Modelling anaerobic digestion of concentrated black water and faecal matter in accumulation system
Elmitwalli, T. ; Zeeman, G. ; Otterpohl, R. - \ 2011
Water Science and Technology 63 (2011)9. - ISSN 0273-1223 - p. 2039 - 2045.
nieuwe sanitatie - afvalwaterbehandeling - anaërobe afbraak - dynamische modellen - feces - urine - huishoudens - biodegradatie - new sanitation - waste water treatment - anaerobic digestion - dynamic models - faeces - urine - households - biodegradation - decentralized sanitation - waste-water - grey water - urban - biodegradability - management - reuse - areas
A dynamic mathematical model based on anaerobic digestion model no. 1 (ADM1) was developed for accumulation (AC) system treating concentrated black water and faecal matter at different temperatures. The AC system was investigated for the treatment of waste(water) produced from the following systems: vacuum toilet for black water (VBW), vacuum toilet for faeces with urine separation (VF), dry toilet (DT), dry toilets for faeces with urine separation (DF), separated faecal matter from conventional black water by filter bag (FB). For evaluation of the AC system treating the proposed waste(water) sources at 20 and 35°C, two options were studied: (1) The filling period of the AC system was constant for all waste(water) sources (either 1, 3 or 6 months) and for each period, the seed sludge volume was varied; (2) The volume of the AC system was constant for all proposed waste(water) sources. The results showed that the filling period of the AC system was the main parameter affecting the system performance, followed by operational temperature, while the increase of the seed sludge volume slightly enhanced the performance of the system. The model results indicated that the filling period of the AC system should be higher than 150 days for obtaining a stable performance. It was found that the hydrolysis of biodegradable particulate chemical oxygen demand (COD) is the rate limiting step, as volatile fatty acid concentration is very low in all experimental conditions (
The chronic toxicity of alcohol alkoxylate surfactants on anaerobic granular sludge
Ginkel, S. van; Kortekaas, S.J.M. ; Lier, J.B. van - \ 2007
Environmental Science and Technology 41 (2007)13. - ISSN 0013-936X - p. 4711 - 4714.
nonionic surfactants - ethoxylates - biodegradability - permeability
The chronic toxicity of an alcohol alkoxylate surfactant used in the pulp and paper industry was observed in methanogenic consortia under unfed conditions. Methanogenic inhibition was not observed until 250 h of famine conditions while in the presence of the surfactant. The delayed onset of inhibition is likely due to the amount of time necessary for the surfactant to partition into the cellular membrane which uncouples cellular energy conservation mechanisms and exhausts internal energy reserves necessary to maintain homeostasis.
Image analysis, methanogenic activity measurements, and molecular biological techniques to monitor granular sludge from EGSB reactors fed with oleic acid
Pereira, M.A. ; Roest, K. de; Stams, A.J.M. ; Akkermans, A.D.L. ; Amaral, A.L. ; Pons, M.N. ; Ferreira, E.C. ; Mota, M. ; Alves, M. - \ 2003
Water Science and Technology 47 (2003). - ISSN 0273-1223 - p. 181 - 188.
slib - oleïnezuur - korrels - afbeelden - methaan - elektroforese - microbiële afbraak - afvalwaterbehandeling - sludges - oleic acid - granules - imagery - methane - electrophoresis - microbial degradation - waste water treatment - gradient gel-electrophoresis - diversity - bacteria - biodegradability - identification - toxicity - dna
Morphological changes in anaerobic granular sludge fed with increasing loads of oleic acid were quantified by image analysis. The combination of this technique with data on-the accumulation of adsorbed long chain fatty acid and with the molecular characterization of microbial community gave insight into the mechanisms of sludge disintegration, flotation and washout
Morphological changes in anaerobic granular sludge fed with increasing loads of oleic acid were quantified by image analysis. The combination of this technique with data on-the accumulation of adsorbed long chain fatty acid and with the molecular characterization of microbial community gave insight into the mechanisms of sludge disintegration, flotation and washout. It was found that the bacterial domain was more affected than the archaeal domain during this process. However, no acetoclastic activity and only a residual hydrogenotrophic activity were detected in the sludge at the end of the operation.