Microbubble or nanobubble technology has attracted attention of scientists in recent years.  It is an important technology in the agriculture, hydroponic, and aquaculture industries.

Some of the applications of nanobubbles which have been explored around the globe are:

• Acceleration of metabolism in vegetables and shellfishes
• Improved shelf stability of products with bubbles (foam products)
• Nutritional supplement carrier in the food industry
• Improved delivery of chemotherapy drugs in cancer patients
• Sterilisation using ozone gas
• Water treatment by flotation

Recently, a hydroponic customer approached Hanna Instruments to provide a solution for testing Dissolved Oxygen in nanobubbles.  Hydroponic growers are using microbubbles to increase the nutrient absorption of crops and to increase the growth of plants. By adding microbubbles, the roots spread and crops grow 1.5 times faster.  The leaves on the crop are greener and the structure of the stems are largely different.

The size of these bubbles are 100 nm (0.0001 mm) and therefore, it could not be effectively measured with the galvanic or polarographic dissolved oxygen probes.   The Hanna HI 98198 OPDO was the right fit for the application because it does not require the flow the polarographic or galvanic sensors require. The dissolved oxygen in the nutrient solution needs to be within a range of  20 ppm to 25 ppm to maximise the effectiveness of the nanobubbles on the crops.  The Optical Dissolved Oxygen Meter’s measurement range is 0.00-50 ppm so it covered the range, and the accuracy of the reading within this range is +/- 1.5% of the reading which was acceptable to the customer.

Applications for microbubbles and nanobubbles will continue to be developed in the future.