Cleaning up tar-contaminated sediments using renewable and recycled materials | Chemical & Engineering News
Volume 94 Issue 25 | p. 8 | Concentrates
Issue Date: June 20, 2016

Cleaning up tar-contaminated sediments using renewable and recycled materials

A biosurfactant from corn gluten meal and hemp combined with polystyrene could reduce remediation costs
Department: Science & Technology
News Channels: Biological SCENE, Environmental SCENE, Materials SCENE
Keywords: pollution, environment, start-ups, business, fossil fuels, energy, biobased materials, materials, manufactured gas, coal tar, hydrocarbon, sediment, remediation, biosurfactant
[+]Enlarge
Polystyrene pellets before (left) and after (right) absorption of coal tar compounds from river sediment.
Credit: Albert Robbat Jr./Tufts University
Photos of polystyrene pellets.
 
Polystyrene pellets before (left) and after (right) absorption of coal tar compounds from river sediment.
Credit: Albert Robbat Jr./Tufts University
[+]Enlarge
Sediment from the Grand Calumet River is loaded into a concrete mixer in the field to test the efficacy of using of a biosurfactant and polystyrene pellets to remediate coal tar contamination.
Credit: Albert Robbat Jr./Tufts University
A photo of a shovel holding river sediment over a portable concrete mixer.
 
Sediment from the Grand Calumet River is loaded into a concrete mixer in the field to test the efficacy of using of a biosurfactant and polystyrene pellets to remediate coal tar contamination.
Credit: Albert Robbat Jr./Tufts University

Many gas plant sites that distilled coal to produce fuel for light and heat in the 1800s and early 1900s remain heavily contaminated with coal tar. Current remediation strategies involve excavating contaminated sediment and hauling it away to dump it, incinerate it, or treat it to desorb contaminants. But mixing contaminated sediments with polystyrene pellets and biosurfactant compounds extracted from corn gluten meal and hemp may provide a way to clean up sediments on-site at lower cost, reports a team led by Albert Robbat Jr. of Tufts University (Soil Sediment Contam. 2016, DOI: 10.1080/15320383.2016.1190955). The researchers mixed contaminated sediments from the Grand Calumet River in Indiana with the biosurfactant and pellets from ground-up polystyrene home insulation panels. The biosurfactant mobilizes the tar, the chemical components of which then stick to the pellets by forming π-π interactions with the polystyrene. The pellets rise to the surface of the mixture while the sediments sink, allowing for easy separation. Using conditions that would remove 80% of the polycyclic aromatic hydrocarbons from the sediments, the team estimates that the approach would reduce treatment costs by 28%.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society
Comments
Robert Buntrock (June 28, 2016 9:22 PM)
Sounds good except how are the contaminated pellets disposed of and at what cost?
Jyllian Kemsley (June 28, 2016 9:40 PM)
The authors suggest that the contaminated pellets could be turned into fuel oil.

Leave A Comment

*Required to comment