Application of membrane technology in activated sludge process

In this work the performances of the Step Sludge Recirculation (SSR) activated sludge process were improved. The process consists of an anoxic stage where denitrification occurs and four aerobic stages where the nitrifications occur. The conventional system was compared with a second system where the secondary clarifier was substituted by a submerged membrane module. Two different types of flat sheet membrane were fitted into the membrane module. The performances were measured by means of a microscopic observation of the microfauna in the activated sludge and other physical-chemical analysis such as solids, TOC, O.U.R. test, total nitrogen, ion determination. The main objective of the work was to optimize the process in order to obtain a maximum in the removal of ammoniacal nitrogen.