Sustainable strategy for enhancing growth of marine diatom and lipid production using RO and AC spent water

Abstract

Sustainable cultivation strategies is a prerequisite for algal biorefineries targeting on reducing water and energy footprint. Thus, in this study, spent waters from the air conditioning unit (SP1), the water purifier/RO unit (SP2) and from the condenser tube of distillation unit (SP3) was filtered, autoclaved and reused in combination with artificial seawater- f/2 (ASW) media for cultivating oleaginous diatoms, Chaetoceros gracilis and Thalassiosira weissflogii and examine its impact on the growth and lipid production. Both strains showed a sharp rise in cell numbers in the test culture setups supplemented with 50% SP1 than in the control. Biomass productivity and total lipid content was highest in 50% SP1 cultures of C.gracilis (0.045 g L⁻¹ d⁻¹; 14.8% DW) and in 100% SP2 and 100% SP3 culture of T.weissflogii (0.06 g L⁻¹ d⁻¹; 19.6% DW), respectively. Indeed, the results validate for the first time the strategy of recycling spent waters recovered from various laboratory and industrial appliances as an optimized media for cultivating diatom algae via a carbon neutral and cost-effective approach.

Funding

DBT-Pan IIT Centre for Bioenergy,(Grant number BT/PR 15650/AAQ/3/815/2016)