Feasibility study of acenaphthene degradation in a novel slurry UV photocatalytic membrane reactor: Effect of operating parameters and optimization using response surface modeling

Abstract

The study focusses on the removal of acenaphthene (ANA) in an indigenously developed UV-TiO2 slurry photocatalytic membrane reactor (PMR). The various operating variables such as pH (3.0–9.0), TiO2 dosage (0.1-0.9 g/L) and initial ANA concentration (1000−3000 μg/L) on removals of ANA and total organic carbon (TOC) were investigated. The experimental results of the integrated photocatalytic membrane process (UV-TiO2 + MS) during the batch study showed ANA and TOC removals of 95.3% and 93.8 % and 93.8 % respectively while the individual processes; photocatalytic process (UV-TiO2) (ANA-80.1 % and TOC-57.6 %) and UF membrane separation (MS) (ANA-51.1 %) exhibited low removal rates with the same experimental conditions. The photocatalytic degradation of ANA followed pseudo-first-order kinetics and the obtained experimental data were analyzed with Response Surface Methodology (RSM) using Design-Expert software. This study also identified the various intermediates that were generated during the photocatalytic membrane treatment of ANA. The ANA and TOC removals were also monitored during continuous process and the highest ANA and TOC removals of 95.1 % and 93.2 % respectively were noticed after 560 min of the reactor run during UV- TiO2 + MS process. Similarly, the highest removals of 80 % ANA and 57.3 % TOC were observed during UV-TiO2 process on the continuous mode of experiments.