Sequencing Batch Reactor: A Sustainable Wastewater Treatment Option for the Canned Vegetable Industry

The treatment of wastewater from the food processing industry, such as canned soup production, presents challenges due to its high organic load and limited nutrient concentrations. This study evaluated the efficiency of a sequencing batch reactor (SBR) in the removal of organic matter, color, turbidity, and nutrients under different solid retention times (SRTs) and operational cycle times (OCTs). The reactor operated with SRTs of 15 and 25 days and an 8-h cycle, and parameters such as COD, BOD5, color, turbidity, nitrogen content, and phosphorus content, as well as COD fractionation were analyzed to assess biodegradability. The results showed high removal rates of organic matter, with 84.8% COD and >90% BOD5, revealing that 54.3% of the COD was readily biodegradable. Significant reductions in color (72.3%) and turbidity (83.3%) were achieved, improving the quality of the treated effluent. Nitrogen removal occurred primarily through assimilation due to the absence of anoxic conditions, while phosphorus was also removed via biomass assimilation. The addition of macronutrients did not significantly influence treatment efficiency, reducing the need for additional inputs and operational costs. This study demonstrates the flexibility and effectiveness of the SBR in treating wastewater with a high organic load and low nutrient concentrations, highlighting its ability to produce a high-quality effluent suitable for discharge or reuse. The novelty of this work lies in combining COD fractionation analysis, nutrient removal mechanisms, and water quality parameters, providing key insights for optimizing biological processes in industrial contexts.