Effect of solids retention time on Microthrix parvicella growth

Noutsopoulos, C; Mamais, D; Andreadakis, A

dc.contributor.author	Noutsopoulos, C	en
dc.contributor.author	Mamais, D	en
dc.contributor.author	Andreadakis, A	en
dc.date.accessioned	2014-03-01T01:24:10Z
dc.date.available	2014-03-01T01:24:10Z
dc.date.issued	2006	en
dc.identifier.issn	0378-4738	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17189
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-33746038129&partnerID=40&md5=7c2f8cfb8613a7e7d26ba2610582c273	en
dc.subject	Bulking	en
dc.subject	Filamentous micro-organisms	en
dc.subject	Foaming	en
dc.subject	Growth kinetics microthrix parvicella	en
dc.subject	Solids retention time (SRT)	en
dc.subject.classification	Water Resources	en
dc.subject.other	Activated sludge process	en
dc.subject.other	Growth kinetics	en
dc.subject.other	Hydrophobicity	en
dc.subject.other	Maintenance	en
dc.subject.other	Sewage sludge	en
dc.subject.other	Bulking	en
dc.subject.other	Filamentous micro-organisms	en
dc.subject.other	Foaming	en
dc.subject.other	Growth kinetics microthrix parvicella	en
dc.subject.other	Solids retention time (SRT)	en
dc.subject.other	Bacteria	en
dc.subject.other	Activated sludge process	en
dc.subject.other	Bacteria	en
dc.subject.other	Growth kinetics	en
dc.subject.other	Hydrophobicity	en
dc.subject.other	Maintenance	en
dc.subject.other	Sewage sludge	en
dc.subject.other	activated sludge	en
dc.subject.other	bacterium	en
dc.subject.other	growth	en
dc.subject.other	microorganism	en
dc.subject.other	Bacteria (microorganisms)	en
dc.subject.other	Candidatus Microthrix	en
dc.subject.other	Candidatus Microthrix parvicella	en
dc.title	Effect of solids retention time on Microthrix parvicella growth	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	2006	en
heal.abstract	The objective of this study was to evaluate the effect of solids retention time ( SRT) on M. parvicella growth and to calculate growth kinetic parameters of this filamentous species. Bench-scale continuous-flow experiments showed that M. parvicella growth can be significantly suppressed at an SRT of lower than 5.7 d for temperatures of between 14 and 18 degrees C. According to the continuous-flow experiments the maximum sludge age for the avoidance of filamentous foaming problems caused by M. parvicella is 6 d for temperatures lower than 18 degrees C. At this sludge age M. parvicella loses its hydrophobicity and therefore its foaming potential. However, even lower SRTs are required in order to achieve a significant suppression of its growth. At SRT values of less than 5.7 d M. parvicella initially forms a shorter. lament (< 150 mu m) with clear spaces inside. laments and variable Gram stain reaction and eventually is eliminated from activated sludge biocoenosis. According to kinetic studies presented in this paper, M. parvicella is a slow growing bacterium with a low maximum specific growth rate of 0.67 1/d and 0.53 1/d under aerobic and anoxic conditions respectively. Maintenance energy requirements of M. parvicella were found to be significantly lower than the maintenance energy of floc forming micro-organisms as well as other filamentous species, thus providing the micro-organism with a significant advantage under starvation conditions prevailing at the majority of the extended aeration activated sludge systems.	en
heal.publisher	WATER RESEARCH COMMISSION	en
heal.journalName	Water SA	en
dc.identifier.isi	ISI:000239039200006	en
dc.identifier.volume	32	en
dc.identifier.issue	3	en
dc.identifier.spage	315	en
dc.identifier.epage	321	en