Streamlining nitrogen removal in Kuwait’s WWTP: A data-driven analysis of BNR process optimization

The elimination of nutrients, especially nitrogen, is an increasingly pressing concern for wastewater treatment facilities (WWTPs). The Sulaibiya WWTP in Kuwait utilizes the conventional Biological Nitrogen Removal (BNR) technique of nitrification-denitrification for secondary treatment. Both Nitrogenous Oxygen Demand (NOD) and Chemical Oxygen Demand (COD) are successfully reduced by this energy-intensive method. The facility employs Reverse Osmosis (RO) for advanced treatment, which, although effective in eliminating all impurities, incurs significant operating expenses, increases energy consumption, and generates brine as a byproduct. This study aims to enhance nitrogen removal efficiency through four optimization scenarios, focusing on minimizing operational costs, reducing energy consumption, eliminating the necessity for tertiary treatment, and ensuring adherence to Kuwait Environment Public Authority (KEPA) standards for irrigation and marine disposal. To assess the possibility of exceeding KEPA standards across five treatment scenarios—the basic model, A 2 /O, A/O, Modified Ludzack Ettinger (MLE), and 4-stage Bardenpho—the study comprised six years of data analysis, modeling of wastewater treatment facilities using GPS-X software, sensitivity analysis, and Monte Carlo simulation. The existing design of the wastewater treatment facility consistently complies with KEPA standards, attaining removal efficiencies of 92.7% for TKN, 95.8% for total suspended solids (TSS), 94.3% for COD, and 95.3% for ammonia nitrogen, even in the absence of tertiary treatment. The research demonstrates that the elimination of the tertiary treatment phase is achievable. The facility's optimal configurations were the A/O process, with removal efficiencies of 97.7% for TKN, 98.3% for TSS, 96.4% for COD, and 98.4% for ammonia, and the MLE process, with efficiencies of 97.7%, 96.8%, 96.4%, and 98.4%, respectively. • Optimizes nitrogen removal in Kuwait's Sulaibiya WWTP while reducing energy and operational costs . • Evaluates five treatment scenarios, achieving KEPA compliance without tertiary and quaternary treatment . • A/O and MLE configurations achieve up to 98% nitrogen removal efficiency . • Proposes a cost-effective, energy-efficient approach to nutrient management in WWTPs.