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Different antibiotics contained in manure, slurry, wastewater or sewage sludge are spread into the environment. The harmful effects of these antibiotics could be minimized by means of immobilization onto bioadsorbent materials. This work investigates the competitive adsorption/desorption of tetracycline (TC) and sulfadiazine (SDZ) onto pine bark, oak ash and mussel shell. The study was carried out using batch-type experiments in binary systems (with both antibiotics present simultaneously), adding 5 equal concentrations of the antibiotics (between 1 and 50 µmol L−1). The adsorption percentages were higher for TC (close to 100% onto pine bark and oak ash, and between 40 and 85% onto mussel shell) than for SDZ (75–100% onto pine bark, and generally less than 10% on oak ash and mussel shell). Pine bark performed as the best adsorbent since TC adsorption remained close to 100% throughout the entire concentration range tested, while it was between 75 and 100% for SDZ. Desorption was always higher for SDZ than for TC. The results of this study could be useful to design practices to protected environmental compartments receiving discharges that simultaneously contain the two antibiotics here evaluated, and therefore could be relevant in terms of protection of the environment and public health

Veterinary antibiotics reaching the environment have become a matter of global concern, since they can cause serious negative impacts on human and ecological health. Therefore, a deep understanding of their behavior and fate once they reach the soil environment is of utmost importance to design and implement appropriate measures that could reduce their potential risks. With this aim, batch-type experiments were carried out to study competitive adsorption and desorption for three sulfonamide antibiotics (sulfadiazine –SDZ-, sulfamethazine –SMT-, and sulfachloropyridazine –SCP-) in six crop soils presenting different characteristics. The results obtained showed that sulfonamides have a low retention in soils, with average adsorption percentages of 40% for SDZ, 44% for SMT and 54% for SCP, and with desorption percentages up to 36% for SDZ and SCP and up to 29% for SMT. The retention of sulfonamides was strongly influenced by the soil organic carbon content (SOC), with higher adsorption and less desorption associated to higher SOC contents. In addition, the hydrophobicity of sulfonamides also had an influence, as higher hydrophobicity resulted in higher affinity for soils, showing the affinity sequences: SDZ ~ SMT bSCP in acid soils, and SDZ ~ SCP bSMT in neutral soils. The results obtained in the ternary systems were very similar to those found in simple systems, indicating the absence of substantial competition for adsorption sites among the three sulfonamides. Despite the low competition among them, these antibiotics have high mobility in soils and, therefore, they imply a significant risk of contamination ofwater bodies, as well as of entering the food chain, generating serious hazards for human and environmental health. Therefore, fertilization of soilswith sulfonamide polluted manures should be controlled, implementing newmeasurements for the pretreatment of manures before their application, thus contributing to a reduction of potential risks.

Veterinary antibiotics are widely used worldwide to treat and prevent infectious diseases, as well as (in countries where allowed) to promote growth and improve feeding efficiency of food-producing animals in livestock activities. Among the different antibiotic classes, tetracyclines and sulfonamides are two of the most used for veterinary proposals. Due to the fact that these compounds are poorly absorbed in the gut of animals, a significant proportion (up to ~90%) of them are excreted unchanged, thus reaching the environment mainly through the application of manures and slurries as fertilizers in agricultural fields. Once in the soil, antibiotics are subjected to a series of physicochemical and biological processes, which depend both on the antibiotic nature and soil characteristics. Adsorption/desorption to soil particles and degradation are the main processes that will affect the persistence, bioavailability, and environmental fate of these pollutants, thus determining their potential impacts and risks on human and ecological health. Taking all this into account, a literature review was conducted in order to shed light on the current knowledge about the occurrence of tetracycline and sulfonamide antibiotics in manures/slurries and agricultural soils, as well as on their fate in the environment. For that, the adsorption/desorption and the degradation (both abiotic and biotic) processes of these pollutants in soils were deeply discussed. Finally, the potential risks of deleterious effects on human and ecological health associated with the presence of these antibiotic residues were assessed. This review contributes to a deeper understanding of the lifecycle of tetracycline and sulfonamide antibiotics in the environment, thus facilitating decision-making for the application of preventive and mitigation measures to reduce its negative impacts and risks to public health

Antibiotics released to the environment are causing public health and sustainability concerns. Taking that into account, we studied the presence of tetracyclines (Tetracycline, Oxytetracycline, Chlortetracycline and Doxycycline) and sulfonamides (Sulfadiazine, Sulfamethazine, Sulfachlorpyridazine and Sulfamethoxypyridazine) in manures, soils and crops from Galicia (Spain), where a high number of cattle, pig and poultry farms exist. We used the HPLC-MS/MS technique to analyze 40 samples of cattle, pig and poultry manure, as well as 65 soil samples, and 27 vegetation samples. The presence of antibiotics was detected in 42% of the manures, 17% of the soils and 44% of crop samples, with maximum concentrations of 106.0 mg kg−1 for individual antibiotics in manures and 0.6 mg kg−1 in soils and plants. The simultaneous presence of several antibiotics was infrequent in soils (only three soils presented two or three antibiotics), and more common in manures and plants, some of them with up to five antibiotics. Pig slurries showed the highest antibiotic concentrations, as well as the highest number of different antibiotics. Crops fertilized with these slurries also showed the highest number of different antibiotics. Antibiotics were detected in 71% of grass and corn samples, and in 33% of wheat grain samples, while they were not detected in potato samples. These results can be very relevant taking into account potential environmental and public health repercussions of antibiotics in soil and water, as well as antibiotics uptake and accumulation in plants, and subsequent incorporation to the food chain.