Low cost, autonomous sensor systems for the monitoring of nutrients in water. Eoin Murray PhD Research Chemist

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1 Low cost, autonomous sensor systems for the monitoring of nutrients in water. Eoin Murray PhD Research Chemist

2 Company Overview Established 1991 Over 50 employees including 40 chemists and engineers Multidivisional company Accredited laboratories Environmental Analysis Chemical Manufacturing Fuel & Oil Analysis Research & Development

3 Nutrient Pollution Globally most prevalent water quality problem (UN 2014). Primarily nitrite (NO 2- ), nitrate (NO 3- ) and phosphate (PO 3-4 ) Eutrophication - excess nutrients entering water bodies Overproduction of algae and aquatic plants Algal Blooms Fish kills Health Impacts

4 Economic Impact 750 M (Netherlands) M (Spain) 3 $2.2 billion (United States) 1 $4 M - Treatment $21 M - Recreation (Lake Erie, Canada) 2 AUD 240 M (Australia) 3 References 1. Alliance for Coastal Technologies Cost of pollution in Canada OECD 2012

5 Low cost in-situ nutrient sensor systems US federal agencies and Alliance for Coastal Technologies set challenge Sensors to measure nitrate and phosphate autonomously Unattended deployments for 3 months, purchase price less than 4500 Systea (Winner of Challenge) Microfluidic based system Colorimetry with optical detection Orthophosphate, nitrate and nitrite Cost of 30,000

6 Funded EU FP7 project Low-cost, deployable early warning pollution device for nutrients (~ 5000) Colorimetric chemistries and microfluidics LED photodiode detection Project Partners - Dublin City University - University of Southampton (NERC) - Kalite Sistem Laboratories - Watec Water Technology

7 System design and configuration Fig. A: Photograph of Aquamonitrix system Fig. B: Simplified schematic of Aquamonitrix system

8 Analytical characteristics Phosphate (PO43-) Nitrite (NO2-) Nitrate (NO3-) Yellow method Griess method Reduction plus Griess 375 nm LED 525 nm LED 525 nm LED mg/l PO mg/l NO mg/l NO3-

9 Electronics and communications IOT - network of sensors Modular Hardware LoRa, Sigfox, NB-IoT, GSM

10 A chromatographic approach Low-cost portable IC system Miniaturised capillary based IC In-house packed capillary column Indirect UV detection Abs. (mau) Column: IC-Pak (4.6 x 50 mm) Eluent: 5 mm Sodium Benzoate Flowrate: 1.00 ml/min Wavelength: 260 nm Sample Volume: 50 µl Anions: Six anion mix (30 mg/l) Minutes

11 Design of portable IC System System Characteristics Lightweight, small platform Low cost components Small volumes of waste Low power consumption

12 Portable Capillary IC System Abs. (mau) Minutes System Characteristics Entire system weighs < 700 g LC platform is 25 x 25 cm System cost ~ 6000 euro Little waste generated Eluent: 1.5 mm NaC₇H₅O₂ Flowrate: 3 µl/min Wavelength: 255 nm Sample Volume: 300 nl Anions: 5, 5, 10 and 15 mg/l Photograph of capillary based IC system

13 System Repeatability Minutes Repeatability of five sequential chromatograms, 300 nl injection volume of 4-anion standard containing 5 mg L -1 F - and Cl -, 10 mg L -1 NO 2- and 15 mg L -1 NO 3- with 255 nm LED Abs. (mau) Analyte Average Retention Time (min) Retention Time RSD (n= 5) Average Peak Area (mau*s) Peak Area RSD (n= 5) F % % Cl % % NO % % NO % %

14 Portable IC Performance Analyte Linear Range (mg L -1 ) R 2 LOD (mg L -1 ) LOQ (mg L -1 ) Fluoride Chloride Nitrate Nitrite Nitrite Nitrate

15 Acknowledgements Mrs Breda Moore Dr Aoife Morrin Prof Dermot Diamond Dr Margaret McCaul Prof Brett Paull Mr Yan Li Prof Mirek Macka Dr Sinead A. Currivan This work has been funded through the Irish Research Council s Employment Based Scholarship Programme, Grant No. EBPPG/2015/127.

16 Thank you