A bifunctional adsorbent with high surface area and cation exchange property for synergistic removal of tetracycline and Cu2+
2014; Elsevier BV; Volume: 258; Linguagem: Inglês
10.1016/j.cej.2014.07.096
ISSN1873-3212
AutoresYan Ma, Qing Zhou, Sicong Zhou, Wei Wang, Jing Jin, Jiawen Xie, Aimin Li, Chendong Shuang,
Tópico(s)Pharmaceutical and Antibiotic Environmental Impacts
ResumoA novel bifunctional adsorbent with high surface area and cation exchange character (HAR-2) was prepared via copolymerization and hydrolysis reactions for the coremoval of tetracycline and Cu2+. HAR-2 possessed large specific surface area of 394 m2/g and high weak cation exchange capacity of 1.06 meq/g. The adsorption kinetics of TC or Cu2+ fitted both pseudo-first-order and pseudo-second order equations in single-substrate solution, whereas the adsorption kinetics were better described by pseudo-second order model in binary solutions. The adsorption of TC was an exothermic process, while the Cu2+ adsorption process was endothermic. The adsorption isotherms of TC and Cu2+ fitted the Langmuir model, suggesting a monolayer adsorption process. The adsorbed amount of TC was pronouncedly enhanced in the presence of Cu2+ due to the formation of tertiary surface complex HAR–Cu2+–TC. Likewise, the adsorption of Cu2+ was significantly improved by forming HAR–TC–Cu2+ complex in the presence of TC. The uptake of Cu2+ increased as pH increased, while the adsorbed amount of TC increased as pH rose from 2 to 3 but decreased when pH was further elevated from 3 to 6. The presence of NaCl exerted no significant influence on the adsorption of TC and negatively affected the adsorption of Cu2+. HAR-2 exhibited high stability over 5 repeated uses, only losing 6.3% and 18.4% of the initial adsorption capacity for TC and Cu2+, respectively.
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