NAPROXEN REMOVAL FROM WASTEWATER BY ENZYMATIC DEGRADATION USING LACCASE

摘要

The occurrence of naproxen (NAP) in aquatic environments constitutes a potential risk to the environment and human health, due to its phytotoxicity. This drug is not metabolized by humans and wastewater treatment plants at high efficiency. The aim of this work is to study genetically modified Aspergillus niger laccase enzyme for the acute removal of NAP. Here, the degradation of NAP was accessed utilizing industrial laccase (LT-100) with the impact of operating parameters such as enzyme loading (0.10-0.18% w/v of an enzyme to NAP), temperature (30-60℃), pH (4-6), and speed of agitation (0-300 rpm). The established optimum condition is temperature 40℃, pH 4.5, degradation time 5 h, and speed of agitation 200 rpm. Under these optimized conditions, 92% degradation was achieved. Further investigation on the degradation kinetics of NAP revealed that the degradation of NAP follows Michaelis-Menten kinetic behavior. The observed values of V_(max) and K_m are 4.48 × 10~(-5) M/min and 5.4 × 10~5 M, respectively. This study could provide useful information for the potential of genetically modified laccase enzyme produced on Aspergillus niger to treat water and wastewater containing NAP.