Pilot-scale UV/H2O2-BAC process for drinking water treatment - Analysis and comparison of different activated carbon columns

An UV/H2O2-BAC combination process was developed and the effects of activated carbon columns with carbon of different ages and particle sizes were compared and inspected under long-term operation conditions. In addition, differences in the microbial community structure of the biological membrane on the surface of the activated carbons was explored by scanning electron microscopy (SEM) and high-throughput sequencing. Furthermore, the removal efficiency of organic matter and the microbial community structure were compared between UV/H2O2-BAC and O-3-BAC processes under the same treatment conditions. The results showed that younger carbon age and smaller particle size were associated with higher organic matter removal rates. Additionally, Actinobacteria and Legionella were the main microorganisms for BAC to degrade hydrogen peroxide, and the microbial species of the four activated carbons were basically the same, differing only in abundance. When compared with the O-3-BAC process, the UV/H2O2-BAC process had higher removal efficiency for organic matter and higher effluent safety. Overall, the results indicate the UV/H2O2-BAC process can be used as an alternative to the O-3-BAC process for control of bromate.