Bioelectrochemical Systems: Microbiology, Catalysts, Processes and Applications

Yuan, Heyang

Bioelectrochemical Systems: Microbiology, Catalysts, Processes and Applications

dc.contributor.author	Yuan, Heyang	en
dc.contributor.committeechair	He, Zhen	en
dc.contributor.committeemember	Morris, Amanda J.	en
dc.contributor.committeemember	Edwards, Marc A.	en
dc.contributor.committeemember	Pruden, Amy	en
dc.contributor.department	Civil and Environmental Engineering	en
dc.date.accessioned	2017-11-02T08:00:16Z	en
dc.date.available	2017-11-02T08:00:16Z	en
dc.date.issued	2017-11-01	en
dc.description.abstract	The treatment of water and wastewater is energy intensive, and there is an urgent need to develop new approaches to address the water-energy challenges. Bioelectrochemical systems (BES) are energy-efficient technologies that can treat wastewater and simultaneously achieve multiple functions such as energy generation, hydrogen production and/or desalination. The objectives of this dissertation are to understand the fundamental microbiology of BES, develop cost-effective cathode catalysts, optimize the process engineering and identify the application niches. It has been shown in Chapter 2 that electrochemically active bacteria can take advantage of shuttle-mediated EET and create optimal anode salinities for their dominance. A novel statistical model has been developed based on the taxonomic data to understand and predict functional dynamics and current production. In Chapter 3, 4 and 5, three cathode catalyst (i.e., N- and S- co-doped porous carbon nanosheets, N-doped bamboo-like CNTs and MoS2 coated on CNTs) have been synthesized and showed effective catalysis of oxygen reduction reaction or hydrogen evolution reaction in BES. Chapter 6, 7 and 8 have demonstrated how BES can be combined with forward osmosis to enhance desalination or achieve self-powered hydrogen production. Mathematical models have been developed to predict the performance of the integrated systems. In Chapter 9, BES have been used as a research platform to understand the fate and removal of antibiotic resistant genes under anaerobic conditions. The studies in this dissertation have collectively demonstrated that BES may hold great promise for energy-efficient water and wastewater treatment.	en
dc.description.abstractgeneral	Water and energy are prerequisites to life. Every day, a lot of energy and money are spent on treating wastewater and producing fresh water. Bioelectrochemical systems (BES) are new technologies that can treat water and wastewater with low energy consumption. BES typically consist of an anode (where microorganisms break down organic matter) and a cathode, and work like a battery. Currently, BES are only studied in laboratories and not applied in real-world situations, because the performance needs to be improved and fundamentals remain to be better understood. The studies in this dissertation aim to address these problems and make BES toward practice. It has been shown in Chapter 2 that, under high salinity, some bacteria grow faster in the anode and the BES can produce higher electricity. It is difficult to understand the roles of every bacterium with current molecular techniques, and thus statistical methods are applied to estimate their possible functions. In Chapter 3, 4 and 5, three materials have been fabricated and functioned as the catalysts for electricity generation. Chapter 6, 7 and 8 have demonstrated how BES can be combined with forward osmosis, a spontaneous water diffusion process, to enhance desalination or achieve self-powered hydrogen production. Mathematical equations have been combined to simulate the process of biological metabolisms, water diffusion and ion migration. In Chapter 9, BES have been shown to remove antibiotic resistant gene, an emerging contaminant caused by the excessive use of antibiotics. The studies in this dissertation have collectively demonstrated that BES may be the answer to future water and wastewater treatment.	en
dc.description.degree	Ph. D.	en
dc.format.medium	ETD	en
dc.identifier.other	vt_gsexam:12898	en
dc.identifier.uri	http://hdl.handle.net/10919/79910	en
dc.publisher	Virginia Tech	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	environmental engineering	en
dc.subject	bioelectrochemical systems	en
dc.subject	wastewater treatment	en
dc.subject	desalination	en
dc.subject	microbial community	en
dc.subject	antibiotic resistance genes	en
dc.subject	catalytic materials	en
dc.title	Bioelectrochemical Systems: Microbiology, Catalysts, Processes and Applications	en
dc.type	Dissertation	en
thesis.degree.discipline	Civil Engineering	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	doctoral	en
thesis.degree.name	Ph. D.	en