Correlation between sludge settleability and image analysis information using Partial Least Squares

Abstract

[Excerpt] Introduction: In activated sludge systems, an adequate balance between the different types of bacteria is essential to ensure an efficient pollution removal, good sludge settling abilities and low suspended solids levels in the final effluent [4]. After the oxidation of the organic matter in the aerated tank, the flocculated biomass is separated from the treated effluent by means of their settling ability in the settling tank. The settling phase is considered a critical stage of the process in which filamentous bulking and deflocculation processes are the most common problems, causing the decrease of the sludge settling ability and effluent quality deterioration [12]. Poor settling biomass is normally attained by an improper aggregate’s formation and filamentous bacteria proliferation, resulting in lower clarifier efficiency. Some malfunctions may occur within the activated sludge system such as pin-point flocs bulking, filamentous bulking, dispersed growth and zoogleal growth [5]. [...]