Optimizing nutrient supplementation strategies for sustainable biological treatment of textile wastewater

With increasing industrialization, urbanization, and the growing impacts of climate change, there is a heightened focus on improving wastewater treatment processes across various sectors. The textile industry—one of the largest water-consuming and wastewater-producing sectors globally—faces major challenges in biological treatment, particularly due to nutrient deficiencies, mainly nitrogen (N) and phosphorus (P). This study addresses these deficiencies by evaluating appropriate nutrient supplementation to optimize biological treatment efficiency at a textile wastewater treatment plant. Based on raw wastewater characterization and current treatment processes, the required nutrient amounts were calculated. Several supplementation scenarios, including animal manures (chicken-pigeon) and synthetic fertilizers [di-ammonium phosphate (DAP) and DAP + urea], were assessed. Results showed that the most effective option was the addition of 13.37 kg of DAP and 68.13 kg of urea daily. The daily costs of these alternatives were calculated as €278 for animal manures, €202.5 for DAP, and €73.5 for DAP + urea. Economic analysis revealed that DAP + urea supplementation was the most cost-effective solution. Nutrient optimization led to a 38 % reduction in operating costs related to chemical treatment. This approach is also expected to reduce the plant’s carbon footprint and contribute positively to climate change mitigation. Future research will explore natural nutrient sources and assess their impacts on treatment efficiency through pilot-scale studies. This work highlights the potential for both cost savings and environmental benefits through sector-specific improvements in wastewater treatment.