Improving Water Quality

Transcription

1 Improving Water Quality Treating Disinfection Byproducts (DBP s) Using Chlorine Dioxide (ClO 2 ) &Hydrogen Peroxide (H 2 O 2 )

2 Total Organic Content & Florida s Groundwater Florida Groundwater

3 Jar Testing Procedures for Chlorine Dioxide (ClO 2 ) Improving Water Quality & Lowering DBP Formation Florida Rural Water Assn

4 Demonstration Format Jar Testing needs to begin, so we will jump right in to that and then cover some of the introductory information while we wait for the Jar Test to be completed. Florida Rural Water Association ~ ClO2, ClO2 & DBPs 4

5 Prepare the 0.3% ClO 2 Standard Solution 1. Read the Safety Data Sheet (SDS) & follow the safety instructions for A & B TwinOxide Powder and ClO 2 Solution Florida Rural Water Association ~ ClO2, Jar Testiong 5

6 Prepare the 0.3% ClO 2 Standard Solution 2. The day before test, prepare the 3,000 mg/l (0.3%) Solution of Chlorine Dioxide (TwinOxide or ClO 2 ) by adding 20 grams of A & B TwinOxide Powder to 1 Liter of Distilled Water. Use a water tight container. Florida Rural Water Association ~ ClO2, Jar Testiong 6

7 Prepare the 0.3% ClO 2 Standard Solution 3. Securely close the container. 4. Do not shake or stir. Florida Rural Water Association ~ ClO2, Jar Testiong 7

8 Prepare the 0.3% ClO 2 Standard Solution 5. Securely close the container and wait according to the timetable. 25 C (77 F) > 3 hours 20 C (68 F) > 4 hours 15 C (64 F) > 5 hours Florida Rural Water Association ~ ClO2, Jar Testiong 8

9 Prepare the 0.3% ClO 2 Standard Solution 6. Shake or stir the solution gently Beware of ClO 2 gas release. 7. TwinOxide solution is ready for use for approx. 30 days write the date of preparation on the container. Florida Rural Water Association ~ ClO2, Jar Testiong 9

10 Prepare the 0.3% ClO 2 Standard Solution 8. Store in a cool and dark place. Florida Rural Water Association ~ ClO2, Jar Testiong 10

11 Raw Water for ClO 2 Jar Test 1. Obtain about 5 gallons of raw water from each well just before starting the jar tests. Use a clean container. When taking the sample it is important to avoid volatizing hydrogen sulfide. No splashing. The sample should not be shaken or stirred. The nozzle should be very close to the surface of the water container. Be careful that the flow is even and quiescent. Florida Rural Water Association ~ ClO2, Jar Testiong 11

12 Test 0.3% ClO 2 Std Solution 1. On the day of the Jar Test, test strength of 0.3% (3,000 mg/l) ClO 2 Standard Solution. The DPD Glycine Powder Pillows have a range mg/l ClO 2 so you need to dilute the standard for testing. 2. Add 1 ml of 0.3% ClO 2 Standard Solution to 1 Liter of Distilled Water. This should give you 3 mg/l ClO 2 Std Soln. 3. Measure the strength of the dilution by testing a 10 ml sample using the Colorimeter. Florida Rural Water Association ~ ClO2, Jar Testiong 12

13 Test 0.3% ClO 2 Std Solution 4. Adjust the jar test spreadsheet according to the strength. 5. For example if the measured strength is 2.5 mg/l, then Cell D9 of ClO2 Std Soln Tab should be modified to read 2,500 ppm. 6. Proceed with the Jar Test Florida Rural Water Association ~ ClO2, Jar Testiong 13

14 ClO 2 Jar Test 1. First, measure and pour 250 ml (0.25 L) of Raw Water into 4 or more 250 ml Beakers. 2. Raw water sample is treated with a different doses of the ClO2 Standard Solution, see Jar Test Tab. 3. Determine the optimal dose of ClO2 by compare the residuals and final water quality achieved in each beaker. Florida Rural Water Association ~ ClO2, Jar Testiong 14

15 ClO 2 Jar Test 4. Record everything spreadsheet Color, Odor, Residuals, Times, etc. 5. Record chemicals & dosages 6. Watch for changes Color & Odor 7. Determine optimal dose of ClO2 by comparing ClO2 residuals and final water quality achieved in each beaker. Florida Rural Water Association ~ ClO2, Jar Testiong 15

16 ClO 2 Jar Testing Procedures FRWA Spreadsheet Raw Water Data Total Organic Carbon (TOC) Sulfide Iron Chloride Turbidity Alkalinity Total Dissolved Solids (TDS) Temperature & ph Florida Rural Water Association ~ ClO2, Jar Testiong 16

17 ClO 2 Jar Testing Equipment Chlorine Dioxide Reagent DPD Powder Pillows, 10 ml Glycine Reagent for DPD testing Florida Rural Water Association ~ ClO2, Jar Testiong 17

18 ClO 2 Jar Testing Equipment Hach Pocket Colorimeter DR 890 About $400 Florida Rural Water Association ~ ClO2, Jar Testiong 18

19 ClO 2 Jar Testing Equipment (1) 1 Liter watertight container for the ClO2 Standard (6) 250 ml Glass Beakers (1) 1 Liter Measuring Cup Timer / Stop Watch Florida Rural Water Association ~ ClO2, Jar Testiong 19

20 TwinOxide A & B Powder (ClO 2 ) Sodium Chlorite Stable inert salts Sodium Bisulfate 20

21 ClO 2 Jar Testing Equipment (1) 5 gallon bucket for raw water, clean Fill container carefully, avoid splashing, jarring, or sloshing (H2S) Florida Rural Water Association ~ ClO2, Jar Testiong 21

22 ClO 2 Jar Testing Equipment (1) 200 µl Micropipet, Variable (12+) µl Pipet Tips Florida Rural Water Association ~ ClO2, Jar Testiong 22

23 ClO 2 Jar Testing Supplies Note Paper Paper Towels (1 or 2 rolls) Distilled Water (2 gallons) Gloves Eye Protection Goggles Cheap bucket for used water Florida Rural Water Association ~ ClO2, Jar Testiong 23

24 ClO 2 Jar Test Optimum dose range is where color / odor decreases most drastically Color & Odor ClO2 Dose Florida Rural Water Association ~ ClO2, Jar Testiong 24

25 ClO 2 Jar Test 0.35 ClO 2 Jar Test 0.3 CLO 2 1 HOUR CLO 2 DOSE Florida Rural Water Association ~ ClO2, Jar Testiong 25

26 Jar Testing Chlorine Dioxide Several systems with mixed results Promising for most applications Smaller systems seem to work best Difficult to test for dosing since H 2 S escapes from water from moment of sampling Pin floc (elemental sulfur / iron) is same as oxidation by chlorine and captured in tanks Florida Rural Water Association ~ ClO2, Jar Testiong 26

27 Chlorine Dioxide Recommendations Iron & sulfur reducing bacteria are likely present in the raw water and will have seeded the existing distribution system chlorination is required to control regrowth in the distribution system. Iron & sulfur reducing bacteria slow working Install automatic flushing valves Florida Rural Water Association ~ ClO2, Jar Testiong 27

28 Jar Testing Procedures for Hydrogen Peroxide (H 2 O 2 ) Improving Water Quality & Lowering DBP Formation Florida Rural Water Assn

29 Prepare the 350 mg/l H 2 O 2 Standard Solution 1. Read the safety data sheet (SDS) & follow the safety instructions for 35% H2O2 Solution 2. The day of test, prepare the 350 mg/l H2O2 Solution by adding 1 ml of 35% H2O2 Solution to 1.0 Liter of Distilled Water. 3. Stir with the pipet. Florida Rural Water Association ~ H2O2, Jar Testiong 29

30 Prepare the 350 mg/l H 2 O 2 Standard Solution 4. Do NOT reuse the pipet tip for anything other than the standard 5. H2O2 standard solution is ready for use. 6. Proceed with the Jar Test Florida Rural Water Association ~ H2O2, Jar Testiong 30

31 H 2 O 2 Jar Test 1. Obtain about 5 gallons of raw water from each well just before starting the jar tests. Use a clean container. When taking the sample it is important to avoid volatizing hydrogen sulfide. No splashing. The sample should not be shaken or stirred. The nozzle should be very close to the surface of the water container. Be careful that the flow is even and quiescent. Florida Rural Water Association ~ H2O2, Jar Testiong 31

32 This image cannot currently be displayed. H 2 O 2 Jar Test 2. First, measure and pour 2.0 Liters of Raw Water into 4 or more Beakers. 3. Leave (1) beaker untreated for comparison 4. Record initial Odor & Color H2O2 Residual (mg/l) 5. Treated Raw water samples with different Doses of H2O2, see Jar Test Tab. Florida Rural Water Association ~ H2O2, Jar Testiong 32

33 H 2 O 2 Jar Test 6. Record everything spreadsheet Color, Odor, Residuals, Times, etc. 7. Record chemicals & dosages 8. Watch for changes Color & Odor 9. Determine optimal dose of H2O2 by comparing H2O2 residuals and final water quality achieved in each beaker. Florida Rural Water Association ~ H2O2, Jar Testiong 33

34 H 2 O 2 Jar Testing Procedures FRWA Spreadsheet FRWA Whitepaper Raw Water Data Total Organic Carbon (TOC) Sulfide Iron Turbidity Alkalinity Total Dissolved Solids (TDS) Temperature & ph Florida Rural Water Association ~ H2O2, Jar Testiong 34

35 H 2 O 2 Jar Testing Equipment CHEMetrics H2O2 Test Kit with Reagent Vials (0 0.8 & 1 10 ppm) Florida Rural Water Association ~ H2O2, Jar Testiong 35

36 H 2 O 2 Jar Testing Equipment (1) 1 Liter Glass Beaker for the H2O2 Standard (4) 2 Liter Glass Beakers / Vases for raw water testing (straight sides) (1) 1 Liter Measuring Cup Timer / Stop Watch Florida Rural Water Association ~ H2O2, Jar Testiong 36

37 H 2 O 2 Jar Testing Equipment Pharmacy Grade 3% Concentration 3% solution = 30,000 mg/l Industrial Grade 35% Concentration Same safety protocols as 12.5% NaOCl 55 gallon drum & feed pump Feed Rate ~ 3 mg/l Florida Rural Water Association ~ H2O2, Jar Testiong 37

38 H 2 O 2 Jar Testing Equipment (1) 5 gallon bucket for raw water, clean Fill container carefully, avoid splashing, jarring, or sloshing (H2S) Florida Rural Water Association ~ H2O2, Jar Testiong 38

39 H 2 O 2 Jar Testing Equipment (1) Hach TenSette Single Channel Pipettor, 1.0 to 10.0 ml, (12+) 10 ml Pipettor Tips (1) Hach TenSette Single Channel Pipettor, 0.1 to 1.0 ml, (12+) 1.0 ml Pipettor Tips Florida Rural Water Association ~ H2O2, Jar Testiong 39

40 H 2 O 2 Jar Testing Equipment Florida Rural Water Association ~ H2O2, Jar Testiong 40

41 H 2 O 2 Jar Testing Supplies Note Paper Paper Towels (1 or 2 rolls) Distilled Water (2 gallons) Gloves Eye Protection Goggles Cheap bucket for used water Florida Rural Water Association ~ H2O2, Jar Testiong 41

42 H 2 O 2 Jar Test Optimum dose range is where color / odor decreases most drastically Color & Odor H2O2 Dose Florida Rural Water Association ~ H2O2, Jar Testiong 42

43 H2O2 Jar Test Before & After Florida Rural Water Association ~ H2O2, Jar Testiong 43

44 H 2 O 2 Jar Test H2O2 Residual should be less than 1.0 mg/l optimal about 0.5 mg/l Objective: Do NOT overfeed H2O2 H2O2 Residual 1.0 mg/l 3.0 mg/l H2O2 Dose Florida Rural Water Association ~ H2O2, Jar Testiong 44

45 Jar Testing Hydrogen Peroxide Several systems with mixed results Promising for most applications Smaller systems seem to work best Difficult to test for dosing since H 2 S escapes from water from moment of sampling Pin floc (elemental sulfur / iron) is same as oxidation by chlorine and captured in tanks Florida Rural Water Association ~ H2O2, Jar Testiong 45

46 Hydrogen Peroxide Recommendations Iron & sulfur reducing bacteria are likely present in the raw water and will have seeded the existing distribution system chlorination is required to control regrowth in the distribution system. Iron & sulfur reducing bacteria slow working Install automatic flushing valves Florida Rural Water Association ~ H2O2, Jar Testiong 46

47 Questions?