Case studies, Applications in field & Technology Validations

Application in field · BIOSET · San Martín de la Vega (Madrid)· WWTP


Two examples of the advances achieved with microbial biosensor technology that have been developed at the level of prototypes and are to be commercialized in phase 3:

A. First automated microbial biosensor, which at an international level was developed for a real application in the environment:

In 1999 Biosensors S.L. already had an initial prototype of MB-BOD. The Tajo Hydrographic Confederation, a body belonging to the Ministry of the Environment of Spain, was interested in 1999 when the prototype was installed for its functional evaluation in the SAICA Station located in the town of San Martin de la Vega, 30 km from Madrid, station in Tajo River were monitored such as pH, conductivity, dissolved oxygen, turbidity, etc., were carried out.

The river Tajo contributes all of its clean waters from the mountains of the north of Madrid to be used in this capital. Once used and purified by the 7 WWTW of Madrid, up to a maximum BOD of 50 ppm as required by Spanish legislation, these waters return to the river Tajo to be used for different purposes, mainly for the irrigation of vegetable fields.

For years, the SAICA station in San Martin de la Vega had detected that the BOD of the water of WWTP, which circulated through the Tajo, often increased its BOD, sometimes to values ​​highly above 50 ppm, with a pattern of BOD analytical peaks that the technicians of the Confederación Hydrographic del Tajo could not understand. This concern was expressed by these technicians from the Confederation to Biosensores S.L. in order to install a prototype of MB-BOD that could contribute to know the causes of these anomalies.

The results obtained by MB-BOD during three months of continuous monitoring of the BOD in the SAICA station of San Martin de la Vega, showed that the episodes causing the uncontrolled spikes of the BOD rise were due to environmentally illegal actions of certain companies throwing  directly its wastewater to the Tajo, without going first through the corresponding WWTP.

When the MB-BOD prototype, located at the SAICA station, started monitoring the BOD at the end of December 1999, results were obtained shown in the graph corresponding to the months of January, February, March and April of 2000. From these Results, it was known that the BOD spikes originated in the factories that illegally were throwing their water into the river without prior purification.

BOD monitoring from January to April 2000.
MB-BOD device was installed in the SAICA water quality control station -Spanish Ministry of the Environment Agency-. A BOD peak value is observed -much higher than the 50ppm, which is the limit allowed by Spanish law- in the water treated by a WWTP. Until that finding, the technicians in charge of controlling the Jarama River water quality were not aware of such BOD peak values.

The water quality technicians of the Hydrographic Confederation quickly announced the results obtained by the MB-BOD to the industries of the area and with these informative actions of these technicians can be seen as, in about 45 days, those uncontrolled spills to the river Tajo of wastewater not purified were ceased due to the fear of the offenders being located and sanctioned. 

The prototype continued to be located at the SAICA station in San Martin, during the evaluation period in the field, for two years. In that period the BOD peaks disappeared almost completely. After this evaluation, the Tajo Hydrographic Confederation did not have the funds to locate another MB-BOD prototype. Based on the information available at that time, it indicates that uncontrolled BOD peaks occurred again with great frequency.

Biosensores S.L. had the satisfaction of being an international pioneer in contributing directly with their biosensor technology to the prevention of excessive BOD contamination caused by uncontrolled spills in the Tajo river water. 

B. Implementation of the MB-BOD equipment to monitor the efficiency of a WWTP:



You can know the contamination due to organic matter in water, and optimize the treatment process of your Waste Water Treatment Works (WWTW), in order to obtain the best results.

With our MB-BOD water samples at an inlet (red) and outlet (blue) of a waste water treatment plant can be monitored.

As indicated in the «milestones achieved» point, there have been several acknowledgments by experts from environmental quality organizations that have positively evaluated the technology achieved in the MB-BOD and its application to the real world. These validations have been carried out during thousands of hours of continuous operation of the equipment in the field. We attach some references: