Multiwavelength fluorescence for the early detection of algal

blooms in Water Treatment Plants

Katie DavageSales Manager

Chelsea Technologies Group

WWEM 2014

Overview of CTG

Why fluorometry?

The TriLux fluorometerPrinciple of operationConstructionSpecificationsExamplesDeployment options

Introduction

Application of sensor technology

Process control & monitoring

Medical diagnostics

Algal biofuel production

Fresh water & coastal monitoring

Offshore pipeline leak detection

Hydrocarbon pollution monitoring

NAD

Tactical Oceanography

Acoustic Target Simulation

Oceanographic research

Sensors & systems

Acoustic transducers

Fisheries

Exhaust gas monitoring

Ballast water monitoring

FerryBox

Security

Water Quality/Treatment

Bio/chem Security

Storage Tank Security

Environmental

Chelsea Technologies Group

3-channel multi-wavelength fluorometerMiniature single window geometry3 excitation wavelengthsCommon detection at 685nm

ApplicationsContribution to chlorophyll fluorescence from light harvesting pigmentsAlgal class studiesBloom detection

3 configurations availableChlorophyll-a, phycocyanin, turbidity (freshwater)Chlorophyll-a, phycoerytherin, phycocyanin (coastal)Chlorophyll-a, phycoerythrin, turbidity (seawater)

TriLux overview

Chelsea Technologies Group

absorbance emission

excited states

ground states

And why measure it?Sensitivity Specificity

Chlorophyll-a

Phycoerythrin

Phycocyanin

Algal pigments

Competing processes:

Photochemistry (P)Non-radiative decay (D)Chlorophyll-a fluorescence (F)

light

PSII

Chlorophyll-a fluorescence

RC

F

D

P

RC

Algal fluorescence induction spectra

Chaetoceros gracilisMarine diatom (Chlorophyll c)

Wavelength (nm)

Dashed line = 685 nmHeavy line = 730 nmLight line = O2 evolution

Wavelength (nm)

Porphyridium cruentumMarine, unicellular red algae

Wavelength (nm)

Ulva sp. (Sea lettuce)Green algae (Chlorophyll b)

Wavelength (nm)

Chroomonas sp. (Cryptophyte)Marine cyanobacterium – more chlorophyll than most cyanobacteria + phycocyanin only

Optical geometry

y = 0.01023x - 0.00238

R2 = 0.99999

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CLOROPHYLL-a CONCENTRATION (ug/l)

RE

AD

ING

Chlorophyll a in acetone

TriLux (Blue) vs laboratory analysis

UNITED UTILITIES TRILUX DEPLOYMENT

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DATE & TIME

[CH

LO

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PH

YL

L-A

] (u

g/l

)

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Amber

Cyanobacteria

Algae Total

Cyanobacteria bloom

Differential response from blue and red excitation

Correlation with increase in cell count

UNITED UTILITIES TRILUX DEPLOYMENT

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DATE & TIME

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Green/Blue

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Cyanobacteria

Algae Total

Signal ratios

Signal ratios improve discrimination

Diatom bloom

THAMES WATER - TRILUX 2

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L

All channels tracking indicating presence of chlorophylls a, b & c

THAMES WATER - TRILUX 1

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In situNon-contact

Non-contact measurement

Watchkeeper

Rugged, wall mounted display unit with onboard data logger and up to 3x 4-20mA outputs

Hawk

Portable, rugged, handheld display/power pack with onboard data logger suitable for use in a wide range of environments