Water recycling is an effective way to reduce water consumption in the industrialization of microalgae-based biomass/bioenergy production. The soluble algal products (SAP) which inhibit the microalgae growth will accumulate in the recycled water. Therefore, the ozone oxidation treatment of SAP produced by Scenedesmus sp. LX1 was studied to reduce the inhibition of SAP. The experimental results showed that there was almost no change in the content of SAP (counted by dissolved organic carbon) after ozonation, but the inhibition of SAP on microalgae growth disappeared. The intrinsic growth rate (r) of Scenedesmus sp. LX1 in the cultivation solution containing untreated SAP was 0.52 d−1, and it rose to 0.95 d−1 after SAP was ozonized. The maximum population growth rate (Rmax) followed a similar trend, increasing from 9.19 × 105 to 13.0 × 105 cells mL−1 d−1. It was suggested that the changes of fluorescence and hydrophilic–hydrophobic/acid–base property of SAP after ozonation leads to the disappearance of SAP inhibition on microalgae growth.
- algal biomass production
- microalgae Scenedesmus sp. LX1
- ozone oxidation treatment
- soluble algal products (SAP)
- water reuse
- First received 12 November 2014.
- Accepted in revised form 11 March 2015.
- © IWA Publishing 2015