APPLICATION OF UVA/LED/TIO2 PROCESS FOR WASTEWATER TREATMENT - PHARMACEUTICAL DEGRADATION AND BACTERIA DISINFECTION

Abstract

In this study, a newly emerged high-power UVA/LED lamp was investigated as an alternative UV radiation source for photocatalytic process. Eight pharmaceuticals belonging to seven clinical drug groups were selected and tested for their degradation efficiency by the UVA/LED/TiO2 system. Results reveal that all of selected pharmaceuticals could be degraded to undetectable level within 20 minutes. Various factors such as light intensity, initial pharmaceutical concentration and catalyst dosage were investigated under continuous illumination. To improve photonic efficiency and degradation rate, different methods including periodic illumination were studied. Various degradation intermediates were also determined for four selected pharmaceuticals by GC/MS. The disinfection study by UVA/LED/TiO2 system was conducted using antibiotic-resistant bacteria as disinfection target. Results show that Log-removal is higher under smaller duty circle and shorter circle time with the same UV dosage applied. Bacteria concentration continue to decrease after the removal of illumination.