Modeling As(V) removal in iron oxide impregnated activated carbon columns

Iron oxide impregnated onto an activated carbon (FeAC) has a high arsenic (As) removal capacity with the potential to be used in existing activated carbon column systems. Objectives of this research were to investigate As(V) removal from aqueous-phase systems using fixed-beds packed with FeAC and to determine if the triple layer model (TLM) with the homogeneous surface diffusion model (HSDM) could describe As(V) removal in the columns. Rapid small-scale column tests (RSST) were conducted at various empty bed contact times (EBCT). Effluent As(V) breakthrough (10 mu g/L) was incipient for the 0.20-min EBCT experiment, whereas similar to 2300 bed volumes of water at 1-mg/L inlet concentration of As(V) was treated at an EBCT of 2.1 min before breakthrough occurred. The TLM with three As(V)-FeAC surface reactions coupled with the HSDM provided accurate prediction of As(V) removal in the RSSCT.