Evaluation of Performance of Hybrid Photolysis-DCMD and Photocatalysis-DCMD Systems Utilizing UV-C Radiation for Removal of Diclofenac Sodium Salt From Water

Abstract

The removal of a non-steroidal anti-infl ammatory drug (NSAID) diclofenac sodium salt (DCF, C 14 H 10 Cl 2 NNaO 2 ) from water in two hybrid systems coupling photolysis or photocatalysis with direct contact membrane distillation (DCMD) is presented. A UV-C germicidal lamp was used as a source of irradiation. The initial concentration of DCF was in the range of 0.005-0.15 mmol/dm 3 and the TiO 2 Aeroxide® P25 loading (hybrid photocatalysis-DCMD) ranged from 0.05 to 0.4 g/dm 3 . Regardless of the applied hybrid system and the initial concentration of DCF, the model drug was completely decomposed within 4 h of irradiation or less. Mineralization was less effi cient than photodecomposition. In case of the hybrid photolysis-DCMD process the effi ciency of TOC degradation after 5 h of irradiation ranged from 27.3-48.7% depending on the DCF initial concentration. The addition of TiO 2 allowed to improve the effi ciency of TOC removal. The highest degradation rate was obtained at 0.3 gTiO 2 /dm 3 . During the process conducted with the lowest DCF initial concentrations (0.005-0.025 mmol/dm 3 ) a complete mineralization was obtained. However, when higher initial amounts of DCF were used (0.05-0.15 mmol/dm 3 ), the effi ciency of TOC degradation was in the range of 82.5-85%. The quality of distillate was high regardless of the system: DCF was not detected, TOC concentration did not exceeded 0.7 mg/dm 3 (1.9 mg/dm 3 in permeate) and conductivity was lower than 1.6 μS/cm.

Removal of non‐steroidal anti‐inflammatory drugs from primary and secondary effluents in a photocatalytic membrane reactor

“…93–94% NAP was removed regardless of TiO 2 loading. We obtained similar results during our earlier investigations on the removal of diclofenac from distilled water . We found that DCF decomposition rate during the first hour of the hybrid photocatalysis–DCMD process was decreasing with increasing photocatalyst loading from 0.05 to 0.4 g dm −3 .…”

“…There are also other configurations of PMRs, in which photocatalysis is coupled with DCMD dialysis or pervaporation . The first from the above mentioned configurations was proposed by our group.…”

“…In earlier work we examined the possibility of removal of ibuprofen and diclofenac from ultrapure water and tap water . The hybrid photocatalysis–DCMD process proved to be effective for the removal of these drugs under the applied conditions.…”

Photocatalytic membrane reactors for water treatment

“…In a successive work, the same authors (Mozia, Darowna, Przepi orski, & Morawski, 2013) reported the removal of a nonsteroidal anti-inflammatory drug (diclofenac sodium salt [DCF]) from water in two hybrid systems coupling photolysis or photocatalysis with DCMD. The results are summarized in Figure 7.14 in terms of TOC amounts in distillate (permeate) at the end of various experiments in comparison with the initial and final amounts of organic carbon in feed solutions.…”

“…The results obtained by Mozia and Morawski (2012) and Mozia et al (2013) showed that, because the MD efficiently separated not only TiO 2 particles, but also organic contaminants present in feed solution, the PMR using DCMD represents a promising method for treatment of waters containing pharmaceuticals. Low permeate (distillate) flux assured relatively long residence time of contaminants, which resulted in high effectiveness of their photodegradation.…”