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BOD: The Case Of The Disappearing Oxygen
Charles Lytle
Posted: Tuesday, May 25, 2010 4:42 PM
Joined: 10/5/2009
Posts: 49


There are eight million stories in the naked laboratory.  This is one of them.

 

I was working the day shift out of management.  It was cool and cloudy in Portland.  My partner's name is Jennifer.  The boss is "Captain" Redding.

 

About 8 AM the call came in:  our dilution water, stable at good saturation for over 13 years, was reading <1.0.  Same old everything...nothing new, lab-wise.

 

The BOD homicide section went into action.  First, the water was checked:  house DI put through Nanopure polishing; point-of-use RO/DI out of a brand new Millipore; a jug of steam distilled.  After suitable bubbling, no oxygen.

 

Second, our "usual" water was shaken like mad at the bench:  good DO.  Started bubbling.  Watched the DO take a dive.  Same for the other two sources.  Conclusion?  It isn't the water.

 

Third, shook some more water:  good DO.  Bubbled:  no DO.  Shook again:  DO slowly started to come up, but not very fast.

 

Fourth, borrowed an oxygen meter from the confined entry guys.  Stuck it in a big Erlenmyer:  % oxygen fine.  Ran in some house air and watched the red light come on and listened to the alarm as the % oxygen left town.

 

Fifth, a member of the A-Team claimed it was oil in the big compressed air tank up in the utility room.  Under pressure, oxygen can react with the oil, which then acts as a scavenger.  Or it's poisoning the well.  It's the only constant in the mystery.  Hmmm.

 

Today:  our building guru explains that the pump is oiless and the air in the utility room is just fine.

 

There are zillions of lab rats out there in WEF-Land.  Somebody has to have a clue, or better yet an answer.

 

Chuck Lytle

 

 


Perry Brake
Posted: Tuesday, May 25, 2010 5:33 PM
Joined: 12/16/2009
Posts: 69


Dum da DUM dum..dum da DUM dum DUMMMMM!  This is the city.  Portland Oregon.  My name is Joe Friday.  I work here.  I'm a BOD cop.

 

You and I have previously communicated on this devious behavior and although I hate to admit it, I have no clues.  SOMETHING has taken its toll on the oxygen at the crime scene, but without isotope prints, DNA samples, or some other conclusive evidence, I don't think we'll ever find the guilty party.

 

Joe


Charles Lytle
Posted: Wednesday, May 26, 2010 7:37 AM
Joined: 10/5/2009
Posts: 49


Just the facts, ma'am:

 

We actually went up to the utility room and checked the oxygen level.  It was just fine, and there were no bodies lying on the floor.  The canary kept on chirping.

 

The big compressor took the fifth amendment and wasn't talking.  There were no visible signs of an altercation with the vacuum system sitting right next to it.

 

So Jennifer put in a requisition for a fairly large size fish tank bubbler.  We now have oxygen in our dilution water, but the case has gone cold.  The CSI squad have taken off their nitrile gloves....for now.

 

Chuck Lytle


James Royer
Posted: Wednesday, May 26, 2010 9:26 AM
Joined: 9/21/2009
Posts: 98


At a station where I previously was assigned we had the utilities in the penthouse. The air intake for the compressor was on the roof as were the chemhood exhausts. Maybe the culprit was from an inside job?


Anonymous
Posted: Wednesday, May 26, 2010 1:21 PM

Is there a back flow, cross connection program for the house air?


Anonymous
Posted: Friday, June 4, 2010 7:51 AM

A cross connection or backflow problem is not possible:  the air pressure and vacuum systems are completely separate.

 

Here we are, a couple of weeks down the road with no solution in sight.

 

We thought about running around the lab and testing various air pressure outlets, but instead have just gone with the fish tank bubbler.

 

Chuck Lytle


Tony Pirondini
Posted: Wednesday, June 9, 2010 4:47 PM
Joined: 6/9/2010
Posts: 1


Degassing the sample with a gas that doesn't contain oxygen seems to be the issue here.

Could a tank of nitrogen, argon, or other non-oxygen containg compressed gas be hooked up into the "air" plumbing?


Anonymous
Posted: Thursday, June 10, 2010 11:02 AM

Check the air piping.  Iron "sucks" oxygen when it oxidizes.  We had that problem with our system, because of moisture build up the iron pipe started oxidizing and using up the oxygen in the line.


Charles Lytle
Posted: Monday, June 14, 2010 9:35 AM
Joined: 10/5/2009
Posts: 49


Anonymous,

 

We got to thinking the same thing.  Our building guru from General Services is going to take the air compressor off line and undo the tank knock-out and check out the inside of the tank.  I'll post the results of the inspection.  You'd think they'd make the tank out of stainless steel or somehow passivate the interior.

 

Chuck Lytle


Handsome Dan
Posted: Monday, June 25, 2012 1:32 PM
Joined: 6/25/2012
Posts: 4


Anonymous has a good theory.
Charles Lytle
Posted: Wednesday, June 27, 2012 7:51 AM
Joined: 10/5/2009
Posts: 49


There's something gratifying about an almost three year old "cold case" still piquing interest.  happy 

 

With only circumstantial evidence, the lab rat grand jury indicted the air compressor, and it was convicted of contributing to the poisoning of ten innocent BOD samples, although the compressor refused to take the stand in its own defense.  At sentencing, it continued its silence, so it was banned for life from bubbling BOD samples.  (Exsanguination was ruled out due to budget considerations.)  Afterwards, it somehow managed to release a statement to the press that it was going to spend the rest of its life tracking down the real culprit.

 

I'll keep you informed.

 

Chuck Lytle


01487708
Posted: Tuesday, October 30, 2012 5:09 PM
Joined: 10/12/2009
Posts: 11


So it is out looking for the one-armed man.

 

Tony is probably right in that a sparging was with a gas that had no oxygen in it.  But if a tank of another gas is not the culprit, then where did the oxygen go from the compressed air??

 

I leave it to the math geeks to figure out how soon oxygen scavaging would take to reduce the compressor to a pile of rust colored powder.