Design and modelling of photobioreactor for the treatment of carpet and textile effluent using Diplosphaera mucosa VSPA

The current study investigated the potential of one less explored microalgae species, Diplosphaera mucosa VSPA, for treating carpet and textile effluent in a conventionally designed 10 L bubble column photobioreactor. To the best of our knowledge, this is the first study to evaluate COD (chemical oxygen demand) removal efficiency by microalgae in carpet effluent. To evaluate D. mucosa VSPA's potential, its growth and bioremediation efficacy were compared to those of a well-known strain, Chlorella pyrenoidosa. D. mucosa VSPA outperformed C. pyrenoidosa in both effluents, with the highest biomass concentration reaching 4.26 and 3.98 g/L in carpet and textile effluent, respectively. D. mucosa VSPA also remediated 94.0% of ammonium nitrogen, 71.6% of phosphate phosphorus, and 91.9% of chemical oxygen demand in carpet effluent, approximately 10% greater than that of C. pyrenoidosa. Both species also removed more than 65% of colour from both effluents, meeting the standard set by governing bodies. Microalgae growth and substrate removal patterns in the photobioreactor were simulated using photobiotreatment and the Gompertz model. Simulation results revealed that photobiotreatment was the better-fit model, concluded based on the coefficient of regression value and the second-order Akaike information criterion test. Modelling studies can assist in increasing the performance and scale-up of the photobioreactor.