Potassium permanganate to oxidize phenol from landfill leachate as treatment process

Ask the Expert Question: 

We would like to use potassium permanganate (KMnO4) to oxidize phenol from landfill leachate as a treatment process (i.e. reduce phenol below POTW required limits) prior to sending leachate to a local POTW. However, we are not sure what could potentially be formed when the KMnO4 oxidizes the phenol and how these subsequent formation products should then be removed. 

Expert Response: 

The reaction product of phenol and permanganate will be 1,4-benzoquinone. It is not regulated, and I suspect that it will be degraded in a biological treatment system. Since your treated leachate is going to a POTW, this should be sufficient to eliminate both the phenol and the by-product.

Ask the Expert Question: 

We also would need to know what potassium permanganate (KMnO4) would do to ammonia, cyanide, hydrogen sulfide and dissolved metals which are also present in the leachate at lesser concentrations than the phenol. 

Expert Response: 

Regarding the reaction of permanganate with the other constituents, I would expect ammonia to be oxidized to nitrate, cyanide to carbon dioxide and nitrate, and sulfide to sulfate. 

With the metals it would depend on the specific metals and their oxidation states.  For example, the leachate probably contains some dissolved ferrous iron because the landfill will be a reducing environment. The reaction with permanganate will convert this ferrous iron to ferric iron, and that would almost certainly result in a ferric oxide precipitate. These constituents are likely to react with permanganate more quickly than phenol, so you will have to add sufficient permanganate to oxidize these before you will get thorough oxidation of the phenol.

Blue ice for shipping laboratory samples

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Can blue ice be used to ship samples to the laboratory?

Expert Response: 

The requirement is to receive environmental samples at 6 degrees Celsius. Any means that can ensure the 6 degree requirement would be suitable. However, it has been demonstrated that blue ice or cooler packs are very poor at lowering sample temperatures to the 6 degree requirement when the sample temperatures upon collection already exceed that temperature. This can result with sample temperatures being above the required temperature when received at the laboratory.

Ice however, will lower sample temperatures even when collected above the desired temperature if there is sufficient contact time between collection and receipt at the laboratory, and when there is sufficient ice to last the journey to the lab. Also, if the trip to the lab is short in duration, it may be necessary to chill the samples in the field prior to packing them for shipment.  Therefore, Ice is the preferred cooling mechanism, and some local enforcement bodies make it a requirement.

Could the use of DEET cause problems with analyses?

TestAmerica receives many questions via its Ask the Experts program, and periodically they are questions that could benefit a large number of our clients. This is a question asked to one of our Experts and we would like to share the question and response.

Ask the Expert Question:

We will be sampling for (among other things) low level VOCs, SVOCs and Pesticides in a grassy area infested with ticks. The sampling plan is to apply tick repellent (probably DEET) to their legs, feet and clothing. The client is concerned that the tick repellent could cause a problem with the analyses, particularly the low level pesticide analysis.

While DEET is not a target, the concern is that it might be picked up during the analysis and cause interference. Have you ever run into this sort of thing before?

We advised the client to apply the repellent and let it dry before they begin sampling, and take care to keep the samples and sampling equipment away from the DEET treated surfaces. Any idea if this is something the client should be concerned about? 

Expert Response:

Although TestAmerica does not specifically analyze for DEET, the compound does fall within the chromatographic range that is analyzed for in the Semi Volatile Organic Compound (SVOC).  Since DEET is not a component in the standards mix, if it is present in a sample, it can be seen as a Tentatively Identified Compound (TIC) in the SVOC analytical run. 

While it is possible for DEET to also appear in an analytical run for Pesticides, we have never specifically experienced DEET interfering with a Pesticides analysis.  This most likely is due to the standards mix for the Pesticides analysis containing each of the target analytes within the EPA Method, which does not include DEET.

With proper application of the repellant as you have directed and the use of appropriate sampling procedures (gloves, care against cross contamination, etc) I would not expect it to be a problem.  I would suggest pre treatment of clothing etc away from the sampling location and supplies if at all possible.  Transfer from hands to equipment may warrant particular attention.