Removal of sulfa antibiotics in low-temperature water using scoria

Scoria, a natural silicate mineral, was used for the adsorption removal of antibiotics from water. The kinetics of adsorption were studied during the experiment and the results showed that the adsorption of three antibiotics (sulfathiazole (ST), sulfamethazine (SM2), and sulfamethoxazole (SMX)) by scoria fit the Freundlich isotherm well. Additionally, batch experiment data were fitted using pseudo first-order and pseudo second-order equations, and the calculated capacities for the three antibiotics were 0.7688, 0.7242, and 0.6341mg/g, respectively. Moreover, the effects of various water chemistry factors on the removal of the three antibiotics were explored, and Fe²⁺ and Mg²⁺ were found to promote the adsorption. The alkalinity and hardness of water both had significant effects on absorption of the three antibiotics by scoria. The carbon content of scoria increased significantly, and energy dispersion spectrum analysis showed that it could remove three sulfa antibiotics from low-temperature (10°C) water effectively. Overall, scoria is an effective natural material for purifying low-temperature water polluted with ST, SM2, and SMX.