2nd UF Water Institute Symposium Abstract

Submitter's Name Omatoyo Dalrymple
Session Name Poster Session: Managing Water and Energy in a Transitioning Environment 2
Category Managing water and energy in a transitioning environment
Poster Number 304
Author(s) Omatoyo Dalrymple,  University of South Florida
  Yogi Goswami,  University of South Florida
  Elias Stefanakos, University of South Florida
  Development of a robust mechanistic model for photocatalytic disinfection of water
  Solar photocatalytic systems are becoming a viable option for water disinfection and offer huge energy savings. They are particularly adaptable for applications in remote and rural areas, where energy supply may be prohibitive. In addition, TiO2 is abundant and relatively cheap and photocatalysis does not produce potentially harmful byproducts such as those produced during chlorination and ozonation. However, design methodologies for photochemical disinfection systems have lagged far behind their chemical detoxification counterparts. This is in part due to the lack of reliable models that aptly describe the inactivation process. The mechanism of inactivation for common indicator organisms such as E coli is still heavily debated. Most of the previous analyses have been based on empirical models, but there is no reason to believe that these models can be extrapolated beyond the range of values for which they have been calibrated. Further, the available models do not adequately and consistently describe photocatalytic disinfection, largely because they are rooted in conventional disinfection which is based on the chemistry of homogeneous reactions. We propose the first robust mechanistic model for the disinfection of bacteria in drinking water which can be used to design large-scale systems. The model is based on the oxidation of membrane lipids within a compartmentalized micro-reactor system with the propagation of radical chain reactions leading to organism inactivation. We define the reaction mechanisms, the reaction kinetics and the conditions under which the model can be considered valid.