AUB ScholarWorks

The combined effect of step-feed and recycling on RBC performance

Show simple item record Ayoub G.M. Saikaly P.
dc.contributor.editor 2004 2017-10-04T11:04:49Z 2017-10-04T11:04:49Z 2004
dc.identifier 10.1016/j.watres.2004.04.013
dc.identifier.issn 00431354
dc.description.abstract The effect of step-feed and recycling on the efficiency of treatment in rotating biological contractors (RBCs) was investigated. Experiments were conducted on a RBC system consisting of two three-stage units. The two units were operated in parallel, one unit as a control with a single feed point and the other in a step-feed mode. Seven experimental runs were conducted, using a simple synthetic wastewater, in which hydraulic loading rates were maintained constant at about 0.094m3-m2d and variable COD concentrations (800-1200mg-L), NH3-N concentrations (104-116mg-L), step-feed ratios (60-40 and 70-30), and recirculation modes. Results indicate that improvements in the treatment efficiencies of RBC systems may be attained by operating the system in a step feed mode as compared to a single point feed mode. Further improvements may also be obtained by inducing effluent recirculation to the inlet stage. In both cases, levels of improvement have shown to be more pronounced for NH3-N removals and DO residual concentrations as compared to COD removals. The combined effect of step feed and recirculation of system effluent on NH3-N removal efficiencies is appreciable. Comparing removal efficiencies between the control, step feed and the combined step-feed-recirculation modes shows an increase of about 26percent. For COD removals, the effect is not that pronounced as the results for the combined modes of operation indicate a limited increase in overall removal efficiency of about 3percent. Supplementing step feed by a recircutation system also markedly improved DO residuals in stages 1 and 2 and to a lower extent in stage 3 of the system. Changing the ratio in the step feed system from 60-40percent to 70-30percent exhibited a slight improvement in NH3-N removal efficiencies as well as improved residual DO concentrations but very limited effect on COD removals. The use of a simple synthetic wastewater in the experiments may limit extrapolation of the findings to actual operation. © 2004 Elsevier Ltd. All rights reserved.
dc.format.extent Pages: (3009-3016)
dc.language English
dc.publisher OXFORD
dc.relation.ispartof Publication Name: Water Research; Publication Year: 2004; Volume: 38; no. 13; Pages: (3009-3016);
dc.source Scopus
dc.title The combined effect of step-feed and recycling on RBC performance
dc.type Article
dc.contributor.affiliation Ayoub, G.M., Dept. of Civ. and Environ. Eng., American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon
dc.contributor.affiliation Saikaly, P., Dept. of Civ. and Environ. Eng., University of Cincinnati, Cincinnati, OH 45221-0071, United States
dc.contributor.authorAddress Ayoub, G.M.; Dept. of Civ. and Environ. Eng., American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon; email:
dc.contributor.authorCorporate University: American University of Beirut; Faculty: Faculty of Engineering and Architecture; Department: Civil and Environmental Engineering;
dc.contributor.authorDepartment Civil and Environmental Engineering
dc.contributor.authorFaculty Faculty of Engineering and Architecture
dc.contributor.authorInitials Ayoub, GM
dc.contributor.authorInitials Saikaly, P
dc.contributor.authorReprintAddress Ayoub, GM (reprint author), Amer Univ Beirut, Dept Civil and Environm Engn, POB 110236, Beirut, Lebanon.
dc.contributor.authorResearcherID Saikaly, Pascal-G-7958-2014
dc.contributor.authorUniversity American University of Beirut
dc.description.cited [APHA-AWWA-WEF A. P. H. A. A. W. W. A. W. E. Federation], 1995, STAND METH EX WAT WA; GUARINO CF, 1977, 50 ANN WPCF C PHIL P, P1; ITO K, 1980, P 1 NAT S RBC TECHN, P1165; JANCZUKOWICZ W, 1992, BIORESOURCE TECHNOL, V42, P241, DOI 10.1016-0960-8524(92)90027-U; KHARAJIAN H, 1984, P 2 INT C FIX FILM B, V1, P709; KLEES R, 1992, WATER SCI TECHNOL, V26, P545; Metcalf and Eddy Inc., 1991, WAST ENG TREATM DISP; NEU KE, 1994, WATER SCI TECHNOL, V29, P197; RUSTEN B, 1984, 2 INT C FIX FILM BIO, V1, P754; Saikaly P., 2001, THESIS AM U BEIRUT B; Surampalli RY, 1997, WATER AIR SOIL POLL, V98, P1; WATNABE Y, 1995, WATER SCI TECH, V31, P195
dc.description.citedCount 20
dc.description.citedTotWOSCount 16
dc.description.citedWOSCount 12
dc.format.extentCount 8
dc.identifier.coden WATRA
dc.identifier.pubmedID 15261538
dc.identifier.scopusID 3142688273
dc.relation.ispartOfISOAbbr Water Res.
dc.relation.ispartOfIssue 13
dc.relation.ispartofPubTitle Water Research
dc.relation.ispartofPubTitleAbbr Water Res.
dc.relation.ispartOfVolume 38
dc.source.ID WOS:000223002900005
dc.type.publication Journal
dc.subject.otherAuthKeyword Ammonia nitrogen
dc.subject.otherAuthKeyword Chemical oxygen demand
dc.subject.otherAuthKeyword Dissolved oxygen
dc.subject.otherAuthKeyword Recirculation
dc.subject.otherAuthKeyword Rotating biological contactors
dc.subject.otherAuthKeyword Step feed
dc.subject.otherChemCAS ammonia, 14798-03-9, 51847-23-5, 7664-41-7
dc.subject.otherChemCAS nitrogen, 7727-37-9
dc.subject.otherChemCAS Ammonia, 7664-41-7
dc.subject.otherChemCAS Nitrogen, 7727-37-9
dc.subject.otherChemCAS Oxygen, 7782-44-7
dc.subject.otherIndex Extrapolation
dc.subject.otherIndex Hydraulics
dc.subject.otherIndex Recycling
dc.subject.otherIndex Rotating biological contractors (RBC)
dc.subject.otherIndex Synthetic wastewater
dc.subject.otherIndex Wastewater treatment
dc.subject.otherIndex ammonia
dc.subject.otherIndex dissolved oxygen
dc.subject.otherIndex nitrogen
dc.subject.otherIndex biological treatment
dc.subject.otherIndex chemical oxygen demand
dc.subject.otherIndex dissolved gas
dc.subject.otherIndex pollutant removal
dc.subject.otherIndex wastewater treatment
dc.subject.otherIndex article
dc.subject.otherIndex chemical oxygen demand
dc.subject.otherIndex concentration (parameters)
dc.subject.otherIndex heavy metal removal
dc.subject.otherIndex priority journal
dc.subject.otherIndex recycling
dc.subject.otherIndex waste water
dc.subject.otherIndex Ammonia
dc.subject.otherIndex Bioreactors
dc.subject.otherIndex Nitrogen
dc.subject.otherIndex Oxygen
dc.subject.otherIndex Water Movements
dc.subject.otherIndex Water Purification
dc.subject.otherWOS Engineering, Environmental
dc.subject.otherWOS Environmental Sciences
dc.subject.otherWOS Water Resources

Files in this item

Files Size Format View

There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record

Search AUB ScholarWorks


My Account