Characterisation by image analysis of anaerobic sludge under shock conditions

• Published in: Water Science & Technology Vol. 41; no. 12; pp. 207 - 214
• Main Authors: ALVES, M, CAVALEIRO, A. J, FERREIRA, E. C, AMARAL, A. L, MOTA, M, DA MOTTA, M, VIVIER, H, PONS, M-N
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Pergamon Press 01.06.2000; IWA Publishing
• Subjects: Anaerobic conditions; Applied sciences; Bacteria; Biological and medical sciences; Biological treatment of waters; Biomass; Biotechnology; Chemical and Process Engineering; Engineering Sciences; Environment and pollution; Exact sciences and technology; Filaments; Fundamental and applied biological sciences. Psychology; Hydraulic retention time; Hydraulic shock; Hydraulics; Image analysis; Image processing; Industrial applications and implications. Economical aspects; Industrial wastewaters; Load distribution; Loading rate; Oleic acid; Organic loading; Pollution; Retention time; Shock; Sludge; Wastewaters; Water treatment and pollution; Image analysis; Bioreactor; Water hammer; Industrial waste water; Upflow anaerobic sludge blanket reactor; Biomass; Waste water purification; Anaerobic digestion; Biological purification
• ISBN: 1900222493; 9781900222495
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2000.0273

In the present work the characterisation by image analysis of anaerobic biomass under organic and hydraulic shocks was performed. The digester was fed with a synthetic substrate, containing 50% oleic acid (as COD). Organic and hydraulic shocks were performed by stepwise increasing the substrate concentration or by reducing the hydraulic retention time. In both cases the organic loading rate changed from 6 to 30 kg COD/m3.d. Hydraulic shock induced a fast decrease in the number of free filaments and in total filament length, which attained a minimum value 51 hours after beginning the shock. The initial filament values were not recovered 340 hours after the hydraulic shock. In the organic shock, the minimum values of these parameters were detected 200 hours after beginning the shock and initial values were recovered 840 hours after. During the hydraulic shock the methanogenic acetoclastic activity was directly correlated to the number and length of free filaments. This result suggests that filaments are predominantly acetoclastic bacteria, probably Methanosaeta.