Arizona State University

Oz Optics Limited

Hyung-Sool Lee

Bruce E Rittmann

Junseok Chae

César I Torres

Seokheun Choi

There is provided a biofilm capacitance microbial electrochemical cell (MEC) sensor to measure organic carbon in water and wastewater rapidly and accurately, represented by the 5-day biochemical oxygen demand (BOD). The MEC runs at charging (open circuit) and discharging (close circuit) conditions alternately to improve the sensitivity, response time and accuracy. The detectable BODconcentrations with the biofilm-capacitance MEC range from 5 to 250 mg/L (R&#x3e;0.9). The MEC sensor enables BODmeasurements at every 2 minutes (1 minute charging and 1 minute discharging), indicating semi-continuous quantification of organic carbon in water and wastewater.

Biocapacitive BOD sensor

The present invention relates generally to a process that helps alleviate the pH gradient between anode and cathode compartments in any biological fuel cell or electrolytic cell configuration in which a pH gradient between anode and cathode is limiting the voltage efficiency. By providing acid to the cathode compartment in the form of CO, the pH gradient is reduced and voltage efficiency and power output are increased. In one embodiment, carbon dioxide produced in the anode chamber is recycled to the cathode chamber.

Bicarbonate and carbonate as hydroxide carriers in a biological fuel cell

A microbial fuel cell includes an anode portion having an anode and a cathode portion having a cathode. The anode is configured to support an electrically conductive biofilm matrix. A cation exchange membrane is positioned between the anode and the cathode. The anode portion and the cation exchange membrane define an anode chamber having a volume of between about 1 &#x3bc;L and about 100 &#x3bc;L and configured to receive an anolyte. The cathode portion and the cation exchange membrane define a cathode chamber having a volume of between about 1 &#x3bc;L and about 100 &#x3bc;L and configured to receive a catholyte. The microbial fuel cell is configured to achieve a Coulombic efficiency of at least 30% and/or a power density of at least of 4.7 &#x3bc;W/cm. The microbial fuel cell is a microelectromechanical system and can be fabricated in an automated production process.

Growing community of inventors

Waterloo, Canada

Hyung-Sool Lee