1. EDGE Outreach Chlorine Generator Lonna Edwards (ECE), Zachary Russo (ECE), Ryan Shamel (ECE) Mark Hogg, Executive Director; Bob Browning, Field Operations; 1500 Arlington Avenue; Louisville, KY 40206

2. Trapped on an island?!

3. The Three Necessities of Survival Food, shelter, but most importantly: clean water!!!

4. Global Epidemic

5. Frightening Statistics

6. “More children die from bad water than war”

7. EDGE Overview

8. What Edge Outreach Does Manufactures, installs, and trains operators in the operation and use of water purification equipment Utilizes membrane cell chlorine generators Started manufacturing the chlorine generators in the Fall of 2011 Trains people to repair water pumps Health and hygiene training

9. Water Purification Humble beginnings in Africa John Snow links cholera to water contamination in 1800’s Louis Pasteur discovers the ‘germ’ in the late 1800’s Water purification for the masses in London, Chicago, and New Jersey Membrane cells are now in common use for chlorine generation and sodium hydroxide production

10. Membrane Cell Chlorine Generator Uses electrolysis to decompose a brine solution (NaCl) into chlorine gas, sodium hydroxide, and hydrogen gas http://www.rod.beavon.clara.net/membrane_cell.htm (modified)

11. Electrochemical Reactions Anode Chamber: 2Cl - -> Cl 2 (gas) + 2e - Chloride ions are oxidized to chlorine gas and free Na + Cathode Chamber: 2H 2 O + 2e - -> H 2 (gas) + 2 OH - Hydrogen ions from the water are reduced to hydrogen gas, leaving behind a solution of sodium and hydroxide ions, i.e. a solution of sodium hydroxide The membrane cell’s successful operation depends on the membrane between the anode and cathode chambers It is a modified PTFE called Naflion (a du Pont polymer) Essentially a cation-exchange membrane The membrane will pass cations (Na + ions), but not anions (OH - ) between the compartments of the cell

12. EDGE Chlorine Generator Chlorine gas released from anode chamber through this tubing

13. EDGE Chlorine Generator Connect to internal electrodes (Black: Cathode Red: Anode)

14. EDGE Chlorine Generator Cathode Chamber

15. EDGE Chlorine Generator Anode Chamber

16. Program Plan

17. Project Goals Design a test capability for the Edge chlorine generator Define facility modifications that are required for production testing of the chlorine generator Develop test procedures that will allow Edge unskilled operators to use the test set, and perform qualification and acceptance test of the manufactured chlorine generators Characterize the new chlorine generator design using the improved test capability

18. Test Improvements Improved test methods Direct measurement of Chlorine Vernier colorimeter and the associated procedures Redesign and develop improved LabView software to automate testing, and incorporate the colorimeter Add potentiostat testing of the chlorine generator to characterize the efficiency of the electrodes The potentiostat was developed by a previous project Improved test procedures It is anticipated that these improved procedures will allow a “bench test” of the chlorine generator, eliminating the need to install the generator in a water purifier in order to test it

19. Test Facility Improvements Properly specified fume hood for operator safety The membrane cell develops free chlorine and hydrogen gas Mixing and use of standard solutions for the tester, requiring additional lab equipment: Balance Mixers Containers Micro-dispensers Etc. Use of a standard power supply, instead of a 12 VDC battery This assures reproducible test results Additional safety equipment Safety glasses, lab coats, gloves, etc.

20. Software Development The LabView code will have to be modified to incorporate the Vernier colorimeter The current code does not provide adequate report generation

21. Potentiostat A potentiostat measures current and voltage at varying potentials Used to better understand the electrochemical properties This is done using cyclic voltammetry Increases potential over a period of time Once a set potential is reached the potential is inverted The current and voltage get measured between the electrodes of the potentiostat as the potential is changed Using a computer interface the potentiostat generates a current vs. voltage graph

22. System Diagram

25. Test Procedures

26. Potentiostat Test Configuration Pour solutions into correct sides of the chlorine generator NaOh into the cathode side NaCl into the anode side Connect the sensors to the chlorine generator just like you would the power supply Connect the potentiostat to the computer using a USB cable

27. Test Procedures Solution preparation Colorimeter calibration Chlorine generator preparation Static/sample measurements Potentiostat Turbidity pH Salinity Chlorine concentration Dynamic measurements Voltage, current, temperature

28. Solution Preparation NaOH Mixed with 20 oz. RO water 1%,5%,10%,15% by weight NaCl Mixed with 20 oz. RO water 1%,5%,10%,15% by weight Colorimeter reagent Hach reagents

29. Colorimeter Calibration Run multiple tests to get the proper calibration on a Vernier Colorimeter Run the chlorine generator for a set amount of time and measure the chlorine level in a water sample using the Vernier and the Hach colorimeters We will compare to a Hach Colorimeter that is already calibrated

30. Colorimeter Calibration The colorimeter works by following Beer’s Law Beer’s Law is a simple law that correlates the absorbance (A), the molar absorbtivity (  ), the path length of the sample (b) and the concentration of the reagent in the sample (c). The path length of the sample is how faw the light travels through the sample. A=  bc

31. Chlorine Generator Test Preparation Add solutions to the proper chambers of the chlorine generator NaOh solution gets added to the cathode side NaCl solution gets added to the anode side Place 500mL of RO water in a beaker that has the chlorine gas tube leading into it Connect the 12V power supply

32. Sample Tests Some parameters must be measured by taking samples Turbidity Will be measured from the beaker collecting the chlorine gas before and after running the generator Free chlorine Will be measured from the beaker which is collecting the chlorine gas periodically while the chlorine generator is running

33. Static Tests Other parameters cannot be measured while the chlorine generator is powered up Electric fields in the cell cause erratic behavior of sensors pH Measured from the anode and the cathode side periodically. Will be looked at by graphing pH vs. time Salinity Measured from the anode side only

34. Dynamic Measurements Voltage Measured to assure that the voltage coming from the power supply is 12V Current Current is believe to change as the chlorine generator runs. Cathode Chamber Temperature Measured to make sure the cathode chamber is not becoming to hot.

35. Turbidity Turbidity is the cloudiness or haziness of water that is caused by individual particles (suspended solids) that cannot typically be viewed Units of turbidity are NTU It is very important to measure turbidity during water purification processes The amount of hypochlorite/chlorine gas required for safe drinking water changes with different turbidity levels Reference: Sodium Hypochlorite Dosage for Household and Emergency Water Treatment, Daniele Lantagne, AWAA Journal Volume 100:8, pgs. 106-119,August, 2008.

36. Instrumentation

37. Instrumentation-Turbidity Sensor Water sample which was purified by using the chlorine generator that is being tested will be placed into the turbidity sensor We will be using Vernier Turbidity Sensor which can measure from 0 to 200 NTU. 1 NTU is standard for unfiltered drinking water, 0.5 NTU for filtered

38. Instrumentation - Voltage Probe Voltage probe will be connected to the chlorine generator to measure approximately 12V across electrodes We will be using Vernier 30 Volts Voltage Probe which is able to measure voltages in the range of -30 to 30 Volts

39. Instrumentation - Current Sensor Current sensor will be connected to the 12VDC Power Supply We will use Vernier High Current Sensor The High Current Sensor has a range of ±10 A

40. Instrumentation - pH Sensor The PH sensor will be placed into a beaker with water which was purified by using the chlorine generator that is being tested We will be using Vernier PH sensor

41. Instrumentation - Salinity Sensor Salinity sensor will be placed in the beaker with water The Salinity Sensor easily and precisely measures the total dissolved salt content in an aqueous solution We will be using Vernier Salinity sensor This sensor has range of 0 to 50,000 ppm Drinking water salinity should be < 3,000 ppm

42. Instrumentation-Temperature Sensor Temperature probe will be placed in the beaker with water We will be using Vernier Stainless Steel Temperature Probe, which has a range of -40 to 273 F

43. Instrumentation - Colorimeter The colorimeter will be used to test the amount of chlorine generated We sill be using a Vernier colorimeter 4 wavelength 5VDC, 25 mV Supply Voltage 40 mV Supply Current

44. Instrumentation - Potentiostat We will use a potentiostat to create graphs of voltage vs. current We are using an Arduino potentiostat

45. Data Acquisition Module All sensors will be plugged into a data acquisition (DAQ) module We will be using 2 SensorDAQ modules, which are made by Vernier. Turbidity Sensor PH Sensor Salinity Sensor Voltage Probe Current Sensor Temp Probe USB to DDMS

46. Current Status LabVIEW training scheduled for March 6th Developing test procedures needed to characterize the chlorine generator

47. Moving Forward Complete LabVIEW code needed to display all tests being performed Complete testing for voltage, current and free chlorine Begin mixing different solutions for testing Determine best case for functional use

48. Questions?