Date of Award

Spring 1-1-2015

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Civil, Environmental & Architectural Engineering

First Advisor

Zhiyong Ren

Second Advisor

JoAnn Silverstein

Third Advisor

Karl Linden

Abstract

Wastewater treatment is a hallmark of advanced society and has evolved throughout history to improve treatment efficiency while reducing harmful effects to humans and surrounding ecosystems. The water-energy nexus is no more apparent than in wastewater treatment and much work is being done currently to reduce the energy footprint of the industry. Anaerobic technologies are at the forefront of this energy revolution because they are capable of producing energy products while performing treatment. One such anaerobic technology is the bioelectrochemical system (BES).

Exoelectrogenic bacteria in BESs oxidize organics while producing direct electrical current. While much work has been done in the field, until now, a bottleneck to BES deployment has been the lack of a scalable reactor configuration. In this study a new compact and high performance spiral wound microbial fuel cell (a type of BES) configuration was developed for wastewater treatment. The 3” long configuration showed high power output of 170 W/m3 treated (effective reactor volume), low internal resistances of under 1Ω (ohmic), high electrode surface area to volume ratios of 700 m2/m3, and treatment capacity of 9.01 kgCOD/day. An automated electrolyte feeding system was also developed as a part of this study to maintain the highest possible system performance during experiments. Power output and hydraulic dead space both increased with electrode packing density, which is a new insight for the spiral wound design.

The manufacturing methods developed for spiral wound BES modules were successfully applied to microbial capacitive deionization (MCD) for oil and gas produced water treatment. 40” long reactors were built with the aid of a custom machine and maximum power and current outputs of 89 W/m3 and 228mA were achieved while removing over 68% of the COD in real produced water. The large scale reactor removed 10.2 gTDS/day although external power was required for the integrated desalination process due to a design error. Custom monitoring and control systems were also developed for the MCD system with a focus on operational simplification for field deployment. As a part of ongoing work, material and process improvements can be made to improve the energy efficiency of the desalination system.

Share

COinS