Heterogeneous photocatalysis for water purification: Contaminant mineralization kinetics and elementary reactor analysis

摘要

AbstractHeterogeneous photocatalysis is the third and newest of an emerging series of photolytic technologies for water treatment and purification. The earlier examples of ultraviolet ozonation and ultraviolet peroxidation involved direct photoactivation of the contaminant and/or dissolved oxidant and are dominated by solution phase chemistry. Photocatalysis, in contrast, involves photoactivation of the heterogeneous catalyst (an example of indirect photochemical processes) and is dominated by reaction events initiated at the catalyst surface. This paper summarizes (1) current rate equations for photocatalyzed simultaneous destruction of multiple oxidizable organic contaminants and (2) simplified convective transport equations appropriate to photoreactor design under various degrees of fluid mixing and simultaneous reaction contributions by heterogeneous (photocatalyzed) as well as homogeneous reactions.