21 replies to this topic

[amoderski]

In the 2011 NCEES Environmental Exam can anyone answer the following:

Question 521 (Find the amount of Butyraldehyde (BA) condensed, lb/day:

What is the formula.
Where does the 359 cubic feet / mole come from?
Is there a better example anywhere of this "type" of problem?

We are basically about a week out from test day. I'm trying to finish the 2011 exam and then work the 2004 exam.
I got a 60% on the practice exam, and most of my errors were in air. I'll take any advice / solutions the board can offer.

Thanks in advance.

[amoderski]

I'm obviously a bit overwhelmed with this exam looming, and also apparently a bit click happy.

Sorry, I'm not sure how to delete the rest.

[okeng]

At 0 deg.C (32F) and 1 atm (14.7psi) molar volume is 22.4 L/gmol (359 ft3/lbmol).

[amoderski]

Thank you Thank you Thank you!!!

Do you have any advice on Question 526 (where is this formula from)??? The EERM has CDI listed in a different fashion.

[Jeffrey]

Do you know the source for #533, or #507 in the 2011 practice exam?

533 is about SVE remediation for soil - how do I know that bacteria cultures would not work for HIGH concentrations of petro in soil?

507 is about measuring NOx attainment by chemiluminescence?

How to we find answers to questions like these during the exam? what's a good reference?

[VTEnviro]

^Haz Waste Mgmt by LaGrega et al is a solid reference for hazmat questions.

As for the NOx one, I have no idea. Here is a link to measurement by chemiluminescence.
http://www.k2bw.com/...uminescence.htm

If you can be a little more specific about these problems, those of us withouth the book in front of us might be able to help.

[Jeffrey]

Sorry I didn't think about others besides AModerski answering. More info:

533:
Which of the following remediation technologies is most effective for removing high concentrations of low-solubiility petroleum compounds from containment soil?
A. pump & treat wells
B. soil wash with a weak sulfuric acid/water mixture
C. injection of bacteria cultures
D. SVE

I looked in La Grega w/o finding anything I knew how to answer the question with. If you know where the answer is in that book or how to decipher the answer from that book, that would be awesome. I've got the book for the exam from our office library.

507
What is the generally accepted method for measuring attainment with NAAQS for NOx?
A. Nondispersive infrared spectroscopy
B. Calorimetric using Saltzman method
C. Pararosaniline method
D. chemiluminescence method

Never heard of ANY of those things before this questions. What the heck?!

thank you!

[envirotex]

For 533.

Thanks for posting the question...bioremediation will not be very effective in this case because high concentrations of hydrocarbons in the subsurface indicate the presence of the a significant non-aqueous phase. Bacteria are only able to degrade components that are dissolved from the non-aqueous phase, not the non-aqueous phase itself. Similarly, very high concentrations of hydrocarbons can be toxic to the bugs as well...This would be a case for a treatment train approach, i.e. removal of a significant portion of the hydrocarbon non-aqueous source through SVE, skimmers (for the saturated zone), etc....followed by bioremediation or downstream treatment of the dissolved phase with bioremediation.

[envirotex]

For 507. The answer is D, chemiluminescence method.

Google "National Ambient Air Quality Standards" (NAAQS) and find the sampling methods manual. You should be able to find the preferred sampling method (including the length of the sample time) for ANY of the criteria pollutants in this manual. It will be a quick table look-up for the correct answer!

[amoderski]

For question 529

Which of the following geophysical measuring techniques would be used to assess the downhole vertical continuity of a clay stratum?

Terrain Conductivity
Resistivity
Gamma Ray Logging
Ground Penetrating Radar

What is a good reference for this, can anyone explain?

Thanks for all your responses so far. I took today off to finish the PM portion of the 2011 exam, so I'm sure the questions will keep rolling. Air & groundwater are my weakest subject areas.

[VTEnviro]

How did I actually pass this thing?

Here's a link for your 529 question. I honestly don't know much about it.
http://www.scribd.co...gation-Ohio-EPA

[amoderski]

Thanks for the reference. I'm working hard to get the 2011 done and then jump to the 2004. I'm really nervous.

[envirotex]

For question 529

Which of the following geophysical measuring techniques would be used to assess the downhole vertical continuity of a clay stratum?

Terrain Conductivity
Resistivity
Gamma Ray Logging
Ground Penetrating Radar

What is a good reference for this, can anyone explain?

Thanks for all your responses so far. I took today off to finish the PM portion of the 2011 exam, so I'm sure the questions will keep rolling. Air & groundwater are my weakest subject areas.

Since the question asks for downhole techniques for vertical continuity, I think the answer should be gamma ray logging...the other techniques are surface geophysical survey methods and would be good for determining the lateral continuity of a clay unit...

Gamma ray logging is useful for determining clay intervals because the log shows a measurement of natural gamma radiation in the materials surrounding the borehole, since clays naturally have high levels of gamma emitters like potassium, the gamma ray response increases when these materials are encountered in a borehole.

There is a such a thing as downhole resistivity logging (more commonly used in the oil biz as oil is a highly resistive fluid), but I'm thinking that they mean a surface resistivity survey or they would have specified resistivity logs. Maybe a good case to flag the question...

[Dleg]

I would have answered gamma ray logging, too, but only because of the "downhole" clue, and 5 years of experience logging wells. I don't know where I would have found that one in my references.

For 507, I took out my trusty Salvato (Environmental Engineering), looked in the index, and had chemiluminescence right away. Salvato is a good reference for just about everything.

[amoderski]

Can someone help with problem 521:

Butyraldehyde (BA) is produced at a rate of 5000 gpd and fed to a 30,000 gallon tank held at 30C and 771 mmHg absolute pressure under nitrogen. The vent is cooled to -18C in a refrigerated condenser. MW of BA 72.11 Vapor Pressure at 30 C: 150 mmHg, Vapor Pressure at -18C: 10 mmHg.
Find the amount of BA condensed (lb/day).

I'm having trouble conceptualizing, the problems and outlining steps, even after looking at the solution.

Any help would be appreciated. Thanks in advance.

[okeng]

As I see it, BA has to be stored under nitrogen to prevent a reaction so you are dealing with two gases held under temperature and pressure and you want to condense out the BA at from 30C to -18C.

In the solution, you convert gallons to cubic feet, then to moles total gas at STP., Then convert that volume to 30C and771mm hg to get total moles of N2 and BA held in the tank. From that get the mole fraction BA at 30C based on partial pressure. Subtract that fraction from total volume at 30C to get moles N2. Using partial pressures, get the mole fraction at -18C..

This is where I loose it a little because Im not sure if this is a standard condensation equation or why it is solved this way because I am unfamiliar but the solution multiplies the moles N2 by moles BA at -18 then divides by 1- moles BA at -18C giving you the moles BA at the outlet. If I see a problem like this on the exam I will simply try to set the equation up similar to this.

Subtracting the moles BA at 30C in the tank from moles BA at the -18C outlet gives you moles condensed then convert to lbs.

I dont know if that helped but maybe talking it through will spark an idea.

[Jeffrey]

There's another air question on this test about NESHAPs for asbestos demo, and it references 40 CRF 61. How would you guys answer that? I've seen other advice on this site that says don't bring the entire CFR, but how else would we get such a random question? I can post the question in its entirety tomorrow.

[okeng]

Even if you brought the entire CFR you would spend a lot of time flipping pages and reading unless you knew exactly where the citation was. I happened to know this one because of my experience with asbestos removal. I think we just need to come to terms with the fact that there will be a couple questions on the exam that unless you worked in the field or happen to have the exact reference, you will just have to guess.

I think the secret will to be solid with the quantitative questions which should carry you through most if not all the way to passing and hope you get some non-quantitative questions that you recognize.

[Jeffrey]

534
For asbestos remediation projects, NESHAPs (40 CFR 61.150) regulates:
A asbestos concentration in building materials to less than 1% by weight
B visible asbestos emissions
C non visible asbestos emissions
D waste disposal to regulated landfills

[envirotex]

As far as the CFRs go...I just printed the ones related to the sample questions that I saw. I figured that if it was important enough to be covered by the sample test, a related question might come up on the real test...

[VTEnviro]

^I did the same. Anytime I saw 123 CFR 456 in a practice question, I printed it out and stuck it in a binder. Helped with a few questions.

[FLBuff PE]

534
For asbestos remediation projects, NESHAPs (40 CFR 61.150) regulates:
A asbestos concentration in building materials to less than 1% by weight
B visible asbestos emissions
C non visible asbestos emissions
D waste disposal to regulated landfills

A.