Laboratory and field tests using microbial electrolysis cells for hydrogen production from agricultural and domestic wastewaters

Microbial electrolysis cells (MECs) are a new method for electrochemical hydrogen production at the cathode based on bacterial electrolysis of organic matter at the anode. The translation of laboratory findings to the field presents several challenges in terms of determining the suitability of wastewaters for treatment (pH, organic matter concentration, and conductivity), architectures needed (scalability of electrode designs, flow through the reactor), variability in conditions (temperature, flow, and composition of the wastewater, and gas evolution and capture. We report here on the first ever translation of laboratory studies to the field using MECs for recovery of energy as hydrogen gas from wastewaters. Several different agricultural wastewaters were first evaluated in the laboratory for electricity generation in a microbial fuel cell, and then they were used for current generation in an MEC. In order to examine the feasibility of the MEC process for an actual wastewater at a larger scale, chose one wastewater type, and we designed and built a 1000 liter pilot scale reactor. The reactor was deployed to a test site in the Napa Valley in California (Napa Wine Company, Oakville, CA). In this talk we will present our findings on the reactor tests begun in September, 2009.