This Presentation will cover

Transcription

1 Ian B Law IBL Solutions, Australia WRRF Project No Los Angeles, 29 August 2012 This Presentation will cover Experiences drawn from: The Windhoek Plant, Nambia; The NEWater Plants in Singapore, and Some Australian plants that have used the method outlined in the Australian Guidelines for Water Recycling to validate their treatment trains. 1

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3 Windhoek, Namibia The New Goreangab Water Reclamation Plant (commissioned 2002) 3

4 Process Flow Diagram 4

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6 A Focus on Multiple Barriers Non treatment barriers such as diversion of all industrial wastes; Treatment barriers for: Physical and organoleptic Microbial and biological Organics and DBPs Macro elements and Stability Operational barriers, e.g. PAC use when required In addition. Concentrate on rigorous monitoring, risk assessment of whole system, ISO and HACCP certification; Training and motivation of the operating staff; Separate Health Research Programme that covers virus testing for cytopathogenic effect and polymerase chain reaction, toxicity (Waterflea lethality and Urease enzyme) as well as Ames Salmonella mutagenicity testing. 6

7 The Demo Plant commissioned in April 2000 Bedok NEWater Plant & Visitor Centre commissioned February 2003 Kranji NEWater Plant commissioned May

8 NEWater Factory Microfiltration ti Reverse Osmosis Secondary Effluent High Quality Product Water UV TOC (mg/l) NEWater Quality - Total Organic Carbon Aug-03 Feb-04 Jul-04 Jan-05 Jul-05 Jan-06 Jul-06 Jan-07 Jul-07 Jan-08 Kranji NEWater Bedok NEWater Seletar NEWater 8

9 NEWater CCPs Action & Shutdown Limits (page 1 of 3) NEWater CCPs Action & Shutdown Limits (page 2 of 3) 9

10 NEWater CCPs Action & Shutdown Limits (page 3 of 3) 10

11 Risk Management Approach Twelve element framework for the management of recycled water quality and use see Framework Case Studies Application of preventative measures (barriers) commensurate with the level of risk Based on risk management Define tolerable risk Assess risk Calculation of health based targets (log reductions) Preventative measures (achieve log reductions) Performance subject to monitoring at a frequency that enables timely intervention End product monitoring only to verify that the management system as a whole is operational 11

12 Tolerable Risk National Guidelines Risk Defined in terms of Disability Adjusted Life Year (DALY s) Years of illness + years lost from premature death Used to assess disease burden Each health effect is rated Examples: DALY = 1 (Death) DALY = (Diarrhoea) DALY = 0 (No Risk) Tolerable risk for reclaimed water 1 is a DALY of 10 6 per person per year consistent with WHO

13 Decision Tree for setting Pharmaceutical Guideline Values 13

14 GWF Process Flow Diagram The Gippsland Water Factory 14

15 LRVs at the Gippsland Water Factory Gippsland Water Factory, Victoria Viruses Protozoa Bacteria Requirements for industrial reuse based on a QMRA Wastewater treatment + UF membranes (MBR) Reverse Osmosis Chlorination free(ct) 4 nc nc Total 6.0 >5 >6 CCPs at the Gippsland Water Factory CCP Process Parameter Monitored CCP1 MBR Flux, TMP, PDT, Turbidity CCP2 RO TOC (LRV), Flux, Recovery, annual dye test CCP3 Chlorination CT with ph input 15

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17 LRVs for the Western Corridor Project Western Corridor Project, Queensland Viruses* Protozoa Bacteria Hl Helminths Requirements for Potable Reuse * Adenovirus Wastewater treatment (BNR) Microfiltration Reverse Osmosis UV disinfection/aox Chlorination Total CCPs at the Western Corridor Project CCP Process Parameter Monitored CCP1 WWTP On line Ammonia CCP2 MF/UF Pressure Decay Test (PDT) CCP3 RO Permeate Conductivity Permeate Sulphate CCP4 UV/AOX Present Power Ratio CCP5 Chlorination CT 17

18 Perth s Groundwater Replenishment Trial Injection bore viewing area 18

19 LRVs at GWRT, Perth Ground Water Replenishment Trial, Perth, WA Viruses* Protozoa Bacteria Requirements for injection into aquifer * Adenovirus Wastewater treatment (BNR) Ultrafiltration Reverse Osmosis UV disinfection Total CCPs at the GWRT Project CCP Process Parameter Monitored CCP1 WWTP DO, Capacity Off line, Effluent Turbidity CCP2 MF/UF Pressure Decay Test (PDT), Turbidity CCP3 RO Each Train: Conductivity Combined Permeate: TOC and Conductivity CCP4 UV Flow, UV Intensity (W/m2) CCP5 Treated Water ph 19

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21 Pilot Plant Commissioned Feb 2008 Treatment Trains Evaluated LRVs from Raw Sewage for Fire Fighting : Virus: 6.5 (Enteric ) Bacteria: (Campylobacter) Protozoa: 5.1 (Cryptosporidium) Preferred Treatment Train Pre O3 BMF Post O3 UV Cl2 Integration of Ozone + BMF with other processes & key design parameters Post Ozone Pre Ozone treatment of secondary effluent achieves pathogen inactivation but high ozone demand, fast reactions and rapid ozone residual decay make this difficult to characterise. Testing indicated that overall ozone treatment was optimised by splitting it both before and after BMF: BMF filtered water has much lower ozone demand than secondary effluent Post Ozone residuals are easily measurable and provide stable decay curves Post Ozone inactivation of protozoa, virus and bacteria can be described by the product of ozone residual concentration x contact time (i.e. CT) Post Ozone dose to achieve inactivation CTs = 2 5 mg/l, min. contact time = 5 mins UV disinfection plant reduced to take advantage of higher UV Transmittance achieved incidentally to achieving ozone treatment objectives Chlorine disinfection plant reduced to take advantage of higher virus inactivation Melbourne Water 21

22 Ozone pathogen inactivation validation strategy Ozone disinfection is well recognised but experience primarily based on drinking water applications Used for effluent disinfection but typically just to achieve low coliforms no formal validation undertaken Post Ozone preferred over Pre ozone for validation to ensure successful outcomes in a timely fashion (project risk management) Post Ozone will be validated for protozoa, virus and bacteria inactivation Protozoa: Extensive on site validation testing using seeded Cryptosporidium BMF effectively addresses particle association concerns Successfully demonstrated no difference in inactivation b/w BMF filtered water and reagent grade water LRV credits to be awarded using USEPA LT2ESWTR guidance Melbourne Water Ozone pathogen inactivation validation strategy (cont.) Virus and bacteria inactivation: Collaborative research project with Dr Karl Linden (University of Boulder, Colorado) to investigate relative resistance of viruses and microbial surrogates to ozone inactivation Viruses are highly susceptible to ozone inactivation E. coli is a suitable surrogate for inactivation studies but it is larger than viruses Investigation using indigenous somatic coliphage indicated virusparticle association in BMF filtered water is not a concern Extensive on site validation ld testing using seeded dde. coli >4 log inactivation demonstrated at <50% of the CT required for 0.6 log Cryptosporidium inactivation Melbourne Water 22

23 Ammonia Reduction Herbicide & Pesticide Removal 100% PERCENTAGE REDUCTI ION 90% 80% 70% 60% 50% 40% 30% 20% REDUCTION BY OZONE REDUCTION BY OZONE+BMF 10% 0% DIURON DIAZINON MECOPROP MCPA SIMAZINE METOCHLOR 24 D PROPOXUR 3,4 DICL ANILINE DICAMBA TRICLOPYR FLUMETURON ATRAZINE TEBUTHIURON DALAPON SIMAZINE (HLCMS) DIURON (HCLMS) TEBUTHIURON (HLCMS) DIAZINON (OP) ATRAZINE (HLCMS) HERBICIDE PESTICIDE 23

24 Under Construction Dec 2012 Commissioning 24

25 Bioreactors and Membrane Tanks 25

26 LRVs at Victor Harbor Victor Harbor, South Australa Viruses* Protozoa Bacteria Requirements for unrestricted outdoor irrigation * Adenovirus Wastewater treatment (BNR) Kubota Flat Sheet Membranes UV Disinfection (36mJ/cm2) Chlorination free(ct 30mg/L/min) 3 nc nc Total 6.0 >5 >6 Conclusions Windhoek and Singapore have systems in place to g p y p ensure optimised operation; multiple barriers, operating procedures and focused SAMPs ; Australia has Recycling Guidelines based on risk identification and management focused on both acute and chronic risks. They have been applied to a number of reuse projects; Validation of schemes around the country is challenging being addressed through development of a National Validation Framework, funded by the AWRCE. 26

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