1. Chlorine Generator Test Apparatus ECE 599, Fall 2011 Vincent Korfhage, Vladimir Chausenko, Sam Ryan, Ryan Ray

2. Background Information Approximately 1 in 8 people do not have safe drinking water. 3.757 million people die yearly due to water-related diseases. Historically, one of the first chlorine generators was developed and used in Louisville in response to ongoing problems with typhoid death rates. For example, after adding the chlorination system to water in Louisville, the typhoid death rate fell from 52.7/100,000 to 0.9/100,000 in 30 years. There are Non-Governmental Organizations (NGOs) that deliver water purifiers to third world countries, and countries needing disaster relief These water purifiers use chlorination to destroy bacteria Water can come from rivers or lakes that are normally not safe to drink from These NGOs need low cost chlorine generators, and they need a capability to test/evaluate commercially available chlorine generators

3. Chlorination of Water There are two commonly used methods to purify water using Chlorine Electrolysis of NaCl in water to produce Sodium Hypochlorite Electrolysis of NaCl in water to produce Chlorine gas Louisville Water Co. uses the Sodium Hypochlorite technique A solution of NaCl in the water to be treated is electrolyzed into NaClO Edge Outreach, a local NGO, uses a chlorine gas generator Chlorine gas is ”bubbled” into the treated water Testing of treated water is required to make certain that the free chlorine residual is between 0.2 and 0.5 mg/l at the point of use

4. Project Requirements Survey and obtain commercially available chlorine generators Develop a procedure for water purification using the selected chlorine generator Develop a test/evaluation capability for the water purification system The test/evaluation system must: Allow the end-user to characterize the efficiency of the chlorine generator Determine whether the correct amount of chlorine is being generated Determine if the chlorine generator is operating adequately to purify the volume of water of interest in a reasonable amount of time

5. Chlorine Generation Options Chlorine Gas Generator Sodium Hypochlorite Generator Both technologies use aqueous NaCl solutions to make chlorine

6. Chlorine Gas Generator Operation Selective permeable membrane allows sodium ions to pass The membrane acts as a barrier to mixing, producing sodium hydroxide and a brine solution that contains chlorine gas The chlorine gas evaporates from the brine solution Hydrogen gas is produced in the sodium hydroxide cell The chlorine gas is then collected and used to purify drinking water.

7. Chlorine Gas Generation http://www.rod.beavon.clara.net/membrane_cell.htm

8. Sodium Hypochlorite Generator Operation Water from the reservoir containing salt (NaCl + H2O) enters the cell The hypochlorite generator electrolyzes the NaCl + H2O solution, creating Hypochlorite (NaOCl), which is then pumped into the reservoir Then Sodium Hypochlorite in the reservoir (NaOCL) decomposes back into (NaCl + H2O) Then this solution enters the cell again, fresh hypochlorite is generated

9. Hypochlorite Generation

10. System Diagram – Hypochlorite

11. System Requirements Implement a water purifier from commercially available components. The hypochlorite water purification system was used as the test article Hypochlorite concentration should be between 2.5 to 3.8 mg/L at the end of the purification cycle Must be 0.2 mg/L of hypochlorite after 24 hours If less then 0.2 mg/L must re-purify Salt concentration in water should not exceed 1g/L Room temperature (25 C) is preferable for water purification Provide a test and characterization capability for the water purification system

12. Test and Management Requirements Measure Data Turbidity pH Salinity Current and voltage of the generator cells during the purification cycle Temperature of water Management System requirements Graphical user interface System configuration Instrument calibration Data acquisition Time tag and store measured data Provide a report capability that summarizes and displays the test data after each purification cycle

13. Major Components Water Purifier Instrumentation (sensors) Data Acquisition Modules Display/Data Management System (DDMS)

14. Water Purifier Intex Salt Water System (chlorine generator) Uses non-iodized salt-water solution to create hypochlorite to purify contaminated drinking water This is low cost, commercially available pool chlorine generator which is used to sanitize water in swimming pools

15. Measurements Turbidity Temperature pH of purified water Current Voltage Salinity

16. Turbidity Turbidity is the cloudiness or haziness of water that is caused by individual particles (suspended solids) that are generally invisible to the naked eye 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.

17. Instrumentation-Turbidity Sensor Water sample which was purified by using the chlorine generator that is being tested places into the turbidity sensor The system uses Vernier Turbidity Sensor which can measure from 0 to 200 NTU. 1 NTU is standard for unfiltered drinking water, 0.5 NTU for filtered

18. Instrumentation-Temp Probe Temperature probe places in the reservoir with water The system uses Vernier Stainless Steel Temperature Probe, which has a range of -40 to 273 F

19. Instrumentation-PH Sensor The PH sensor places into a reservoir with water which was purified by using the chlorine generator that is being tested (The normal range for pH in drinking water is 6.5 to 8.5) The system uses Vernier PH sensor

20. Instrumentation-Current Sensor Current sensor connects to the 12VDC battery Current level depends on charge of the battery (2-5 Amps for fully charged and 20-40 Amps for discharged battery) The system uses Vernier High Current Sensor The High Current Sensor has a range of ±10 A

21. Instrumentation-Voltage Probe Voltage probe connects to the chlorine generator to measure approximately 12V across electrodes The system uses Vernier 30 Volts Voltage Probe which is able to measure voltages in the range of -30 to 30 Volts

22. Instrumentation-Salinity Sensor Salinity sensor places in the reservoir with water The Salinity Sensor easily and precisely measures the total dissolved salt content in an aqueous solution The system uses Vernier Salinity sensor This sensor has range of 0 to 50,000 ppm Drinking water salinity should be < 1,000 ppm (normally drinking water is 100 ppm)

23. Data Acquisition Modules All sensors plug into 2 Data Acquisition Modules The system uses 2 SensorDAQ USB interface cards, which are made by National Instruments. Turbidity Sensor PH Sensor Salinity Sensor Voltage Probe Current Sensor Temp Probe USB to DDMS

24. Display/Data Management System Graphical User Interface (GUI) Displays test value data on graphs Allows user to take measurements, start and end test cycles Data Acquisition and Logging Acquires data from Data Acquisition Modules Measurement values from test cycle are time- stamped and stored in CSV file Generator serial number can be stored with test data

25. GUI Requirements Use LabVIEW to develop an application that: Provides an easy to use GUI Display current, voltage, water temperature, pH and salt concentration in water, voltage across electrodes and turbidity of water Display a running clock once experiment begins Provide an area to enter serial number

26. Graphical User Interface

27. Data Acquisition and Logging

28. Prompt to save.CSV file

29. Data Logging The measurements are stored for later analysis

30. Testing Initial Functionality Testing Test Procedure Test Setup Test Runs and Results

31. Initial Functionality Testing Test functionality and accuracy of each sensor connected to the test apparatus Test for manual prompting of start, stop, and sample functionality in user interface application of DDMS Test display of data in graphs of GUI after user prompt Test generation of.CSV file and proper data logging within.CSV file

32. Test Procedure Place sensors in appropriate ports of sensorDAQs Assign Sensor Ports within User Interface Run Program within LabVIEW Application Dedicate an area for file to save Place sensors in beakers Start Data Acquisition Program Press “Sample” button at desired time intervals End Data Acquisition Program at desired time. Observe logged data in.CSV file

33. Test Setup

34. Test Runs and Results First test run was with tap water mixed with sea salt at 1g/L Chlorine went from.5ppm to 3ppm in 20min of run time Current increased and voltage decreased slightly Temperature rose slightly Second test run was tap water mixed with sea salt at 1g/L mixed with soil to imitate river water Chlorine took 10min longer to get from.5ppm to 3ppm Current was initially higher to begin the experiment Turbidity was much higher

35. Recommendations Additional voltage sensors to measure pump data along with cell data assuming multiple powers sources may be used. Locate an inexpensive chlorine sensor to measure chlorine in solution. Implement sensors for continuous sampling while sensors are in reservoir. Test different generators to determine which is the most efficient. Implement LabVIEW program on handheld device or in stand alone application for field testing.

36. Questions?