UVT-Ingenieurbüro für Umwelt- und Verfahrenstechnik
|Online analyzer for continuous monitoring of chemical oxygen demand (COD):|
- during oxidation of
water pollutants the spent oxygen will be mea-
sured in the gas phase
results are comparable with those obtained with standard methods
the sensor has no contact with the waste water (no cross sensitivities)
sewage matrix does not affect precision of measurement (there is no need for extra calibration with waste water)
measurement is ecologically friendly, there are no toxic waste such as e.g. mercury
pollutants were cracked by ozone as one of the strongest
oxidizing reagents. Under the selected reaction conditions even
degra- dable compounds were broken by hydroxyl radicals generated
The reaction takes place in a closed system, where waste water sample and ozone gas are mixed in- tensively.
Sewage ingredients are oxidised by ozone, and not spent ozone gas disintegrates nearly completely to oxygen.
Dependent on demand for oxidation more or less oxygen reaches into the gas phase. The amount of oxygen not used for oxidation is detected by a highly sensitive sensor.
In contrast to many other procedures the Oxi-Jet COD analyser measures the real oxygen consump- tion and therefore the real COD!
Analytical results obtained by monitoring with Oxi-Jet are in conformity with those obtained by standard methods.
The measuring precision is independent of the wastewater composition. In comparison with other measuring devices (such as SAC probes) a cali- bration with the respective wastewater matrix is not necessary.
|Innovative gas phase measurement|
Oxygen consumption during oxidation is moni- tored by a highly sensitive sensor in the gas phase.
The sensor does not come in contact with waste water and has not to be regenerated.
Thus incorrect measurements due to cross sen- sitivities with waste water pollutants (e.g. high salt concentrations) were avoided and a high precision of monitoring is reached.
Performance of the COD monitor is still im- proved by automatic calibration and error recognition during self check. Reliable long- term COD measurement can be permitted even under rough sewage treatment plant work con- ditions.
|Comfortable handling and operation reliability|
||The handling of the Oxi-Jet COD
monitor is realized by an efficient handheld computer (PDA).
All functions are simply attainable in few levels of clearly structured hierarchy by using 6 push buttons and a touchscreen.
Alarm and status reports as well as trend indication of measured values in the graphical display offer additional comfort.
The datalogger function enables storage of mea- sured data on a SD Card to provide optimal data security even during power failure. Saved data can be transmitted to a PC for further handling with a spreadsheet application.
A password input is required for system manage- ment intervention.
An integrated ozone gas sensor ensures internal leakage monitoring with automatic shut off.
|Economic COD analysis|
between price and
performance of Oxi-Jet COD monitor is very favorable due to the
integration of few multifunctional components. There were made no
compromises with regard to efficiency.
The entire liquid management - sucking in, dilu- ting and discharging - is realized by means of only one high precision syringe pump.
Great value were set on low consumption and low costs of reagents for economical operation. Only technical oxygen and a buffer solution has to be supplied. There is no need to dispose toxic waste like mercury or dichromate.
Regarding to the modular design of the COD analyzer, system components can be changed easily. Upgrading of functions is possible at any time. In addition to the basic functions the expansion of the measuring range, a two-channel operation and the measurement of individual samples are feasible.
The flexible system concept offers the possibility to create individual solutions (e.g. specific measuring range) in cooperation with the custo- mer. This can be simply realized by an inex- pensive software update.
|The Oxi-Jet COD
monitor is equipped with a mo- dule for sample preparation.
Waste water sample will be filtered via the built in coarse filter.
Module and tubes for sampling can be cleaned automatically by using pneumatic pressure im- pulses. Hence a long-term operation of the COD analyzer can be supported even if complicated samples with tendency to blockage (e.g. paper industry) are analysed.
| Technical data:
Oxidation by ozone
Measuring range (selectable):
I ..... 100 mg/l COD
II ..... 1.000 mg/l/COD
III ..... 10.000 mg/l COD
other ranges on demand
5 - 10 min.
no interference of soft particles ø < 2 mm
automatically and manually
4 - 20 mA
0 - 10 V
RS 232 C
3 alarm limit outputs
(bi-polar, potential free, 2 programmable)
600 x 600 x 500 (W x H x D in mm)
approx. 40 kg
measurement of single samples
Measuring range up to 50.000 mg/l COD
Technical modification reserved
Awarded with the
Hönower Straße 35, D-10318 Berlin
Telefon: +49 (030) 50176350
Fax: +49 (030) 50176351
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