Use Biofilters or Give Up Diary Products to Lessen Greenhouse Gases

Source: Pratt, C. et al. 2013. http://pubs.acs.org/doi/full/10.1021/es303225h

Dairy farms use ponds to collect effluent wash down from milking sheds. These ponds are a substantial source of methane. A methane biofilter can mitigate this problem because they contain methanotrophs that oxidize methane and convert it into water vapor and CO₂. The study concluded that volcanic soil biofilters are more adequate compared to compost biofilters because volcanic biofilters do not produce substantial amounts of N₂O which is a harsher greenhouse gas than methane. The big downside to biofilters is that CO₂ is produced, but CO₂ is not as harsh as methane. The upside to biofilters includes that they are self-maintaining systems needing minimal maintenance and the biomass that is growing on the filters can be harvested for fuel.

Pratt, C., Deslippe, J., and K. R. Tate. 2013. Testing a Biofilter Cover Design to Mitigate Dairy Effluent Pond Methane Emissions. Environ. Sci. Technol. 47: 526-532.