Study on the preparation mechanism and dephosphorization effect of SW-ceramsite.

To address environmental challenges such as eutrophication caused by excessive phosphorus discharge and low resource utilization of solid waste, this study investigates the factors influencing the physical properties of ceramsite from solid waste (SW-ceramsite) through sintering method, and its adsorption performance. The results shown that under the optimal conditions of additive dosage 9 g/100 g mixture, sintering temperature 1100 °C, heating rate 10 °C/min, and holding time 5 min, the values of breaking and wear rates and void fraction were 0.35% and 69.6%, respectively. Grey relation analysis indicated that the additive dosage was the most influential factor, followed by sintering temperature and heating rate, with holding time being the least impact. The equilibrium adsorption capacity (q) of SW-ceramsite for phosphorus was 1.85 mg/g. The adsorption process was better described by the Freundlich adsorption isotherm, as well as by the pseudo-first-order and pseudo-second-order kinetic models, and was characterized as non-spontaneous and exothermic. After nine regeneration cycles, The q of SW-ceramsite decreased by only 0.185 mg/g, with a regeneration loss rate was just 4.988%, suggesting good reusability. The findings suggest that the SW-ceramsite holds promise for treatment of phosphorus-containing wastewater.