DaphTox II - Biomonitoring using Daphnia
Sensitive detection of toxic substances in water via computer-assisted digital image analysis
- bbe DaphTox II - Biomonitoring using Daphnia
The bbe DaphTox II observes daphnids, commonly known as "water fleas", under the influence of constantly running sample water. Based on the Extended Dynamic Daphnia Test, bbe developed a new sensitive method to detect hazardous compounds in water from rivers (source-water protection), plants, distribution systems and production drains to preserve human health and to monitor water.
Sensitivity data are available here.
Sample water (0.5 - 2 l/h) continuously runs through the measuring chamber containing the daphnia. The live images obtained using a CCD-camera are evaluated online with an integrated PC to analyse changes in the behaviour of the daphnia. If the change is statistically significant, an alarm is triggered. The method of image analysis enables a series of measurement methods and plausibility tests to assess the daphnia's behaviour using different criteria.
Measurement using digital image analysis
- Measurement parameters of the daphnia
Observation of speed parameters:
- average speed
- speed distribution
- distance between daphnia
Observation of behaviour:
- swimming height
- location
- fractal dimension: measurements
for turns and circling movements, curviness
Observation of growth:
- determination of daphnia size
Toxicity Index
The concept of the toxicity index is based on the evaluation of certain measurands, such as speed or height, and changes in these measurands. Only when 2 or more of the measurands simultaneously show unusual results within a fixed period of time does the DaphTox II trigger an alarm.
- Software screenshot: the parameter settings determine the calculation of the toxicity index
Applications
Surface water applications
- dam monitoring
- waterway analysis and assessment
- general environmental monitoring
Drinking water applications
- intake assessment
- drinking water supply
Research applications
- risk analysis
- limnological work
- research and education
Features
Chamber and camera
- 1-chamber system with up to 10 daphnids or other organisms
- optional 2-chamber system with enhanced reliability
- easily removable daphnia chamber - prevents air bubbles and increases detection rate
Sample preparation
- integrated sample treatment (microfiltration, ultrasonic cleaning and pre-heating)
- air-cooled peltier element - no separate cooling water
Low maintenance, few consumables
- simple operation:
15" touchscreen PC with splash-proof flexible USB keyboard (supplied), Windows XP software - automatic, prepared concentrated algae feeder syringe
- no algae culture necessary - fewer tube connections
Data transfer options
- LAN
- Modem
- Relays
- 4-20 mA
- USB
- ModBus
Software
The database software is used to record and analyse the data.
The most important features are...
- easy data analysis and management
- new upper and lower threshold values for all relevant measurands
- parameterisation of the measurements
- saving of data and parameters in a database
- graphic display of measurement values
- data export to Excel or text files
- two protected user levels
- print function
