%0 Journal Article
%T Uptake of Sulfadiazine Sulfonamide from Water by Clinoptilolite
%A Zhaohui Li
%A Christie Stockwell
%A Jacqueline Niles
%A Skylar Minegar
%A Hanlie Hong
%J Applied and Environmental Soil Science
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/648697
%X The interactions between sulfadiazine (SDZ), a sulfonamide antibiotic, and clinoptilolite, a hydrophilic zeolite, were investigated under batch experimental conditions. The uptake of SDZ on the zeolite followed a linear sorption isotherm under neutral pH conditions. Higher SDZ uptake on the zeolite was observed when solution pH was below the or above the values of SDZ, while minimal SDZ uptake was observed when the solution pH was between the and values of SDZ. These observations suggested that hydrophobic interaction between SDZ and the zeolite was minimal due to the hydrophilic nature of the substrate. Electrostatic interactions and ion bridging were attributed to the elevated SDZ uptake under low and high pH conditions. As SDZ had a low value, the hydrophilic nature of the substrate prevented extensive uptake of SDZ, which could contribute to its extensive detection in the environment, including surface water and wastewater. 1. Introduction The worldwide use of veterinary antibiotics poses a continuous threat to the environment. Used extensively in human and animal medicine, sulfonamide antibiotics (SAs) were highly stable towards hydrolysis, resulting in accumulations in the environment [1]. Neutral and cationic SAs interacted primarily with external surfaces, instead of intercalating into the swelling clay mineral montmorillonite [2]. However, conflicting results were reported on the stability of adsorbed SAs to solid surfaces. Adsorption of SAs to mineral soil colloids was weaker and resulted in a stronger desorption from clay-size fractions [3]. The distribution coefficients ( ) of SAs were overall low, <10£¿L/kg on many types of soils, thus likely to be highly mobile in the environment [4¨C6]. Slightly high values were reported for SAs sorption on pure clays, while organic matter had higher affinities for neutral SAs than smectite clays [7]. Sulfadiazine [SDZ, 4-amino-N-(2-pyrimidinyl)benzenesulfonamide] is a widely used potent antibacterial agent belonging to SAs. [8]. It was the second highest sold antibiotic in UK with a usage of 14 tons in 2000 [9]. Due to its extensive use in veterinary medicine and frequent detection in the environment, a few studies were conducted on SDZ adsorption on soil materials and manure [3, 10]. In addition, a detailed literature review on the analysis, fate, and effects of SDZ on soil ecosystems indicated that, in applying manure from antibiotic-treated animals to arable soils, SDZ could reach the environment, but the fate and transformation processes and the consequences for soil microorganisms and soil functions
%U http://www.hindawi.com/journals/aess/2013/648697/