Supplementary_Data_Experimental_Methods_and_Process_Optimization

The supplementary data describe an integrated study on sludge conditioning, ceramsite preparation, and phosphorus removal performance. Kaolin was evaluated as a dual-function material for both conditioning and ceramsite fabrication, with polyaluminum chloride (PAC) as a reference. Conditioning efficiency was optimized by varying dosage and pH, and assessed via specific resistance to filtration (SRF), settling performance, cake moisture content, filtrate CODcr and turbidity. The conditioned sludge was subsequently used to produce ceramsite with kaolin and sodium silicate through mixing, pelletizing, drying, and sintering. Process parameters were optimized using single-factor and L9 orthogonal experiments, identifying key influences on density, strength, and water absorption. The resulting ceramsite exhibited effective phosphorus removal under varying particle sizes, pH, and initial concentrations, demonstrating its potential for sludge valorization and wastewater treatment.