Dipsersion of ozon into seawater - trials, analysis and validation
The latest project results involve a thorough literature review on kinetics of gas liquid dispersion and methods for feeding ozone into water, and a test setup for trials involving feeding and dispersion of ozone into seawater and testing of devices for a micro-bubble generation gas liquid mixing.
Literature review
A thorough literature study and database search has been carried out on kinetics of gas liquid dispersion as well as available methods used for feeding of ozone to water. Moreover, the literature review covered the marine chemistry involved in ozonation of seawater.
Trials on feeding and dispersion of ozon into seawater
A test setup was constructed at Kristineberg Marine Research Station (KMRS) on the South West coast of Sweden for trials involving feeding and dispersion of ozone into seawater, and testing of devices for micro-bubble generation gas liquid mixing. The test setup was also used for eco-toxicological experiments, studying the effect of ozonation of seawater on settling, survival and growth of blue mussels (Mytilus edulis) and chemical analyses on formation of ozonation by-products. KMRS is the largest field station for marine research in Sweden and one of Europe’s most modern marine research laboratories with facilities for conducting experimental work and for keeping live organisms for prolonged periods. Seawater for the experiments was extracted from two depths (5m and 30m depth).
Size and density analysis of generated micro-bubbles
The ozone feeding and dispersion unit has been developed by integrating a micro-bubble generating and a gas-liquid dispersion device ensuring maximised mass transfer. Analyses of generated bubble size and density has been analysed using imaging technique and computation with a program developed under LabView. The bubble size has been found to be a determining factor for effective ozone mass transfer.
Validation of ozon feeding and dispersion unit
The eco-toxicological and chemical investigations were used for validating the performance of the ozone feeding and dispersion unit. For eco-toxicological studies, larvae of Mytilus edulis considered to be highly resistant to ozone, were collected from the sea and cultivated. One group of specimen was subjected to ozonated sea water at different TRO levels for different periods of time, in addition to batch tests. Impact of the ozonation has been compared continuously with a reference group of specimen. Parallel with this, ozonated seawater was analysed to measure the levels of generated bromates and halocarbons.
