Scum yield and effectiveness of a hydrostatic removal device: case study of Laboreaux STP

This paper aimed to evaluate the effectiveness of a device to remove scum from the inner part of gas-liquid-solid separators of a full-scale upflow anaerobic sludge blanket reactor treating domestic sewage, as well as determining the scum yield coefficient for different reactors’ operating conditions. The experiments were carried out at the Laboreaux sewage treatment plant (Itabira, Minas Gerais, Brazil) and the effectiveness of the scum removal device was fully demonstrated, with median efficiencies ranging from 65 to 90%. The average scum yield varied from 6.8 to 14.6 mL of scum formed per kg COD applied.