BODTOX: from research to application implementation
The intention to develop a device capable of quickly determining the level of water pollution has been cherished by the team since 2016, when incidents of massive fish deaths occurred across Vietnam's provinces. After learning about technologies that can be applied to the goal of early warning of water pollution, Dr. Phuong realized that biosensors could be a suitable solution for Vietnamese conditions. In 2017, with the first grant of 30,000 yen from KURITA-AIT Foundation for water research, Dr. Phuong obtained the funding, although not much, but enough to purchase some basic chemicals and equipment to start realizing her idea.
With the goal of creating technological products with high applicability, the research team chose a separate path that does not overlap with the biosensor research currently being conducted in the world. Not choosing the direction of research and development of biosensors, which required expensive research equipment as well as qualified laboratories, the team focused on developing a complete equipment system with new measuring principles and new bioreactor combined with conventional DO sensors. This approach is expected to help the team develop biosensors that can be mass-produced with low cost and locally available materials.
The idea of the semi-continuous measurement principle proposed by Mr. Nguyen Phuc Hoang Duy has brought many advantages to the BODTOX technology, compared to continuous or batch measurement methods such as research and commercial currently developing biosensors: simply use a dissolved oxygen sensor that can determine both input and output oxygen; at the same time can shorten measurement time (compared to continuous method) and can determine BOD in real time (compared to batch method). In addition, the idea of a compact bioreactor, which can be built in the field of operation without the need for highly specialized people, was conceived with the aim of making the sensor system simpler and easier to operate, importantly, has lower investment and operating costs than existing equipment on the market.
However, until 2018, when the research team received funding from Vietnam Academy of Science and Technology for an Academy-level independent project "Research and manufacture biosensors applied in rapid and continuous analysis of biochemical oxygen demand (BOD)” code VAST07.01/19-20, a complete system of equipment has been realized. Followed by days of arduous testing to find out the process of making the media, culturing and immobilizing the microorganisms, importantly, the measurement procedure so that the results obtained from the device coincide with the results obtained from measured results by traditional method of determining BOD5. After two years of implementing the project, the team has achieved certain successes, such as making a simple and inexpensive device for measuring time of only 10 minutes, capable of quickly determining BOD5 in aquatic wastewater and water from canals in inner Ho Chi Minh City with the largest coefficient of variation < 10% (with traditional method of measuring BOD5, < 20%) and there is no statistical difference between two measurements when using the model wastewater according to the formula from Organization for Economic Cooperation and Development (OECD) as standard solution. Furthermore, the results obtained outside the scope of the topic show that this technology is completely applicable to measuring the total toxicity of water sources. With this parameter, authorities can issue early warnings to promptly prevent environmental disasters without having to accurately identify toxins present in water sources.
In order for this technology to be applied in practice, the accuracy compared to traditional BOD5 measurement method needs to be further studied on different types of real wastewater, as well as the ability to determine toxicity in water containing different toxins. One of the limitations of the rapid BOD5 prediction method using biosensor is that its accuracy is highly dependent on the selection of the correct calibration solution. Accordingly, the calibration solution should have the same degree of biodegradation as the wastewater to be analyzed, but for ease of practical application it must have the simplest possible composition. Moreover, the development of equipment to improve automation with low cost also needs to be studied.
The research group of Dr. Pham Thi Thuy Phuong and colleagues
The research team continues to receive financial support from NAFOSTED Fund for the applied research project: "Research and develop a simple, low-cost method and device for application in online analysis of biological oxygen demand (BOD5)", code: NCUD.02-2019.52 in the first year of the program. Thanks to this funding, the team has continued to carry out further research and development activities to perfect BODTOX technology. The team continues to research and develop a non-contact valve and liquid transport system, making the sensor system simple, easy to operate and maintain.The improvement of the standard solution also makes the measurement results more and more accurate, the determination of toxicity due to heavy metals in water has also been successful with high sensitivity.
The work "A novel biosensing system for rapid estimation of BOD5 and sensitive detection of toxicity in water (BODTOX)" has won Hitachi Global Foundation's Best Innovation Award. Dr. Phuong shared that the work is still being completed by the research team with ultimate goal of biosensor technology that will soon be applied in the field of water quality monitoring.
DO measuring chamber
Non-contact valve set
Translated by Phuong Ha
Link to Vietnamese version