Enhancement of the potential biodegradability and the mineralization of a pesticides mixture after being treated by a coupled process of TiO2-based solar photocatalysis with constructed wetlands
Colina-Márquez, José | 2014-04-28
Solar heterogeneous photocatalysis is an advanced oxidation technology, which allows a successful treatment of
many recalcitrant and emergent pollutants, such as: pesticides, industrial dyes and pharmaceutical compounds.
Nonetheless, despite its effectiveness, the costs of applying this process are high when it is necessary to achieve a
complete mineralization or to obtain an environment-friendly effluent. Photocatalytic–biological coupled systems
have become in a feasible alternative able to treat efficiently these pollutants. In this work, a coupled system
consistent of two compound parabolic collectors (CPC) solar photoreactors and a subsurface flow constructed
wetland (SFCW) at pilot-scale was tested for degrading a mixture of commercial pesticides used in sugar cane
crops. For measuring the process performance, regarding to the pollutant removal, the increase of the BOD5/COD
ratio and the total organic carbon (TOC) removal were estimated for each separated system and the coupled system.
Three different levels of solar UV accumulated energy and feed flow-rates to the SFCW were considered for the
experimental design. The pilot-scale coupled system increased the BOD5/COD ratio from 0.15 to 0.90, and the TOC
removal (total mineralization) was around 80%.