【作者】 张鹏；

【导师】 刘云国；

【作者基本信息】 湖南大学 ， 环境科学与工程， 2020， 硕士

【摘要】 自全球工业化开始以来,环境雌激素已成为一个新兴且严重的问题,其在世界各地的水中的浓度迅速增加。其中,17β-雌二醇（E2）是一种常见且强效的雌激素化合物。鉴于E2对人类及野生动物健康构成了严重威胁,运用高效的技术将E2从水体中去除是必要的。基于高活性自由基的高级氧化技术（AOPs）被广泛认为是一种有效的绿色技术,可以将难降解有机污染物降解为无害或低毒的化合物,甚至可以降解为CO₂和H₂O。其中,基于硫酸根自由基的AOPs近年来吸引了广泛关注。硫酸根自由基(SO₄^?-)可来自于过硫酸盐（PS）。一般情况下,PS未被激活时有机分解的氧化电位较低,为避免过多能量或化学输入,近年来,一些研究试图通过在碳质材料上固定金属或金属氧化物来激活PS。本文中,以生物炭为基体、高铁酸钾为活化剂,采用一步法合成新型铁掺杂石墨化生物炭（Fe@GBC）,应用于活化PS降解E2。表征结果表明,Fe@GBC成功掺杂了铁粒子并具有多孔石墨化碳结构。为了评价Fe@GBC的适用性,系统考察了初始p H、催化剂用量和PS浓度等反应参数对Fe@GBC/PS系统的影响,并测量评价了Fe@GBC材料的重复使用性和稳定性。在掺杂的铁粒子与多孔石墨碳结构的协同作用下,Fe@GBC展现了对PS的高活化性及对E2的强降解能力（90分钟内降解效率几乎100%）。通过自由基猝灭实验和电子自旋共振（ESR）分析发现,硫酸根自由基和羟基自由基均对E2的降解起作用,其中硫酸根自由基起主导作用。此外,Fe@GBC/PS在复杂水介质中也表现出良好的降解性能。总的来说,简单的一步合成策略和优越的性能使Fe@GBC成为过硫酸盐活化和水污染物降解的理想催化剂。更多还原

【Abstract】 Since the inception of global industrialization,environmental estrogens have become an emerging and serious concern,and its concentration in water around the world has increased rapidly.Among them,17β-estradiol（E2）is a common and potent estrogen compound.Given the serious threat posed by E2 to human and wildlife health,it is necessary to remove it from water with efficient techniques.Advanced oxidation processes（AOPs）based on highly reactive radicals are widely regarded as an effective and green technology for degradation of recalcitrant organic contaminants into harmless or low toxic compounds,or even CO₂ and H₂O.Among them,sulfate radical(SO₄^?-)based AOPs generated from persulfate（PS）have attracted much attention in recent years.Recently,some researches have attempted to immobilize metals or metal oxides on carbonaceous materials to activate PS.In this work,a novel iron-doped graphitic biochar（Fe@GBC）,which was synthesized by one-step method using biomass-derived biochar as precursor and potassium ferrate（K₂Fe O₄）as activator,was applied to activate persulfate（PS）for the degradation of 17β-estradiol（E2）.The characterizations indicated that Fe@GBC was successfully doped with iron particles and possessed a porous graphitic carbon structure.In order to evaluate the applicability of Fe@GBC,the effects of various reaction parameters,such as initial p H,catalyst dosage,PS concentration,as well as the reusability and stability of Fe@GBC were systematically investigated.With the synergistic effect of doped iron particles and porous graphitic carbon structure,Fe@GBC exhibited a high activity for PS activation and great degradation capacity to E2（almost 100%degradation effciency within 90 min）.Through radical quenching experiments and electron spin resonance（ESR）analysis,it found that both SO₄^?-and OH^?were responsible for the degradation of E2,while SO₄^?-played a dominant role.Moreover,Fe@GBC/PS also exhibited good degradation performance in complex water matrices.Overall,the facile one-step synthetic strategy and superior performance make Fe@GBC an alternative catalyst for persulfate activation and aqueous pollutants degradation.更多还原