3RD INTERNATIONAL CONGRESS ON TECHNOLOGY - ENGINEERING & SCIENCE - Kuala Lumpur - Malaysia (2017-02-09)

Removal Of Ciprofloxacin Hydrochloride From Aqueous Solution Using Cuo Nanoparticles: Kinetic And Thermodynamic Studies
Over the past few years, a large number of pharmaceuticals have been detected in surface, ground and drinking waters. Pharmaceutical industries release waste water containing toxic contaminants into the environment. Among the different classes of drugs, fluoroquinolone family of antibiotics used in human and veterinary medicine causes serious threat to the ecosystem and to human health due to their high consumption. Ciprofloxacin hydrochloride (1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid) is commonly used broad-spectrum antibiotic agent of fluoroquinolone family. Adsorption is the most versatile and widely used method for the removal of pharmaceutical pollutants due to its efficiency and ease of operation at large scale. In recent years, nano metal oxides have been extensively used for the removal of pollutants from waste water. In the present work adsorption of ciprofloxacin hydrochloride from aqueous solutions, using CuO nanoparticles has been studied using batch experiments. CuO nanoparticles have been synthesised by precipitation method and characterized using X-Ray Diffraction, U.V and TEM. The average particle size, as determined from the XRD data, is 19.96 nm. The UV absorption spectrum of CuO nanoparticles exhibits a strong absorption band at about 278 nm, indicating that the suspension is stable and the obtained CuO nanoparticles are well-dispersed particles. TEM images shows that the size of CuO nanoparticles is very consistent and the average particle size was estimated to be 20 nm. Effects of initial drug concentration (10-100mg/l), contact time(15-165 mins.), pH (1-14) and temperature (250–450C) on adsorption capacity of CuO nanoparticles has been investigated. Maximum removal 79.5% is obtained at pH 4, contact time 135 mins, drug concentration 100 mg/l and adsorbent dose 100mg at 298 K. Data at optimum conditions have been subjected to isotherm analysis and fits to Freundlich, Temkin and Dubinin-Radushkevitch isotherm models. Adsorption isotherm studies suggest that physical and monolayer adsorption occurs and adsorption capacity is of the order of 0.810 mg/g. Kinetic studies reveal that the process follows first order kinetics as obtained from the general rate equation and Lagergren equation. Application of the Morris Weber equation suggests that intra-particle diffusion occurs but is not the rate determining step. The effect of temperature was investigated by varying temperatures ranging from 25o - 45o C. The amount of drug adsorbed increases from 0.810 to 0.824 to 0.837 mg/g with increase in temperature from 298 K to 308K and 318K respectively. The value of thermodynamic parameter G0 is found to be -3.344 x 103 indicating feasibility and spontaneous nature of adsorption. The values of H0 and S0 are 7.482 x 103 and 35.91 respectively, which suggests that the process is endothermic with increase in randomness at solid solution interface occurs during adsorption.
Keywords: Adsorption, Batch studies, Isotherm analyses, Kinetics, Thermodynamic parameters.
Neeta Sharma, Neha Dhiman