Substrate clogging is one of the bottlenecks restricting the sustainable operation of constructed wetland.   

According to the previous research conducted by the group led by Prof. WU Zhenbin from Institute of Hydrobiology (IHB) of Chinese Academy of Sciences, the blocking parts of vertical subsurface constructed wetlands mainly occurs on the substrate surface and upper packing layer, and refractory biomass pollutants are one of the main components of clogging materials in wetland.    

A novel composite photocatalyst with hydrophobicity modified Sr/TiO2-PCFM was synthesized and prepared. The results indicated that the composite photocatalyst possessed a pure and highly crystalline anatase TiO₂ layer and large specific surface area. The photodegradation of acephate by Sr/TiO₂-PCFM was investigated under various conditions. The kinetics of the acephate photodegradation were found to follow that of a pseudo-first-order reaction.The acephate-preferred photocatalytic performance of the modified Sr/TiO₂-PCFM with hydrophobic characteristics was explored for the first time in this study.  Related papers have been published in Chemical Engineering Journal. 

Researchers found that the photocatalytic degradation process for the modifiedSr/TiO₂-PCFM preferred acephateover methylene blue (MB) in the acephate/MB mixture under ultraviolet light irradiation.    

The study highlights that the modified Sr/TiO₂-PCFM is a promising candidate for the preferential degradation of refractory organic matter in organophosphorus pesticides contaminated wastewater.    

The research has theoretical and practice significance in giving full play to the purification effect of surface substrate and degrading clogged organic matter on the surface substrate of constructed wetland.
  

Schematic diagram of photocatalytic priority degradation (Image by IHB)