Innovative optimization of modified waste cotton cloth biofilm reactor for sustainable domestic wastewater treatment

This study evaluated the performance of a Modified Waste Cotton Cloth Biofilm Reactor (MWCC-BR) as a novel and low-cost biofilm carrier for optimizing domestic wastewater treatment in a decentralized system. The study employed an orthogonal experimental (OE) design and Principal Component Analysis (PCA) to assess the impact of key operational parameters, including hydraulic retention time (HRT), dissolved oxygen (DO), temperature, and filling rate (FR), on the removal efficiencies (RE) of chemical oxygen demand (COD), total phosphorus (TP), and ammonium nitrogen (NH₄⁺-N). The PCA revealed significant correlations between influent characteristics and treatment performance, with higher influent COD and TP concentrations enhancing pollutant degradation. It also provided valuable insights for optimizing system performance and offered a robust framework for real-world applications. Under optimal conditions, MWCC-BR achieved RE of 96.5 % for COD, 82.8 % for NH₄⁺-N, and 60.1 % for TP. This study demonstrates the potential of MWCC-BR to align with Sustainable Development Goal 6 (clean water and sanitation) by providing a cost-effective, environmentally friendly solution for wastewater treatment, solid waste recycling, and environmental protection. • Optimized MWCC-BR is an innovative recycling method for wastewater treatment. • High pollutant removal: 96.5 % COD, 82.8 % NH₄⁺-N, 60.1 % TP efficiency. • PCA-driven optimization links influent characteristics to performance. • Sustainable, low-cost solution for large-scale wastewater treatment. • Supports SDG 6: clean water, sanitation, and environmental protection.