purpose, a tubular Flow-Through-Reactor (FTR) configuration with recycling was built. The TC degradation was improved with oxygen saturation, presence of degradation products and recirculation rate.The TC depletion reachs 50% in the FTR and 90% in a stirred tank reactor (CSTR) using crushed monoliths.These results indicate the importance of maintaining a high co-substrate concentration near active sites. A model coupling mass transfers with a Michaelis-Menten kinetics was applied to simulate the TC degradation in real wastewaters at actual TC concentration (2.8 10 -4 ppm). Simulation results show that industrial scale FTR reactor should be suitable to degrade 90% of TC in 5 h at a flow rate of 1 mL/min in a single passage flow configuration. Nevertheless, the process could certainly be further optimized in terms of laccase activity, oxygen supply near active sites and contact time.