Using airborne technology to quantify and apportion emissions of CH4 and NH3 from feedlots

Abstract

A novel airborne approach using the latest technology in concentration measurements of methane (CH4) and ammonia (NH3), with quantum cascade laser gas analysers (QCLAs) and high-resolution wind, turbulence and other atmospheric parameters integrated into a low- and slow-flying modern airborne platform, was tested at a 17 000 head feedlot near Charlton, Victoria, Australia, in early 2015. Aircraft flights on 7 days aimed to define the lateral and vertical dimensions of the gas plume above and downwind of the feedlot and the gas concentrations within the plume, allowing emission rates of the target gases to be calculated. The airborne methodology, in the first instance, allowed the emissions to be qualitatively apportioned to individual rows of cattle pens, effluent ponds and manure piles. During each flight, independent measurements of emissions were conducted by ground-based inverse-dispersion and eddy covariance techniques, simultaneously. The aircraft measurements showed good agreement with earlier studies using more traditional approaches and the concurrent ground-based measurements. It is envisaged to use the aircraft technology for determining emissions from large-scale open grazing farms with low cattle densities. Our results suggested that this technique is able to quantify emissions from various sources within a feedlot (pens, manure piles and ponds), as well as the whole feedlot. Furthermore, the airborne technique enables tracing emissions for considerable distances downwind. In the current case, it was possible to detect elevated CH4 to at least 25 km and NH3 at least 7 km downwind of the feedlot.

Emissions of volatile organic compounds (VOCs) from concentrated animal feeding operations (CAFOs): chemical compositions and separation of sources

“…But, waste cleaning time/practices in the facility were unknown, owing to no access to the facility. Previous mobile and aircraft measurements have also observed enhancements of NH 3 and CH 4 concentrations downwind of animal pens in cattle feedlots (Miller et al, 2015;Hacker et al, 2016). The time variations of two VOCs, acetic acid and acetone, followed reasonably well with both NH 3 and CO 2 , suggesting that animals and their waste contributed to the enhancements of the two VOCs.…”

Simultaneous multicopter-based air sampling and sensing of meteorological variables

“…In comparison to the actual number of dairy cows measured methane concentrations were plausible. For further investigation, an approach similar to that of Hacker et al (2016) would be suitable to calculate emission rates by flying upwind and downwind of the farms and measuring the vertical and horizontal extent of the plume.…”

Ultrafine particles over Germany – an aerial survey

“…Size distributions in these 'background' areas do not contain particles in the lowest size bins below 10 nm and the geometrical mean diameters (GMD) (!30 nm) is well above that of fresh emissions (B15 nm). This procedure does not estimate the lowest number concentrations occasionally observed in an area but accounts for enhanced background levels in a polluted atmosphere (Lenschow et al, 2001;Van Poppel et al, 2013;Hacker et al, 2016).…”