Sewage treatment is currently an expensive process but a new discovery has allowed them to cut the cost in half and also create renewable natural gas. This process was described by the Washington State University team in the Chemical Engineering Journal. They produced 200% more natural gas and cut the cost by 50% in comparison to the current process. “This technology basically converts up to 80% of the sewage sludge into something valuable,” said Professor Birgitte Ahring of WSU’s School of Chemical Engineering and Bioengineering, and one of the authors of the paper.
The renewable gas that is being produced can be used like any other fossil fuel for heating, electricity, and transportation without the high climate effect that fossil fuels have. Wastewater treatment facilities are said to be very bad for the environment both from emissions and what they produce. The team pretreated the sludge that the plants produce which caused the cost of sewage treatment to go down from $494 to $253 per ton of dry solids.
The team had used a bacterial strain to achieve this to convert the gas to methane and then learned that the result was 99% pure methane “This (bacterial strain) bug doesn’t need anything—it is a workhorse,” said Ahring in a news release. “It doesn’t need organic additives or a lot of nursing. It does well with water and a vitamin pill.” The team believes that this process should become widespread to all sewage treatment plants.
