MIXOTROPHIC MICROALGAE CULTIVATION IN SUGARCANE VINASSE CLARIFIED BY ELECTROCOAGULATION AND FILTRATION

Sugarcane vinasse as mixotrophic microalgae growth medium was investigated by performing electrocoagulation and following filtration as clarification preliminary step. Electrolysis was carried out using aluminum electrodes and constant current mode. Electrocoagulated vinasse filterability was assessed by constant pressure filtration using Whatman filter paper No 1. Mixotrophic cultivation was
performed growing Desmodesmus sp. microalgae in the clarified medium with light source of 2 klux and 12:12 h photoperiod. Parallel heterotrophic cultivation experiment was performed as a control to assess light influence. Results indicated high turbidity removal, easy filterability and pH adjustment near to BG11 standard microalgae propagation medium by the clarification step. Growing rates and
biomass yield were superior with light source, suggesting mixotrophic metabolism.