纳米TiO2光催化降解酸性粒子元青溶液的研究

对纳米 Ti O2 光催化氧化法降解酸性粒子元青溶液进行了试验研究。结果表明 ,反应符合一级反应 ,反应速率常数为2 .9× 10 - 3min- 1。确立的最佳工艺条件 :催化剂的用量为 4.0 g·L- 1 ,溶液的 p H为 6.3 8,空气的体积流量为 12 0 m L· min- 1 ,在此最佳工艺条件下 ,酸性粒子元青的降解率达到 92 .3 %。且测得反应的表现活化能 Ea为 -17.9k J· mol- 1 。     

TiO2/H2O2/UV和TiO2/O3/UV降解对氯苯甲酸和喹啉的试验研究

主要叙述TiO2/H2O2/UV和TiO2/O3/UV体系降解对氯苯甲酸(4-CBA)和喹啉的试验研究.研究表明,(1)在TiO2/H2O2/UV体系里目标物降解速度先随过氧化氢投加量的增加而提高,但超过一定浓度之后便开始下降;(2)在TiO2/O3/UV体系中,目标降解物的反应速度都非常快,且臭氧浓度高的时候降解速度更快;(3)二氧化钛催化剂在TiO2/O3/UV体系中作为积极因素有助于提高反应速率,而在TiO2/H2O2/UV体系是消极因素,会降低反应速率.     

Azo-dyes photocatalytic degradation in aqueous suspension of TiO2 under solar irradiation

The photodegradation of two common and very stable azo-dyes, i.e. methyl-orange (C₁₄H₁₄N₃SO₃Na) and orange II (C₁₆H₁₁N₂SO₄Na), is reported. The photocatalytic oxidation was carried out in aqueous suspensions of polycrystalline TiO₂ irradiated by sunlight. Compound parabolic collectors, installed at the “Plataforma Solar de Almería” (PSA, Spain) were used as the photoreactors and two identical reacting systems allowed to perform photoreactivity runs for the two dyes at the same time and under the same irradiation conditions. The disappearance of colour and substrates together with the abatement of total organic carbon content was monitored. The main sulfonate-containing intermediates were found to be in lower number in respect to those obtained under artificial irradiation. In particular there were no more evidence of the presence of hydroxylated transients. The dependence of dye photooxidation rate on: (i) substrate concentration; (ii) catalyst amount; and (iii) initial pH was investigated. The influence of the presence of strong oxidant species (H₂O₂, S₂O₈²⁻) and some ions (Cl⁻, SO₄²⁻) on the process was also studied.     

Catalytic activity of Ru/Al2O3 for ozonation of dimethyl phthalate in aqueous solution

With dimethyl phthalate as the model pollutant and Ru/Al(2)O(3) as catalyst, this paper systemically investigates the removal of total organic carbon (TOC) of system. Our results have confirmed that Ru/Al(2)O(3) can significantly increase the effect of ozonation. TOC removal in 120 min can reach 72% while only 24% with ozone alone. The optimal catalyst preparing condition was 0.1 wt% Ru content, 600 degrees C calcination temperature, 0.5-1.0mm particle diameter, which is characterized by a high surface area and a large population of surface active sites. The contrasting experiments of ozone alone, catalyst adsorption after ozonation, and catalytic ozonation confirmed that catalytic reaction was the most important process to TOC removal in system with Ru/Al(2)O(3) as catalyst.     

超声波-光催化联合降解苯酚废水研究

超声降解和光催化降解均为自由基历程的高级氧化技术,同时,超声空化能够改善传质效果,因此,二者耦合能否产生协同效果是值得研究的。本文考察了苯酚溶液的超声降解、光降解、光催化降解、超声-光催化降解以及温度对光降解和光催化降解的影响。结果表明,40kHz,0.4w/cm2的超声波对苯酚没有明显的降解作用,而对光催化降解只有轻微的促进作用。光降解和光催化降解的过程曲线显著不同,但温度对二者均有显著的促进作用。     

NiFe2O4/ZnAl-LDH吸附去除水中Cr(VI)

采用共沉淀法合成磁性复合材料NiFe2O4/ZnAl-LDH,通过静态吸附试验考察复合材料去除水中Cr（VI）的性能,系统地研究了溶液初始pH值、吸附剂投加量、吸附时间和温度等因素对Cr（VI）去除效果的影响。结果表明,当溶液初始pH值为2、初始Cr（VI）浓度为50 mg·L-1、吸附剂投加量为4 g·L-1时,吸附过程在240 min内达到平衡,此时Cr（VI）的去除率为89.5%。动力学和吸附等温式的研究表明：NiFe2O4/ZnAl-LDH吸附Cr（VI）的过程符合准二级动力学和Langmuir等温吸附模型。热力学参数表明该吸附过程为自发、放热的反应过程,低温有利于吸附剂对Cr（VI）的吸附。吸附剂经4次再生后对Cr（VI）仍有83.1%的去除率,且其在外加磁场的作用下能快速与水溶液分离,因此NiFe2O4/ZnAl-LDH可作为去除水中Cr（VI）的良好吸附剂。     

Effective utilization of mahua oil blended with optimum amount of Al2O3 and TiO2 nanoparticles for better performance in CI engine

Environmental Science and Pollution Research - The current research work focuses mainly on improving the performance and emission characteristics of nanoparticle-blended mahua oil-fueled diesel...     

常见阴离子对TiO2/H2O2/O3体系氧化效能的影响

酸性条件下考察了常见阴离子对TiO2/H2O2/O3氧化效率的影响,目标化合物为羟基自由基的探针化合物乙酸。结果表明,硫酸根和硝酸根对体系氧化乙酸的效率几乎没有影响。加入磷酸盐可以减缓H2O2的分解速率,进而导致乙酸的降解效率下降,这可能与其在TiO2表面的吸附作用有关。在初始pH为3.0时,氯离子对子乙酸的降解速率具有明显的抑制作用,氯离子浓度越高,抑制作用越明显。当溶液初始pH大于4.4以上时,氯离子对乙酸的降解效率几乎没有影响。以上结果对推动TiO2/H2O2/O3体系处理酸性废水意义较为突出。     

多孔MoS2/g-C3N4材料对水环境中四环素的降解

通过浸渍-高温煅烧法制备多孔MoS2/g-C3N4光催化剂,采用X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、N2吸附-解吸、紫外-可见光(UV-vis)漫反射吸收光谱对材料进行表征;并在可见光照射下,对四环素(TC)进行光催化降解。结果表明,催化剂量为2.0 g·L-1、pH为5.0时,对TC的去除效果最好,可见光照射180 min,MoS2/g-C3N4(1.0%-MC)复合材料对TC的降解率可达80.6%。反应完成后,复合材料循环利用5次,其降解效率仍保持在70.0%以上。浸渍-高温煅烧法所制备的MoS2/g-C3N4光催化剂具有良好的应用前景。     

Fe3O4纳米磁性微粒对全氟辛烷磺酸盐的吸附

采用共沉淀法合成Fe3O4纳米磁性颗粒,用透射电子显微镜（TEM）、X射线衍射仪（XRD）以及振动样品磁强计（VSM）对Fe3O4纳米磁性颗粒的粒径、形貌和磁性进行表征并研究Fe3O4纳米磁性微粒对全氟辛磺酸盐的吸附。结果表明：在PFOS初始浓度4 mg/L,pH为3,反应时间24 h,Fe3O4纳米磁性微粒投加量1.25 g/L,对全氟辛磺酸盐去除率达到90%。Fe3O4纳米磁性微粒对PFOS的吸附符合Freundlich吸附方程。     

超顺磁性纳米Fe3O4的制备及其类Fenton反应性能

以二甘醇/乙二醇醇热法制备了超顺磁性纳米Fe3O4,采用场发射扫描电子显微镜（FE-SEM）、X射线衍射（XRD）以及磁滞回线等手段对制备的纳米Fe3O4进行表征,并通过纳米Fe3O4/ H2O2类Fenton反应降解罗丹明B废水考察了纳米Fe3O4/H2O2的性能及其稳定性。研究表明,制备的纳米Fe3O4不仅分散性好、规整球状结构,磁性强且粒径比较均匀,平均粒径约为80 nm;从单因素实验（纳米Fe3O4投加量、H2O2/Fe3O4的摩尔比、pH以及反应时间）与正交实验获得了最佳反应条件：纳米Fe3O4投加量为2 g·L-1,pH=4,H2O2/Fe3O4摩尔比为4：1,反应时间为3 h,此时罗丹明B与TOC去除率分别为100%和35%。重复4次使用纳米Fe3O4,通过表征发现纳米Fe3O4颗粒的晶体结构不变但是发生了团聚,纳米Fe3O4的催化性能有所下降。     

磁性BiOI/Fe3O4的合成及光催化降解水中的双酚S

利用简单的共沉淀法在室温条件下制备了磁性空心蜂窝状的BiOI/Fe3O4光催化剂,采用X射线衍射（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）、紫外-可见光漫反射谱仪（UV-vis）、N2吸附-解析BET技术和振动磁强计（VSM）等仪器对其进行表征,并在可见光下催化降解双酚S（BPS）。结果表明,催化剂量为1.0 g·L-1、pH为9.0时,对BPS的去除率最高,可见光照90 min,BiOI/Fe3O4复合光催化剂对BPS的去除率可达90.6%。反应结束后,复合光催化剂在外加磁场作用下从反应体系中分离,循环实验5次后,其光催化效率仍保持在85.0%以上,表现出良好的稳定性。降解过程主要包含羟基自由基和光生空穴的氧化作用。沉淀法制备BiOI/Fe3O4简单可靠,条件可控,所制备的BiOI/Fe3O4具有良好的应用前景。     

BiVO4联合H2O2或K2S2O8光催化降解布洛芬

以水热法制备了BiVO4光催化剂,并用X射线衍射和扫描电镜对其进行表征。在模拟太阳光照射下,以布洛芬为目标污染物,考察了BiVO4联合H2O2或K2S2O8工艺对布洛芬的光催化降解效果,得出了H2O2或K2S2O8的最佳投加量。通过淬灭实验,研究了光催化联合体系降解布洛芬的机制。X射线衍射谱图表明所合成的BiVO4光催化剂为纯的单斜晶相,扫描电镜结果表明制备的粉末形貌单一,且呈现微球状。加入H2O2或K2S2O8后,一定程度上促进了BiVO4光催化降解布洛芬的效率,H2O2和K2S2O8的最佳投加量分别为3.0 mmol·L-1和1.5 g·L-1。BiVO4/H2O2/hν体系和BiVO4/K2S2O8/hν体系降解水中布洛芬主要是基于·OH自由基的氧化作用。通过对比2个体系中·OH和O2·-对布洛芬降解速率的贡献,发现K2S2O8对BiVO4光催化体系的促进作用远远大于H2O2对该体系的促进作用。     

Efficient degradation of crystal violet in magnetic CuFe2O4 aqueous solution coupled with microwave radiation

Nanoscale copper ferrite was prepared by co-precipitation method, while citrate acid assisted method was used as reference. Microwave-induced degradation of crystal violet was performed with synthesized copper ferrite, and the behavior of copper ferrite in this process was studied by X-ray photoelectron spectroscopy, SEM/EDS and vector network analyzer. Microwave radiation could greatly enhance the activity of copper ferrite in organic oxidation. The variant of copper and iron on the surface and in the inner core of copper ferrite was studied here. Copper ferrite presents relatively low dielectric loss. Meanwhile, microwave radiation makes a faster degradation than conventional heating process, indicating an indispensable non-thermal effect of microwave with copper ferrite in the process. Microwave induced holes could be responsible for the efficient degradation. The effect of annealing on crystallization and degradation process was considered here, and the intermediates and products were studied by GC-MS and LC-MS to provide a comprehensively evaluation of degradation.     

Radiolysis of aqueous phenol solutions with nanoparticles. 1. Phenol degradation and TOC removal in solutions containing TiO2 induced by UV,gamma-ray and electron beams

Aqueous phenol solutions containing TiO(2) nanoparticles were irradiated with ultraviolet (UV), gamma-ray and electron beams. Organic compounds were fully removed by each type of radiation in the presence of the particles. The absorbed energy of the ionizing radiation (gamma-ray and electron beams) needed for removal was much lower than that of UV photocatalysis. Phenol was decomposed by the ionizing radiation in the absence of the nanoparticles and the addition of TiO(2) had no significant effect on phenol decomposition rate. Instead, total organic carbon (TOC) removal using the ionizing radiation was accelerated drastically by TiO(2). It is suggested that TiO(2) particles affect the intermediate compounds produced through the decomposition of phenol. The amount of removed TOC per absorbed energy were compared in the absence and the presence of TiO(2) nanoparticles. Radiolysis with the nanoparticles showed consistently high rate and high efficiency of TOC removal.     

EDTAD-modified cassava stalks loaded with Fe3O4: highly efficient removal of Pb2+ and Zn2+ from aqueous solution

Environmental Science and Pollution Research - In this study, a novel magnetic cassava stalk composite (M-EMCS) was prepared through modification with ethylenediamine tetraacetic anhydride (EDTAD)...     

在Ru/Al2O3催化剂上用H2对SO2选择性催化还原的研究

本文对用H2来使SO2选择性催化还原为单质硫在Ru/Al2O3催化剂上的行为进行研究.当物料比经过优化确定为SO2/H2=12.8时,在500℃下,SO2的转化率为90%以上,单质硫的产率为70%左右.比较于其他的催化还原SO2的催化剂,本催化剂采用金属而不是金属硫化物,这样既省去了催化剂预硫化的过程,同时也使在有氧条件下的选择性催化还原成为可能.实验考察了O2及水蒸气存在对过程的影响.在实验过程中发现,H2S作为中间产物生成,可推论该过程在催化剂上分两步进行SO2首先在催化剂金属上被H2深度还原为H2S,然后在Al2O3载体的酸性中心上SO2与H2S发生Claus反应产生单质硫.     

RuO2/La2O3/TiO2悬浮体系中直接耐晒黑G的光催化降解

钛酸丁酯为前驱体,采用溶胶-凝胶-浸渍法制备RuO2/La2O3/TiO2复合光催化剂,以紫外灯为光源,研究了催化剂组成、煅烧温度、溶液pH值等因素对直接耐晒黑G(DFBG)光催化降解的影响.结果表明掺杂量w(La2O3)1.39%、w(RuO2)0.12%、煅烧温度500℃(2 h)、溶液pH值7.3时,光催化活性最佳.当通气量为200 mL/min,催化剂投加量为150mg时,50 mg/L的DFBG溶液经60 min降解,其降解率近100%.DFBG的光催化降解服从Langmuir-Hinshelwood动力学模型,测得相应的动力学参数k=7.42×10-3mmol/L·min,K=19.54 L/mmol.     

Fe3O4/SDS磁性纳米颗粒吸附水体中的Cd2+和Zn2+

一种新型纳米固相萃取吸附剂,由阴离子表面活性剂十二烷基磺酸钠(SDS)包裹在Fe3O4磁性纳米颗粒表面形成,用于吸附水溶液中的重金属离子。研究了吸附过程的主要影响因素(如SDS浓度、溶液pH等)以及解吸过程的最佳条件,并对其机理进行了初步的探讨。研究结果表明,共沉淀法制备的Fe3O4颗粒粒径分布均匀,平均粒径约为54 nm;SDS浓度为300 mg/L时,Fe3O4/SDS磁性纳米颗粒吸附Cd2+和Zn2+的能力最强;在一定浓度范围内,Fe3O4/SDS体系对Cd2+和Zn2+的吸附平衡数据符合Langmuir吸附等温方程,饱和吸附量分别为22.42 mg/g和13.95 mg/g。最终结果表明,Fe3O4/SDS磁性纳米颗粒具有较强磁分离能力和较好的吸附效果。     

磁性CoFe2O4/MgAl-LDH去除水中的磷酸盐

采用共沉淀法制备了磁性复合材料CoFe2O4/MgAl-LDH,通过静态吸附实验研究了CoFe2O4/MgAl-LDH对磷酸盐的吸附性能,考察了吸附剂投加量、溶液pH值、吸附时间、温度、共存离子等因素对磷酸盐去除效果的影响。结果表明,在实验条件下,CoFe2O4/MgAl-LDH对磷酸盐的吸附量随溶液pH值的增大而逐渐降低,吸附的最佳pH值为1.5。磁性CoFe2O4/MgAl-LDH对磷酸盐的吸附动力学符合准二级动力学模型,吸附等温线符合Langmiur等温吸附模型,理论最大吸附容量为105.37 mg/g。吸附热力学参数表明,CoFe2O4/MgAl-LDH对磷酸盐的吸附是自发、吸热的过程。