I-Corps: Microbial Photoelectrochemical Hybrid System for Wastewater Treatment and Hydrogen Generation

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

With the drastic increase of human population, there is an ever-growing demand for energy and clean water for the continuous economic growth and suitable inhabitation on earth. Over the years, the federal government has applied distinct strategies to address these two needs separately: the municipal wastewater is collected by local wastewater plants for purification and subsequent reuse as reclaimed water, while the energy source is mainly based on natural gas, and crude oil. Apparently, these two strategies are decoupled. Million tons of wastewater are produced from industrial and agricultural operations each year, and about 25 billion US dollars are spent annually for wastewater treatment in the United States alone. Meanwhile, the use of natural gas/petroleum generates a lot of greenhouse gas and toxic chemicals, which pose a serious threat to the environment, and also leads to additional cost to treat the pollution. There is an urgent need to employ energy-efficient processes for wastewater treatment, and simultaneously recover the "wasted energy" contained as organic matters in wastewater. Microbial fuel cell technology represents a novel approach to produce bioelectricity and treat wastewater simultaneously has drawn significant attention worldwide. The key innovation of the proposed microbial photoelectrochemical device/technology is the successful demonstration of hydrogen generation (instead of bioelectricity) in a sustainable manner using sunlight and municipal wastewater as the only energy sources. The microbial photoelectrochemical cell device is a system that can remove soluble chemical oxygen demand (SCOD) in wastewater and simultaneously recover the "wasted energy" stored in the organic wastes for photochemical generation of hydrogen gas, a chemical fuel with high energy density. This team has demonstrated the feasibility of hydrogen gas production in a lab-scale microbial photoelectrochemical device using municipal wastewater and sunlight as the sole energy sources. It represents not only a brand new approach to address the renewable energy needs for U.S., but also an emerging business opportunity for U.S.. The U.S. is among the world's largest producers of activated sludge (from wastewater). There are more than 16000 wastewater treatment facilities nationwide, and spend billions of dollars per year to treat water. A successful microbial photoelectrochemical system can efficiently convert wastewater into commercially valuable chemical fuels. The device can be readily transferred to the market place by forming partnerships or establishing collaborations with these existing microbial technology companies such as in-state municipal wastewater treatment facility, food and beverage industry, farms and water industry.