Optimizing algal-bacterial systems for efficient sugar cane wastewater treatment: Pollutant removal and biomass...

Sugarcane wastewater is highly biodegradable; however, conventional single-treatment processes are constrained by its excessive organic load. Here, we integrated anaerobic acidification with microalgal bioaugmentation to establish an algal-bacterial symbiotic system, leveraging metabolic synergies within functional microbial consortia. The results demonstrate that this system enables the synergistic integration of anaerobic and aerobic bacteria with microalgae, forming a highly efficient metabolic network that enhances water purification. By systematically investigating environmental determinants of water purification and biomass dynamics in conjunction with response surface methodology (RSM), we optimized environmental parameters. The optimized parameters included an aeration rate of 267 mL/min, a light intensity of 6985 lx, and a 12:12 h light-dark photoperiod. Under optimized conditions, the system achieved a COD removal efficiency of 98.56 % and a biomass yield of 3.43 g/L, underscoring dual efficacy in organic load reduction, aeration demand minimization, and resource recovery. This work provides a sustainable approach for treating high-strength sugarcane wastewater through integrated algal-bacterial processes.