改性竹蔗渣生物炭对水中阿莫西林的去除性能研究

Biochar was prepared using special Fujian Bainianzhe bagasse (Chinese sugarcane bagasse) for removal of amoxicillin(AMX) from aqueous solution. The adsorption efficacy of unmodified (BBAC) and phosphoric acid (H3PO4) modified biochar (PBBAC), both of which were prepared at three different pyrolysis temperatures (250°C,450°C,650°C), was investigated. It was foundthat P-BBAC650 prepared using the solid-to-liquid mass ratio of 1:1.16 (bagasse: H3PO4) at 650 ℃ was most effective in AMX removal.13The adsorption of AMX onto P-BBAC650 was then examined as a function of contact time, pH value, sorbent dosage, the initialconcentration of AMX and temperature. Results showed that the maximum adsorption of AMX at equilibrium (up to 96.0%) occurredafter 60 min under ambient conditions (pH 5.6 and 25 ℃), at 1.33 g/L P-BBAC650 and the initial AMX concentration of 50 mg/L. Also,the Langmuir and Freundlich adsorption isotherm equations were utilized to model the adsorption process. According to Langmuirisotherm fitting result, the optimal adsorption capacity was 198.8 mg/g at 65 ℃. Thermodynamic parameters suggested that theremoval of AMX by P-BBAC650 is a spontaneous and endothermic process, with increasing entropy. Furthermore, Brunauer-EmmettTeller analysis (BET), Scanning electronic microscopy (SEM) and X-ray diffraction (XRD) were conducted to investigate the structuraland adsorption properties of P-BBAC650. Fourier transform infrared spectroscopy (FTIR) was also applied to understand the mechanismof adsorption of AMX onto P-BBAC650. All results indicated that P-BBAC650 had a high specific surface area of 723.85 m2 g-1, anaverage pore size of 4.72 nm and excellent morphological properties for efficient removal of AMX, the main mechanisms of AMXadsorption on P-BBAC650 would be electrostatic attraction and hydrogen bonding. Therefore, biochar P-BBAC650 may be used as apromising adsorbent of antibiotics in contaminated waters.