Current online water quality monitoring methods and their suitability ...

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eliability for continuous water quality monitoring within each barrier in the PRW system. It onlyprovides recommendations based on researchers’ and industry experience with online analysers.5.1 Organic Load IndicatorsOnline parameters that can indicate the organic load of the water source are essential to ensure theintegrity of all barriers within the PRW closed loop system. This is primarily because the PRW isdesigned to remove organic matter from the wastewater to produce high purity drinking water. Inaddition, organic levels in Barriers 6 and 7 can cause disinfection by-product formation, and theirpresence is also used as a surrogate to indicate microbial contamination 4, 78 .Table 2loadingsOrganic parameters or indicators required to be measured at each barrier to indicate organicParameter B1 B2 B3 B4 B5 B6 B7 CommerciallyAvailableBOD 5 √ √ YesCOD √ √ YesTOC √ √ √ YesDOC √ √ YesSuspendedSolids√ √ √ √ YesTurbidity √ √ √ √ √ √ √ YesCommercially Available SensorsTable 2 lists the parameters required to be measured at each barrier to indicate organic loadings.Currently there are online sensors available for monitoring all of these parameters; however theirsuitability for Barriers 1, 2 and 2/3 is questionable due to the variability in the matrix composition (seeAppendix 1 for more information).BOD 5There are a number of instruments commercially available: those which use various means to measurethe oxygen respiration rate of sewage sludge, and those based on chemometric algorithms to estimateBOD from UV-visible absorption. Some examples are given below:AppliTek Ra-BOD® On-line BOD analyzerDirect BOD measurement using respiration rate (mgO 2 /l.h) of sludge from the WWTPEndress+Hauser Biox-1010This rapidly measures BOD 5 from the dilution factor required to keep the DO level constant in a smallonline bioreactor fed by wastewater diluted with air saturated water.Advantages: Has a high measuring range; and Does not require chemicals.Disadvantages: Requires sample conditioning.s::can; Endress+Hauser StipscanThese employ UV-Vis absorption and chemometric algorithms to quantify BOD 5 non-destructively inreal-time. They use the spectral absorbance values around 250-380 nm to indirectly quantify BODusing UV-Vis absorption patterns.Current Online Water Quality Monitoring Methods and Their Suitability for the Western CorridorPurified Recycled Water Scheme Page 18
Advantages: Sample acquired in-line with limited pre-treatment; and Can rapidly determine concentrations in a non-destructive manner.Disadvantages: Method is not direct and hence is matrix dependent. This can lead to measurement errors ifmatrix changes substantially; and May require frequent calibration if matrix composition continually changes e.g. every twoweeks if system has not been developed on monitoring site in question. Works best if themonitoring site of interest has been incorporated into its data training base, and has turbidity
Page 1 and 2: Current Online Water Quality Monito
Page 3 and 4: ACKNOWLEDGEMENTSThis research was u
Page 5 and 6: CONTENTSAcknowledgements...........
Page 7: EXECUTIVE SUMMARYThis report forms
Page 11 and 12: The multi-barrier treatment process
Page 13 and 14: The number of parameters per catego
Page 15 and 16: Online analysers operating within t
Page 17 and 18: Table 1Number of water quality para
Page 19 and 20: Additional background information (
Page 21 and 22: sensors that are stable slow to dri
Page 23: that it can handle more than one re
Page 27 and 28: These sensors are once again based
Page 29 and 30: 5.3 Inorganic parametersThere are a
Page 31 and 32: The majority of analytical methods
Page 33 and 34: For Barriers 1, 6 and 7 where the m
Page 35 and 36: 5.7 PesticidesCurrently there are n
Page 37 and 38: Recently, Hach introduced an Event
Page 39 and 40: 6.2 Summary of RecommendationsThe f
Page 41 and 42: 7. REFERENCES1. Queensland Water Co
Page 43 and 44: 63. WTW (2008) The IQ SENSOR NET XT
Page 45 and 46: Appendix 1: Review of Commercially
Page 47 and 48: CompanyNameYSIHANNAInstrumentsMettl
Page 49 and 50: Appendix 2: Review of Research Deve
Page 51 and 52: ReferenceGutirrez M et al. (2008).
Page 53 and 54: ReferenceRodriguez-Mozaz S et al. (
Page 55 and 56: ReferenceBohrer F et al (2008).J.AM
Page 57: Urban Water Security Research Allia

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