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Tap
into the Power of Real-time Monitoring
Real-time monitoring
of water quality can take many forms, from inexpensive handheld
instruments requiring discrete samples to automated, on-line monitoring
and control systems to elaborate offshore ocean buoys with profiling
instrument packages. The one thing they all have in common is that
they have in situ sensors taking water quality measurements in real
or near real-time. As a whole, the selection of in situ sensors
is on the rise and the power consumption, size and price are falling.
Literally anywhere you can think of where there is natural water
is a potential candidate for a real-time water monitoring system
(ex: buoys, cruise ships and ferries, docks, piers, water plants,
etc.). The time has arrived where a real-time monitoring system
is a practical solution for most researchers and monitoring groups.
The benefits should be clear; increasing sample intervals by orders
of magnitude that will add enormously to improving our understanding
and monitoring of natural systems.
Several of the
factors adding to the growth in real-time monitoring of water quality:
- Smaller and
more energy efficient sensors
- Anti-biofouling
systems (wipers and brushes, copper screens and shutters, coatings,
etc.)
- Longer lasting
batteries and high capacity data loggers
- Improved
communication and telemetry
- Increasing
number of companies offering integrated, turn-key systems
- Decreasing
price
- Increasing
number of sensors and sensor companies
- More user
friendly sensors and software
- Increasing
environmental problems and awareness
At Turner Designs,
we have embraced advances in smaller and more energy-efficient instrument
components to offer the smallest, most reliable, and affordable
fluorescence sensors available. Most recently we have launched the
CYCLOPS- 7 submersible fluorometer that will allow many more people
to take advantage of fluorescence technology by making it easier
to integrate into remote monitoring platforms, due to the small
size and energy efficiency, and offering it at a more affordable
price. In addition, we are expanding the number of applications
we offer by launching cyanobacteria models for all of our on-line
and field instruments (see Instruments
in Action) which includes a cyanobacteria version of the AlgaeWatch
on-line fluorometer. The detection of in vivo cyanobacteria
with any of our instruments is sensitive enough to act as an early
warning system of potential cyanobacteria blooms. This is of particular
interest within the water resource market where cyanobacteria blooms
increase filter run times, produce taste & odor causing compounds
and potentially toxic compounds. Fluorescence based early warning
systems can warn of increasing cyanobacteria biomass that can then
trigger more specific tests (e.g. ELISA, HPLC, etc.) that can confirm
the presence of specific species or compounds.
We encourage
you to contact us to discuss instrument applications and how we
can help you with your real-time monitoring needs.
Some useful
references and links focused on real-time monitoring:
- Glasgow,
H.B., Burkholder J.M., Reed R.E., Lewitus A.J., Kleinman J.E.,
2004. Real-time remote monitoring of water quality: a review of
current applications, and advancements in sensor, telemetry, and
computing technologies. J. Exp. Mar. Biol. Ecol. 300 (2004) 409-448.
For re-prints, contact Howard Glasgow at howard_glasgow@ncsu.edu
- Chesapeake
Bay Monitoring
http://mddnr.chesapeakebay.net/eyesonthebay/index.cfm
- Monitoring
and Event Response for Harmful Algal Blooms
http://www.cop.noaa.gov/Fact_Sheets/MERHAB.html
- Monitoring
on Ferries
http://w3k.gkss.de/projects/ferrybox/
- Real Time
Monitoring from the Mystic River, CT (USGS)
http://engineering.tufts.edu/cee/group/EMPACT/Site6/ENGLISH/Mystic4.htm
- Real-Time
Turbidity, Temperature and Salinity Data from Queensland, Australia
http://www.epa.qld.gov.au/projects/water/
Yours truly,
Rob Ellison
Director of Sales and Marketing
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Partner
News: Turner Designs and Hydrolab announce addition of CYCLOPS-7
to the Hydrolab DataSonde multi-parameter platform
Turner Designs
has designed a Chlorophyll a sensor specifically for integration
into the Hydrolab DataSonde. This sensor is based on the CYCLOPS-7
technology, and offers the most accurate Chlorophyll a measurement
available on a multi-parameter instrument.
Real-time, in
vivo monitoring of Chlorophyll a using a Hydrolab DataSonde
is extremely valuable for helping a researcher understand the productivity
of a lake. The advantage offered when using a multi-parameter DataSonde
with the Chlorophyll sensor is that the researcher can also monitor
parameters such as Dissolved Oxygen and pH at the same time as their
Chlorophyll measurements. These additional parameters are important
to fully understand the productivity of the lake because the amount
of oxygen that is being produced or absorbed, as well as the changes
in pH that coincide with algal productivity, are critically important
to completing the full picture of the lake's health.
Kellie Merrell,
an aquatic ecologist at the Vermont Agency of Natural Resources,
has been measuring water quality with Hydrolab instruments for 12
years. The agency routinely monitors water quality at over 200 lakes
in the state of Vermont, and they are especially interested in monitoring
Chlorophyll.
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1: Hydrolabs DataSonde showing integration of Turner Designs
CYCLOPS-7 sensor. |
Kellie has recently
started to use the Hydrolab sondes paired with Turner Designs' Chlorophyll
a sensor to help the agency understand the trophic status of the
lakes and detect bloom conditions real-time. The ability to make
in vivo measurements of Chlorophyll can give the agency immediate
data to tell them if the lake is experiencing hypereutrophic or
oligotrophic conditions. Kellie then uses the data from the other
sensors, including Dissolved Oxygen, pH, Conductivity, Redox, and
Temperature, to understand the complete picture of the lakes' health.
The agency
greatly benefits from the ability to collect data for several parameters
at once with only one instrument... the time and equipment savings
add up very quickly! Most importantly, the data that the agency
collects with the Hydrolab sonde and Turner Chlorophyll sensor correlates
extremely well with their extracted Chlorophyll analyses, so they
can be sure they are collecting accurate data.
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Figure
2: The Turner Designs CYCLOPS-7 fluorometer is available
on Hydrolab's DataSonde 4a and MiniSonde 4a Instruments.
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Hydrolab, a
Hach Company brand, has designed and manufactured multi-parameter
water quality monitoring instruments for over 40 years. Their product
lines include the DataSonde, MiniSonde, and Quanta. Sensors are
available on these instruments to measure Temperature, Dissolved
Oxygen, Conductivity, pH, ORP, Depth, and Turbidity, among others.
Turner Designs has developed a line of fluorometers that are integrated
into Hydrolab instruments, including Chlorophyll a, Rhodamine
WT, and Blue-Green Algae (Cyanobacteria). For questions regarding
these instruments, contact Hydrolab at (800) 949-3766 or (970) 669-3050,
or by email at sales@hydrolab.com.
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 Jim McCormick, our Tech Support Manager, has been with Turner
Designs for over 15 years and has extensive expertise with our entire
line of instruments.
"Jim's Corner" will feature common questions that provide a better
understanding of the operation of our units. Please feel free to send
your technical question to Jim.
Question:
We want to connect
the CYCLOPS-7 to a Data Logger that can only accept a maximum signal
input of 2 volts. Can we adapt the 5 volt signal output of the CYCLOPS-7
to this level without losing any dynamic range?
Answer:
Yes, by creating
a simple voltage divider circuit, the 5 volt signal output from
the CYCLOPS-7 can be scaled down to meet the lower voltage requirement
of your Data Logger. This circuit consists of two Resistors connected
in series, that should be installed at the Data Logger input connections.
The Data Logger should have an input impedance greater than 1 Meg-ohm
for the resistor values stated here. The resistors should be rated
at ¼ watt or higher.
If R1 is 150K
ohms and R2 is 100K ohms, when the voltage from the CYCLOPS-7 is
5 volts, the voltage across R2 will be 2 volts. Refer to the Equation
and Figure below.
5volts X (R2
/ (R1 + R2)) = 2 volts
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Figure
1: Graphical representation of a simple voltage divider
circuit.
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CYCLOPS-7
Real-Time Data Aids Study of Basin Scale Dynamics of Open Ocean
Ecosystems
 The
Atlantic Meridional Transect (AMT) programme (1995 - present) takes
advantage of the biannual passage of the BAS research vessel James
Clark Ross from the UK (50°N) to the Falkland Islands (50°S)
to study basin scale patterns and dynamics of open-ocean planktonic
ecosystems (more information can be found at http://www.amt-uk.org).
An interest in open-ocean plankton has led to our understanding
of the importance of various groups of cyanobacteria along the AMT
transect: the dominance of small (< 0.002 mm) prochlorophytes
in the subtropical gyres, the importance of small Synechococcus
in equatorial and temperate waters and the vital nitrogen-fixing
role of large (> 2 mm) colony-forming Trichodesmium in equatorial
waters. Small cyanobacteria are usually detected through the collection
of discrete water samples and flow cytometric analysis, where cell
size and phycoerythrin fluorescence are used to identify the different
groups. Trichodesmium is collected with nets (or buckets!) and microscopic
examination of large water-volumes gives their abundance. A technique
that detects both is highly advantageous, allowing targeted sampling
and a better understanding of the ecology of marine cyanophytes.
During the 14th
AMT cruise (April - June, 2004) we took advantage of the opportunity
to use one of the new CYCLOPS-7 fluorometers set to detect phycoerythrin
(a pigment mostly found in cyanobacteria). Due to their insolubility
in water, the cyanophyte pigments phycoerythrin and phycocyanin
cannot be extracted or eluded with standard pigment analysis and
thus our knowledge of the full pigment suite of open-ocean communities
has been limited. The use of the CYCLOPS-7 will provide us with
a better understanding of the pigments, community structure and
optical properties of the water-column.
 Having
sailed through the rough waters off the Falkland Islands ("roaring
40s") and into the South Atlantic Gyre we were able to attach
the CYCLOPS-7 fluorometer to our standard CTD package and gain real-time
profiles of phycoerythrin and cyanophyte distribution. The appeal
of using new technology on the AMT cruises is that the interdisciplinary
nature of the cruise allows novel measurements to be related to
other more traditional oceanographic measurements (e.g. chlorophyll
a concentration, rates of carbon fixation, nutrient concentrations)
as well as more specialised ones (e.g. Dimethylsulphide concentration).
Although the
results are preliminary and still being validated (frozen and preserved
samples to be analysed) several interesting results have come about
from the use of the Cyclops-7. Phycoerythrin was highest in waters
with high chlorophyll-a concentration, shallow nitraclines (defined
as the 1 mM nitrate contour), and high rates of carbon fixation.
Preliminary cell counts show that the source of the phycoerythrin
changes with latitude: from Synechococcus and Trichodesmium in equatorial
waters to Synechococcus and eukaryotic flagellates (Cryptomonads)
in northern temperate waters.
 Over
the next few months, pigment analysis will allow us to compare phycoerythrin
fluorescence to other phytoplankton pigments: previous knowledge
of the distribution of such pigments indicates that phycoerythrin
fluorescence shows a very similar distribution to the photoprotectant
cyanophyte-related pigment, zeaxanthin. Analysis of preserved water
samples may allow the phycoerythrin signal to be related to Trichodesmium
abundance, as it was noticed during the cruise that when Trichodesmium
was present in the water-column the Cyclops-7 signal was highly
spiky. Analysis of particle absorption samples and attempts to calibrate
the fluorometer will allow us to estimate the concentration of phycoerythrin
and its ratio to other phytoplankton pigments.
Many thanks
to Turner Designs and RS Aqua (especially Charlotte Deeley) for
the opportunity to use the CYCLOPS-7, which will become a regular
feature on our CTD package during future cruises (AMT-15 sails September
2004!). I would also like to thank fellow AMT scientists for access
to their preliminary data from the cruise which has aided in the
interpretation of the CYCLOPS-7 signal so far (Dr Mike Zubkov, Ms
Jane Heywood and Ms Katie Chamberlain) and Jon Short and Dougal
Mountifield (UKORS) for technical support.
 Dr
Alex Poulton (aljp@soc.soton.ac.uk)
Research Fellow: Atlantic Meridional Transect (AMT) programme
Southampton Oceanography Centre, UK.
http://www.amt-uk.org
(Ocean
Data View used courtesy of R Schitzler)
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 Technically
Speaking, It All Adds Up…….
is a series
of articles for people who want to obtain the best possible results
from their fluorometer. This month's article will describe some
good measurement practices to produce consistent and reliable readings
when using submersible fluorometers in the lab. The effects of sensor
positioning, optimum bench top characteristics, etc will be described.
The principles apply to all submersible fluorometers when used for
making lab measurements.
Introduction:
Does this scenario sound familiar? You are using your submersible
fluorometer in the lab for doing some dye concentration measurements:
you check the sensor using your solid secondary standard - no change
in the reading. So, you know the sensor is still calibrated, and
producing consistent and reliable results using the solid secondary
standard. However when you measure the very same dye as last time,
you get a significantly different reading!! What is going on?? (It's
not the dye changing).
Explanation:
All fluorometers work by measuring the light emitted by naturally
fluorescent compounds such as chlorophyll, or from man-made fluorescent
materials such as tracer dyes. The emitted light results from exciting
the measurement sample with light at an optimum wavelength to cause
the sample to fluoresce.
Now it will
be obvious that it is important to control the measurement setup
to minimize the effects of reflected light, and to ensure that no
additional fluorescent light sources are introduced.
Practical
Implementation:
The following factors all impact the accuracy, consistency and reliability
of measurements made with submersible fluorometers used in the lab:
1. Use
a Glass Beaker for your water samples. (Avoid plastic beakers -
plastic fluoresces, and will interfere with the sample fluorescence)
2. Place
the glass beaker on a Non-Reflective Surface, preferably black.
(A black cloth under the beaker will achieve the desired result).
3. Ensure
that the sensor is at least 3 inches above the bottom of the glass
beaker, see Figure 1.
4. Ensure
that the sensor is in the center of the glass beaker, and has more
than 1 inch clearance between the cirumference of the sensor and
the inside surface of the beaker. Turner Designs recommends using
a 1L Glass Beaker.
5. Check
that the optical surface of the sensor is free of air bubbles.
6. To
maximize consistency between measurements, place sensor at exactly
the same height for each sample. This is most easily done using
a Lab Stand.
7. Finally,
of course, be sure your sensor is calibrated, (see User's Manual
for Calibration Procedure).
Summary:
Following the above steps will significantly contribute to the accuracy,
consistency and therefore reliability of your measurements with
submersible fluorometers in the lab.
For the Turner
Designs submersible fluorometers, an alternative way to ensure that
the measurement environment is optimized is to use the appropriate
flow cap accessory. Contact Turner Designs for additional information.
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Pelorus
uses CYCLOPS-7 Fluorometer to Characterize Effectiveness
of Remedial Fluid Through BioNets™
About
Pelorus:
Pelorus Environmental & Biotechnology Corp. (Pelorus)
provides environmental and biotechnology solutions for water,
air, and soil contamination situations. Their environmental
services include bioremediation, chemical oxidation, remediation
services, water treatment systems, and air treatment systems.
Noted for pioneering Environmental Biotechnology applications
and hydraulic fracturing and monitoring their services include
biocatalyst development for bioremediation and biotransformation
of organic molecules to valuable chemical intermediates,
and renewable energy processes, molecular environmental
diagnostics, fermentation process development and characterization
of biodegradation pathways of organic compounds and the
delivery of these processes into the subsurface.
Project
Overview:
A recent project, in conjunction with the Artemis Consulting
Group was to evaluate the performance of an existing groundwater
and soil remediation system. One aspect of the remediation
design consists of a patented subsurface treatment area
called Bionets. The Bionets are horizontally stacked, hydraulically-emplaced,
sand-filled or other solid support filled propagations or
fractures. Each Bionet consists of three to four horizontally
emplaced fractures. During remediation, the fractures within
each Bionet are repeatedly filled with Pelorus proprietary
bio-amendments for the purpose of selective dechlorination
of specific volatile-organic-compounds (VOCs), otherwise
know as constituents-of-concern (COCs).
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Figure
1: Example of Bionet Structure showing Tracer
Injection Scenario
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Remediation
Objectives:
The Bionets consist of multiple zones of artificially emplaced
porous materials positioned beneath the ground surface at
various depths within the zone of contamination. Pelorus
wanted to lace the injectate with Rhodamine dye during injections
into each of these Bionets to determine which interval was
the primary pathway for nutrient migration. By determining
which pathway is the primary pathway, Pelorus could modify
the existing treatment program at the site to focus injection
into those primary zones. This would result in better utilization
of their proprietary nutrients resulting in a reduction
in chemical costs, and by focusing the remediation to target
horizons (primary Bionet migration pathways) the modeled
times to reach the remediation objectives, and subsequently,
the long-term monitoring costs might be reduced.
Investigation
Approach:
Pelorus wanted a way to map or determine the preferred migration
path of the injected remedial fluid through the Bionets
in both saturated and unsaturated soils at the subject facility.
It was
Pelorus's intent to use a Turner Designs Fluorometer to
search for the presence of their injectate augmented with
Rhodamine in several environmental monitoring wells positioned
down-gradient from the point of tracer injections. In addition
to monitoring for the presence of Rhodamine dye in selected
monitoring wells, Pelorus had a need to vertically profile
the water column in each well to identify potential COC-stratification
of the water column. Pelorus selected the Turner Designs
CYCLOPS-7 fluorometer to meet their specific needs. This
fluorometer had the outside dimensions, resolution capabilities,
durability, programmability, deployment, and pricing options
needed for this project.
Vertical
Profiling was required, and therefore they ordered 70 feet
of cable for the device.
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Graphic
1: Pelorus site setup for monitoring with CYCLOPS-7
in a 2.00" ID PVC well casing.
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Methodology:
The intent was to lower the fluorometer into the monitor
wells incrementally at one-foot intervals to the bottom
of the well (typically 25 -30 feet) and evaluate the water
column within the well casing for the presence of injected
Rhodamine dye. Measurements of fluorescence would be recorded
at one foot intervals thus creating a vertical fluorescence
profile of the water columns. This process was conducted
before, during, and after the initial injections, then again
once every week for several weeks.
In addition
to fluorometer profiling, dissolved oxygen (DO) electrical
conductance (EC), pH, temp, and oxygen-reduction-potential
(ORP) were also vertically profiled.
Results:
Two Bionet locations were tested following injection of
Rhodamine-laced fluids. Following analysis of all the field
data, the fluorometer results provided Pelorus with some
exceptional results:
- Defined
zones of stratification not previously identified;
- Determined
which fracture zone in the tested Bionet is the primary
zone;
- Helped
further characterize site hydrogeology and;
- Allowed
Pelorus to better understand fluid migration paths, nutrient
uptake times; dispersion, and seepage velocities of our
remedial fluids.
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Chart
shows that the flow occurred through the fracture
at 14.3 feet. Bioremediation would be focused at this
depth achieving economic savings by minimizing the
amount of chemical needed.
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Additional Information:
For more details on this and other Pelorus remediation programs,
please contact:
Pelorus Environmental & Biotechnology Corp
3528 Evergreen Parkway
Evergreen, Colorado 80439
vbarlock@pelorusenbiotech.com
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Waterproof
Magnetic Reed Switch Solution Controls CYCLOPS-7 Gain
Introduction
Scientists at the Space and Naval Warfare Systems Center San
Diego (SSC-SD) have developed a quick technique to manually
change gain ranges on the CYCLOPS-7 fluorometer. The technique
was developed to facilitate making the gain changes in wet
field conditions during small boat operations. The CYCLOPS-7
with switch was successfully used to map out fluorescein dye
on recent surveys.
Switch
Construction
A three-position switch that could ground one of two gain
control lines or neither line was required. As is many times
the case, there was little budget or time available as the
system was required shortly after it was purchased. Custom
manufactured cable and underwater switches were expensive
and required weeks of lead-time. The solution was to construct
a three-way switch from locally available materials. The materials
used were 1/2" PVC pipe, pipe tee, pipe union, two magnetic
reed switches and a magnet. The switch assembly also served
to join the CYCLOPS-7 cable to the cable from the CTD.
All power
and signal wires were routed straight through the to the CTD
cable, except for the two gain control lines. These were connected
to the magnetic reed switches so that when the switches were
closed the line would be grounded. The switches were bonded
to the inside of the lower half of the union, positioned 180
degrees apart (see figure below). The magnet was bonded in
place on the inside of the upper half of the union. By rotating
the upper half of the union the magnet could be placed in
proximity to one of the reed switches, closing that reed switch
and thereby connecting the control to ground. The gain setting
of the CYCLOPS-7 was controlled by rotating the union fitting
so that one of the switches was closed or neither was closed.
Polyurethane potting material was used to fill the interior
of the PVC pipe to waterproof the wiring assembly.
CYCLOPS-7
Deployment
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Figure
2. Surface fluorescein dye distribution during a
mixing zone test. The strong gradient in dye concentrations
indicates rapid mixing with ambient waters.
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The CYCLOPS-7
with range change switch was utilized in April 2004 to look
at dye released from Navy drydock pump systems to evaluate
receiving water mixing zones. The CYCLOPS-7 was attached to
a SeaBird 19 CTD using the cable containing the ranging switch.
Surface water dye concentrations were mapped by towing the
CTD with attached CYCLOPS-7 sensor during various tidal conditions.
One survey
result is shown in Figure 2 in units of relative fluorescence.
The data from these surveys suggest that the drydock discharges
are rapidly mixed with the ambient water. It turned out that
the range in concentrations observed was sufficiently characterized
by the mid range of the CYCLOPS-7 and the switch was not needed
for this particular set of surveys. However, it is expected
that quickly changing ranges will be important for other planned
surveys and for measuring dye concentrations of the starting
mixture prior to discharge.
For further
information contact:
Chuck
Katz or Greg Anderson
E-mail: chuck.katz@navy.mil
or greg.anderson@navy.mil
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Figure
1. Schematic of manual gain switch for CYCLOPS-7
fluorometer.
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