Boffins put supercomputer on the scent of a perfect landfill deodorizer

Is this what they mean by garbage collection?

Anyone who’s driven by a landfill is all too aware of the stinky consequences of our lifestyles.

And while waste management experts have got pretty good at masking these noxious scents, usually by burying them under a many feet of earth, that’s not always practical or applicable to other odorous industries, such as sewer treatment and agriculture. In these scenarios, it’s not uncommon for odor-neutralizing compounds to be employed in the form of a gas or mist.

Unfortunately, these compounds aren’t cheap and it can be a bit of a crap shoot when it comes to their effectiveness. And so a group of scientists in Louisiana teamed up with the San Diego Supercomputing Center (SDSC) in the US to help clear that up using computing power.

Their research, published in the Academia Letters journal, explored the use of the AMBER molecular dynamics toolkit running on SDSC’s Comet supercomputer to maximize the effectiveness of these odor neutralizers.

The aim of this research being to see if it was possible to use high-performance computing to determine the best composition of odor neutralizers before any expensive industrial-level experimentation and product development is performed, and potentially share what kinds of composition seem to work best for a given job.

Introduced in 2015, Comet is a petascale supercomputer cluster build around Intel’s Xeon E5-2680v3 CPUs and Nvidia’s K80 and P100 GPUs, which combined offer 2.76 petaFLOPS of peak performance.

SDSC touts the system as the supercomputer for the 99 percent, and is available to researchers under the Extreme Science and Engineering Discovery Environment program.

“In this study, we use molecular dynamics to access the role molecular displacement and dispersion may play in neutralizing toluene — an aromatic compound that has a two-fold representation in old wastes and leachate when compared to fresh waste,” the authors wrote, adding that the compound’s significant level of “superficial emission on landfills” made it an ideal subject for study.

Specifically, the scientists simulated the diffusion and dispersion of certain compounds, which together are used to neutralize toluene, one of more than a 100 volatile chemicals responsible for making landfills so unpleasant.

To neutralize the stench, several deodorizing chemicals are used. And according to the scientists’ findings, the exact mix of these chemicals can have a marked impact on how effective they are. The research simulated how quickly these deodorizing chemicals dispersed into the atmosphere.

“The results of this study reveal that the effectiveness of an odor neutralizer is dependent on its molecular components and their diffusion rates over time,” the authors wrote. In short, it was shown that these components diffuse at different speeds, and that's useful to know when designing a deodorizer that's supposed to be fast acting or long lasting. This data, or studies following up this work, could help in choosing the right chemicals for making the best deodorizer for a given application.

In an SDSC blog post, Sylvester Tumusiime, one of the authors on the paper, touted the use of supercomputers and molecular dynamics to address challenging societal or environmental issues that directly impact people’s lives on a daily basis.

“Our preliminary study shows how supercomputers and molecular dynamics techniques enable cost-effective analysis of important societal/environmental issues that impact the daily lives of ordinary people,” said Tumusiime, who is the Louisiana Public Health Institute's informatics manager. “The computing resources ... demonstrated that molecular dynamics could be a cost-effective means for testing the composition of candidate odor neutralizers prior to embarking on expensive industrial phases."

This study is interesting as a proof of concept for the use of supercomputing in this area of science, and it doesn't give a complete picture. For one, the scientists limited their research to neutralizing toluene, and the actual mix of noxious chemicals that contribute to landfill’s particular odor profile varies wildly.

“This simulation profile is only acting as a proof of concept to the ability to use [molecular dynamics] to access similar interactions,” they wrote. ®