Exploring microalgae immobilization and advanced photo bioreactors for enhanced wastewater treatment efficiency

Water pollution is still an essential environmental threat and the conventional wastewater treatment techniques are not always effective to eliminate water based contaminants. This review examines the potential of microalgae-based bioremediation to treat wastewater, especially focusing on application of immobilized microalgae in photobioreactor (PBR) systems. The review incorporates a quantitative analysis of pollutant-removal efficiencies, a comparative evaluation of the cost effectiveness of the passive versus active immobilization approaches, and an overall optimization model of the PBR functioning. The PBR changes in the design and parameters have brought about a greater improvement in the performance of the treatments. Besides this, the review elucidates the mechanisms by which immobilization leads to an increase in biomass retention, development of resilience to environmental perturbation and even sustaining high concentrations of nutrient and heavy metal extraction in a variety of wastewater systems. A combination of these technological and quantitative findings provides a strategic pathway on how microalgae-based wastewater treatment can be applied in the laboratory and in practical industrial applications in a climate-positive manner.