氧化石墨烯及其改性材料对内分泌干扰物去除的研究
发布时间：2019-06-17 13:57
【摘要】：环境内分泌干扰物是由人类、动物的生活及工业生产所产生的干扰激素分泌的一类有害物质。内分泌干扰物由于很难被生物降解且具有抗氧化性等长期存在于环境中,对于人类健康和环境产生很大的危害,因此如何经济高效地治理水体中的内分泌干扰物已经成为水处理领域研究的热点。吸附法的最大优势在于对生物法难以处理的金属离子和难降解的有机物有较好的处理效果,在饮用水源中的内分泌干扰物类污染物的去除方面应用很多。本论文在实验室中合成不同氧化程度的氧化石墨烯、GO-Ti O2和GO-CTAB三种吸附剂,并对三种吸附剂进行物理化学性质的表征。然后利用这三种吸附剂对水中四环素和双酚A(BPA)进行吸附去除实验,研究温度、初始浓度、吸附时间、溶液p H和阳离子浓度等因素对吸附过程的影响。结合吸附剂的表征结果和吸附实验数据,得到如下结论:GO-1、GO-2、GO-3对四环素的吸附:(1)石墨经过氧化后得到的GO-1、GO-2和GO-3表面都含有不同程度的羧基和羟基等官能团,晶型和结构也发生了相应的变化,随着氧化程度的增加,其表面的氧含量也随之升高。(2)GO-1、GO-2和GO-3对四环素具有很好的吸附性能,实验条件下,25℃时GO-1、GO-2和GO-3对四环素的最大吸附量分别为为74.63mg/g、55.25mg/g和47.26mg/g,且吸附过程在150min内达到吸附平衡。吸附等温线均能用Frendlich方程很好的拟合,吸附为非均质吸附过程,吸附动力学均可以用拟二级动力学方程进行拟合。(3)随着溶液p H值的增加,GO-1、GO-2、GO-3对四环素的吸附量逐渐降低,酸性环境下更有利于吸附的进行。溶液中阳离子的存在会降低吸附剂对四环素的吸附量,影响的大小顺序为Ca2+K+≈Na+。(4)碱性溶液可以对吸附平衡后的GO-1进行脱附,脱附效果良好,脱附后仍具有较高的吸附量,吸附剂具有较好的循环再生性能。GO-Ti O2对四环素的吸附:(1)Ti O2通过水热反应聚合在GO表面,使GO的晶型和结构有所改变,复合材料中含有Ti元素,表明GO-Ti O2吸附剂的成功合成。(2)GO-Ti O2对四环素具有优越的吸附能力,实验条件下,25℃时GO-Ti O2对四环素的最大吸附量为117.98mg/g,吸附等温线能用Freundlich方程很好的拟合,吸附为吸热反应,以物理吸附为主。吸附动力学均可以用拟二级动力学方程进行拟合,吸附过程属于非均质吸附,受边界层扩散的影响。(3)p H显著影响GO-Ti O2对四环素的吸附,随着p H值的增加,吸附量逐渐降低。二价阳离子Ca2+明显抑制了吸附的进行。(4)吸附后的吸附剂可在紫外光照射下进行光降解再生,光降解再生率为81.20%,再生4次后对四环素的吸附量为87.96mg/g,再生性能良好。GO-CTAB对BPA的吸附:(1)通过FTIR、XRD、EDS等手段对GO-CTAB进行表征分析可知,CTAB已成功包覆在GO表面,GO的晶型发生了改变。(2)GO-CTAB相比G和MWCNT对BPA具有更好的吸附能力,25℃条件下GO-CTAB、G和MWCNT对BPA的最大吸附量分别为236.18mg/g、12.42 mg/g和81.76 mg/g,吸附等温线均能用Langmuir方程很好的拟合,吸附为放热的熵减少的过程。吸附动力学均可以用拟二级动力学方程进行拟合,吸附过程属于单层吸附,边界层扩散会影响吸附剂BPA的吸附。吸附过程在150min内达到吸附平衡。(3)在酸性和中性范围内,GO-CTAB、G和MWCNT对BPA的吸附量变化很小,在碱性条件下吸附量明显降低。阳离子的存在会增强BPA在GO-CTAB上的吸附效果,其中Ca2+对其吸附量增加的效果最明显。(4)吸附平衡后的GO-CTAB可在0.1mol/L的Na OH碱性溶液中进行脱附,脱附效果良好,脱附4次后仍具有较高的吸附量,吸附剂具有较好的循环再生性能。
[Abstract]:Environmental endocrine disruptors are a kind of harmful substance secreted by human, animal and industrial production. Endocrine disruptors, which are difficult to be biodegraded and have oxidation resistance, are very harmful to human health and the environment, so how to economically and efficiently manage the endocrine disruptors in the water body has become a hot spot in the field of water treatment. The biggest advantage of the adsorption method is that the metal ions and the hard-degradable organic matters which are difficult to be treated by the biological method have better treatment effect, and the adsorption method has a plurality of application in the removal of the endocrine disruptors in the drinking water source. In this paper, three kinds of adsorbents such as graphene oxide, GO-TiO2 and GO-CTAB were synthesized in the laboratory, and the physical and chemical properties of the three kinds of adsorbents were characterized. The effects of temperature, initial concentration, adsorption time, solution p H and cation concentration on the adsorption process were studied. The adsorption of GO-1, GO-2 and GO-3 on the tetracycline was obtained by combining the characterization results of the adsorbent and the experimental data. (1) The GO-1, GO-2 and GO-3 surfaces obtained after the oxidation of the graphite contain functional groups of different degrees, The crystal form and the structure have also changed correspondingly, and with the increase of the oxidation degree, the oxygen content of the surface of the crystal form also increases. (2) GO-1, GO-2 and GO-3 have good adsorption property to tetracycline. Under the experimental conditions, the maximum adsorption amount of GO-1, GO-2 and GO-3 on tetracycline at 25 鈩，
本文编号：2501037
[Abstract]:Environmental endocrine disruptors are a kind of harmful substance secreted by human, animal and industrial production. Endocrine disruptors, which are difficult to be biodegraded and have oxidation resistance, are very harmful to human health and the environment, so how to economically and efficiently manage the endocrine disruptors in the water body has become a hot spot in the field of water treatment. The biggest advantage of the adsorption method is that the metal ions and the hard-degradable organic matters which are difficult to be treated by the biological method have better treatment effect, and the adsorption method has a plurality of application in the removal of the endocrine disruptors in the drinking water source. In this paper, three kinds of adsorbents such as graphene oxide, GO-TiO2 and GO-CTAB were synthesized in the laboratory, and the physical and chemical properties of the three kinds of adsorbents were characterized. The effects of temperature, initial concentration, adsorption time, solution p H and cation concentration on the adsorption process were studied. The adsorption of GO-1, GO-2 and GO-3 on the tetracycline was obtained by combining the characterization results of the adsorbent and the experimental data. (1) The GO-1, GO-2 and GO-3 surfaces obtained after the oxidation of the graphite contain functional groups of different degrees, The crystal form and the structure have also changed correspondingly, and with the increase of the oxidation degree, the oxygen content of the surface of the crystal form also increases. (2) GO-1, GO-2 and GO-3 have good adsorption property to tetracycline. Under the experimental conditions, the maximum adsorption amount of GO-1, GO-2 and GO-3 on tetracycline at 25 鈩，
本文编号：2501037
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