Cultivation of indigenous Chlorococcum sp. in aquaculture wastewater under various light color and biomass harvesting using membrane filtration: A simultaneous wastewater treatment and biomass production

Abstract

This study investigates the potential of the microalga Chlorococcum sp. for treating real aquaculture wastewater under varying LED light spectra (red, blue, white, violet) and harvesting biomass using polyvinylidene fluoride (PVDF) membranes. Among the tested conditions, red light yielded superior results, achieving 100 % nitrogen removal, 98.77 % phosphorus removal, and 77.21 % COD reduction by the 15th day, alongside the highest biomass production (2.00 ± 0.14 g/L) with the lowest energy consumption (1.08 kWh). Blue light is the next most effective spectra for nutrient removal, while white and violet lights demonstrated moderate performance, consuming 1.80 kWh and 1.62 kWh, respectively. The PVDF membrane exhibited high harvesting efficiency, with flux declining to 125.6 Lm⁻²h⁻¹ at the fourth cycle due to fouling and a flux recovery ratio (FRR) of 1.463 ± 0.078. The operational cost of the peristaltic pump used for harvesting was low, at approximately $0.0965. These findings highlight the efficacy of optimizing light spectra for simultaneous aquaculture wastewater remediation and biomass production, coupled with membrane filtration technology for efficient biomass recovery. This study provides a framework for integrating microalgal cultivation into sustainable wastewater management systems.