气相色谱法测定饮水中1,2,3-三氯苯的方法研究

建立了液液萃取-气相色谱法测定饮用水1,2,3-三氯苯的方法。根据测定研究,得出其方法检出限为0.05ug/L,建立的曲线回归系数高于0.995,回收率在91.17%-106.25%之间,符合要求。     

MWNTs及MWNTs/TiO_2对水中1,2,3-三氯苯的吸附特性研究

采用批量平衡实验,对比研究了多壁碳纳米管（MWNTs）及多壁碳纳米管/二氧化钛复合材料（MWNTs/TiO2）对水中1,2,3-三氯苯的吸附特性。结果表明,在相同条件下,MWNTs及MWNTs/TiO2对1,2,3-三氯苯（1,2,3-TCB）的最大吸附量分别为71.8 mg/g和3.05 mg/g,pH值在2~11之间变化时,两者的吸附均不受pH值变化的影响。2种吸附剂的吸附过程均符合拟二级动力学方程,但MWNTs/TiO2对1,2,3-TCB的吸附速率常数为0.4159 g/（mg.m in）,约为MWNTs的50倍左右,说明MWNTs/TiO2具有更强的吸附驱动力。1,2,3-TCB在2种吸附剂上的吸附过程均可用Freund lich吸附等温线来描述,其热力学参数吉布斯自由能△G0均为负、标准焓变△H0与熵变△S0均为正表明,MWNTs及MWNTs/TiO2吸附1,2,3-TCB过程为自发吸热反应。与MWNTs相比,MWNTs/TiO2具有可光催化再生的优点,能用于被污染水体的原位修复。     

Application of magnetite-activated persulfate oxidation for the degradation of PAHs in contaminated soils

In this study, feasibility of magnetite-activated persulfate oxidation (AP) was evaluated for the degradation of polycyclic aromatic hydrocarbons (PAHs) in batch slurry system. Persulfate oxidation activated with soluble Fe(II) (FP) or without activation (SP) was also tested. Kinetic oxidation of PAHs was tracked in spiked sand and in aged PAH contaminated soils at circumneutral pH. Quartz sand was spiked with: (i) single model pollutant (fluorenone) and (ii) organic extract isolated from two PAH contaminated soils (H and NM sampled from ancient coking plants) and was subjected to oxidation. Oxidation was also performed on real H and NM soils with and without an extraction pretreatment. Results indicate that oxidation of fluorenone resulted in its complete degradation by AP while abatement was very low (<20%) by SP or FP. In soil extracts spiked on sand, significant degradation of 16 PAHs was observed by AP (70-80%) in 1 week as compared to only 15% by SP or FP systems. But no PAH abatement was observed in real soils whatever the treatment used (AP, FP or SP). Then soils were subjected to an extraction pretreatment but without isolation of organic extract from soil. Oxidation of this pretreated soil showed significant abatement of PAHs by AP. On the other hand, very low degradation was achieved by FP or SP. Selective degradation of PAHs was observed by AP with lower degradation efficiency towards high molecular weight PAHs. Analyses revealed that no by-products were formed during oxidation. The results of this study demonstrate that magnetite can activate persulfate at circumneutral pH for an effective degradation of PAHs in soils. However, availability of PAHs and soil matrix were found to be the most critical factors for degradation efficiency.     

MWNTs及MWNTs/TiO2对水中1,2,3-三氯苯的吸附特性研究

采用批量平衡实验,对比研究了多壁碳纳米管（MWNTs）及多壁碳纳米管/二氧化钛复合材料（MWNTs/TiO₂）对水中1,2,3-三氯苯的吸附特性。结果表明,在相同条件下,MWNTs及MWNTs/TiO₂对1,2,3-三氯苯（1,2,3-TCB）的最大吸附量分别为71.8 mg/g和3.05 mg/g,pH值在2~11之间变化时,两者的吸附均不受pH值变化的影响。2种吸附剂的吸附过程均符合拟二级动力学方程,但MWNTs/TiO₂对1,2,3-TCB的吸附速率常数为0.4159 g/(mg·min),约为MWNTs的50倍左右,说明MWNTs/TiO₂具有更强的吸附驱动力。1,2,3-TCB在2种吸附剂上的吸附过程均可用Freundlich吸附等温线来描述,其热力学参数吉布斯自由能△G⁰均为负、标准焓变△H⁰与熵变△S⁰均为正表明,MWNTs及MWNTs/TiO₂吸附1,2,3-TCB过程为自发吸热反应。与MWNTs相比,MWNTs/TiO₂具有可光催化再生的优点,能用于被污染水体的原位修复。     

O3/H2O2工艺降解1,2,4-三氯苯的优化设计

考察用不同的氧化剂降解1,2,4-三氯苯（TCB）,3种不同方法对TCB的去除效果存在较大差别,其处理效果依次为：H2O2〈O3〈O3/H2O2。采用响应面法优化O3/H2O2工艺降解TCB的条件。结果表明,TCB初始浓度和H2O2投加量对TCB去除效果影响较大。TCB的降解符合准一级反应动力学规律,最佳降解条件为TCB初始浓度0.3 mg/L,pH=8.13,H2O2投加量0.40 mmol/L,O3转化率75%。在此条件下,TCB的平均去除率为91.5%,与预测值93.1%吻合度较高。     

工业废铁屑活化过硫酸盐降解水中环丙沙星的研究

为了有效降解水中的喹诺酮类抗生素环丙沙星(CPFX),降低处理成本,利用工业废铁屑(IWFe)活化过硫酸盐(PS)降解CPFX,探索了IWFe的粒径、反应体系初始pH、PS/CPFX(质量比)对CPFX降解效果的影响,并且研究了反应动力学、自由基的生成以及使用前后IWFe的变化。结果表明,IWFe+PS体系对CPFX的去除率超过90%,随着IWFe粒径的变小和PS/CPFX的增大,CPFX的去除率增加。在中性条件下,CPFX的去除率最大。IWFe的表面氧化物主要为Fe_3O_4和α-FeOOH,其中Fe~(2+)可活化PS产生·SO_4~-和·OH,·SO_4~-和·OH对CPFX的去除率的贡献分别为47.7%和21.9%。使用后,IWFe上Fe~(2+)的减少低于Fe~(3+)的增加,表明IWFe内核的Fe~0也参与了PS的活化。本研究提供了一种高效、低成本的有机废水处理方法,对实际工程具有一定的参考价值。     

Trends in Fenton and photo-Fenton processes for degradation of antineoplastic agents in water matrices: current knowledge and future challenges evaluation using a bibliometric and systematic analysis

Environmental Science and Pollution Research - Antineoplastic agents present potential hazards to human health and the environment. For this reason, these compounds have attracted a great deal of...     

钴金属-有机骨架活化过硫酸钠降解废水中的盐酸土霉素

采用新制备的钴金属-有机骨架(Co-MOF)和过硫酸钠(PS)分别作为催化剂和氧化剂,并通过Co-MOF活化PS降解废水中的盐酸土霉素,考察Co-MOF浓度、PS浓度、pH及温度对降解盐酸土霉素的影响。SEM、TEM、XRD及XPS等结果证明,Co-MOF成功地被合成。降解实验结果表明,与单独的Co-MOF、PS相比,Co-MOF/PS的降解性能有大幅度的提高。当pH=5、温度30 ℃、Co-MOF为200 mg·L⁻¹以及PS为2 000 mg·L⁻¹时,5 min后对20 mg·L⁻¹盐酸土霉素的降解率最高达到97.1%。在催化剂的重复使用实验中,Co-MOF第4次运行对盐酸土霉素的降解率由97.1%(第1次)降低至82.1%,这表明Co-MOF材料可以重复利用降解盐酸土霉素。Co-MOF降解盐酸土霉素实验反应前后的XRD和XPS数据表明Co-MOF具备良好的稳定性。以上研究结果可为新型高效降解体系的开发及其在水环境污染控制领域的应用提供参考。     

氮掺杂碳催化剂活化过一硫酸盐的活性位点分析及其对双酚A的降解机制

为了探究氮掺杂碳催化剂中不同类型缺陷点位在活化过一硫酸盐((PMS))时的反应活性,以碳黑和二氰二胺混合物为前驱体,通过热解得到了一系列不同氮掺杂量的碳催化剂(CN_x),并对所制备催化剂的缺陷度、化学组分以及PMS活化性能进行了研究。结果表明,增加碳催化剂中的高活性氮杂质缺陷点位可有效促进催化剂的PMS活化性能;不同本征缺陷点位对PMS活化性能也表现出显著差异。活性物种淬灭实验、顺磁共振分析和电化学分析等结果表明,CN_x/PMS体系对双酚A(BPA)的降解过程遵循以单线态氧(¹O₂)为主导的非自由基途径,催化剂表面的电子传递机制也有一定贡献。以上研究结果可为识别氮掺杂碳催化剂中的活性点位和高活性催化剂的定向合成提供参考。     

Extraction procedures for the study of phytotoxicity and degradation processes of selected triketones in a water ecosystem

Simple and effective extraction methods based on matrix solid-phase dispersion (MSPD), dispersive liquid–liquid microextraction (DLLME), and solid-phase extraction (SPE) coupled with high-performance liquid chromatography with diode array detector (HPLC-DAD) were developed to determine triketone herbicides—sulcotrione (SUL), mesotrione (MES), tembotrione (TEMB), and their degradation products—in plant tissues and water samples. The extraction procedures were employed to enable quantification of the accumulation of selected triketone herbicides and their degradation products in a model aquatic plant, Egeria densa. To obtain comprehensive information about the triketones' influence on an aquatic plant, changes in chlorophyll concentration in plants exposed to these triketones were monitored. The average recovery ranged from 58 to 115 % (coefficients of variation 7–12 %) for plant tissues and from 52 to 96 % (coefficients of variation 8–20 %) for water samples. The limit of detection (LOD) for the MSPD–HPLC-DAD procedure was in the range of 0.06–0.23 μg/g, whereas for DLLME–HPLC-DAD and SPE–HPLC-DAD, LOD was in the range of 0.06–0.26 μg/mL. Symptoms of the phytotoxicity of sulcotrione, mesotrione, tembotrione, and their degradation products (decrease of chlorophyll concentration in plant sprouts) were observed for E. densa cultivated in water with herbicide concentrations of 100 μg/L. Moreover, the tembotrione degradation product exhibited a high level of accumulation and low metabolism in plant tissues in comparison to the other triketones and their degradation products.     

Comparison between UVA- and zero-valent iron-activated persulfate processes for degrading propylparaben

Conventional wastewater treatments are not efficient in removing parabens, which may thus end up in surface waters, posing a threat to aquatic biota and hu     

热活化过硫酸钾降解呋虫胺

以新烟碱类杀虫剂呋虫胺为目标污染物,以过硫酸钾为氧化剂,研究不同热活化条件下过硫酸钾对呋虫胺降解率的影响。实验结果表明:呋虫胺的降解率与溶液中过硫酸钾的浓度成正比;随着温度的升高,呋虫胺的降解率也逐渐升高;虽然中性时呋虫胺的降解率稍高于酸性和碱性时的降解率,但pH的变化对呋虫胺的降解率影响不大;Cl-和HCO3-对反应的影响比较复杂,当溶液中的Cl-和HCO3-的浓度低于5 mmol/L时,均促进呋虫胺的降解,而浓度升高时则抑制呋虫胺的降解;通过添加自由基捕获剂发现,该反应体系中同时存在·SO4-和·OH,但起主要作用的是·SO4-。     

不同基质与布水方案下人工湿地水分运移的模拟

以垂直潜流人工湿地为背景,采用饱和-非饱和土壤水分运动Richards方程,基于HYDRUS-3D模型对2种具体土质、不同布水方案下土壤水分运移情况进行了数值模拟,并依据相关数值结果进行水力停留时间的计算.模拟结果显示,土质的渗透性对表层土壤含水量影响很大;相同布水总量下,布水次数增加将导致砂土表层土壤含水量峰值降低、土壤水力停留时间减小.研究可为潜流人工湿地基质、布水模式的选择提供相关科学依据.     

背景水质对过流式VUV/UV反应器降解水中阿特拉津的影响

为探究连续流进水模式下水中复杂的背景物质对真空紫外/紫外 (VUV/UV) 高级氧化工艺效率的影响,采用过流式VUV/UV反应器,考察了水中不同浓度的氯离子 (Cl^–) 、碱度 (HCO₃^–) 、硝酸盐 (NO₃^–) 和溶解性有机物 (DOM) 对微量污染物阿特拉津 (ATZ) 降解的影响。结果表明,上述背景组分对ATZ的VUV/UV降解均表现出一定的抑制作用,辐照时间为30 s时,ATZ去除率从空白组中的57%分别最多下降至33%、29%、40%和35%,且过流式条件下的抑制程度与文献中序批式反应器中的略有不同。污染物去除率下降的原因在于,一方面,三种无机阴离子都对VUV辐射有一定的蔽光效应,NO₃^–强于Cl^–强于HCO₃^–;另一方面,VUV辐照下Cl^–产生的Cl·和Cl₂^•–、NO₃^–产生的NO₂·和HO·都能补充水中氧化性自由基浓度,使得VUV贡献的ATZ降解速率常数的抑制程度低于VUV光子被阴离子竞争吸收的比例,但HCO₃^–对HO·较强的清除作用则导致了ATZ的降解速率常数的快速下降。低浓度DOM在VUV/UV辐照下可能产生的活性物种抵消了其对VUV/UV辐射的蔽光效应,但高浓度DOM对HO·的清除作用仍使其对ATZ降解产生了显著的抑制。在所有考察的水质条件下,ATZ降解所需的单位能耗E_EO介于0.61~1.56 kWh·m^-3。     

新型过硫酸盐活化技术降解有机污染物的研究进展

在利用过硫酸盐氧化降解有机污染物过程中,以过硫酸盐活化所产生强氧化性的硫酸根自由基至为关键,综述了近来过硫酸盐的新型活化技术,其中以零价金属材料,含铁矿石,含铁复合材料,活性炭及含碳复合材料,含醌结构有机物活化为主线展开。通过介绍各种活化机理以及相应活化技术在降解有机污染物的研究,继而提高过硫酸盐降解有机污染物的潜在研究与应用价值。     

钒氧化物对过硫酸盐降解2,4-二硝基甲苯的影响

钒是土壤中普遍存在的微量元素,钒氧化物对过硫酸盐(PS)降解有机污染物的影响及作用机制目前还不明确。以三氧化二钒(V₂O₃)、二氧化钒(VO₂)和五氧化二钒(V₂O₅)为研究对象,探究了不同PS/钒氧化物体系对2, 4-二硝基甲苯(2, 4-DNT)的降解性能和相关机理。结果表明：不同PS/钒氧化物体系对2, 4-DNT的降解性能具有显著差别,其中PS/V₂O₃体系表现出较强的氧化能力;在反应10 h后,PS/V₂O₃体系中2, 4-DNT的降解率为77.2%,且准一级动力学模型可以很好地描述PS/V₂O₃体系对2, 4-DNT的降解过程。电子自旋共振分析和自由基淬灭实验结果表明,羟基自由基是降解2, 4-DNT的主要自由基。V₂O₃浓度、PS浓度和初始pH是影响PS/V₂O₃体系降解2, 4-DNT的重要因素。2, 4-DNT的降解率随V₂O₃含量升高而先升高后降低,在V₂O₃ 为5.0 mmol·L⁻¹时,2, 4-DNT的降解率最高(91.70%);随着PS浓度的升高,在PS/V₂O₃体系中2, 4-DNT的降解率亦显著提升;当初始pH分别为3.0、5.0、7.0和9.0时,反应10 h后,V₂O₃活化PS对2, 4-DNT的降解率分别为85.91%、80.07%、80.72%和85.72%。以上研究结果可为进一步明确土壤和地下水基质对过硫酸盐原位化学氧化的影响提供参考。     

Effect of Fenton treatment on the aquatic toxicity of bisphenol A in different water matrices

Battery tests serve as integral tools to decide whether a treatment process is ecotoxicologically safe or not. In the present study, a battery of toxicity tests was employed to elucidate the toxicity of the potential endocrine-disrupting pollutant bisphenol A (BPA) and its advanced oxidation products. For this purpose, BPA was subjected to Fenton treatment in the growth medium of the test organisms employed as well as in real lake water. Treatment results indicated that BPA removals were fast and complete within less than a minute, whereas total organic carbon (TOC) removals were rather incomplete, speaking for the accumulation of refractory degradation products. The presence of chloride and/or natural organic matter influenced H₂O₂ consumption rates and the treatment performance of the Fenton’s reagent as well. The sensitivity of the selected test organisms for BPA and its Fenton treatment products in different water matrices was found in the following decreasing order: the freshwater microalgae (Pseudokirchneriella subcapitata) > the freshwater cladoceran (Daphnia magna) > marine photobacteria (Vibrio fischeri).     

Fenton试剂和活化过硫酸钠氧化降解土壤中的二氯酚和三氯酚

氯酚类物质（chlorophenols, CPs）在环境介质中广泛存在且具有很强环境毒性。为探究化学氧化修复场地氯酚类污染的可行性,通过室内实验、模拟搅拌实验、现场中试,开展应用Fenton试剂和活化过硫酸钠氧化降解土壤CPs的研究。结果表明,化学氧化可有效降解土壤中的CPs,在氧化剂用量和CPs总量摩尔比为15:1时,CaO活化Na2S2O8能高效降解土壤中的二氯酚（2,4-DCP）和三氯酚（2,4,6-TCP）,室内实验和现场中试的去除率均达90%以上,处理后的2,4-DCP和2,4,6-TCP浓度均低于《展览会用地土壤环境质量评价标准》（HJ 350-2007）A类标准限值。Fenton试剂在室内实验中降解率达90%以上,但现场中试对2,4-DCP和2,4,6-TCP的降解率仅为66.1%、23.8%,处理后2,4-DCP浓度仍超过A类标准限值1倍以上。此外,在修复过程中,约70%的2,4-DCP、2,4,6-TCP会向液相转移,因此,需要关注修复系统引入水后污染物向液相中的转移可能造成的二次污染。研究结果可为氯酚类污染土壤的修复提供新思路,并为实际工程应用提供理论依据。