锰氧化物改性生物炭基质材料对典型喹诺酮类抗生素的吸附及其在人工湿地的应用

Adsorption of Typical Quinolone Antibiotics by Manganese Oxide-Modified Biochar Substrate and Its Application in CWs

以废弃花生壳为原料,制备锰氧化物改性生物炭球(MBCB)用于去除水中的环丙沙星(CIP)和恩诺沙星(ENR),探究MBCB对CIP和ENR的吸附特性及在人工湿地中的应用效果.结果表明,负载锰氧化物的MBCB对CIP和ENR的吸附过程分别符合准一级和准二级动力学模型,混合吸附过程符合准二级动力学模型,Langmuir和Freundlich等温模型都可以较好地拟合MBCB对CIP和ENR的吸附过程,在25℃条件下,通过Langmuir模型拟合出的对CIP和ENR的最大吸附量分别为3.84 mg·g^(-1)和2.01 mg·g^(-1).MBCB对CIP和ENR的吸附过程主要受到内扩散和边界层扩散的控制,是自发的吸热过程,氢键和静电相互作用参与到吸附过程当中.添加MBCB作为基质的人工湿地对CIP和ENR的平均去除率达70.7%和62.9%,分别为对照组的1.625倍和1.719倍.同时,添加MBCB的湿地微生物丰度和多样性所受影响相对较小,这说明MBCB能缓解人工湿地中CIP和ENR的毒性,保证人工湿地对抗生素的去除效果.

Manganese oxide-modified biochar(MBCB)was prepared from waste peanut shells to remove ciprofloxacin(CIP)and enrofloxacin(ENR)from wastewater.The adsorption characteristics of CIP and ENR by MBCB and its application effect in constructed wetlands were investigated.The results showed that manganese oxide was successfully loaded on MBCB,and the separate adsorption process of CIP and ENR by MBCB conformed to the quasi first-order and quasi second-order kinetic models,respectively.Additionally,the mixed adsorption process conformed to the quasi second-order kinetic model.Langmuir and Freundlich isothermal models could better fit the adsorption process of MBCB for CIP and ENR.At 25℃,the maximum adsorption capacities of CIP and ENR fitted by the Langmuir model were 3.84 mg·g^(-1) and 2.01 mg·g^(-1),respectively.The adsorption process of CIP and ENR by MBCB was mainly controlled by internal diffusion and boundary layer diffusion,which is a spontaneous endothermic process.Hydrogen bonding and electrostatic interaction were involved in the adsorption process.The average removal rates of CIP and ENR in the constructed wetland with MBCB as the substrate were 70.7%and 62.9%,which were 1.625 and 1.719 times higher than those in the control group,respectively.At the same time,compared with those of C-CWs,the microbial abundance and diversity of M-CWs supplemented with MBCB were relatively less affected,indicating that MBCB could alleviate the toxicity of CIP and ENR in constructed wetlands and ensure the removal effect of antibiotics in constructed wetlands.