竹炭表面改性对两种抗生素吸附性能的影响

Adsorption of two antibiotics by modified bamboo-based carbon

采用磷酸(H3PO4)和氢氧化钠(Na OH)对竹炭表面进行改性,并考察其对环丙沙星(CIP)和诺氟沙星(NOR)的吸附性能.结果表明,2种改性竹炭对环丙沙星和诺氟沙星均有良好的吸附效果.经H3PO4改性后的竹炭对环丙沙星和诺氟沙星两类抗生素最大平衡吸附容量分别可达到88.14和65.17 mg/g,经Na OH改性后的竹炭对环丙沙星和诺氟沙星两类抗生素最大平衡吸附容量分别可达到82.23和69.02 mg/g.与Langmuir方程相比,2种抗生素的吸附过程更适合用Freundlich方程来进行描述,也表明了竹炭对这2种抗生素的吸附属于非均匀性吸附.两者的吸附过程更符合二级反应动力学方程.经H3PO4改性后竹炭提高了表面酸性基团的数量,可以在一定程度上增加竹炭对亲水性药物的吸附量.而Na OH改性会增加竹炭表面的碱性基团的数量,同时在一定程度上增强了竹炭对憎水性药物的吸附量.

The surface bamboo-based activated carbon was modified by phosphoric acid （H3 PO4 ） and sodium hydroxide （NaOH）,and its adsorption capacity to two kinds of quinolones antibiotics ciprofloxacin （CIP）and norfloxacin （NOR）was investigated.The result indicated both modified bamboo-based activated carbon have well adsorption ability for NOR and CIP.The maximum equi-librium adsorption capacities to CIP and NOR after by H3PO4 modification were 88.14 and 65.17 mg/g,respectively;the maximum equilibrium adsorption capacities to CIP and NOR after by NaOH modification can reach to 82.23 and 69.02 mg/g,respectively.Compared with Langmuir equation, adsorption of NOR and CIP by bamboo-based carbon could be better described by Freundlich equa-tion.This result indicated that the process of adsorption antibiotics on the bamboo-based carbon be-longs to heterogeneity adsorption.The results showed that the adsorption process of CIP and NOR better followed pseudo-second-order kinetic equation.After H3 PO4 modification,the number of a-cidic hydrophilic groups on the bamboo charcoal surface increase,and it will improve the adsorption of hydrophilic antibiotics to some extent.Sodium hydroxide modified bamboo charcoal can increase the surface basic functional groups,which would improve its adsorption to hydrophobic antibiotics.