Abstract: Photocatalytic oxidation (PCO) process is an effective way to deal
with organic pollutants in wastewater which could be difficult to be degraded
by conventional biological treatment methods. Normally the
TiO_2 powder in nanometre size range was directly used as
photocatalyst for dye degradation in wastewater. However the titanium dioxide
powder was arduous to be recovered from the solution after treatment. In this
application, a new form of TiO_2 (i.e. pillar pellets
ranging from 2.5 to 5.3 mm long and with a diameter of 3.7 mm) was used and
investigated for photocatalytic degradation of textile dye effluent. A test
system was built with a flat plate reactor (FPR) and UV light source(blacklight
and solar simulator as light source respectively) for investigating the
effectiveness of the new form of TiO_2. It was found that
the photocatalytic process under this configuration could efficiently remove
colours from textile dyeing effluent. Comparing with the
TiO_2 powder, the pellet was very easy to recovered from the
treated solution and can be reused in multiple times without the significant
change on the photocatalytic property. The results also showed that to achieve
the same photocatalytic performance, the FPR area by pellets was about 91%
smaller than required by TiO_2 powder. At least
TiO_2 pellet could be used as an alternative form of
photocatalyst in applications for textile effluent treatment process, also
other wastewater treatment processes.