Investigation of Cr(III) removal from wastewater with the use of MBR combined with low-cost additives

Malamis, S; Katsou, E; Chazilias, D; Loizidou, M

dc.contributor.author	Malamis, S	en
dc.contributor.author	Katsou, E	en
dc.contributor.author	Chazilias, D	en
dc.contributor.author	Loizidou, M	en
dc.date.accessioned	2014-03-01T01:30:57Z
dc.date.available	2014-03-01T01:30:57Z
dc.date.issued	2009	en
dc.identifier.issn	0376-7388	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/19689
dc.subject	Adsorption	en
dc.subject	Chromium	en
dc.subject	Fouling	en
dc.subject	Ion-exchange	en
dc.subject	MBR	en
dc.subject	Minerals	en
dc.subject	Wastewater	en
dc.subject.classification	Engineering, Chemical	en
dc.subject.classification	Polymer Science	en
dc.subject.other	Batch filtration tests	en
dc.subject.other	Chemical precipitations	en
dc.subject.other	Combined systems	en
dc.subject.other	Elevated temperatures	en
dc.subject.other	Final effluents	en
dc.subject.other	High pH	en
dc.subject.other	Industrial waste waters	en
dc.subject.other	Initial chromium concentrations	en
dc.subject.other	Ion-exchange capacities	en
dc.subject.other	MBR	en
dc.subject.other	Membrane bioreactors	en
dc.subject.other	Mineral additions	en
dc.subject.other	Mineral additives	en
dc.subject.other	pH values	en
dc.subject.other	Removal efficiencies	en
dc.subject.other	Ultra-filtration membranes	en
dc.subject.other	Adsorption	en
dc.subject.other	Bentonite	en
dc.subject.other	Biochemical oxygen demand	en
dc.subject.other	Chemicals removal (water treatment)	en
dc.subject.other	Chromium	en
dc.subject.other	Chromium compounds	en
dc.subject.other	Clay minerals	en
dc.subject.other	Concentration (process)	en
dc.subject.other	Effluents	en
dc.subject.other	Environmental Protection Agency	en
dc.subject.other	Industrial water treatment	en
dc.subject.other	Ion exchange	en
dc.subject.other	Ion exchangers	en
dc.subject.other	Ions	en
dc.subject.other	Membrane fouling	en
dc.subject.other	Membranes	en
dc.subject.other	Metal recovery	en
dc.subject.other	Microfiltration	en
dc.subject.other	Mining	en
dc.subject.other	pH effects	en
dc.subject.other	Precipitation (chemical)	en
dc.subject.other	Silica	en
dc.subject.other	Silicate minerals	en
dc.subject.other	Ultrafiltration	en
dc.subject.other	Wastewater	en
dc.subject.other	Wastewater reclamation	en
dc.subject.other	Wastewater treatment	en
dc.subject.other	Zeolites	en
dc.subject.other	Minerals	en
dc.subject.other	bentonite	en
dc.subject.other	chromium	en
dc.subject.other	mineral	en
dc.subject.other	vermiculite	en
dc.subject.other	zeolite	en
dc.subject.other	adsorption	en
dc.subject.other	article	en
dc.subject.other	biofouling	en
dc.subject.other	bioreactor	en
dc.subject.other	filtration	en
dc.subject.other	heavy metal removal	en
dc.subject.other	industrial waste	en
dc.subject.other	ion exchange	en
dc.subject.other	pH	en
dc.subject.other	precipitation	en
dc.subject.other	priority journal	en
dc.subject.other	sludge	en
dc.subject.other	ultrafiltration	en
dc.subject.other	waste water	en
dc.subject.other	waste water management	en
dc.title	Investigation of Cr(III) removal from wastewater with the use of MBR combined with low-cost additives	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.memsci.2009.01.028	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.memsci.2009.01.028	en
heal.language	English	en
heal.publicationDate	2009	en
heal.abstract	This work investigated the removal of Cr(III) from wastewater with the use of a combined system of a membrane bioreactor (MBR) together with low-cost mineral additives. The additives employed were zeolite, bentonite and vermiculite. These minerals have high adsorption and ion-exchange capacity. Sludge from an MBR was enriched with an initial chromium concentration of 320 ppm and the pH value was adjusted in order to minimize chemical precipitation. Batch filtration tests were conducted using ultrafiltration membranes having a nominal pore size of 0.04 mu m. The results show that ultrafiltration membranes with no mineral addition Could remove significant Cr(III) from the final effluent with removal efficiencies ranging between 43.2 and 69.2%. The addition of specific mineral concentration could further increase the chromium removed from the final effluent, reaching very high removal efficiencies. The ion-exchange capacity of minerals followed the order bentonite > vermiculite > zeolite. The combined system of MBR with 10 g/l bentonite or 10 g/l vermiculite at pH 8.0 and MLSS = 4.5 g/l was able to produce a final effluent with Cr(III) concentrations of 0.003 and 0.010 ppm respectively which meets the recommended reuse guidelines of US EPA of 0.1 ppm required for long-term irrigation. At pH 5.5 the addition of 10 g/l of zeolite, vermiculite and bentonite achieved removal efficiencies of 81.5, 95.2 and 99.5% respectively with the latter condition resulting in a final effluent of 1.76 ppm. Furthermore, it was found that high pH and MLSS values and elevated temperatures favour the Cr(III) removal in this system. Sludge MLSS values above 6.0 g/l at pH 5.5 resulted in Cr(III) removal >68%, while pH values above 7 for MLSS = 4.5 g/l resulted in Cr(III) removal efficiencies >95%. The impact of the mineral addition on membrane fouling was also investigated. It was found that all minerals mitigate fouling and it follows the Order zeolite > bentonite > vermiculite. However, the high initial Cr(III) concentrations in sludge resulted in increased membrane fouling. The results show that this system of MBR combined with low-cost minerals can effectively remove chromium and can therefore be used to treat industrial wastewater to a level that can be lower than the US EPA limit of 0.1 ppm required for reuse applications, Provided that certain conditions are met. (C) 2009 Elsevier B.V. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	Journal of Membrane Science	en
dc.identifier.doi	10.1016/j.memsci.2009.01.028	en
dc.identifier.isi	ISI:000265503600002	en
dc.identifier.volume	333	en
dc.identifier.issue	1-2	en
dc.identifier.spage	12	en
dc.identifier.epage	19	en