Jar Testing Machines – Not Just for Making High End Martinis Anymore Robin Lee, P.E.

AWWA Spring Conference 2008 Agenda  Background Questions  History  Modern Day  Mechanics  Benefits of jar testing

AWWA Spring Conference 2008 Background Questions  How many people have done a jar test?  How many people do routine jar tests?  Why or why not? – Not trained. – Time consuming. – Don’t understand how to interpret results.

AWWA Spring Conference 2008 Goal of Today’s Presentation  Debunk the numerous reasons/excuses for not performing jar test.  Show jar test value (other than just stirring martinis).  Prove that jar tests are not that hard.  Illustrate the many reasons why jar tests should be done.  And of course, have a little fun....

AWWA Spring Conference 2008 Why Martinis?!?  The methods to make martinis has been around since 1887 and remain relatively the same, however—  The ingredients have changed!  AND WE STILL DRINK MARTINIS!

AWWA Spring Conference 2008 How Martinis are Similar to Jar Tests  The methods to conduct a jar test date back to 1920s and have stayed relatively the same...  BUT the ingredients and concepts have changed! Old ConceptsNew Concepts Metal Salts ACH/PACL Polymers Manufactured polymers TurbidityTotal organic carbon Standard pHpH Adjustment Multiple testsChemTrac  Not grandpa’s recipe anymore!!

AWWA Spring Conference 2008 History  First jar test run on the Sacramento in the 1920s  Similar design and methods used today  Used to be conducted on regular basis.... As much as once per week!

AWWA Spring Conference 2008 Modern Day  Many plants rely on the same chemicals and focus more on changing dosages and not chemicals  New employees do not have “hands on experience” with water chemistry  Many jar test machines collect dust

AWWA Spring Conference 2008 Mechanics  How to run a jar test  Calibration  How to interpret results

AWWA Spring Conference 2008 How to Run a Jar Test – Select Chemicals and Doses  What has been used in the past  Try new coagulants, coagulant aids, and/or filter aids  Research new manufactured polymers  Test a variety of coagulants using Chemtrac to determine how they work on raw water

AWWA Spring Conference 2008 How to Run a Jar Test – Interpreting Chemtrac Results Dose Charge Optimum dose range is where charge decreases most drastically - +

AWWA Spring Conference 2008 How to Run a Jar Test – Run Test  Fill 6 jars with raw water  Prepare chemical dosages  Determine Mixing Times/Energy by mimicking plant  Example Mixing Scheme – 1 min 295 rpm (rapid) – 5 minute 100 rpm – 5 min 60 rpm – 5 minute 30 rpm – Settle for 30 minutes

AWWA Spring Conference 2008 How to Run a Jar Test - Calibration Stage 1 Stage 2 Stage s s s -1 Flocculation Settling Filtration Rapid Mix Add coagulant aids Add polymers/coagulants Add filter aids

AWWA Spring Conference 2008 How to Run a Jar Test – Determining Mixing Scheme Speed, rpm G, s -1 Find energy from plant Then determine mixing speed from graph Graph Created by: Camp, 2930s

AWWA Spring Conference 2008 How to Run a Jar Test – Interpretation  Create record keeping sheet  Record chemicals and dosages  Watch for floc formation time and type – Haze – Pin – Heavy  “Best physical floc”  Record filtered water TOC and turbidity

AWWA Spring Conference 2008 How to Run a Jar Test – Filterability Test  Sample all or best floc sample  Filter sample (0.45 µ)  Test for turbidity and TOC in settled water and filtered water

AWWA Spring Conference 2008 Flow Chart of Procedures Start with routine dosing scheme (between 10-30mg/L Run Test Inspect each jar for best physical appearance of floc Is there a good floc formation? YES NO Try new coagulant dose, coagulant aid, or pH adjustment Filter and test sample for turbidity and TOC NO YES Did the coagulant decrease TOC & turbidity? Optimize dosing scheme by a few mg/L. Optimize until exact dose is determined

AWWA Spring Conference 2008 Why Jar Test  React to changing water conditions and standards  Optimize coagulation  Best water quality  Use less chemicals  Save money

AWWA Spring Conference 2008 The Benefits Shown Graphically $ Dose Turbidity $ Cost Savings

AWWA Spring Conference 2008 Let’s Review Today’s Message  You are now trained to run a jar test.  Jar tests may be time consuming, but considering the benefits or money and water quality, it is small price to pay.  You should now understand how to interpret results, it can even be qualitative.

AWWA Spring Conference 2008 Questions