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Trace Metal Filters/Filtering Apparati

  • 16 Jun 2014 2:22 PM
    Message # 3007968
    Zach Dahlgren (Administrator)

    This question has been adduced by Kent Loader and the folks at the Dry Creek Lab. If anyone has some helpful information to provide to the subject, please feel free to post on this topic. Thanks!

     

    "I was wondering if anyone out there has an apparatus for collecting dissolved metals? Our new permit has 4 dissolved metals that are at very low concentrations, e.g. Cd is 0.51 ug/L.
    I have been using trace grade acids and running my samples on an TJA ICP 61E, Supertrace. I have found that most (90%) of my filtered samples have higher concentrations than
    the non-filtered aliquot. I have been using fecal membrane filters (0.45 um) with TSS acid rinsed TSS funnels and various other syringe filters with the same results.
    Does anyone out there know of trace metal clean filters and perhaps a filtering apparatus that they are using that works?"

     

  • 17 Jun 2014 10:06 AM
    Reply # 3008488 on 3007968
    Dawn Cowell

     

    We use the Environmental Express filtermate filters along with their cups.  They are nice and handy because we can pour the sample into the cup and then press the filter right on into it.  Takes away the excess filtration apparatus and vaccum and so forth.  You can see a picture of them here:

     http://www.envexp.com/products/2-Metals/MD-Metals_Digestions/FM-FilterMate

     

    We use this system for both our digested samples which need to be filtered and the dissolved samples. 

    ~ Dawn, City and County of Broomfield 

  • 18 Jun 2014 9:24 AM
    Reply # 3009281 on 3007968
    Jo

    Our Laboratory has had great success in decreasing background metals contamination (25-65% decrease of certain metals) using a multi-procedural approach.  First we implemented clean sampling techniques using EPA M1669.  We actually use a modified version of the method and it still works well.  Secondly, for D & PD metals, we switched to Pall Groundwater capsule filters (Pall GWV product# 12178, 1 ea.; # 12179, 10 ea; #12180, 50 ea.).  Thirdly, we installed 2 AirClean clean bench workstations - 1 in which we prepare standards/samples; the second small one houses our autosampler.  Even if you can't implement clean sampling and the clean benches, we found the filters alone made a big difference over bench top filtering.  They are expensive but worth it.  Good Luck.

  • 19 Jun 2014 3:17 PM
    Reply # 3011971 on 3007968
    Greg Moore

    We also have had great results from the Environmental Express items as has Dawn (Vicki's a master at it)!


    Greg Moore

    City of Golden

  • 21 Dec 2015 7:45 PM
    Reply # 3713277 on 3009281
    Claudia
    If they are filtering ( etheir by a plain spun filter or ion exchange, or a combination of both) then they will reduce the contaminants in the water, and could possibly use it as coolant again. If they are doing a straight cascade of filters before release then they will reduce volume of low level waste considerably, they just need to add cascades until the reading is at local background, which probably will leave water that is classifiable as having the same makeup as bottled water.Will result in a pile of contaminated filters to be stored until they decay, but if they simply keep moving the filters up the cascade as the first becomes blocked, and put the newest at the end, you will do a lot of capture for a minimal amount of media. The pump may be uncleanable at the end, from material driven into the volute and impeller, so a cheap pool pump or pond pump probably would be best, and a few sand filters filled with ion exchange resin in series at the outlet will probably work as a quick and dirty filter. All available off the shelf, and can be thrown together quickly.
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