Download presentation
Presentation is loading. Please wait.
Published byMartina Moore Modified over 9 years ago
1
Jar Testing Machines – Not Just for Making High End Martinis Anymore Robin Lee, P.E.
2
AWWA Spring Conference 2008 Agenda Background Questions History Modern Day Mechanics Benefits of jar testing
3
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.
4
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....
5
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!
6
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!!
7
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!
8
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
9
AWWA Spring Conference 2008 Mechanics How to run a jar test Calibration How to interpret results
10
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
11
AWWA Spring Conference 2008 How to Run a Jar Test – Interpreting Chemtrac Results Dose Charge Optimum dose range is where charge decreases most drastically - +
12
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
13
AWWA Spring Conference 2008 How to Run a Jar Test - Calibration Stage 1 Stage 2 Stage 3 100 s -1 60 s -1 30 s -1 Flocculation Settling Filtration Rapid Mix Add coagulant aids Add polymers/coagulants Add filter aids
14
AWWA Spring Conference 2008 How to Run a Jar Test – Determining Mixing Scheme 1020 30 40 50 60 70 80 90 100 200 Speed, rpm 500 400 300 200 100 80 60 50 40 30 20 10 G, s -1 Find energy from plant Then determine mixing speed from graph Graph Created by: Camp, 2930s
15
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
16
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
17
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
18
AWWA Spring Conference 2008 Why Jar Test React to changing water conditions and standards Optimize coagulation Best water quality Use less chemicals Save money
19
AWWA Spring Conference 2008 The Benefits Shown Graphically $ Dose Turbidity $ Cost Savings
20
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.
21
AWWA Spring Conference 2008 Questions
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.