Bound water content of biological sludges in relation to filtration and dewatering

Katsiris, N; Kouzeli-Katsiri, A

dc.contributor.author	Katsiris, N	en
dc.contributor.author	Kouzeli-Katsiri, A	en
dc.date.accessioned	2014-03-01T01:06:48Z
dc.date.available	2014-03-01T01:06:48Z
dc.date.issued	1987	en
dc.identifier.issn	0043-1354	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/9614
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0023455087&partnerID=40&md5=db1922f2a3dad28a629964d5e81b6032	en
dc.subject.classification	Engineering, Environmental	en
dc.subject.classification	Environmental Sciences	en
dc.subject.classification	Water Resources	en
dc.subject.other	CHEMICAL OPERATIONS - Coagulation	en
dc.subject.other	IONS - Absorption	en
dc.subject.other	BOUND WATER	en
dc.subject.other	CHEMICAL CONDITIONING METHODS	en
dc.subject.other	SEWAGE SLUDGES	en
dc.subject.other	SLUDGE DEWATERING	en
dc.subject.other	SEWAGE TREATMENT	en
dc.subject.other	polyelectrolyte	en
dc.subject.other	blood clotting	en
dc.subject.other	sewage treatment	en
dc.subject.other	sludge conditioning	en
dc.subject.other	sludge dewatering	en
dc.subject.other	theoretical study	en
dc.title	Bound water content of biological sludges in relation to filtration and dewatering	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	1987	en
heal.abstract	This paper presents the results of an extensive analytical investigation on the mechanisms involved in filtration of biological sludges by studying the changes in the 'bound water' content of activated and mixed digested sludges when they were subjected to several physical, and chemical processes. A new method for determining bound water in sludges, based on differential thermal analysis (DTA), was developed which proved reliable and fast. Water in sludges exist in two states, as 'free' or bulk water and as 'bound' water which is held by the solid state either by sorption on specific sites, i.e. functional groups of the proteins and other macromolecules and/or restricted within pores and capillaries. Water binding by sludge displayed similar behaviour to the absorption of ions. All chemical coagulants (FeCl3, AlCl3, FeSO4) and cationic polyelectrolytes resulted in a reduction of the specific resistance and the bound water content of the sludge which was due to the replacement of water molecules by the adsorbed coagulant. Heat treatment of activated and digested sludge at 130°C resulted in a reduction of bound water by 30% whereas freezing and thawing reduced bound water by 70%.This paper presents the results of an extensive analytical investigation on the mechanisms involved in filtration of biological sludges by studying the changes in the 'bound water' content of activated and mixed digested sludges when they were subjected to several physical, and chemical processes. A new method for determining bound water in sludges, based on differential thermal analysis (DTA), was developed which proved reliable and fast. Water in sludges exists in two states, as 'free' or bulk water and as 'bound' water which is held by the solid state either by sorption on specific sites, i. e. , functional groups of the proteins and other macromolecules and/or restricted within pores and capillaries. Water binding by sludge displayed similar behavior to the adsorption of ions. All chemical coagulants (FeCl//3, AlCl//3, FeSO//4) and cationic polyelectrolytes resulted in a reduction of the specific resistance and the bound water content of the sludge which was due to the replacement of water molecules by the adsorbed coagulant.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	Water Research	en
dc.identifier.isi	ISI:A1987L181700004	en
dc.identifier.volume	21	en
dc.identifier.issue	11	en
dc.identifier.spage	1319	en
dc.identifier.epage	1327	en