A novel chitosan-coated Fe–Cu CNS loaded with CMC–Alginate composite for adsorptive removal of ciprofloxacin from water
Geetha Gopal, M. Joyce Nirmala, Amitava Mukherjee
Abstract
Indiscriminate usage of antibiotic, Ciprofloxacin (CIPRO) poses a serious environmental threat by accumulating in the water bodies. A novel clay-nanosheet supported with Fe-Cu nanocomposite was developed for CIPRO removal using an eco-friendly approach. This composite was immobilised in a biodegradable chitosan-coated Alginate-CMC matrix to form nanocomposite beads for ease of usage in the column reactors. About 90% CIPRO removal was attained through batch mode under optimal conditions (20 mg/L CIPRO; bead loading 2000 mg/L; bead weight 0.15 g; contact period 300 min; and pH - 6). Effect of various environmental factors such as salts NaCl and CaCl 2 (0.05, 0.1, 0.2, 0.5 and 1 M), and micro contaminants humic acid and polyethylene (1, 2, 3, 4 and 5 M) on CIPRO adsorption by NC beads was studied. Pseudo-second order kinetics was observed by the removal process and Langmuir isotherm by the adsorption with a maximum removal capacity of 485.58 mg/g. The effects of various reaction parameters such as the flow rate (1, 2 and 3 mL/min), initial CIPRO concentration (20, 40 and 60 mg/L) and bed height (3, 5 and 7 cm) were studied in the column reactors. The residual toxicity of composite beads interacted CIPRO solution was analysed with environmentally relevant algae such as Chlorella sp . and Scenedesmus obliquus , and the studies confirmed significant reduction in their toxic effects.