Development of surface-engineered super-hydrophobic antifouling membrane based microalgal photobioreactor for enhancing CO2 sequestration and biomass productivity.

Escalating the efficacy of microalgal cultivation process is proposed in photobioreactor by using an innovative membrane-based bubble sparger for efficient dissolution of gas phase CO2 using Scenedesmus sp. Surface functionalization was done on tubular ceramic substrates using Hexadecyltrimethylsiloxane (HDTMS) for enhancing mass transfer and antifouling property. The optimum membrane was found to be super-hydrophobic, contact angle >153°. The membrane sparger (HMS) based system resulted in higher biomass concentration (2.26 g/l) and higher CO2 bio-fixation efficiency (0.57 g CO2/l/day) after seven days compared to 0.69 g/l and 0.15 g CO2/l/day for the conventional bubble sparger (CBS) system. Moreover, for HMS system biomass concentration and CO2 bio-fixation efficiency increases up to 3.12 g/l and 0.80 g CO2/l/day respectively using dairy wastewater (50%). The overall study demonstrates the applicability of proposed process for enhancing Scenedesmus sp. biomass productivity and CO2 sequestration in membrane photobioreactor (C-MPBR) process using industrial waste resources along with minimizing microalgae induced biofouling of the spargers.