Activated Microalgae-Activated MLSS Bacteria Consortium Synergistically Improves Phycoremediation Kinetics: A...

Rapid and efficient wastewater treatment processes with valuable resource recovery are the need of the hour for developing robust, sustainable, and integrated biological systems. This study introduces a novel parallel bioactivation approach combining Chlorella vulgaris and mixed liquor suspended solids (MLSSs) bacterial consortium for wastewater treatment in an outdoor high-rate algal pond (HRAP). C. vulgaris was activated separately in suboptimal nutrient concentrations (0.1×) with respect to the standard commercial medium for 2 days before treatment. Separately activated bacterial MLSS was incorporated into activated C. vulgaris, making an AM-AB consortium. The AM-AB consortium demonstrated enhanced nutrient remediation with nitrogen removal efficiency of 99.9% after 6-h treatment and complete removal of phosphate (< 0.01 mg L^-1) in 2 h of treatment. The maximum specific removal rate for total nitrogen reached 49.81 mg g^-1 h^-1, whereas ammonia showed high substrate affinity (Ks = 0.53 mg L^-1). The consortium achieved 81.73% BOD reduction, indicating the synergistic interaction between microalgae and bacteria, supporting the potential of the AM-AB consortium for biological wastewater treatment.