dry cleaning solvent (PCE) remediation
dry cleaning solvent (PCE) remediation
(OP)
What's the latest and greatest destroyer of perchloroethylene (PCE)in the groundwater? I've got a groundwater headache (apx 45 ppm) and I'd like to pump and treat as aggressively as nature will allow. Any thoughts will be appreciated.





RE: dry cleaning solvent (PCE) remediation
RE: dry cleaning solvent (PCE) remediation
RE: dry cleaning solvent (PCE) remediation
RE: dry cleaning solvent (PCE) remediation
RE: dry cleaning solvent (PCE) remediation
RE: dry cleaning solvent (PCE) remediation
IMHO in-situ bioremediation of PCE with sodium lactate has proven over the last 4 years to be a very economical approach to remediating dry cleaning sites contaminated with PCE. The sodium lactate is diluted to 5-20% of the delivered concentration and then injected into the saturated zone in the highest concentration area through a direct push injection or via a well. The lactate is fermented to form organic acids that then provide bioavailable hydrogen for the sequencial dechlorination of the PCE to TCE to DCE to VC to ethene and ultimately to carbon dioxide, water and chloride.
Dr. Kent Soreneson at INEEL has published quite a bit on full scale remediations. You can find info on this project at both http://tech.inel.gov/tech-detail.asp?id=149 and at http://www.jrwtechnologies.com/Literature.htm . The second site gives several case studies including a drycleaner site.
RE: dry cleaning solvent (PCE) remediation
I've had alot of luck with the molasses injection in the source area, or some other carbon sourcr. If the regulatory agencies will allow it, potassium permanganate does quite nicely as there are no daughter products spawned. The offshoot is that groundwater will take on amn orange color for a small time and there's also the possibility of releasing free iron. It's much more efficient than pump-and-treat.ddt
RE: dry cleaning solvent (PCE) remediation
Good Luck.
RE: dry cleaning solvent (PCE) remediation
RE: dry cleaning solvent (PCE) remediation
RE: dry cleaning solvent (PCE) remediation
RE: dry cleaning solvent (PCE) remediation
http://www.clu-in.org/studio/napl_121002/ppframe2.cfm?s=59&p=32&res=800x600&simul=1
Also, you can check out the JRW Technologies web site (www.jrwtechnologies.com) for specific information on bioremediation products and case studies.
RE: dry cleaning solvent (PCE) remediation
Funnel and gate will also work to control migration, but won't address the source. In the long run, it might still be cheaper to use a funnel and gate because the present value of the hazardous waste you'll create through excavation will be high compared to the present value of monitoring your gate. I like funnel and gate over in-situ bio knowing nothing about site hydrogeology, but either might be the right answer. In-situ chemical oxidation to remove the source followed by one or the other might also be worth looking at.
So, it all depends on what the client wants. Most clients (in this case, I assume it's either a government agency or an insurance company) would pay a little extra (not twice) to get the liability off their books.
Jeff
RE: dry cleaning solvent (PCE) remediation
Donovoids response might only partially solve your problem because lactate is a hydrogen donor which will helps dechlorinate compounds requiring anaerobic degradation (i.e., PCE to TCE then to DCE). Therefore, lactate would potentially stall out when you get to DCE. The reductive dechlorination of DCE to VC and VC to ethene to carbon dioxide requires aerobic conditions and so you would need a source of oxygen to complete the reductive dechlorination.
1ddt's response is interesting. Investigate possible fouling considerations when using molasis.
RE: dry cleaning solvent (PCE) remediation
The other advantage of sodium lactate is that it lowers the interfacial tension between the DNAPL and aqueous phase and increases the mass transport gradient by between 10 to 50 times the natural dissolution rate. At INEEL that 100+ year project has been cut down to a 10 year project. For most drycleaning sites it takes 12 to 18 months to get complete remediation.
The cost advantages of treating the source areas at drycleaner sites with this BET technology are significant.
RE: dry cleaning solvent (PCE) remediation
RE: dry cleaning solvent (PCE) remediation