ASCE has honored the writing team of Marc A. Santos, P.E., M.ASCE; Richard F. Carbonaro, Ph.D., P.E.; and Robert R. Sharp, Ph.D., P.E., with the 2019 Samuel Arnold Greeley Award for the paper “Control Strategies for the Mitigation and Removal of Attached Manganese Biofilms,” in the January 2018 issue of the Journal of Environmental Engineering.
In the selected work, the team investigated the use of chlorine dioxide (ClO2) and sodium hypochlorite (NaOCl) with rotating annular reactors (ARs). Results showed that low (0.5 mg/L as ClO2) and high (1.0 mg/L as ClO2) doses of ClO2, and 2.0 mg/L as Cl2 of NaOCl, were effective at mitigating biofilm to different extents by oxidizing readily available dissolved manganese (Mn) and iron (Fe) and/or inactivating biofilm populations. The most effective biofilm control strategy tested was a 2.0 mg/L dose of NaOCl, which provided significant reductions of suspended bacteria (2.1 log reduction), established biofilm (2.5 log reduction), and new biofilm growth (3.2 log reduction). Results from this study suggest that the implementation of treatment strategies for the control of existing and future biofilms should consider both (1) the removal of readily available metals by oxidation and (2) the direct inactivation of attached bacteria.
The Samuel Arnold Greeley Award is presented for papers on the design, construction, operation, or financing of water supply pollution control, storm drainage, or refuse disposal projects.