多种碳质材料对磺胺类抗生素的吸附特性与机理研究

发布时间：2018-11-14 17:41

【摘要】：随着抗生素的大量使用,越来越多的抗生素通过各种途径进入环境介质。由于抗生素本身的难降解性加上处理工艺的有限性,大大增加了其对环境和人体及动物体的危害。磺胺类抗生素因生产成本低、化学性质稳定、抗菌谱广等优势而被大量应用。近年来我国的地表水、地下水及污水处理厂进出水中均能检测到磺胺类抗生素,严重威胁环境安全和人类健康,寻求高效的磺胺类抗生素去除技术刻不容缓。碳质材料以其高比表面积、丰富的孔结构以及强相互作用,常被用于解决环境污染问题,但同时利用多种碳质材料(包括净水厂用活性炭、家用净水设备滤芯活性炭、石墨烯、氧化石墨烯等)对磺胺类抗生素的吸附特性和机理进行对比研究的较少。本实验以十五种碳质材料为吸附剂研究了其对磺胺类抗生素的吸附去除性能与机理。以磺胺甲基嘧啶(SM1)、磺胺二甲基嘧啶(SM2)和磺胺甲恶唑(SMX)为吸附质。通过研究吸附剂吸附磺胺甲恶唑的平衡时间、平衡吸附量、动力学和等温线参数确定出各类材料中性能好的四种碳质材料。通过扫描电镜(SEM)、比表面积和孔体积分析及红外光谱(FT-IR)等手段对吸附剂进行了表征。对单一吸附体系,研究了碳质材料对SMX的吸附解吸特性,包括不同水化学条件(温度、pH值、离子强度、吸附剂投加量、污染物溶液初始浓度和反应时间等)、动力学、等温线、热力学等对吸附效果的影响,分析了碳质材料的吸附机理。对共吸附体系,通过固定竞争物质浓度,研究了不同温度下竞争物质SM1和SM2对主要物质SMX吸附等温线的影响。通过以上研究,得出了吸附反应的最佳因子组合,并从多个角度对吸附机理进行解释。实验结果表明大部分碳质材料的吸附过程符合Freundlich等温吸附模型,根据模型参数知,碳质材料对SMX的吸附容易进行;通过动力学实验得出,实验数据符合拟二级动力学模型和颗粒内扩散模型;通过热力学实验得出,吸附反应自发进行。以氢氧化钠为解吸液,对吸附剂进行的一系列解吸再吸实验,结果表明活性炭的解吸效果很好,解吸之后的吸附性能变化不大,为实际环境中吸附剂的再生回收、循环利用提供了依据。共吸附体系SMX等温线结果表明,主要物质高浓度时加入竞争物质可提高吸附剂对主要物质的吸附量,更好的发挥吸附剂的吸附性能,为多种污染物的同时高效去除提供了新思路。
[Abstract]:With the extensive use of antibiotics, more and more antibiotics enter environmental media through various channels. Because the antibiotic itself is difficult to degrade and the treatment process is limited, the harm to the environment, human body and animal body is greatly increased. Sulfonamides are widely used because of their low production cost, stable chemical properties and wide antibacterial spectrum. In recent years, sulfanilamide antibiotics can be detected in the surface water, groundwater and sewage treatment plant in China, which is a serious threat to environmental safety and human health. It is urgent to seek efficient removal technology of sulfanilamide antibiotics. Carbon materials, with their high specific surface area, rich pore structure and strong interaction, are often used to solve environmental pollution problems, but at the same time, many kinds of carbon materials (including activated carbon for water purification plant, filter activated carbon for household water purification equipment, graphene) are used. The adsorption characteristics and mechanism of sulfanilamides were seldom studied. Fifteen carbon materials were used as adsorbents to study the adsorption and removal mechanism of sulfanilamides. Sulfamethazine (SM1), sulfamethazine (SM2) and sulfamethoxazole (SMX) were used as adsorbents. By studying the equilibrium time, equilibrium adsorption capacity, kinetics and isotherm parameters of adsorption of sulfamethoxazole with adsorbent, four kinds of carbonaceous materials with good properties were determined. The adsorbent was characterized by scanning electron microscope (SEM) (SEM), surface area and pore volume analysis and infrared spectroscopy (FT-IR). For a single adsorption system, the adsorption and desorption characteristics of carbon materials to SMX were studied, including different hydrochemical conditions (temperature, pH value, ionic strength, adsorbent dosage, initial concentration of pollutant solution and reaction time, etc.), kinetics, etc. The adsorption mechanism of carbon materials was analyzed by the influence of isotherm, thermodynamics and so on. The effects of SM1 and SM2 on the adsorption isotherms of the main compounds SMX at different temperatures were studied by fixing the concentration of competitive substances in the co-adsorption system. Through the above research, the best combination of factors for adsorption reaction was obtained, and the adsorption mechanism was explained from several angles. The experimental results show that the adsorption process of most carbon materials accords with the Freundlich isothermal adsorption model. According to the model parameters, the adsorption of SMX on carbon materials is easy. According to the kinetic experiments, the experimental data are in accordance with the pseudo-second-order kinetic model and the intraparticle diffusion model, and the thermodynamic experiments show that the adsorption reaction proceeds spontaneously. A series of desorption and readsorption experiments were carried out with sodium hydroxide as desorption solution. The results showed that the desorption effect of activated carbon was very good, and the adsorption performance of activated carbon after desorption had little change, which was the regeneration and recovery of adsorbent in actual environment. The basis of recycling is provided. The results of SMX isotherm showed that the amount of adsorbent could be increased when the main substances were high concentration, and the adsorption properties of the adsorbent could be improved. It provides a new idea for the efficient removal of various pollutants at the same time.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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