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dc.contributor.advisorLeiknes, TorOve
dc.contributor.authorCheng, Tuoyuan
dc.date.accessioned2016-05-12T06:10:34Z
dc.date.available2017-05-12T00:00:00Z
dc.date.issued2016-05
dc.identifier.citationCheng, T. (2016). Polishing of Anaerobic Secondary Effluent and Symbiotic Bioremediation of Raw Municipal Wastewater by Chlorella Vulgaris. KAUST Research Repository. https://doi.org/10.25781/KAUST-VDSK8
dc.identifier.doi10.25781/KAUST-VDSK8
dc.identifier.urihttp://hdl.handle.net/10754/609122
dc.description.abstractTo assess polishing of anaerobic secondary effluent and symbiotic bioremediation of primary effluent by microalgae, bench scale bubbling column reactors were operated in batch modes to test nutrients removal capacity and associated factors. Chemical oxygen demand (COD) together with oil and grease in terms of hexane extractable material (HEM) in the reactors were measured after batch cultivation tests of Chlorella Vulgaris, indicating the releasing algal metabolites were oleaginous (dissolved HEM up to 8.470 mg/L) and might hazard effluent quality. Ultrafiltration adopted as solid-liquid separation step was studied via critical flux and liquid chromatography-organic carbon detection (LC-OCD) analysis. Although nutrients removal was dominated by algal assimilation, nitrogen removal (99.6% maximum) was affected by generation time (2.49 days minimum) instead of specific nitrogen removal rate (sN, 20.72% maximum), while phosphorus removal (49.83% maximum) was related to both generation time and specific phosphorus removal rate (sP, 1.50% maximum). COD increase was affected by cell concentration (370.90 mg/L maximum), specific COD change rate (sCOD, 0.87 maximum) and shading effect. sCOD results implied algal metabolic pathway shift under nutrients stress, generally from lipid accumulation to starch accumulation when phosphorus lower than 5 mg/L, while HEM for batches with initial nitrogen of 10 mg/L implied this threshold around 8 mg/L. HEM and COD results implied algal metabolic pathway shift under nutrients stress. Anaerobic membrane bioreactor effluent polishing showed similar results to synthetic anaerobic secondary effluent with slight inhibition while 4 symbiotic bioremediation of raw municipal wastewater with microalgae and activated sludge showed competition for ammonium together with precipitation or microalgal luxury uptake of phosphorus. Critical flux was governed by algal cell concentration for ultrafiltration membrane with pore size of 30 nm, while ultrafiltration membrane rejected most biopolymers (mainly polysaccharides). Further research would focus on balancing cell growth, specific nutrients removal, and specific COD change by utilizing rotating biological contactor.
dc.language.isoen
dc.subjectEffluent Polishing
dc.subjectPhycoremediation
dc.subjectChlorella Vulgaris
dc.subjectUltrafiltration
dc.subjectOil and Grease
dc.titlePolishing of Anaerobic Secondary Effluent and Symbiotic Bioremediation of Raw Municipal Wastewater by Chlorella Vulgaris
dc.typeThesis
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Division
dc.rights.embargodate2017-05-12
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberGhaffour, NorEddine
dc.contributor.committeememberWei, Chun-Hai
thesis.degree.disciplineEnvironmental Science and Engineering
thesis.degree.nameMaster of Science
dc.rights.accessrightsAt the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis became available to the public after the expiration of the embargo on 2017-05-12.
refterms.dateFOA2017-05-12T00:00:00Z


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