Experimental and Kinetic Studies on Penicillin G Adsorption by Lemna minor
Davoud Balarak
Department of Environmental Health, Health Promotion Research Center, School of Public Health, Zahedan University of Medical Sciences, Zahedan, Iran.
Ferdos Kord Mostafapour
Department of Environmental Health, Health Promotion Research Center, School of Public Health, Zahedan University of Medical Sciences, Zahedan, Iran.
Ali Joghataei *
Student Research Committee, Qom University of Medical Sciences, Qom, Iran.
*Author to whom correspondence should be addressed.
Abstract
This study examined the ability of dried duckweed (Lemna minor) to remove soluble Penicillin G from aqueous solution. Batch experiments were conducted to investigate the effects of pH, contact time, initial Penicillin G concentration, biomass dose and temperature on penicillin G adsorption. Maximum adsorption capacity of the duckweed was 36.18 mg g-1 when 94.6% of the Penicillin G was removed. The adsorption equilibriums were analyzed by Langmuir, Freundlich, Temkin and BET isotherm models. It was found that he data fitted to Langmuir better than isotherm other models. Batch kinetic experiments showed that the adsorption followed pseudo-second-order kinetic model with correlation coefficients greater than 0.99. The adsorption capacity of penicillin G increased from 31.11 to 41.82 mg/g with increasing the temperature from 20 to 50, indicating that the process is endothermic. According to achieved results, it was defined that Lemna minor not only was an inexpensive absorbent, but also a quite effective factor in removal of Penicillin G from water and wastewater.
Keywords: Adsorption, Lemna minor, Penicillin G, antibiotic, kinetic.