Removal of Two Quinolone Antibiotics from Aqueous Solution by the Municipal Sewage Sludge-based Adsorbent

TAO Huchun†, GONG Yiwei, ZHANG Lijuan, DING Lingyun, ZHANG Shanfa

Shenzhen Key Laboratory for Heavy Metal Remediation and Reclamation, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055; † E-mail: taohc@pkusz.edu.cn

Abstract The municipal sewage sludge was used as an raw material to prepare the sewage sludge-based adsorbent (SSA) by HNO3 activation, NAOH activation and H2O2 oxidation modification. The removal of ciprofloxacin (CIP) and lomefloxacin (LOM) from aqueous solution and the influencing factors were studied. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to characterize the microstructure and functional groups on the surface of SSA. The effects of adsorbent dosage, temperature, the initial ph of solution, the ionic strength and other factors on the removal of CIP and LOM by SSA were investigated. The results showed that the modified SSA activated by 0.1 M HNO3 was most effective for removal of CIP and LOM. The rough structure of the modified adsorbent could provide more sites for antibiotic adsorption, and the oxygen-containing functional groups were able to form hydrogen bonds to enhance the adsorption of organic matters in solution. When the antibiotic concentration was 10 mg/l, the adsorption capacity of CIP and LOM was 8.95 and 7.28 mg/g, and removal rates were 90% and 73%, respectively. The adsorption process of CIP and LOM on the modified SSA was in accordance with the pseudo-second-order model, and Langmuir isotherm equation could well describe the adsorption behavior of CIP and LON on the modified SSA, which proved that adsorption process was monolayer chemisorption. The adsorbent removed 84% CIP and 67% LOM after 5 cycles,