Improving UV seawater disinfection with immobilized TiO2: Study of the viability of photocatalysis (UV254/TiO2) as seawater disinfection technology

Industries located in coastal areas and maritime transport are economic activities that use large amounts of seawater. In most cases, this water requires disinfection treatment to avoid fouling problems in industrial facilities or to prevent environmental impacts after used seawater is released. This study proposes the photocatalysis with immobilized TiO2 as a disinfection treatment for seawater and evaluate its efficacy by comparing with UV254 radiation treatment. The experiments were carried out employing artificial seawater and using an annular UV reactor in the laboratory scale tests. Two species of marine bacteria were used as microbial indicators of the treatment efficacy: Alteromonas sp and Corynebacterium stationis. The photocatalytic treatment had faster disinfection kinetics than that using UV254 light for both bacteria species, being necessary between 30 and 33% less UV dose to achieve the same level of disinfection. The catalyst used for photocatalytic treatment showed a progressive decay of activity until its complete inactivation after 215 h of treatment, due to factors such as fouling or catalyst loss.