酿酒酵母纳米Fe3O4复合材料制备及其对含铅废水的去除性能

以酿酒酵母纳米Fe₃O₄复合材料为吸附材料，以去除率为响应值，对含铅工业废水进行铅去除效果研究。通过单因素实验和响应面法实验相结合对酿酒酵母纳米Fe₃O₄复合材料的铅吸附效果进行研究。单因素实验结果表明pH值为6,铅浓度为10 mg/L,投加量为140颗，温度为30℃,转速为200 r/min时酿酒酵母纳米Fe₃O₄复合材料对铅的去除效果较好。在单因素实验，选取对铅去除影响较大的pH值、投加量和温度三个因素，以铅的去除率为响应值，采用Box-Behnken响应面分析法(BBD)探讨这3种因素对铅去除率的影响以及各个因素之间的交互作用。结果表明，酿酒酵母纳米Fe₃O₄复合材料最佳去除铅的工艺条件为pH值为6,投加量为140颗，温度为33.5℃,该条件下酿酒酵母纳米Fe₃O₄复合材料对小于10 mg/L的铅废水中铅的去除率大于92.3%,达到污水排放标准。     

秸秆纤维素基水凝胶负载Fe3O4/Cu催化剂还原硝基苯甲酸

利用废弃小麦秸秆为原料，通过离子液体法制备了小麦秸秆纤维素基水凝胶(SCH)，合成了磁性秸秆纤维素基水凝胶负载Fe₃O₄(SCH@Fe₃O₄)催化剂。将SCH@Fe₃O₄催化剂经原位固定铜离子和化学还原法合成了原位负载的SCH@Fe₃O₄/Cu催化剂，并研究了该催化剂活化NaBH₄催化还原硝基苯甲酸(NA)的性能。同时，优化了催化剂投加量、NaBH₄投加量、NA初始浓度和反应温度对NA催化还原效果的影响。SCH@Fe₃O₄/Cu催化剂活化NaBH₄还原NA的性能优于商品纳米零价铁，该过程能够抵抗水体背景阴离子的干扰，具有优异的稳定性。此外，SCH@Fe₃O₄/Cu催化剂饱和磁化强度为13.1 emu/g，说明其具有强磁性，易于从水体中分离，实现催化剂的回收利用。...     

高效催化电芬顿法处理老龄垃圾渗滤液

开发了一种处理垃圾渗滤液的新型催化剂。将纳米Fe3O4@MOF作为催化剂应用于垃圾渗滤液的电芬顿处理,考察了Fe₃O₄@MOF投加量、渗滤液初始p H、H₂O₂投加量等因素对COD去除效果的影响。结果表明,当Fe₃O₄@MOF投加量为0.75 g/L,反应120 min后,COD的去除率达到70.8%,色度的去除率达到了94.25%。GC-MS和三维荧光结果显示,渗滤液中大分子有机物及富里酸和腐殖酸类物质得到了很好的降解转化,可生化性得到了提升。说明Fe3O4@MOF是一种高效的电芬顿催化剂。     

Mn3O4-MnOOH复合材料催化过硫酸氢钾降解罗丹明B

在碱性条件下，使用H₂O₂部分氧化Mn(OH)₂制备了Mn₃O₄-MnOOH复合材料，并将其作为过硫酸氢钾活化剂用于催化氧化降解水中难降解染料罗丹明B。采用X射线衍射仪(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)等多种手段表征了材料的物理化学性质，确定了其为内部Mn₃O₄、外部MnOOH的二元纳米片状核壳式结构。通过考察不同催化体系下罗丹明B的降解效果可得Mn₃O₄-MnOOH复合材料具有比单一锰氧化物更好的催化效能。在此基础上，进一步考察溶液初始pH、催化剂投加量、KHSO₅投加量、污染物浓度等因素对染料降解的影响，确定了适宜的反应条件，即pH为4，催化剂投加质量浓度为0.1 g/L,KHSO₅投加浓度为0.325 0 mmol/L，污染物初始质量浓度为50 mg/L，该条件下，反应30 min后，罗丹明B去除率...     

Z型异质结Fe3O4@MoS2@SDS光催化降解抗生素的研究

通过超声的方法将十二烷基硫酸钠(SDS)修饰至Fe₃O₄@MoS₂表面，得到Z型异质结Fe₃O₄@MoS₂@SDS光催化剂，考察了Fe₃O₄@MoS₂@SDS光催化降解四环素(TC)的降解率。结果表明，在光照2 h后，Fe₃O₄@MoS₂@SDS对TC的去除率达到89.7%,远高于Fe₃O₄@MoS₂(57.6%)、MoS₂(43.4%)、Fe₃O₄(26.7%);Fe₃O₄@MoS₂@SDS对TC的光降解过程符合一级动力学。在TC的光降解过程中h⁺、·O^-₂、·OH...     

Fe3O4基类Fenton催化剂的改性及应用研究进展

Fe₃O₄作为尖晶石型非均相类Fenton催化材料,具有绿色无毒、价廉易得、催化活性较高等优点,但纯相Fe₃O₄催化剂存在H₂O₂利用率低、适用pH范围窄、活性位点少以及难以回收等问题,影响其实际应用。通过改性Fe₃O₄或优化反应体系使其具有更高的催化活性是当今国内外学者的研究重点。简述了Fe₃O₄的理化特性以及类Fenton催化机理,分析了限制Fe₃O₄催化活性的主要因素,并在此基础上总结了形貌调控、元素掺杂、与载体复合等改性方法在提升Fe₃O₄催化活性方面的研究进展以及Fenton与其他氧化技术协同提升Fe₃O₄基催化剂催化活性的机理和应用现状。总结历年来研究成果可知,催化剂自身调控策略以及Fenton体系协同优化均对Fe_3<...     

KMnO4、UV/H2O2预氧化对微污染水中消毒副产物生成势影响研究

采用高锰酸钾（KMn O₄）、紫外/过氧化氢（UV/H₂O₂）两种预氧化方式,通过改变氧化剂的投加量对三卤甲烷（THMs）、卤乙腈（HANs）生成势去除效果进行研究。结果表明两种预氧化方式均能很好的削减生成势,其中 UV/H₂O₂预氧化效果较佳。在 KMn O₄预氧化过程中,KMn O₄投加量为 5 mg/L 时,THMs、HANs 生成势去除率分别为82.7%、80.2%;在 UV/H₂O₂预氧化过程中,紫外光强 12 W,H₂O₂投加量为 5 mg/L 时,THMs、HANs 生成势减少幅度较大,生成势去除率分别增长到 83.1%、83.7%。当两种预氧化方式的氧化剂投加量均大于 5 mg/L 时,两种物质生成势去除率增长缓慢并趋于平缓。     

高效三维电极电Fenton降解苯酚实验研究

酚类化合物是一种有毒污染物,难以生物降解。电Fenton技术是去除酚类物质的有效手段之一。通过热溶剂—涂覆—焙烧法制备Fe₃O₄负载碳纳米管修饰泡沫镍(Fe₃O₄/CNT/NF)粒子电极,可在电解系统中同时产生H₂O₂和Fe²⁺。以Fe₃O₄/CNT/NF作为粒子电极构建三维电极电Fenton系统对苯酚进行降解,苯酚去除率明显高于基于Fe₃O₄/NF和NF粒子电极的三维电极及二维电极体系。对反应条件进行优化后,在降解时间60 min、极板间距3.0 cm、Fe₃O₄/CNT/NF粒子电极投加量8.0 g/L、电流350 mA、电解质浓度100 mmol/L、初始pH为4的条件下,苯酚去除率可达76.23%。猝灭实验结果表明,该体系中羟基自由基(·OH)在降解过程中起主要作用。此外,电极稳定性能优异,6次循...     

太阳光/TiO2-γ-Al2O3光催化处理垃圾渗滤液的研究

采用液相共沉淀法制备了TiO₂-γ-Al₂O₃复合催化剂,在其最佳合成条件下,比较了太阳光/TiO₂-γ-Al₂O₃与UV/TiO₂处理垃圾渗滤液的性能。结果表明,当Ti（SO₄）₂与Al₂（SO₄）₃·18H₂O摩尔配比为1:2、聚乙二醇2000投加质量分数为1.25%、焙烧温度为650℃时,TiO₂-γ-Al₂O₃的催化活性最强。当催化剂投加量与垃圾渗滤液COD质量比为1.75、反应时间为90 min、渗滤液pH为3时,太阳光/TiO₂-γ-Al₂O₃对COD、NH₄⁺-N的去除率几乎达到最高,分别为81.97%和54.95%,...     

Fe0类Fenton氧化处理农药中间体废水

通过单因素实验探究了Fe⁰类Fenton氧化处理农药中间体废水过程中的最适Fe⁰和H₂O₂投加量、初始pH值和最佳处理时间，研究了处理后出水BOD₅/COD_Cr(B/C)值、体系中亚铁和总铁含量以及·OH的变化规律。结果表明Fe⁰类Fenton体系中，最适Fe⁰投加量为6.59 g/L,H₂O₂投加量为3.33 g/L,初始pH=3,处理时间为50 min, COD_Cr去除率达到42.50%。相比于传统Fenton体系，Fe⁰类Fenton体系COD_Cr 去除率提高了约17%,出水B/C值达到0.34,加速了·OH的产生，H₂O₂添加量明显减少，铁的利用效率得到提高，可以有效减少含铁污泥的生成。     

Fe2O3/改性沸石催化剂的制备及其催化臭氧氧化对氯苯酚

为了提高非均相催化臭氧氧化体系处理难降解有机废水的效率，分别以十六烷基三甲基溴化铵（CTMAB）改性的天然沸石和Fe(NO₃)₃·9H₂O溶液作为载体和活性组分前体，采用浸渍法制备Fe₂O₃/改性天然沸石催化剂（MNZ），利用能谱仪（EDS）、扫描电镜（SEM）、傅里叶变换红外光谱仪（FTIR）、X射线衍射仪（XRD）、X射线光电子能谱仪（XPS）、N₂-吸附/脱附等方法分析催化剂的结构和组成，研究其催化臭氧氧化对氯苯酚的效果和催化机制。结果表明：Fe₂O₃/MNZ催化剂保持了天然沸石的表面结构。Fe₂O₃均匀负载在沸石表面，属于典型的分子筛结构，比表面积、孔容和孔径分别为12.776m²/g、0.042cm³/g和3.932nm。在对氯苯酚初始浓度为100mg/L、臭氧浓度为2.6mg/L、温度为25℃、pH为7.0±0.2的条件下，对氯苯酚和化学需氧量（COD）去除率分别为87.26%和48.83%。天然沸石与Fe₂O₃共同促进臭氧分解生成强氧化能力的羟基自由基（·OH），提高了对氯苯酚的去除率，反应体系遵循羟基自由基作用机理。     

Enhanced activity of an In–Fe2O3/H-ZSM-5 catalyst for NO reduction with methane

Selective reduction of NO by CH₄ on an In–Fe₂O₃/H-ZSM-5 catalyst was investigated in the presence of excess oxygen. Compared with In/H-ZSM-5, the In–Fe₂O₃/H-ZSM-5 catalyst with high Fe₂O₃ contents showed higher activity in a wide range of reaction temperatures. It was found that the addition of Fe₂O₃ yielded a promotion effect on CH₄ activation. The influence of water vapor on NO conversion was also investigated. The activity of the In/H-ZSM-5 catalyst has been found to be strongly inhibited by water vapor, while the In–Fe₂O₃/H-ZSM-5 catalyst remained fairly active in the presence of 3.3% steam.     

Development of Fe2O3-CeO2-TiO2/γ-Al2O3 as catalyst for catalytic wet air oxidation of methyl orange azo dye under room condition

In order to develop a catalyst with high activity and stability for catalytic wet air oxidation (CWAO) process at room temperature and atmospheric pressure, we prepared Fe₂O₃-CeO₂-TiO₂/γ-Al₂O₃ by consecutive impregnation, and determined its properties using BET, SEM, XRF, XPS and chemical analysis techniques. The degradation of an azo dye, methyl orange, in CWAO process with Fe₂O₃-CeO₂-TiO₂/γ-Al₂O₃ used as catalyst at room temperature and atmospheric pressure was also investigated, and the results show that the catalyst has an excellent catalytic activity in treating synthetic wastewater containing 500 mg/L methyl orange, and 98.09% of color and 96.08% of total organic carbon (TOC) can be removed in 2.5 h. The degradation pathway of methyl orange was analyzed by UV–vis and FT-IR spectra. The result of leaching tests shows the catalyst has an excellent stability with negligible leaching ions, and the leaching of Ce is effectively controlled by adding Ti, because Ce and Ti in the catalyst take the form of compound oxides, and the deactivation of the catalyst in successive runs is caused by the adsorption of intermediates on the surface and coverage of the active sites. The catalytic activity of the deactivated catalyst can be generally restored by rinsing it in hydrochloric acid followed by calcination.     

Fe/Al_2O_3催化剂催化氧化兰炭废水

采用浸渍法制备Fe/Al_2O_3催化剂,采用BET、XRD和穆斯堡尔谱等进行结构和性能表征。以自制Fe/Al_2O_3为催化剂,应用催化湿式过氧化氢氧化技术处理COD为6 742 mg·L-1的兰炭废水,通过建立正交实验确定最佳实验条件,结果表明,在p H=4、过氧化氢添加量9.6 m L、反应时间150 min和反应温度80℃条件下,兰炭废水COD去除率达66.30%。对催化氧化后的废水进行GC-MS分析,确定最终氧化产物主要为乙酸。表明自制Fe/Al_2O_3催化剂具有优良的催化效果,并使大分子难降解有机污染物分解为易生化的小分子污染物,甚至被完全分解矿化。     

Catalytic ozonation of thymol in reverse osmosis concentrate with core/shell Fe3O4@SiO2@Yb2O3 catalyst:Parameter optimization and degradation pathway

In this work, a novel catalyst of Fe_3O_4@SiO_2@Yb_2O_3 was prepared and the degradation of thymol in reverse osmosis concentrate using ozonation was explored. The operational parameters, such as ozone dosage(8–48 mg·min~(-1)),initial thymol concentration(20–100 mg·L~(-1)), initial pH value(3–11), and catalyst Fe_3O_4@SiO_2@Yb_2O_3dosage(0.2–1.0 g), were studied focusing on the thymol degradation and COD removal. The results indicated that the increase in ozone dosage, initial p H value, and Fe_3O_4@SiO_2@Yb_2O_3dosage accelerated the thymol degradation and COD removal, while the increase in initial thymol concentration hampered the effect of ozonation. A pathway of thymol degradation by catalytic ozonation was proposed based on the intermediates detected by gas chromatography-mass spectrometer and ion chromatography. This paper can provide basic data and technical alternative for pollutant removal from reverse osmosis concentrate by ozonation.     

Catalytic reduction of SO2 over supported transition-metal oxide catalysts with C2H4 as a reducing agent

This work investigates performances of supported transition-metal oxide catalysts for the catalytic reduction of SO₂ with C₂H₄ as a reducing agent. Experimental results indicate that the active species, the support, the feed ratio of C₂H₄/SO₂, and pretreatment are all important factors affecting catalyst activity. Fe₂O₃/γ-Al₂O₃ was found to be the most active catalyst among six γ-Al₂O₃-supported metal oxide catalysts tested. With Fe₂O₃ as the active species, of the supports tested, CeO₂ is the most suitable one. Using this Fe₂O₃/CeO₂ catalyst, we found that the optimal Fe content is 10 wt.%, the optimal feed ratio of C₂H₄/SO₂ is 1:1, and the catalyst presulfidized by H₂+H₂S exhibits a higher performance than those pretreated with H₂ or He. Although the feed concentrations of C₂H₄:SO₂ being 3000:3000 ppm provide a higher conversion of SO₂, the sulfur yield decreases drastically at temperatures above 300 °C. With higher feed concentrations, maximum yield appears at higher temperatures. The C₂H₄ temperature-programmed desorption (C₂H₄-TPD) and SO₂-TPD desorption patterns illustrate that Fe₂O₃/CeO₂ can adsorb and desorb C₂H₄ and SO₂ more easily than can Fe₂O₃/γ-Al₂O₃. Moreover, the SO₂-TPD patterns further show that Fe₂O₃/γ-Al₂O₃ is more seriously inhibited by SO₂. These findings may properly explain why Fe₂O₃/CeO₂ has a higher activity for the reduction of SO₂.     

磁性纳米Fe3O4@TiO2可见光下光催化还原Cr(Ⅵ)

通过溶胶-凝胶法、水热法和煅烧法,成功制备出具有光催化活性的Fe₃O₄@TiO₂磁性纳米复合材料,将超顺磁性的Fe₃O₄与TiO₂复合,实现材料的快速回收与可见光响应能力的结合。进一步将Fe₃O₄@TiO₂磁性纳米复合材料应用于Cr(Ⅵ)的去除,实验结果表明,在可见光照射下Fe₃O₄@TiO₂对Cr(Ⅵ)的去除能力是P25的1.96倍。并深入探究了Fe₃O₄@TiO₂中TiO₂含量、Cr(Ⅵ)溶液的pH以及空穴去除剂对Fe₃O₄@TiO₂可见光下光催化还原Cr(Ⅵ)能力的影响,实验表明当Fe₃O₄@TiO₂中TiO₂含量为1.0 g/g,添加甲酸作为空穴去除剂并且溶液pH=2时Fe₃O₄@TiO₂对Cr(Ⅵ)的去除能力最佳,此条件下Cr(Ⅵ)的去除率达到99.85%,重复使用4次,催化能力依然保持较高水平。此外,Fe₃O₄@TiO₂对5~500 mg/L浓度范围内的Cr(Ⅵ)都具有良好的去除能力。Fe₃O₄@TiO₂磁性纳米复合材料对Cr(Ⅵ)具备优异的去除能力,具有良好的应用前景。     

介孔Fe2O3/SBA-15催化臭氧氧化含酚废水

含酚废水来源广泛自然条件下难以去除,酚类物质毒性大对生态环境和人类生活健康造成了较严重的影响。本文选取了有机废水处理中较为高效的臭氧催化氧化技术,使用臭氧氧源曝气产生大量的含氧自由基,催化氧化降解酚类有机物,同时对活性中心载体进行了优化,选取制备了一类水热稳定性好及机械强度高的多孔材料,使用这些多孔材料对活性中心Fe₂O₃进行了再组装,合成了一系列表面富集Fe₂O₃的SBA-15介孔薄膜材料,由于SBA-15材料较大的比表面积、丰富的孔隙结构、高度分散的活性中心,在臭氧催化氧化含酚废水中取得了较好效果。苯酚溶液初始浓度为100mg/L (COD 238mg/L)、Fe₂O₃(5)/SBA-15催化剂投加量为30g、臭氧气体流量为2mg/min、废水HRT为5min、流量为0.8L/h的条件下,该催化剂能高效连续稳定运行500h不易失活,其COD去除率仍能保持在65%以上,催化剂活性依然保持在83%以上。Fe₂O₃/SBA-15类介孔催化材料在深度处理含酚废水中具有工业化应用潜质。     

Ethylene dimerization over NiSO4 supported on Fe2O3-promoted ZrO2 catalyst

The NiSO₄ supported on Fe₂O₃-promoted ZrO₂ catalysts were prepared by the impregnation method. Fe₂O₃-promoted ZrO₂ was prepared by the coprecipitation method using a mixed aqueous solution of zirconium oxychloride and iron nitrate solution followed by adding an aqueous ammonia solution. No diffraction line of nickel sulfate was observed up to 20 wt.%, indicating good dispersion of nickel sulfate on the surface of Fe₂O₃–ZrO₂. The addition of nickel sulfate (or Fe₂O₃) to ZrO₂ shifted the phase transition of ZrO₂ (from amorphous to tetragonal) to higher temperatures because of the interaction between nickel sulfate (or Fe₂O₃) and ZrO₂. 15-NiSO₄/5-Fe₂O₃–ZrO₂ containing 15 wt.% NiSO₄ and 5 mol% Fe₂O₃, and calcined at 500 °C exhibited a maximum catalytic activity for ethylene dimerization. NiSO₄/Fe₂O₃–ZrO₂ catalysts was very effective for ethylene dimerization even at room temperature, but Fe₂O₃–ZrO₂ without NiSO₄ did not exhibit any catalytic activity at all. The catalytic activities were correlated with the acidity of catalysts measured by the ammonia chemisorption method. The addition of Fe₂O₃ up to 5 mol% enhanced the acidity, surface area, thermal property, and catalytic activities of catalysts gradually, due to the interaction between Fe₂O₃ and ZrO₂ and due to consequent formation of Fe–O–Zr bond.     

Ag-Zn_3(VO_4)_2光催化剂催化降解甲基橙溶液

采用水热法结合高温热处理制备Ag-Zn_3(VO_4)_2光催化剂,研究催化剂在可见光下降解甲基橙溶液的性能,并考察催化剂用量、甲基橙溶液初始浓度、pH值、盐效应和H_2O_2用量对光催化性能的影响,评价Ag-Zn_3(VO_4)_2光催化剂的重复使用性能。结果表明,在催化剂用量2.0 g·L~(-1)、甲基橙溶液初始浓度20 mg·L~(-1)和溶液pH=6.2条件下光照反应5 h,甲基橙溶液脱色率可达99.18%,Na_2SO_4对光催化降解甲基橙起抑制作用,且随着溶液中盐浓度增加,抑制作用更明显。H_2O_2在一定浓度范围可促进光催化降解甲基橙,100 mL甲基橙溶液中30%H_2O_2加入量为1.0 mL时,甲基橙溶液脱色率可提高21.68个百分点。催化剂重复使用5次后,光照5 h的甲基橙溶液脱色率仍可达到75.99%。