Experimental study on phosphorus removal performance from water by SW-ceramsite in a fixed-bed column

Based on the previous research on the preparation of solid waste ceramsite (SW-ceramsite), the phosphorus removal performance from aqueous solution by SW-ceramsite in a fixed-bed column was investigated. Characterization results showed that the S_BET, pH_pzc, pore volume, bulk density and void fraction values of pretreated SW-ceramsite were 4.18 × 10⁴ cm²/g, 9.83, 3.05 × 10³ cm³/g, 1.37 g/cm³ and 69.8%, respectively. Column experiments indicated that under optimal operating conditions of an initial pH of 5, an initial phosphorus concentration of 5 mg/L, a reaction temperature of 323 K, and an initial flowrate of 40 mL/min, the breakthrough curve (BTC) exhibited an irregular "S" shape, and the breakthrough and saturation times were 80 h and 155 h, respectively. Kinetic analysis demonstrated that compared with the Adams-Bohart model, the Yoon-Nelson model better described the phosphorus removal behavior from water by SW-ceramsite in a fixed-bed column. Grey relation analysis (GRA) results suggested that except for initial flowrate, the assumed effects of initial pH, initial concentration, and reaction temperature on the BTC were consistent with the GRA outcomes, implying that the GRA method can be used to determine the relative influence of the aforementioned factors on the phosphorus removal performance from water in a fixed-bed column packed with SW-ceramsite. Furthermore, after eight regeneration cycles, the breakthrough and saturation times of SW-ceramsite packing decreased by 30% and 12.9%, respectively, suggesting that it has a certain regenerative ability.