1. Mark Ledger MD Agua Africa Mark Titus Product Manager HACH

3. Original Equipment Manufacturer Custom Design and Fabrication Full Spectrum of Filtration Single Media, Dual Media Cartridge Filtration, Bag Filtration Decolourisation, Ion Exchange, DI Iron Removal Ultrafiltration Nanofiltration Reverse Osmosis Disinfection Process Chemicals Marine Engineering ®

4. Biotechnology and Bio Engineering Custom Bio Augmentation programs Selective Bacterial / Enzyme solutions Powders, Solids & Liquid formulations: Industrial / Institutional Agriculture Waste Water Treatment Environmental Bio – Remediation Aqua Culture

5. HTH Scientific – Industrial, Municipal & Commercial ProductsIndustrial HTH ChipsAquacultureBeverage Granular ChlorineBreweriesDairy Stabalised Chlorine TabletsCanneriesMeat Process Chlorine TabletsVinyardsOrchards AlgaecidesPaper & PulpPoultry Metal RemoversTanneriesVegetables CommercialMunicipal Clinical Pools and TanksIndustrial Water MiscellaneousPotable Water RestaurantPrivate Water In Line Feeder Systems Reservoir Chlorination System HTH Controller Units, On line Control & Dosing On line chlorine monitoring and control Automated dosing systems Cal Hypo chips, TCIA, HTH granules Reservoir treatment scientific floaters

6. HACH Scientific Analytical Laboratory Equipment Laboratory Chemicals,Reagents and Media All parameters ( Acidity – Zinc ) Fine chemicals and Supplementary Reagents Single Parameter Test Kits Multi Parameter Test Kits Test Kit Replacement Parts & Reagent re orders Microbiological Laboratory supplies Laboratory and Field instruments Meters and Probes Spectrophotometers and Colorimiters Sample Cells Laboratory and Portable Turbidity Meters General Laboratory Equipment Supplies A – Z of laboratory requirements

7. Linkages & Considerations…… No plant can be designed to be effective without correct analytical information No plant can be operated correctly without accurate analytical information No process can be properly managed without correct analytical information Environmental impact cannot be evaluated without correct analytical information Effective chemical treatment programs cannot be managed and assessed without accurate analytical information. Key is…… understanding and following the correct methodology, process selection, procedures, interpretation and management of your results and information.

8. Application and desired quality of analysis

9. LDO – Luminescent Dissolved Oxygen HACH IntelliCAL Probes Why measure DO ? Applications / Where ? Considerations / Factors Technology / Uniqueness How ? Benefits / Advantages

10. What is Dissolved Oxygen? Dissolved oxygen (DO) is simply a measurement of the amount of oxygen gas dissolved in water. O2O2 O2O2 O2O2

11. Why Measure Dissolved Oxygen? Important indicator of water quality Related to: –Water pollution –Water treatment processes –Chemistry of metals –Biological activity

12. Where is DO Measured? DO Monitoring Points: –Equalization Basin –Aeration Basin –Nitrification Basin –Aerobic/Anaerobic Digester –Plant Effluent

13. Why is DO Measured? Wastewater collection –H 2 S control –Aeration control – i.e. Compressors –Chemical control – i.e. Hydrogen peroxide Equalization basin & Raw junction chamber –Odor control –Pre-aeration to reduce BOD loading –Sudden DO drop may indicate industrial discharge

14. Why is DO Measured…? Aeration basin –Maintain adequate DO level for aerobic organisms, yet low enough DO to conserve energy! Oxidation ditch –Maintain rotor depth and speed Sequencing batch reactor –Use DO levels, rather than time, to control process

15. Where is DO Measured? Trickling filter/RBC effluent channel –Measure effluent channel DO to ensure low recycle rates while maintaining adequate aeration –Ensure proper aeration exists from zoogleal slime development Biological nutrient removal process –Nitrification process maintains DO between 2 - 3 mg/L –Anoxic zone DO < 0.5 mg/L –Anaerobic zone DO < 0.2 mg/L

16. Where is DO Measured…? Final effluent channel –Ensure plant effluent meets discharge/permit /legislative requirements Up and downstream from plant effluent –Ensure effluent does not damage receiving waters

17. Factors Affecting DO DO Saturation tables provide DO saturation concentration based on temperature and pressure

18. Factors Affecting DO DO Solubility as a function of temperature and salinity

19. DO Meter intelliCAL DO meter and probe are used to measure dissolved oxygen concentration electrochemically.

20. DO Meter Advantages Ease of use Limits exposure to chemicals Safe disposal of samples Fast Accurate measurement in colored samples or samples containing suspended solids

21. The Hach LDO Sensor : T hermistor Blue LED Red LED Photo diode Luminescent Dissolved Oxygen

22. How Does HachLDO Work? A sensor is coated with a luminescent material. Blue light from an LED strikes the luminescent chemical on the sensor. The luminescent chemical instantly becomes excited. LED Photo Diode Probe Sensor LED

23. Excitation Pulse How does HachLDO work ? LDO Sensor Sensor cap LED Photo Diode Sensor LED

24. How Does HachLDO Work? As the excited chemical relaxes, it releases red light. The red light is detected by a photo diode. The time it takes for the chemical to return to a relaxed state is measured LED Photo Diode Probe Sensor LED

25. 1 without O 2 Emission Profile Excitation Pulse How Does HachLDO Work? LDO Sensor Sensor cap LED Photo Diode Sensor LED

26. How Does HachLDO Work? When oxygen contacts the luminescent chemical, the intensity of the red light decreases The amount of time it takes for the material to relax is reduced LED Photo Diode Probe Sensor LED Oxygen Luminescent Indicator Molecules Gas Permeable Polymer Matrix Clear, Gas Impermeable Substrate

27. 1 without O 2 Emission profile Excitation Pulse 2 with O 2 How Does HachLDO Work? LDO Sensor Sensor cap LED Photo Diode Sensor LED Oxygen

28. How Does HachLDO Work? The higher the oxygen concentration, the less red light that is given off by the sensor. Oxygen Concentration Red Emission Light

29. How Does HachLDO Work? The intensity of the red light is not whats being measured. Whats being measured is the time it takes after excitation for red light to be given off. –Lifetime of luminescence LED Photo Diode Probe Sensor LED

30. How Does HachLDO Work? A red LED is also present in the probe. Between flashes of the blue LED, a red LED of known intensity, is flashed on the sensor. The red LED acts as an internal standard (or reference) for a comparison to the red light given off by the luminescent chemical. LED Photo Diode Probe Sensor LED

31. Advantages of LDO Reduced Maintenance –No membrane to replace No more stretching of Teflon and worrying about air bubbles –No electrolyte to foul or poison No H 2 S poisoning of the electrolyte No more punctured membranes

32. Advantages of LDO Reduced Maintenance –No anode or cathode No cleaning of anodes No more coating of electrodes

33. Advantages of LDO Frequent Calibration Not Required –No anode to consume and no electrolyte to deplete means extremely stable measurements –Internal standard with Red LED –No interference from pH swings, wastewater chemicals, H 2 S, or heavy metals

34. Advantages of LDO Accurate and Stable Readings –With nothing to interfere with the readings, HachLDO produces more stable measurements for a longer time Speed! –Turn it on and its running! –Response time of less than 30 seconds to 90%! Simple Operation and Maintenance Only one replacement part Inexpensive sensor cap is simple to replace quickly

35. TNTplus – Auto detecting and running of analytical methods Barcoding Multiple cell capability Automatic method detection Autoblanking 240 pre programmed water analysis methods 50 possible user entered calibrations The selection criteria…… application and results

36. Whats the benefit of correct and accurate analytical testing and reporting? Regulations or Permits –Am I in compliance? Process control –Is my plant operating correctly? –Is it time for preventative maintenance? Problems and Troubleshooting –What is wrong with my system? –How can I fix it? Thank you for your attention

37. Mark Ledger MD Agua Africa Mark Titus Product Manager HACH