Optimizing composite mineral materials for efficient treatment of cotton pulp black liquor

Cotton pulp black liquor (CPBL), a challenging pollutant from cotton linter pulping, exhibits high chroma, alkaline pH, and low biodegradability, rendering conventional treatment methods inefficient and costly. In this study an optimized composite mineral adsorbent (OCMA) was developed using natural minerals, which enhanced its capacity to remove chemical oxygen demand (COD), ammonia nitrogen, and chroma through compositional optimization. Experimental results showed the maximum removal efficiency of 96% for decolorization, 93% for COD reduction, and for 80% ammonia nitrogen elimination under optimal conditions (3:1 adsorbent ratio, 0.8 g/L dosage, 25 °C, pH 7). A comprehensive characterization via SEM, BET, FTIR, and XRD analyses revealed the structural and mechanistic basis for the enhanced performance of OCMA. The innovative mineral composite design overcomes traditional process limitations, providing an efficient and eco-friendly solution for recalcitrant wastewater treatment. This work demonstrates significant potential for environmental remediation and sustainable resource utilization, highlighting its simple operation, cost-effectiveness, and high treatment efficiency in addressing the critical challenges in industrial wastewater management. • A composite mineral was prepared using natural materials. • The material removed chroma, organic matter and ammonia nitrogen. • The two minerals showed structural and functional complementarity. • Pores and surface groups improved adsorption efficiency.