(cest2017_00450) A novel high retention enzymatic bioreactor system for the removal of pharmaceuticals and personal care products

摘要

In previous studies we developed an enzymaticbioreactor coupled with an ultrafiltration (UF) membrane,which prevented enzyme washout, thereby allowingcontinuous enzymatic degradation of pharmaceuticals.Moreover, some resistant compounds such as naproxenand salicylic acid were retained by enzyme gel layerformed on membrane surface, subsequently resulting intheir enhanced biodegradation. Based on this observation itwas postulated that integration of high retentionmembranes with an enzymatic bioreactor can facilitatebiodegradation of recalcitrant compounds by retaining bothenzyme and PPCPs. This study explores a novel membranedistillation-enzymatic bioreactor (MD-EMBR) system forthe removal of PPCPs including four pharmaceuticalsnamely, diclofenac, naproxen, salicylic acid and ibuprofenas well as two ingredients of personal care productsnamely, oxybenzone and salicylic acid using purifiedlaccase from genetically modified A. oryzae. The resultsconfirmed almost complete retention (>95%) of the PPCPsby the MD membrane. Of particular interest was the factthat the complete retention of the PPCPs improved theenzymatic degradation (10-30%) of compounds that havebeen reported to be poorly removed in UF-EMBR.Addition of 1-hydrozybenzotriazole improved theoxidation reduction potential of the solution in theenzymatic bioreactor by 16%, thereby enhancing thedegradation of diclofenac, naproxen, salicylic acid andibuprofen by 5-22%. Toxicity analysis showed that thefinal effluent of MD-EMBR system was nontoxic.