Activated sludge morphology characterization through an image analysis procedure

Abstract

-This work deals with the development of a digital image analysis procedure to characterize microbial flocs obtained in three different WWTP: a bench-scale Sequencing Batch Reactor (SBR) dealing with phenol and nitrogen biological removal, a municipal treatment unit (Ilha do Governador, Rio de Janeiro, Brazil) and an industrial wastewater treatment plant (Ciba -Estrada do Colégio, Rio de Janeiro, Brazil). The developed procedure permits to obtain its morphological parameters like equivalent diameter, compactness, roundness and porosity properties as well as the fractal dimension. This procedure was validated and lead to identify the major relationships between the analysed morphological parameters. A minimum of 300 flocs should be included in the image analysis and a significant influence of the sample dilution step on the mean size of the flocs was verified. The porosity parameter positively correlated with the fractal dimension of microbial aggregates indicating the that highly porous flocs are very irregular.

Illumination Compensated Segmentation of Microscopic Images of Activated Sludge Flocs

“…It is because quantification and morphology of flocs are used to characterize the abnormal conditions in activated sludge process [4][5][6][7][8]. As show in the table III, the proposed algorithm performed better than all others in terms of quantification too.…”

“…They used Canny's algorithm with bi-level thresholding. A sequence of algorithms for segmentation and morphological analysis was proposed by Perez et al [8]. The algorithms included back-ground correction, histogram equalization, and median filter.…”

A method for calculating the surface area of numerically simulated aggregates

“…Perez et al [1] estimated the morphological parameters of fractal aggregates by digital image analysis using commercial software Image-Pro Plus Ò . The relationships between the morphological parameters were analyzed and the results indicated that the highly porous aggregates are very irregular.…”

“…Go-chess method for the calculation of a 2D aggregate surface 1. For interpretation of color inFigs.…”

Influência Da Intensidade De Aeração E Da Concentração De Oxigênio Dissolvido (Od) Na Dimensão De Flocos De Lodo Ativado E Na Qualidade Do Efluente Final

“…Esse tipo de processo possui uma remoção eficaz de poluentes e se consolida basicamente em duas etapas: (1) a biodegradação e (2) a separação física da biomassa do sobrenadante por força gravitacional (Perez et al, 2006;Wilén et al, 2008). Para a etapa da biodegradação, a qual ocorre no tanque de aeração, especificamente, é necessário o suprimento de oxigênio.…”