Simulated sugar factory wastewater remediation kinetics using algal–bacterial raceway reactor promoted by Polyacrylate polyalcohol

• Copolymer Polyacrylate alcohol was used for the first time in this research work.
• Polyacrylate polyalcohol induced pH neutralisation of the cultivation medium.
• C. vulgaris cultivation yielded in photosynthetic oxygenation of 11 mg l−1 d−1.
• Immobilised C. vulgaris cultivation resulted in 89% removal of COD in 96 h.

The remediation kinetics of simulated sugar factory wastewater (SFW) using an algal–bacterial culture (ABC) of Chlorella vulgaris in association with Pseudomonas putida in a raceway reactor was found to be enhanced by 89% with the addition of 80 ppm of copolymer Polyacrylate polyalcohol (PAPA). This was achieved by efficient suspension of the ABC throughout the water body maintaining optimum pH and dissolved oxygen that led to rapid COD removal and improved algal biomass production. The suspension of the ABC using the co-polymer PAPA maintained a DO of 8–10 mg l−1 compared to 2–3 mg l−1 when not suspended. As a result, the non-suspended ABC only achieved a 50% reduction in COD after 96 h compared to a 89% COD removal using 80 ppm PAPA suspension. In addition, the algae biomass increased from 0.4 g l−1 d−1 for the non-suspended ABC to 1.1 g l−1 d−1 when suspended using 80 ppm PAPA.