Three Questions

[atle]

I've got three questions for the environmental exam if anyone out there has time to answer.

1. In the Freundlich Equation, is there some convention for the units of q, K(f), C, and n. I find the units defined differently in different references. For example, sometimes C is in micrograms per Liter, but other times it is partial pressure. I've found log K(f) defined as the slope, but I just did a problem where K(f), itself is the slope.

2. Any one know where to find acceptable infiltration and inflow rates to sewer lines?

3. I read a post on the other board that the exam does not have units in the answers. Anyone know if this is true? I don't see how many of the questions could be answered without at least know whether to answer in US or SI units.

Much Thanks.

 

[klk]

Since all of my references are at work, I can't answer the first two questions. I can say for the 2nd question that its highly unlikely they'd ask you to assume a I&I rate on the test. I found that they pretty much gave you all the info you needed (and more) to solve the problem, otherwise its possible to get more than one answer.

As for the 3rd question, its only partially true. The units are given in the problem statement but are not listed next to any of the answers. So when you're reading the problem, circle the units and write it down next to the answers to remind you. Often, the equation you use to solve the problem will result in one set of units and they'll request the answer in a different set of units. Of course, the answer you found in the original set of units WILL be listed, thus in your excitement to realize you answer is listed among the options, you'll end up selecting the wrong one. I almost fell into this trap several times on the exam, and only because I had extra time to review my answers at the end did I realize my mistakes and was able to correct them.

 

[atle]

Since all of my references are at work, I can't answer the first two questions. I can say for the 2nd question that its highly unlikely they'd ask you to assume a I&I rate on the test. I found that they pretty much gave you all the info you needed (and more) to solve the problem, otherwise its possible to get more than one answer.

As for the 3rd question, its only partially true. The units are given in the problem statement but are not listed next to any of the answers. So when you're reading the problem, circle the units and write it down next to the answers to remind you. Often, the equation you use to solve the problem will result in one set of units and they'll request the answer in a different set of units. Of course, the answer you found in the original set of units WILL be listed, thus in your excitement to realize you answer is listed among the options, you'll end up selecting the wrong one. I almost fell into this trap several times on the exam, and only because I had extra time to review my answers at the end did I realize my mistakes and was able to correct them.

Thanks, As long as they tell me what units they want.

 

[Dleg]

I can't even remember what the Freudlich equation is right now.

For the acceptable I&I rates, don't sweat it - I know where you are getting that worry from (exam 1 in Schneiter's practice exams,. right?). That said, the best reference is probably the "Ten State Standards", which says that a new plant should be designed for a hydraulic load of 100 gallons per capita per day, and that includes reasonable I&I. For existing systems, I&I needs to be evaluated on a case-by-case basis. This is all in Chapter 10 (which is, oddly enough, the first chapter).

Schneiter took his solution from some data contained in Chapter 30 of the 10 State Standards, under the criteria for conducting a hydrostatic test, which gives the value of 100 gallons per inch of pipe diameter per mile per day (aka 9L per mm pipe diamter per km per day), with a minimum positive head of 2 feet. Not sure if that's really the best choice, but chances are, you will not have to make that choice on the exam - the figure would probably be given to you.

 

[RIP - VTEnviro]

I've got three questions for the environmental exam if anyone out there has time to answer.
1. In the Freundlich Equation, is there some convention for the units of q, K(f), C, and n. I find the units defined differently in different references. For example, sometimes C is in micrograms per Liter, but other times it is partial pressure. I've found log K(f) defined as the slope, but I just did a problem where K(f), itself is the slope.

All I know is that it deals with adsorption columns. I don't remember anything else about it. Sorry.

2. Any one know where to find acceptable infiltration and inflow rates to sewer lines?

I was always told to use 300 gal/inch diameter/mile of pipe/day. But there is a range of reasonable values. The exam will specify a value to eliminate ambiguity.

3. I read a post on the other board that the exam does not have units in the answers. Anyone know if this is true? I don't see how many of the questions could be answered without at least know whether to answer in US or SI units.

you are correct, there are no units in the answer. But the problem statement is phrased like..."The discharge rate, in gallons/minute, is most nearly...

One of the distractor answers is often the right answer in the wrong units.

Much Thanks.

 

[atle]

I can't even remember what the Freudlich equation is right now.
For the acceptable I&I rates, don't sweat it - I know where you are getting that worry from (exam 1 in Schneiter's practice exams,. right?). That said, the best reference is probably the "Ten State Standards", which says that a new plant should be designed for a hydraulic load of 100 gallons per capita per day, and that includes reasonable I&I. For existing systems, I&I needs to be evaluated on a case-by-case basis. This is all in Chapter 10 (which is, oddly enough, the first chapter).

Schneiter took his solution from some data contained in Chapter 30 of the 10 State Standards, under the criteria for conducting a hydrostatic test, which gives the value of 100 gallons per inch of pipe diameter per mile per day (aka 9L per mm pipe diamter per km per day), with a minimum positive head of 2 feet. Not sure if that's really the best choice, but chances are, you will not have to make that choice on the exam - the figure would probably be given to you.

Thanks and you're right. That was where it's from. I don't know that it would have occurred to me to look at a standard like the 10 States you cite for a way to solve the problem. Now, I've done enough of the Schneither problems, struggling with misc. standards and constants, that I've decided I'm just not going to worry about it. If that doesn't work, I'll have a studying strategy for April.

:brickwall:

 

[RIP - VTEnviro]

Some of Shneiter's values are out of left field. Not that they aren't reasonable assumptions, you just don't know where he picked them out of.

 

[FLBuff PE]

Three questions?

1. What is your name?

2. What is your quest?

3. What is the color of your exam pancil? (To be answered when the board is back up and running after the exam)