Biological removal of ions: Principles and applications

Tsezos, M

dc.contributor.author	Tsezos, M	en
dc.date.accessioned	2014-03-01T02:44:29Z
dc.date.available	2014-03-01T02:44:29Z
dc.date.issued	2007	en
dc.identifier.issn	10226680	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/31845
dc.subject	Bioprecipitation	en
dc.subject	Bioreduction	en
dc.subject	Biosorption	en
dc.subject	Metal	en
dc.subject	Metalloids	en
dc.subject	Radionuclides	en
dc.subject.other	Active biomass	en
dc.subject.other	Active process	en
dc.subject.other	Anoxic environment	en
dc.subject.other	Bio-precipitation	en
dc.subject.other	BIofilm reactors	en
dc.subject.other	Biological reactor	en
dc.subject.other	Biological reductions	en
dc.subject.other	Biological removal	en
dc.subject.other	Bioreduction	en
dc.subject.other	Bioreductions	en
dc.subject.other	Biosorbents	en
dc.subject.other	Carrier material	en
dc.subject.other	Desorption process	en
dc.subject.other	Fluidized bed reactors	en
dc.subject.other	Full scale	en
dc.subject.other	Immobilization process	en
dc.subject.other	Inorganic moieties	en
dc.subject.other	Insoluble hydroxides	en
dc.subject.other	Metal-organic complexes	en
dc.subject.other	Microbial biomass	en
dc.subject.other	Microbial cells	en
dc.subject.other	Microbial metabolism	en
dc.subject.other	Microenvironments	en
dc.subject.other	Moving bed	en
dc.subject.other	Organic molecules	en
dc.subject.other	Packed bed reactor	en
dc.subject.other	Rotating biological contactor	en
dc.subject.other	Sorption-desorption cycles	en
dc.subject.other	Species interactions	en
dc.subject.other	Stand -alone	en
dc.subject.other	Terminal electron acceptors	en
dc.subject.other	Toxic compounds	en
dc.subject.other	Treatment process	en
dc.subject.other	Treatment technologies	en
dc.subject.other	Water streams	en
dc.subject.other	Biofilms	en
dc.subject.other	Biomass	en
dc.subject.other	Biosorption	en
dc.subject.other	Cells	en
dc.subject.other	Chemical reactors	en
dc.subject.other	Complexation	en
dc.subject.other	Coordination reactions	en
dc.subject.other	Cost reduction	en
dc.subject.other	Desorption	en
dc.subject.other	Fluid catalytic cracking	en
dc.subject.other	Fluidization	en
dc.subject.other	Fluidized beds	en
dc.subject.other	Ion exchange	en
dc.subject.other	Ion exchangers	en
dc.subject.other	Ions	en
dc.subject.other	Metabolism	en
dc.subject.other	Packed beds	en
dc.subject.other	Pelletizing	en
dc.subject.other	Radioisotopes	en
dc.subject.other	Radiometry	en
dc.subject.other	Resins	en
dc.subject.other	Reusability	en
dc.subject.other	Technology	en
dc.subject.other	Toxicity	en
dc.subject.other	Cell immobilization	en
dc.title	Biological removal of ions: Principles and applications	en
heal.type	conferenceItem	en
heal.identifier.primary	10.4028/www.scientific.net/AMR.20-21.589	en
heal.identifier.secondary	http://dx.doi.org/10.4028/www.scientific.net/AMR.20-21.589	en
heal.publicationDate	2007	en
heal.abstract	Microbial cell - soluble species interactions can be part of technologies for the treatment of metal/metalloid and radionuclide bearing water streams in order to sequester the targeted species. Interactions of microbial cells and soluble targeted species include passive and active processes of metabolically inactive or active biomass, and result in the reduction of their mobility and toxicity. Different parts of the cell may sequester targeted species via processes such as complexation, chelation, coordination, ion exchange, precipitation and reduction. Collectively, these mechanisms have been referred to as sorption and the overall phenomenon as biosorption. The term biosorption is generally used to describe the passive interaction of microbial biomass with targeted species. The technologies based on these processes, lead to the set up of units, mainly in the form of packed bed reactors similar to the configuration of ion exchange resins reactors, placed at the end of a treatment process as a polishing stage. In order to maintain durability of the sorbent, the microbial cells harvested from different sources, are formulated into particles by way of immobilization - pelletization. In the early years of Biosorption, a significant effort was devoted to study the reusability of the sorbent by repeated sorption - desorption cycles, in order to reduce the operating cost of the technology. The availability of the biosorbent material, the reversibility of the desorption process, the presence of competing co-ions and organic molecules, posed significant scepticism and finally serious doubt about the industrial applicability of biosorption as a stand alone technology. However the mechanisms are active and present in biological reactors, and can contribute to overall species sequestering. Biological reactors based on active microbial biomass as alternative to passive sorption, exploit the self regenerating features of living biomass along with the traits of microbial metabolism. Active cells produce metabolites (i.e. EPS, simple inorganic moieties etc.) interacting chemically with the targeted species. The active biomass offers the additional attractive feature of forming biofilms on the surface of carrier materials allowing a natural way of cell immobilization. Different biofilm reactor configurations e.g. static or moving bed filters, fluidized bed reactors, rotating biological contactors support the development of biofilms. Conditions such as temperature, pH, presence of toxic compounds etc. should be considered in the applicability of the technology. Important metabolically mediated immobilization processes for metal/metalloid and radionuclide species are bioprecipitation and bioreduction. Bioprecipitation processes include the transformation of soluble species to insoluble hydroxides, carbonates, phosphates, sulfides or metal - organic complexes as a result of the microbial metabolism. In the case of biological reduction, the cells may use the species as terminal electron acceptors in anoxic environments to produce energy or reduce the toxicity of the cells microenvironment. Such processes form the basis for treatment technologies which are recently developed and applied both in pilot and full scale. © 2007 Trans Tech Publications.	en
heal.journalName	Advanced Materials Research	en
dc.identifier.doi	10.4028/www.scientific.net/AMR.20-21.589	en
dc.identifier.volume	20-21	en
dc.identifier.spage	589	en
dc.identifier.epage	596	en