Photoautotrophic consumption of phosphorus by Scenedesmus obliquus in a continuous culture. Influence of light intensity

A study has been made of the growth of the microalga Scenedesmus obliquus i n a continuous photobioreactor operating as a chemostat. The influence of l ight intensity was analysed at different rates of dilution, under limited a s well as saturating intensities of illumination. In order to achieve effic ient removal of phosphorus (P) from the liquid medium, it is advisable to o perate at a high light intensity with the working dilution rate near the cr itical maximum dilution rate. At all light intensities, conditions of maxim um P removal differed from those of maximum biomass productivity, the forme r being displaced at higher dilution rates. The removal of P from the mediu m was aided by surface adsorption to the cells and the culture vessel. (C) 1999 Elsevier Science Ltd. All rights reserved.