STUDIES ON THE USE OF CALCIUM HYPOCHLORITE IN THE TiO2 MEDIATED DEGRADATION OF PHARMACEUTICAL WASTEWATER
The present study investigates the effect of addition of calcium hypochlorite in the titanium dioxide (TiO2) mediated degradation
of bio-recalcitrant wastewater from pharmaceutical industry. The degradation studies were carried out in photoreactor irradiated
with ultraviolet (UV) light at 365 nm under slurry mode. The reduction in chemical oxygen demand (COD) was estimated as an
index of degradation. The influence of process parameters viz., catalyst dose, pH, oxidant concentration and source of light
(UV/Solar) on degradation was studied. The degradation efficiency was also compared with hydrogen peroxide (H2O2) which has
been widely used as an oxidant in the photocatalytic systems. The degradation efficiency of wastewater with oxidant alone was
found to be comparatively less. Degradation of 67% was achieved in UV/TiO2 system at optimized conditions (3.0 g/L TiO2, pH
4) after 7 h of irradiation. The use of calcium hypochlorite (0.25 g/L) along with TiO2 (3.0 g/L) at pH 4 has been found to
increase the degradation efficiency of wastewater up to 82% which would facilitate the recycling of wastewater from
pharmaceutical industry.