环境中的抗生素代表了严重的污染威胁。在这些新兴的污染物中,离子载体抗球虫药由于其潜在的生态影响而受到特别关注,坚持环境,以及促进抗菌药物耐药性的作用。为了研究离子载体抗生素盐霉素(SAL)在原料和改性粘土吸附剂上的吸附/解吸,使用0.5克粘土吸附剂与10毫升增加剂量的SAL溶液混合的每个样品进行间歇式实验,在室温下,接触时间为24小时。使用HPLC-UV设备一式三份进行所有测量。研究了三种不同的天然(原始)和改性粘土样品,命名如下:AM(含51%方解石),HJ1(含32%高岭石),和HJ2(具有32%的微斜线)。实验使用三个pH范围进行:酸活化粘土在3.33和4.49之间,8.39-9.08对于天然粘土,碱活化粘土为9.99-10.18。结果表明,当添加低浓度的抗生素(从5到20μmolL-1)时,超过98%的SAL被几乎所有的粘土强烈吸附,无论粘土的物理化学和矿物学组成或其pH值。当添加更高的SAL浓度(40和100μmolL-1)时,抗生素的吸附显示pH依赖性配体吸附机制:(i)随着pH升高而高度降低(对于原始和碱活化的AM和HJ1粘土),而(ii)随着pH值的降低(在酸活化的粘土上)略有降低。在测试的吸附方程中(Freundlich,朗缪尔,和线性),Freundlich模型被确定为最适合拟合与所研究粘土上的SAL吸附相对应的数据。所有粘土样品的SAL解吸率始终低于10%,特别是对于酸活化的粘土,由于阳离子桥接吸附机制,当添加最低浓度的抗生素时。此外,应该强调的是,解吸值可以随着SAL浓度的增加而增加,但他们总是保持在20%以下。总的来说,这里研究的粘土(包括原始的和改性的)为去除兽用抗球虫抗生素SAL提供了一种经济有效的替代方案,在环境修复和抗生素污染管理方面具有潜在的积极和实际影响,特别是作为污染土壤的改良剂,以增强其对SAL的吸附能力。此外,在水处理过程中使用这些粘土可以提高减轻水生系统中抗生素污染的效率。
Antibiotics in the environment represent a substantial pollution threat. Among these emerging pollutants, ionophore anticoccidials are of special concern due to their potential ecological impact, persistence in the environment, and role in promoting antimicrobial resistance. To investigate the adsorption/
desorption of the ionophore antibiotic salinomycin (SAL) on/from raw and modified clay adsorbents, batch-type experiments were performed using 0.5 g of clay adsorbent mixed with 10 mL of increasing doses of SAL solutions for each sample, at room temperature, with a contact time of 24 h. All measurements were conducted in triplicate employing HPLC-UV equipment. Three different natural (raw) and modified clay samples were investigated, which were denominated as follows: AM (with 51% calcite), HJ1 (with 32% kaolinite), and HJ2 (with 32% microcline). The experiments were carried out using three pH ranges: between 3.33 and 4.49 for acid-activated clays, 8.39-9.08 for natural clays, and 9.99-10.18 for base-activated clays. The results indicated that, when low concentrations of the antibiotic were added (from 5 to 20 μmol L-1), more than 98% of SAL was strongly adsorbed by almost all clays, irrespective of the physicochemical and mineralogical composition of the clays or their pH values. When higher SAL concentrations were added (40 and 100 μmol L-1), the adsorption of the antibiotic showed pH-dependent ligand adsorption mechanisms: (i) highly decreased as the pH raised (for the raw and base-activated AM and HJ1 clays), while (ii) slightly decreased as the pH decreased (on the acid-activated clays). Among the adsorption equations tested (Freundlich, Langmuir, and Linear), the Freundlich model was identified as the most suitable for fitting the data corresponding to SAL adsorption onto the studied clays. SAL
desorption from clays was consistently below 10% for all the clay samples, especially for the acid-activated clays, due to cation bridging adsorption mechanisms, when the lowest concentration of the antibiotic was added. Additionally, it should be stressed that the
desorption values can increase with rising SAL concentrations, but they always remain below 20%. Overall, the clays here investigated (both raw and modified) provide a cost-effective and efficient alternative for the removal of the veterinary anticoccidial antibiotic SAL, with potential positive and practical implications in environmental remediation and antibiotic pollution management, particularly by serving as amendments for contaminated soils to enhance their adsorption capacities against SAL. Additionally, using these clays in water treatment processes could improve the efficiency of mitigating antibiotic contamination in aquatic systems.