CA Grade 1 Wastewater Math, Part 1 of 4 HD

hello and welcome to my video tutorial on California wastewater math for the grade 1 exam this is specific to California if you're in another state I can't guarantee the validity of any of the material in here on your exam but my guess would be that they are probably relatively the same this is for grade 1 math in California grade 1 is the lowest exam that an operator can try to take the highest would be a grade 5 exam so what we're going to be going over today is pretty basic my name is Christian Williams I'm an operator in California and I wanted to make these videos to help people out who are maybe struggling with the math and don't understand exactly what they need to do and the steps they need to go about to accomplish it so I wanted to make these to help you guys out and today what we're going to be covering is the pounds formula and I will teach you the Davidson PI formula which is a way to bypass algebra it helps operators who aren't very good with algebra to figure out this formula we are going to paint a room we are going to do percent efficiency and percent removal which are both exactly the same we're going to find volume of cylinders like a clarifier and squares like an aeration Basin we're going to find the detention time of a clarifier we will be doing chlorine dose demand and residual and we will be doing we're over flow rate for a clarifier and hydraulic and surface loading which are exactly the same as one another all right so let's get started so first I want to teach you the Davidson PI formula if you read along it's used primarily for the pounds formula but can be used with other formulas as well if you use it with other formulas that requires manipulation on your own I don't have time to go for other formulas maybe I'll make a video some other time and the way the pie works is this is what you would draw out on your piece of paper to show your work this is you showing your work right here what you do is you make all these cells right in here and this is what you're going to label them so in the form in them in the question they'll give you flow I want you to put your flow in here they're going to give you the concentration in milligrams per liter I want you to put the bat in here and then then this number right here is a constant number it won't change not on the grade one and so this number is always here eight point three four pounds per gallon one gallon of water weighs eight point three four pounds and what you do is anything on the bottom half of this circle is multiplied together to give you the top half of this circle so they'll give you flow concentration and then this is your constant put this in there put that in there you multiply this by this by this and it will give you pounds over whatever per day now this can also work backwards if they gave you the pounds per day and wanted to know the concentration or the flow what you would do is you would put pounds per day and if they gave you the concentration you would put it in here you would put this number down here because it's your constant and if you took this number and divided it by everything on the bottom that you have you would wind up with flow or if you had flow and you wanted to find concentration you would divide pounds by flow by 8.34 and it would give you your concentration in milligrams per liter and now the tip that they kind of give operators to do is to cover up whatever you're looking for with your thumb so if you're looking for milligrams per liter you would cover this up with your thumb and that would let you know to divide pounds by MGD by eight point three four and if you were looking for pounds you would cover this up with your thumb and you would multiply all these guys to to get your pounds per day I know we're going to go over that in two examples and so the first example so they giving you a flow of four mg d and influent B OD concentration of 250 milligrams per liter and they want you to find out how many pounds of beauty' per day so the formula without the PI formula looks like this it's mg d times 8.3 for pounds per gallon times milligrams per liter that is the flow that they'll give you on the cheat sheet for pounds but we're not going to use that we're gonna use our pie chart because that helps operators out so I want you to go ahead and draw out your circle your pie and I want you to fill it in with all this information I want you to filled in with your flow and your Beauty concentration and that 8.34 pounds per gallon and when you're done it should look something like this so I put it in my flow for MDD which I got from right here put in my concentration 250 milligrams per liter which I got from right here I've got eight point three four pounds per gallon which is my constant and I want to find out how many pounds per day of bo d are coming into my plant so when I multiply this by this by this it's just like down here flow times eight point three four times concentration flow times eight point three four times concentration you should wind up with eight thousand three hundred and forty pounds of bo d per day and that's it it's a very simple question like I said this this pie really helps operators out a lot when they're struggling with algebra so let's go on to the next question which is going to be what I was talking about worth you cover up this and they give you this you divide to find out the concentration so uh here we go they give you a flow of four I'm GD and they give you pounds eight thousand three hundred and forty and they want to know the VOD concentration in milligrams per liter so if you were to do this briefly this is what the formula would look like and this is why the pie is nice because instead of memorizing three formulas to figure out any part of this pie all you have to do is are all one pie and know that anything below is multiplied to get the top and anything in the top is divided by the bottom to find one of the bottom ones so but algebraically its pounds per day divided by mg D times eight point three four pounds per gallon but instead of using that we're gonna go ahead and draw it our pie so I want you to draw the pie and fill it in with the information eight thousand three hundred and forty pounds per day which is from right here for mg d from right here eight point three four pounds per gallon which is your constant and what we want to find is the concentration milligrams per liter so if you take your pounds and divide it by 4 mg d and divide it by eight point three four pounds per gallon you should get two hundred and fifty milligrams per liter which other was exactly the same question as the last one we did when we wanted to find pounds per day they gave us a concentration of 250 milligrams per liter so that's the way the pie formula works it's really helpful for struggling operators so I recommend you go this route when doing pounds very helpful very helpful all right let's move on

Channel: CAwastewater

Views: 109,689

Rating: 4.9182482 out of 5

Keywords: CA, California, wastewater, waste, water, math, grade, one, BOD, COD, organic, Loading, Surface, hydraulic, loading, pounds, pie, dose, demand, residual, chlorine

Id: qRNG-RwxIKc

Length: 8min 6sec (486 seconds)

Published: Thu May 14 2009