scholarly journals Response to “Comment on ‘A Pilot-Scale Field Study: In Situ Treatment of PCB-Impacted Sediments with Bioamended Activated Carbon’”

2019 ◽  
Vol 53 (10) ◽  
pp. 6104-6105
Author(s):  
Rayford B. Payne ◽  
Upal Ghosh ◽  
Harold D. May ◽  
Christopher W. Marshall ◽  
Kevin R. Sowers
Keyword(s):  
Activated Carbon ◽  
Field Study ◽  
Pilot Scale ◽  
Scale Field

A Pilot-Scale Field Study: In Situ Treatment of PCB-Impacted Sediments with Bioamended Activated Carbon

2019 ◽  
Vol 53 (5) ◽  
pp. 2626-2634 ◽  
Author(s):  
Rayford B. Payne ◽  
Upal Ghosh ◽  
Harold D. May ◽  
Christopher W. Marshall ◽  
Kevin R. Sowers
Keyword(s):  
Activated Carbon ◽  
Field Study ◽  
Pilot Scale ◽  
Scale Field

PFAS immobilization using in-situ application of colloidal activated carbon at a geologically complex site

2021 ◽  
Author(s):  
Fritjof Fagerlund ◽  
Georgios Niarchos ◽  
Lutz Ahrens ◽  
Dan Berggren Kleja ◽  
Jonny Bergman ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Groundwater Flow ◽  
Preferential Flow ◽  
Pilot Scale ◽  
Lessons Learned ◽  
Aviation Industry ◽  
Novel Technologies ◽  
Permeable Barrier ◽  
Hydrogeological Parameters

<p>Due to the exceptional persistence and resistance to degradation of per- and polyfluoroalkyl substances (PFASs), novel technologies for in-situ treatment and remediation of these pollutants are urgently needed. While there is still a need for more evidence from well-documented field applications, a promising technique is the use of activated carbon (AC) sorbents that can immobilize PFASs in groundwater and thereby prevent further spreading of the contaminants.</p><p>In Arboga Sweden a small fire-fighting training area connected to aviation industry is contaminated by PFAS from aqueous film forming foams (AFFFs). This site has been characterized for PFAS contamination and hydrogeological parameters affecting the spreading of contaminants with the groundwater in a few smaller site investigations since 2016 and continuous monitoring since 2018. In November 2019 colloidal activated carbon (CAC) was injected in a pilot-scale test to study the capability of CAC to immobilize PFASs in a part of the contamination plume.</p><p>The complex geology of the site made the injection of CAC challenging and special measures had to be taken to avoid excessive preferential flow of the CAC particles even at low-pressure injection. The injection pattern was modified and CaCl<sub>2</sub> was injected downstream of the CAC injection to reduce CAC mobility and create a defined zone of CAC intercepting the PFAS plume in the groundwater, thus acting like a PFAS-immobilizing permeable barrier.</p><p>PFAS concentrations were initially reduced by 74% (for a sum of 11 PFASs) directly downstream of the CAC-barrier. However, a few months later PFAS concentrations rebounded to levels equally high or higher than before CAC injection, after which the levels have been going down again. The reasons to the rebound are likely connected to seasonal changes and fluctuations in the groundwater flow directions, causing bypass of the permeable CAC barrier. Lessons learned from applying CAC injections at this field site include the key importance of understanding the groundwater flow patterns and its temporal variability. CAC was able to produce significant reduction in PFAS concentrations (74%), but only when the PFAS plume was properly intercepted. The results illustrate the challenges with application of permeable barrier techniques particularly at geologically complex field sites. At such sites, sorbents for immobilization of PFAS plumes in groundwater should be applied in the most straightforward location where a year-round interception of the plume can be obtained.</p>

Pilot-scale injection of colloidal activated carbon for PFAS immobilization at a contaminated field site

2020 ◽  
Author(s):  
Fritjof Fagerlund ◽  
Georgios Niarchos ◽  
Lutz Ahrens ◽  
Dan Berggren Kleja ◽  
Jonny Bergman ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Seasonal Changes ◽  
Preferential Flow ◽  
Pilot Scale ◽  
Contaminated Site ◽  
Flow Paths ◽  
Groundwater Levels ◽  
Geological Setting ◽  
Scale Test

<p>Per- and polyfluorinated alkyl substances (PFASs) are extremely recalcitrant contaminants that pose a challenge for remediation in soil and groundwater due to their chemical stability and resistance to degradation. They are used in numerous consumer products and their use in firefighting aqueous-film-forming foams has led to worldwide contamination of groundwater resources associated with airports and firefighting training areas. One of the currently most promising in-situ treatment techniques is stabilization using activated carbon (AC) sorbents that can immobilize PFASs in the soil and prevent further spreading from a contaminated site. However, few documented field studies exist.</p><p>In this study we investigated in-situ stabilization of PFASs by injection of colloidal activated carbon (CAC, PlumeStop®) at a PFAS contaminated site in Arboga, Sweden. Prior to the design of the pilot-scale test and CAC injection, the geology and state of contamination were carefully characterized and PFAS concentrations and groundwater levels were monitored continuously for almost one year. CAC was injected to create a defined zone of PFAS-sorption where PFASs from the contaminant plume would be sorbed to CAC and removed from the flowing groundwater, similar to a permeable reactive barrier. The effect of the injected CAC was studied by monitoring PFAS concentrations in the groundwater up- and down-gradient as well as within the CAC barrier both before and after injection. General water chemistry and groundwater levels were also monitored.</p><p>The site characterization showed that there are two distinct source zones of PFAS contamination with different contamination signatures. Continuous baseline monitoring prior to CAC injection did not show any major changes in PFAS concentrations, but revealed seasonal variations in the groundwater levels and flow patterns, leading to seasonal changes also in the direction of contaminant transport. The CAC injection pilot-scale test was therefore designed to shield the down-gradient evaluation wells in small part of the plume accounting for seasonal changes. The geological setting of the site mainly is clayey till soil of relatively low hydraulic conductivity on top of crystalline bedrock, but there are also high permeability flow paths. The low-pressure CAC injections were hence designed and adapted to avoid excessive preferential flow of CAC and achieve a good distribution of CAC in the intended treatment zone (barrier).</p><p>Preliminary results from the monitoring showed strong reduction of all measured PFASs within and directly down-gradient of the CAC barrier. These results indicate that the installation of the CAC barrier was successful despite a relatively complex geological setting where fast preferential flow paths exist. The continuing monitoring will show how the CAC performs over time.</p>

Pilot-Scale Field Study for Ammonia Removal from Lagoon Biogas Using an Acid Wet Scrubber

2013 ◽  
Author(s):  
Hongjian Lin ◽  
Xiao Wu ◽  
Curtis Miller ◽  
Jun Zhu ◽  
Lara Jane Hadlocon ◽  
...  
Keyword(s):  
Field Study ◽  
Pilot Scale ◽  
Ammonia Removal ◽  
Scale Field ◽  
Wet Scrubber

Pilot scale field studies of in situ bioremediation of chlorinated solvents

1992 ◽  
Vol 32 (2-3) ◽  
pp. 145-162 ◽  
Author(s):  
Lewis Semprini ◽  
Gary D. Hopkins ◽  
Paul V. Roberts ◽  
Perry L. McCarty
Keyword(s):  
Chlorinated Solvents ◽  
Field Studies ◽  
Pilot Scale ◽  
In Situ Bioremediation ◽  
Scale Field

Arsenic Species Transformation and Transportation in Arsenic Removal by Fe-Mn Binary Oxide–Coated Diatomite: Pilot-Scale Field Study

2011 ◽  
Vol 137 (12) ◽  
pp. 1122-1127 ◽  
Author(s):  
Kun Wu ◽  
Ruiping Liu ◽  
Huijuan Liu ◽  
Fangfang Chang ◽  
Huachun Lan ◽  
...  
Keyword(s):  
Field Study ◽  
Arsenic Removal ◽  
Arsenic Species ◽  
Pilot Scale ◽  
Binary Oxide ◽  
Species Transformation ◽  
Scale Field
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