The Biological Performance of a Novel Electrokinetic-Assisted Membrane Photobioreactor (EK-MPBR) for Wastewater Treatment

Abstract

Developing an effective phycoremediation system, especially by utilizing microalgae, could provide a valuable approach in wastewater treatment for simultaneous nutrient removal and biomass generation, which would help control environmental pollution. This research aims to study the impact of low-voltage direct current (DC) application on Chlorella vulgaris properties and the removal efficiency of nutrients (N and P) in a novel electrokinetic-assisted membrane photobioreactor (EK-MPBR) in treating synthetic municipal wastewater. Two membrane photobioreactors ran in parallel for 49 days with and without an applied electric field (current density: 0.261 A/m2). Mixed liquid suspended soils (MLSS) concentration, chemical oxygen demand (COD), floc morphology, total phosphorus (TP), and total nitrogen (TN) removals were measured during the experiments. The results showed that EK-MPBR achieved biomass production comparable to the control MPBR. In EK-MPBR, an over 97% reduction in phosphate concentration was achieved compared to 41% removal in the control MPBR. The control MPBR outperformed the nitrogen removal of EK-MPBR (68% compared to 43% removal). Induced DC electric field led to lower pH, lower zeta potential, and smaller particle sizes in the EK-MPBR as compared with MPBR. The results of this novel study investigating the incorporation of Chlorella vulgaris in an electrokinetic-assisted membrane photobioreactor indicate that this is a promising technology for wastewater treatment.

Microalgae-Enabled Wastewater Remediation and Nutrient Recovery through Membrane Photobioreactors: Recent Achievements and Future Perspective

“…The integration of electrochemical processes in PBRs has been proven to stimulate the growth of microalgae [135], improve nitrogen and phosphorus removal efficiency [136], and mitigate membrane fouling [137]. An MPBR incorporated with a low-voltage direct current was developed for the treatment of synthetic municipal wastewater using Chlorella vulgaris [138]. While achieving a biomass production that was comparable to the conventional MPBR, the electrokinetic-assisted MPBR achieved a significantly higher phosphorous removal, with an overall removal of 97.98% compared with the 41.81% achieved by the conventional MPBR.…”