Triclosan removal by laccase immobilized on mesoporous nanofibers: Strong adsorption and efficient degradation

Triclosan is difficult to remove or degrade in natural aquatic environment due to its stable chemical structure and low concentration. This study aimed to enhance its removal rate from water through combining the biocatalytic activity of laccase with high adsorption capacity of mesoporous materials. Vinyl-modified poly(acrylic acid)/SiO2 nanofibrous membranes prepared in this work possessed mesoporous structure (pore size 1.73-3.54 nm, pore volume 0.379 cm(3)/g) and high specific surface area (542.91 m(2)/g). Laccase was immobilized on the membranes through covalent crosslinking and the enzyme loading was about 417 mg/g. The physical, chemical, biochemical properties of the immobilized laccase and its application in triclosan removal were comprehensively investigated. The immobilized laccase showed better storage stability and higher tolerance to the changes in pH and temperature compared with free laccase. It also exhibited a better performance (65% removal, 2 h) in triclosan removal than free laccase (29.2% removal, 2 h) under the optimum conditions (pH = 4, 30 degrees C). The results demonstrated that the mesostructure of nanofibers was beneficial for the adsorption and degradation of triclosan. It may provide a new idea for removal of organic pollutants from water environment using enzyme and adsorption technology. (C) 2014 Elsevier B.V. All rights reserved.