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Accueil du site → Doctorat → États-Unis → 2014 → Microbial fuel cell for wastewater treatment : heavy metal removal, sewage sludge treatment, and its potential application in wastewater reuse in irrigation

Oregon State University (2014)

Microbial fuel cell for wastewater treatment : heavy metal removal, sewage sludge treatment, and its potential application in wastewater reuse in irrigation

Abourached, Carole

Titre : Microbial fuel cell for wastewater treatment : heavy metal removal, sewage sludge treatment, and its potential application in wastewater reuse in irrigation

Auteur : Abourached, Carole

Université de soutenance : Oregon State University

Grade : Doctor of Philosophy (Ph. D.) in Biological and Ecological Engineering 2014

Résumé
While water scarcity and energy demand are continuously increasing in the world, alternative sources are needed to meet the requirement of a growing population. Microbial Fuel Cell (MFC) is a sustainable technology that converts organic matter in wastewater into electricity, thus it can be a potential alternative source for water and energy. Although significant advances in MFC research have been accomplished in the last few years, improvement in power generation and decrease in material cost are still necessary to bring MFC into practical application. The main goal of this work is to contribute in making MFC more applicable in industrial and municipal facilities, and to evaluate its scaling up for real world application. First, heavy metal removal by MFC was studied. Simultaneous high power generation (3.6 W/m²) and high Cd (90%) and Zn (97%) removal efficiencies were achieved in a single chamber air-cathode microbial fuel cell (MFC). The maximum tolerable concentrations (MTCs) that did not affect power output were 200 μM for Cd and 400 μM for Zn. Gradual increase of metals concentrations lead to much slower reduction in voltage output. Biosorption and sulfides precipitation are the major mechanisms for the heavy metal removal in the MFCs. This study expanded MFC application for the treatment of industrial waste streams containing both organic matter and heavy metals. Then, enhancement of sewage treatment by MFC was investigated. Although energy costs required for wastewater treatment are offset by methane production from sewage sludge treatment, not all the energy is extracted from sludge and effluents need additional treatment, such as aeration, to meet environmental regulations. MFC has been used to convert organic matter in sludge into electricity. However, improvement of power production is still needed. We studied the effect of fermentation pre-treatment and a novel design cloth-electrode assembly microbial fuel cell (CEA-MFC) on electricity production from sewage sludge. Fermentation pretreatment of sludge effectively increased the soluble organic matter and improved the reactor performance. The optimum fermentation time was 96 hours and resulted in maximum power density of 1200 mW/m², which is 275% higher than those previously reached in MFC systems. Thus, MFCs could be added successfully to existing wastewater treatment infrastructure for more efficient energy conversion. Last, we examined the feasibility of using MFC technology for field application before irrigation. Although wastewater use in irrigation resolves the problem of water shortage, it also presents a threat to the environment. Thus, wastewater treatment before irrigation is needed. MFC has potential to treat wastewater and generate electricity simultaneously while leaving low residual concentrations of nutrients in the effluent. In order to investigate the economic returns from using MFC to treat wastewater before agricultural application, a case study involving food wastewater in a semi-arid region was considered. The various profits from treated water, produced electricity and nutrients in effluent were evaluated. The effluent water quality was compared to environmental regulations. The analysis showed that MFC is a promising technology that can resolve issues of water and energy shortage and thus can ensure food s

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Page publiée le 6 novembre 2014, mise à jour le 7 mars 2019