Jar Testing of Chemical DosagesPrepared ByMichigan Department of Environmental QualityOperator Training and Certification Unit

Jar TestingDetermination of most effective chemicalDetermination of most effective dosageDetermination of optimum point of applicationEvaluation of polymers

Jar TestingEquipment Needed:

Gang Stirrer6 Graduated Beakers, 1500 ml2 Graduated Pipets, 10 ml1 Graduated Cylinder, 1000 mlScale for weighing chemicalsAnalytical Equipment

Jar TestingPreparation of Stock SolutionsFor alum, lime, other dry materials:Use a 1 % solution. Dissolve 10 grams into 1000 ml distilled water. (1 ml = 10 mg/l in 1000 ml)

For Ferric Chloride, other liquid materials:Use a 1 % solution. Obtain % solution and specific gravity from supplier.

Dilute appropriate volume up to 1000 ml to make a 1 % (10,000 mg/L) solution. (1ml=10 mg/l in 1000 ml)Preparation of Stock Solutions

Solution Dilution45 % X 1.49 X V1 = 1 % X 1000 mlHave 45 % Ferric Chloride Solution(Specific Gravity 1.49)Need 1000 mls of a 1 % (10,000 mg/L) Sol.C1 X V1 = C2 X V2= 14.91 ml

Jar TestingFor Dry or Liquid Polymers:

Use a 0.01 % (100 mg/L) solution. Weigh 0.1 gram and dissolve in 1000 ml distilled water.

(1 ml = 0.1 mg/l in 1000 ml)Preparation of Stock Solutions

Blank 5 mg/L 10 mg/L 15 mg/L 20 mg/L 25 mg/LCalculate the volume of a 1 % Ferric Chloride solution that would be added to get the dosage required.1000 ml1% = 10,000 mg/L 10,000 mg/L X ? ml = 5 mg/L X 1000 ml? ml = 5 X 0.1 = 0.5 ml10 X 0.1 = 1.0 ml15 X 0.1 = 1.5 ml20 X 0.1 = 2.0 ml25 X 0.1 = 2.5 mlJar Testing Calculations

Jar Testing CalculationsA jar test indicates that the required amount of phosphorus removal can be achieved using a dosage of 3 ml of a 1% ferric chloride solution in a liter of wastewater. What is the dosage in mg/L?C1 X V1 = C2 X V2

10,000 mg/L X 3 ml = ? mg/L X 1000 ml

Jar Testing Using the 1000 ml graduated cylinder, add 1000 ml wastewater to each beaker.

Using the graduated pipets, dose each beaker with the desired concentration of metal salt or polymer, increasing concentration from left to right.

Operate stirrer to simulate plant process.

Determine best dosage level by analysis of supernatantProcedure

Gang StirrerAddition of ChemicalsRapid MixSlow Mix - FlocculateSettle

Determine which dosage is best for meeting requirements

Chemical Handling After jar testing has been used to determine best chemical dosage in mg/L, pounds of chemical needed per day into a given flow or volume can be calculated.lbs/day = MGD X 8.34 lbs/gal X mg/Lie) A dosage of 25 mg/L Ferric Chloride is needed. The flow to be treated is 350,000 gallons per day. How many lbs of Ferric Chloride will have to be fed each day?lbs/D = 0.35 MGD X 8.34 lbs/gal X 25 mg/L = 73 lbs/D FeCL3

Chemical Handling Given lbs/d of dry chemical to feed, need to calculate the gallons of solution to feed.Specific Gravity = the number of times heavier or lighter the solution is than water1 gallon of water weighs 8.34 lbsSpecific gravity of water = 1.000Specific Gravity

If a solution has a Specific Gravity of 1.510,then this solution is 1.510 times heavier thanwater.

8.34 lbs/gal X 1.510 = 12.59 lbs/galA solution with a Specific Gravity of 0.750would weigh:8.34 lbs/gal X 0.750 = 6.255 lbs/galSpecific Gravity

Obtain S.G. from Supplier or by Using a Hydrometer

Chemical Handling Strength of Concentrated Solutions are usually given as Percent by WeightIn 100 lbs of a 35 % solution there are 35 lbs of dry chemical35 % = 35 per 100

If the weight of a gallon of solution is known, the weight of dry chemical in each gallon of the solution can be calculated:A 40% solution has a specific gravity of 1.43B. Determine the lbs of dry chemical in each gallon.

Chemical Handling Feed Rates

If the lbs per day of chemical to be fed is known, and we know the pounds of dry chemical in each gallon of the solution, the gallons per day of solution to be fed can be calculated.

ie) 150 lbs per day ferric chloride are to be fed. The solution to be used is 38% with a specific gravity of 1.413. Calculate the gallons of solution to feed each day.8.34 lbs/gal X 1.413 = 11.78 lbs/gal

0.38 X 11.78 lbs/gal = 4.48 lbs dry chem/gal150 lbs/d dry chem needed 4.48 lbs dry chem/gal= 33.5 gal/dayChemical Handling

Chemical Handling Pumping Rate Calculations

Given gallons per day of chemical needed, calculate gallons per minute

Calibration of Chemical Feed Pump

1. Set pump at known setting2. Start pump and collect at the application point a measured amount in a known period of time.3. Repeat for various settings.4. Convert to needed units.

Chemical Feed Summary1. Determine lbs/day of dry chemical needed. 2. Determine the weight (lbs/gal) of the soln.

3. Determine weight of dry chem in each gallon.

4. Determine gallons per day to be fed.

5. To Determine pumping rate in gallons/minute: mg/L X MGD X 8.34 lbs/gal = lbs/d dry chem 8.34 lbs/gal X Sp.Gr. = lbs/gal (liquid weight) lbs/gal (liquid wt) X % soln = lbs dry/gallonLbs dry needed per day = gal/day to be fed lbs dry/gallon

Chemical Handling Calculations Example Problem #11. Calculate the pounds per day of FeCl3 that must be added to the wastewater flow.Jar Test Results23 mg/L FeCl3 Dosage NeededWastewater Flow300,000 gallons per day

Ferric Chloride SolutionSpecific Gravity1.500Concentration45 %Work Calculations on Separate PaperAnswers Given on Next Slides2. Calculate the weight in pounds of a gallon of the FeCl3 solution. 3. Calculate the pounds of dry FeCl3 per gallon of the solution.4. Calculate the number of gallons of the FeCl3 solution that must be fed per day. 5. How many gallons per minute must the chemical feed pump be set to deliver ?

Chemical Handling Calculations Example Problem #11. Calculate the pounds per day of FeCl3 that must be added to the wastewater flow.Jar Test Results23 mg/L FeCl3 Dosage NeededWastewater Flow300,000 gallons per day

Ferric Chloride SolutionSpecific Gravity1.500Concentration45 %lbs/d = 23 mg/L X 8.34 lbs/gal X 0.30 MGD= 57.55 lbs/d

3. Calculate the pounds of dry FeCl3 per gallon of the solution.12.51 lbs/gal X 0.45 = 5.63 lbs dry/gallon8.34 lbs/gal X 1.500 = 12.51 lbs/gal2. Calculate the weight in pounds of a gallon of the FeCl3 solution.

4. Calculate the number of gallons of the FeCl3 solution that must be fed per day. 5. How many gallons per minute must the chemical feed pump be set to deliver ?

Calculate the number of milliliters per minute that must be fed of a 49 % Aluminum Sulfate solution with a specific gravity of 1.33 to dose a flow of 150,000 gallons per day at 25 mg/L.Chemical Handling Calculations Example Problem #2Work Calculations on Separate PaperAnswers Given on Next Slide

Calculate the number of milliliters per minute that must be fed of a 49 % Aluminum Sulfate solution with a specific gravity of 1.33 to dose a flow of 150,000 gallons per day at 25 mg/L.25 mg/L X 0.15 MGD X 8.34 lbs/gal = 31.28 lbs/d8.34 lbs/gal X 1.33 X 0.49 = 5.44 lbs dry/gal15.11 ml/minChemical Handling Calculations Example Problem #2

120 gallons/day of a ferric chloride solution was fed into a flow of 2.5 MGD. The ferric chloride solution had a concentration of 40 % and a specific gravity of 1.430. Calculate the chemical dosage in mg/L. Chemical Handling Calculations Example Problem #3Work Calculations on Separate PaperAnswers Given on Next Slide

120 gallons/day of a ferric chloride solution was fed into a flow of 2.5 MGD. The ferric chloride solution had a concentration of 40 % and a specific gravity of 1.430. Calculate the chemical dosage in mg/L. 8.34 lbs/gal X 1.430 X 0.40 = 4.77 lbs dry/gal120 gal X 4.77 lbs dry/gal = 572.5 lbs dry/day572 lbs/day = 2.5 MGD X 8.34 lbs/gal X mg/LChemical Handling Calculations Example Problem #3

Jar Testing of Chemical DosagesPrepared ByMichigan Department of Environmental QualityOperator Training and Certification Unit