Study of anaerobic biological wastewater treatment using membrane technology

Πλεύρη, Αργυρώ; Plevri, Argyro

dc.contributor.author	Πλεύρη, Αργυρώ	el
dc.contributor.author	Plevri, Argyro	en
dc.date.accessioned	2024-09-05T09:57:40Z
dc.date.available	2024-09-05T09:57:40Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/60135
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.27831
dc.rights	Default License
dc.subject	AnMBR	el
dc.subject	Wastewater treatment	el
dc.subject	Biogas production	el
dc.subject	Modeling	el
dc.subject	Circular economy	el
dc.subject	Τεχνολογία μεμβρανών	el
dc.subject	Τεχνικές επεξεργασίας λυμάτων	el
dc.subject	Βιώσιμες περιβαλλοντικές πρακτικές	el
dc.subject	Αναερόβιοι Βιοαντιδραστήρες Μεμβρανών (AnMBR)	el
dc.subject	Λύματα υψηλού ορφανικού φορτίου	el
dc.title	Study of anaerobic biological wastewater treatment using membrane technology	en
dc.title	Διερεύνηση της αναερόβιας βιολογικής επεξεργασίας λυμάτων με χρήση μεμβρανών	el
dc.contributor.department	Sanitary Engineering Laboratory	el
heal.type	doctoralThesis
heal.classification	Environmental Technology	en
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2023-11-24
heal.abstract	Amidst the accelerating global urgency for sustainable environmental practices, wastewater treatment techniques, like the Anaerobic Membrane Bioreactor (AnMBR), are rising to the forefront of technological innovations. AnMBR stands out not just for its unmatched energy efficacy in treating wastewater but also for its secondary, yet equally vital, role in generating biogas—a sustainable energy alternative. But like all groundbreaking innovations, the AnMBR too faces its share of challenges. The system's reliance on anaerobic bacteria, which is notorious for its slow growth rate, combined with performance variability due to fluctuating organic loads, poses real-world operational challenges. A detailed 3.5-year research initiative aimed to dissect these challenges. To investigate the performance of anaerobic wastewater treatment through the incorporation of membrane technology, a 40 L laboratory scale AnMBR with a flat sheet submerged membrane along with a 40 L reservoir for trapping and measuring the biogas produced have been installed and set in operation. Specifically, through long term bench scale experiments, the impact that different temperatures and also different operating conditions have on the efficiency of AnMBR was evaluated. The efficiency of the AnMBR was investigated, in the temperature range 14-26oC, opeating at four different hydraulic retention times (HRTs) that were 2 d, 1 d, 12 h and 6 h. Each HRT is divided into two different temperature ranges corresponding to winter and summer conditions. With a decrease in HRT, there was a decline in effluent quality and an increase in membrane fouling. During the summer, at an average temperature of 24°C, the AnMBR produced permeate water with an average Chemical Oxygen Demand (COD) of 51±5 mg·L-1 at an HRT of 2 days. The effluent COD increased to 67±6 mg·L-1 for an HRT of 1 day and 91±4 mg·L-1 for an HRT of 12 hours, under the same temperature conditions. At an HRT of 6 hours, the COD removal efficiency was further reduced, with values of 177±18 for winter and 121±8 for summer. In general, the findings were multifaceted: while the treatment offered by shorter HRTs is attractive in terms of cost reduction, it occasionally triggered spikes in COD levels, more so during the colder months. Conversely, the balmy Mediterranean summers favored the AnMBR operation, with 12-hour HRTs been sufficient to achieve both short treatment time and efficiency. Yet, the winter season brought its set of challenges, with efficiency metrics sometimes toeing the line of regulatory compliance. To bridge these operational and seasonal inconsistencies, the study investigated performance-enhancing by FeCl₃ addition. When administered at a Fe+3 dose, within the 25 mg/L to 30 mg/L concentrations range, this chemical additive showcased a slight enhancement in COD removal efficiencies. Its integration also heralded a substantial reduction in effluent Total Phosphorus (TP) concentrations, effectively sidelining the membrane fouling—an issue that could drastically curtail AnMBR's operational life and efficiency. Specifically, the addition of 25 mg FeCl3 L -1 improved the performance of the AnMBR. Average effluent COD concentrations without FeCl3 addition were 177±21 mg/L, while after the addition of 25 mg FeCl3 L -1 and 30 mg FeCl3 L-1 COD decreased to 147±8 mg/L and 149±11 mg/L, respectively. Moreover, effluent TP decreased by 75% with the dosage of 25 mg FeCl3 L -1 and was almost completely removed with 30 mg FeCl3L-1. The membrane performance was slightly improved by FeCl3 dosing while biogas production was not affected by iron addition. To further evaluate the energy efficiency of AnMBR, an energy balance was conducted based on the results obtained from the operation of the lab-scale AnMBR throughout this investigation. According to the findings, an energy balance was found favorable for all the scenarios tested. The total electrical energy that can be extracted from AnMBR for the winter and the summer periods was found to be in the range of 0.3 – 0.8 KWh/KgCODrem and 0.4 – 0.9 KWh/KgCODrem, respectively. Within the context of this research a mathematical model was applied to simulate AnMBR operation. The Anaerobic Digestion Model ADM1, integrated within the versatile Matlab/Simulink platform and a comprehensive Global Sensitivity Analysis (GSA) were undertaken. This analytical approach demystified the complex operational dynamics intrinsic to AnMBR systems. The model was calibrated with real-world experimental data for 2-day winter HRTs, especially in parameters like Qgas. Following model calibration, computational predictions, when evaluated across the five distinct operational scenarios, largely mirrored experimental findings. However, certain runs, such as the 1-day HRT during both seasons, presented notable variations. Based on the findings of this PhD thesis, a clear narrative emerges: The AnMBR system, while holding immense potential as a dual-purpose solution for wastewater treatment and sustainable energy generation, operates within a complex web of variables. Whether it's the seasonal temperature variations, the fine-tuning of HRTs, or the strategic deployment of additives like FeCl₃, achieving optimal performance requires a harmonious alignment of all these factors. This study, by juxtaposing empirical findings with computational modeling, charts a roadmap for both researchers and practitioners, offering a holistic blueprint for harnessing the full potential of AnMBR systems in varied real-world settings.	el
heal.sponsor	This research is co-financed by Greece and the European Union (European Social Fund- ESF) through the Operational Programme «Human Resources Development, Education and Lifelong Learning» in the context of the project “Strengthening Human Resources Research Potential via Doctorate Research – 2 nd Cycle” (MIS-5000432), implemented by the State Scholarships Foundation (ΙΚΥ).	en
heal.advisorName	Μαμάης, Δανιήλ	el
heal.advisorName	Mamais, Daniel	en
heal.committeeMemberName	Mamais, Daniel
heal.committeeMemberName	Noutsopoulos, Constantinos	en
heal.committeeMemberName	Malamis, Simeon	en
heal.committeeMemberName	Lyberatos, Gerasimos	en
heal.committeeMemberName	Melidis, Paraschos	en
heal.committeeMemberName	Stasinakis, Athanasios	en
heal.committeeMemberName	Fountoulakis, Michael	en
heal.committeeMemberID	Μαμάης, Δανιήλ	el
heal.committeeMemberID	Νουτσόπουλος, Κωνσταντίνος	el
heal.committeeMemberID	Μαλαμής, Συμεών	el
heal.committeeMemberID	Λυμπεράτος, Γεράσιμος	el
heal.committeeMemberID	Κωνσταντίνος, Μελίδης	el
heal.committeeMemberID	Στασινάκης, Αθανάσιος	el
heal.committeeMemberID	Φουντουλάκης, Μιχαήλ	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Πολιτικών Μηχανικών	el
heal.academicPublisherID	ntua
heal.numberOfPages	372 σ.	el
heal.fullTextAvailability	false