Design and development of mini-photobioreactor system for strategic high throughput selection of optimum microalgae-wastewater combination

Abstract

This study establishes an innovative and economic mini-photobioreactor system (mPBR) providing an optimum microalgae-wastewater screening tool. This study enables the effectiveness of microalgae in wastewater treatment by enhancing its productivity through improved operating conditions such as controlled light, temperature, and agitation. This was achieved by designing 1-L photobioreactor with multiple mPBR to enable the screening of nine microalgal cultures (native and procured) under similar operating conditions (Light-11,000 Lux; Aeration - 1.5 LPM; Temperature- 25 ± 2 ◦C) using three wastewaters [sewage treatment plant (STP), dairy processing industry (DWW), and slaughterhouse processing unit (SWW)]. The native cultures outperformed for nutrient recovery with best treatment in PA4 accounting 45–72% sCOD removal and, 90–98% NO3􀀀 -N, NH4+-N, and PO43􀀀 -P removal, with simultaneous biomass production of 1.7–2.3 gL􀀀 1. To conclude there was up to 31% increase in the microalgal biomass production, lowering incubation time from earlier reported 12 days in a stationary flask to 3 days in the mPBR.