Sorption of tetracycline to sediments and soils: assessing the roles of pH, the presence of cadmium and properties of sediments and soils
Sorption of tetracycline to sediments and soils: assessing the roles of pH, the presence of cadmium and properties of sediments and soils
复制标题
DOI：
10.1007/s11783-010-0265-3
复制
发表时间：
2010-11
影响因子：
--
通讯作者：
Guixiang Zhang;Xitao Liu;Ke Sun;Ye Zhao;Chunye Lin
中科院分区：
文献类型：
--
作者：
Guixiang Zhang;Xitao Liu;Ke Sun;Ye Zhao;Chunye Lin
进行批量吸附实验以评估在存在和不存在镉 (Cd) 的情况下四环素 (TC、H3L) 在沉积物和土壤上的吸附行为，该行为受沉积物和土壤的 pH 和性质的影响。结果表明，沉积物对 TC 的吸附比土壤具有更强的非线性和更高的能力。 TC 的吸附也强烈依赖于环境因素和沉积物/土壤特性。较低的 pH 值有利于通过阳离子交换机制吸附 TC，这种情况在 pH 值高于 5.5 时也会发生，此时 TC 以两性离子 (H2L0) 或阴离子（HL− 和 L2−）形式存在。然而，当pH值高于7时，由于TC削弱了氧化铝的Al-O键和氧化铁的Fe-O键，可能会发生配体促进TC的溶解。天然有机质（NOM）在TC吸附中比阳离子交换容量（CEC）和粘土含量发挥更重要的作用。 Cd(II)的存在增加了沉积物和土壤对TC的吸附，这是由于Cd2+与沉积物/土壤表面的H+离子交换导致平衡溶液pH值降低的结果。 TC 吸附的增加还与 TC-Cd 复合物的形成有关，其中 Cd2+ 充当沉积物/土壤和 TC 之间的桥梁。
Batch sorption experiments were conducted to evaluate the sorption behavior of tetracycline (TC, H3L) on sediments and soils in the presence and absence of cadmium (Cd), as affected by pH and properties of sediments and soils. The results indicated stronger nonlinearity and higher capacity of TC sorption on sediments than on soils. Sorption of TC also strongly depended on environmental factors and sediment/soil properties. Lower pH facilitated TC sorption through a cation exchange mechanism, which also took place at pH values above 5.5, where TC existed as a zwitterion (H2L0) or anions (HL−and L2−). When pH was above 7, however, ligand-promoted dissolution of TC might occur due to TC weakening the Al-O bond of aluminum oxide and the Fe-O bond of iron oxide. Natural organic matter (NOM) plays a more important role in TC sorption than cation exchange capacity (CEC) and clay contents. The presence of Cd (II) increased TC sorption on both sediments and soils, which resulted from the decrease of equilibrium solution pH caused by Cd2+exchange with H+ions of sediment/soil surfaces. The increase of TC sorption was also related to the formation of TC-Cd complexes, where Cd2+acted as a bridge between the sediment/soil and TC.