Simultaneous adsorption and desorption of tetracycline and cadmium on alluvial soil of Aligarh (India).

Interaction of Cadmium (Cd) and a widely-used veterinary antibiotic tetracycline (TC), on the basis of their adsorption and desorption on alluvial soil, was studied using the batch experiments. The results indicated that adsorption and desorption isotherms of Cd and TC on the soils were well fitted with the Freundlich equation. There was an apparent sorption-desorption hysteresis of Cd and TC in soil, which will probably pose a threat to soil-environmental quality and human health. The adsorption of Cadmium or tetracycline in the combined form was more than individual. This can be attributed to increasing Cd adsorption via the bridge of TC, or stronger affinity of the TC-Cd complex to soil minerals than Cd or TC. The presence of Cd enhanced the hysteresis effect of TC sorption -desorption (H= 0.886-0.904). Similarly, the hysteresis effect of Cd sorption - desorption in presence of TC was more than Cd alone (H=0.882-0.925). The hystersis effect was more for Cd in presence of TC than forTC in presence of Cd, denoting binding of Cd on soil surface was stronger in presence of TC than Cd alone. It is thus important to consider the interaction between Cd and TC while studying on the fate of Cd and TC in soil environment.