Fenton反应处理活性皂青印染废水的实验研究

采用Fenton反应对活性皂青印染废水进行降解试验,考察了Fenton试剂摩尔比、硫酸亚铁和双氧水的投加量、pH值、反应温度等因素对印染废水色度去除率和COD去除率的影响,优化了Fenton反应降解活性皂青印染废水的适宜工艺条件。结果表明,在FeSO4/H2O2摩尔比为2∶3,废水pH值为5.0,反应温度为40℃的条件下,Fenton反应对活性皂青印染废水有很好的处理效果:印染废水色度去除率达到99.9%,COD去除率达到89.4%。     

FeSO4/H2O2/UV体系处理化纤厂棉浆粕黑液的研究

Fenton法是处理难降解有毒有机污染物的一种有效的方法.以棉浆粕黑液为研究对象,讨论了H2O2和FeSO4投加量、pH值、搅拌时间等因素对废水CODCr去除率的影响,将紫外光照引入Fenton试剂能提高废水中有毒有机污染物的降解速度,提高氧化能力 .实验确定了最佳工艺条件:pH=7,FeSO4投加量4 g/L,H2O2投加量为1.13%(V/V),搅拌时间15 min,此时CODCr去除率达到66.96%.     

饱和活性炭原位氧化再生及其在染料生化废水深度处理中的应用

以浙江省某染料厂吸附染料生化废水饱和的活性炭为研究对象,采用Fenton试剂对其进行原位氧化再生,将再生后的活性炭用于同种废水的吸附。考察了再生时间、双氧水投加量、pH值、H2O2与Fe2+物质的量比、Fenton试剂投加方式等因素对再生吸附效果的影响,得到了活性炭再生的最佳条件。结果表明,Fenton原位氧化方法对活性炭再生具有较好的效果,当pH值为1、双氧水投加量为1 mL/g、H2O2与Fe2+物质的量为20∶1、再生时间为180 min时,再生炭重新吸附废水,COD和TOC再生率分别达到49.93%、36.80%。经再生活性炭吸附处理,出水可以达到部分工业回用水要求。为期半年的半工业试验表明,活性炭吸附效果与小试结果基本吻合。     

Fenton氧化法处理焦化废水的影响因素研究

采用Fenton试剂氧化法处理某钢铁厂焦化废水,对影响Fenton试剂处理焦化废水效果的因素进行分析,包括H_2O_2投加量、n[Fe~(2+)]∶m[H_2O_2]、p H值、反应温度、反应时间等。结果表明,对于该焦化废水最佳反应条件为:H_2O_2投加量50 m L/L(即每升水样投加量为50 m L),n[Fe~(2+)]∶m[H_2O_2]=1∶10,p H=3,反应温度为30℃,反应时间30 min,废水COD去除率可达到70%~79%。该研究为高浓度难降解废水处理提供了数据支持。     

TiO2悬浆体系光催化降解酸性红B动力学分析

采用TiO2悬浆体系, 以高硼紫外灯为光源, 考察了酸性红B 光催化降解中溶液初始质量浓度、催化剂投加量、无机盐、空气通入量、pH 值对光催化降解速率影响.用Langmuir-hinshelwood 方程描述酸性红B光催化动力学行为. 结果表明:初始质量浓度增加, 反应由一级向零级过渡; 催化剂投加量在0.5～2.5 g/L时, 30 mg/L酸性红B一级反应速率常数与投加量成线性关系; 5种溶解性无机盐对光催化降解酸性红B存在抑制作用, 阴离子影响大于阳离子; 通入空气影响动力学行为, 改变反应级数.本实验在pH 值为3时光催化降解效果最佳, 且酸性条件下比碱性下条件效果更好;TiO2表面吸附能力随pH 值增大而减弱,光催化过程控制步骤在酸性和碱性条件不同.     

Fenton法处理煤气废水的动态实验研究

对Fenton试剂处理煤气废水进行了研究，探讨了Fenton氧化阶段pH、温度、HRT、H2O2投加量、Fe^2＋投加量等因素对COD去除率的影响，确定了最佳处理条件。结果表明，当pH在7．0—7．6范围内，温度为30℃，H2O2投加量为70mL，Fe^2＋投加量为30mL，搅拌60min时，COD去除率在80％以上，处理效果比较好。     

Na2Ti6O13纳米带的制备及其光降解活性艳橙染料废水的研究

用微乳法和熔盐法结合制备出了Na2Ti6O13纳米带,并用XRD,SEM对其进行表征;研究了Na2Ti6O13在紫外光下对偶氮染料活性艳橙(X-GN)的降解,并探讨了pH值、催化剂投加量和外加H2O2氧化剂对光催化效率的影响。实验表明,Na2Ti6O13具有很好的光催化性能,30W紫外灯下光催化60min对25mg/LX-GN的降解率最高可达94.1%;反应液pH值过高或过低会影响催化剂活性,最佳pH值为5.7;一定范围内,光催化效率随催化剂投加量的增加而提高,但投加量大于1.0 g/L时,催化效率反而下降;适当投加H2O2能显著提高降解效果。     

铁碳微电解-微波强化Fenton联合工艺处理垃圾渗滤液膜滤浓缩液

利用铁碳微电解-微波强化Fenton联合工艺处理垃圾渗滤液膜滤浓缩液,探讨了微波功率、微波作用时间、H2O2投加量对微电解出水处理效果的影响。同时将铁碳微电解出水COD浓度、微波功率、微波作用时间、H2O2投加量对处理效果的影响建立了正交试验,结果表明:各因素对COD去除率影响的主次关系为:微电解出水COD微波功率H2O2投加量微波作用时间。     

Fe3O4@SiO2微球作为非均相Fenton催化剂结合超声降解亚甲基蓝模拟废水

采用水热法制备Fe_3O_4纳米微球,用Stber工艺法表面修饰Fe_3O_4制备Fe_3O_4@SiO_2磁性微球,将其作为非均相Fenton催化剂,并结合超声降解亚甲基蓝(MB)模拟印染废水。通过单因素分析实验,考察了初始pH值、H_2O_2投加量、Fe_3O_4投加量等条件对非均相Fenton反应的影响。结果表明,pH值为3,Fe_3O_4@SiO_2投加量为3. 00 g/L,超声10 min,H2O2投加量为2. 00 m L/L,反应时间1 h,反应温度30℃,此时MB的去除率可达到99. 9%。     

Fenton试剂在处理高岭土选矿废水中的应用研究

介绍了Fenton试剂处理难降解有机废水的作用机理,初步探讨了H2O2投加量、硫酸亚铁用量及反应时间对水样处理效果的影响.结果表明:仅H2O2作用时,色度去除率达到98%以上,处理后水样色度小于5;在硫酸亚铁投加量为150mg/L时,氧化后废水的COD质量浓度只有29.62 mg/L;水样甲醛在反应10min时去除率超过99%,反应2 h后无机离子浓度大大降低.     

Cu/γ-Al2O3的制备及对活性艳红X-3B的脱色性能研究

为实现活性染料X-3B废水在常温常压下高效地脱色,以过渡金属为活性组分、活性氧化铝(γ-Al_2O_3)为载体,采用等体积浸渍法制备了一系列M/γ-Al_2O_3(M=Cu2+、Fe3+、Zn2+、Mn2+)负载型催化剂,并考察其对活性艳红X-3B模拟染料废水的脱色性能,同时考察了活性组分、焙烧温度、负载量、催化剂投加量、氧化剂用量及pH值等因素对活性艳红X-3B脱色性能的影响规律。结果表明,常温常压下,以Cu2+为活性组分,焙烧温度为350℃、负载量为4%(质量分数)、氧化剂H_2O_2浓度为58 mmol/L、催化剂投加量为1.2 g/L、pH值为5~7、反应50 min时,催化剂对活性艳红X-3B废水的脱色效果最佳,脱色率可达95%以上。平行试验表明,Cu2+的存在可增加载体表面的吸附中心,H_2O_2可分解产生HO·,当两者共存时,活性艳红X-3B在催化剂表面主要发生化学吸附与催化氧化两种反应过程,且染料在Cu/γ-Al_2O_3上发生的吸附作用明显大于H_2O_2分解产生HO·而引发的催化氧化作用。动力学试验表明,活性艳红X-3B反应过程动力学模型与初始质量浓度有关,大于等于200 mg/L时,符合准一级动力学方程。     

浸渍液pH值对V-Mo/Ti脱硝催化剂性能的影响研究

为提升V-Mo/Ti催化剂的脱硝性能,在催化剂制备过程中调节浸渍工艺参数,制备了一系列不同浸渍液pH值的催化剂,采用XRD、N2-吸附脱附、拉曼光谱、UV-Vis、H2-TPR、NH3-TPD等手段对催化剂进行表征,考察了pH值的变化对催化剂物理化学性能的影响,采用固定床微型反应器对催化剂的脱硝性能进行评价。结果表明,降低浸渍液pH值,可以抑制催化剂上VOx物种的聚合,提升催化剂的还原性能,有利于提升催化剂的脱硝效率,降低脱硝反应过程中N2O生成量。同时,浸渍液pH值的变化,也会影响催化剂的酸性性能。当浸渍液pH值低于3.64时,催化剂酸性性能显著降低,造成催化剂脱硝性能降低;当浸渍液pH值控制在3.64时,催化剂的还原性能和酸性性能匹配较好,从而显示了较高的脱硝性能。     

Ethanol Steam Reforming in a Microchannel Reactor

The reaction between ethanol and water was studied in the temperature range of 400–600°C at atmospheric pressure over supported catalysts in a microchannel reactor. The supported catalysts prepared by washcoating and impregnation were active in the ethanol steam reforming but differ in their performance. The metal nature, metal loading and type of the carriers markedly influence the catalytic activity and selectivity of the catalysts. Among them Rh-based catalysts exhibited the highest catalytic activity, as compared to Co and Ni-based catalysts. Bimetallic Rh-Ni catalysts exhibit significant improvement in terms of ethanol conversion and hydrogen selectivity and the promoting role of the Ni and CeO₂ addition is discussed. The bimetallic Rh-Ni catalyst promoted by CeO₂ was stable for at least 100 h without any detectable degradation in performance.     

Degradation of gaseous 1,2-dichloroethane using a hybrid cuprous oxide catalyst

A hybrid catalyst (CZ50) of cuprous oxide and zeolite was prepared and used in a catalytic system in which gaseous 1,2-dichloroethane (1,2-DCE) was degraded. The effects of relative humidity (15 and 65%) and wavelength of irradiation (ultraviolet, blue, green and red light) on the degradation of 1,2-DCE were studied. The experimental results reveal that the hybrid catalyst degraded the hazardous material under visible light. A comparison of the results obtained under ultraviolet and red irradiation at a relative humidity of 15% revealed almost equal degradation efficiencies of 83.8 and 82.2%, respectively. In the system with hybrid catalysts, a lower relative humidity favored 1,2-DCE degradation, indicating that relative humidity critically affects the degradation of hazardous materials. The most important result was that the intermediates of the degradation of 1,2-DCE included ethane, carbon dioxide, and formic acid yielded, which are mostly harmless and non-toxic materials. The experimental results indicated that the method could effectively be used to degrade hazardous materials to provide a healthy and safe environment for workers.     

Electro-Fenton degradation of cationic red X-GRL using an activated carbon fiber cathode

We reported the study of the degradation of the azo dye cationic red X-GRL by the electro-Fenton process using an activated carbon fiber cathode. The electrogeneration of hydrogen peroxide in solution using different material cathodes fed with air was investigated, and the results revealed that the activated carbon fiber cathode was more effective compared to the graphite cathode. The decolorization and mineralization of cationic red X-GRL were also determined. The effect of the operating parameters, such as the initial Fe²⁺ concentration, temperature and initial dye concentration, was investigated. The optimum Fe²⁺ catalyst concentration values for the degradation of cationic red X-GRL was found to be 5 mM. The rate of decolorization and mineralization of dye could be accelerated by increasing the temperature. In addition, the decolorization and total organic carbon (TOC) removal efficiency decreased with the increasing initial dye concentration, while the TOC removal increased. Two different transition metal ions (Cu²⁺ and Mn²⁺) were applied as substitutes for ferrous sulfate for evaluating catalytic effect. The results indicated that Cu²⁺ and Mn²⁺ were more effective than Fe²⁺ in catalyzing the degradation of the dye.     

An efficient and clean oxidative bromination reaction of phenol catalyzed by ammonium salt of heteropoly acids supported on silica

An efficient and eco-friendly oxidative bromination reaction of phenol has been achieved by treatment with KBr–H₂O₂ in the presence of a catalytic amount ammonium salt of molybdophosphoric acid or phosphotungstic acid that supported on silica, which were synthesized by sol–gel method. The physicochemical characterization indicated that supported catalysts still retained its Keggin type and the particles were well dispersed onto the surface of silica support. The evaluated results of liquid phase bromination of phenol showed that these catalysts exhibited high catalytic oxybromination activity and high para substituted selectivity, and good stability was also observed after recycling three times. Meanwhile, no highly toxic and corrosive materials were used and formed in the reaction process, which makes this process environmentally benign. The influences of the reaction time, catalyst amount and solvent on oxidative bromination reaction were also investigated.     

Low temperature CO oxidation over Pd–Ce catalysts supported on ZSM-5 zeolites

A series of Pd–Ce supported ZSM-5 zeolite catalysts for CO oxidation at low temperature were prepared by co-impregnation method. The effect of Pd–Ce synergistic function, Ce loadings, and properties of ZSM-5 zeolite on low temperature CO catalytic oxidation was investigated in detailed. The results showed that the Pd and Ce loading on ZSM-5 zeolite support at the same time enhanced catalytic activity compared with only Pd or Ce loading on ZSM-5 zeolite support. The properties of ZSM-5 zeolite had a strong influence for CO oxidation. Through the research, the ZSM-5 zeolite with high silicon aluminum ratio and small size also was helpful for CO oxidation. Among these catalysts, the catalyst with 19 wt% Ce loading displayed the highest catalytic activity. Chemical and physical properties of catalysts were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). XRD and TEM showed that Pd species were highly dispersed on the surface of ZSM-5 zeolite, which was strongly dependent on the amounts of Ce loading and the interaction among Pd species, Ce promoter and ZSM-5 support. The addition of CeO₂ improved the dispersion of Pd species over ZSM-5, and synergistic function of Pd and CeO₂ enhanced the catalytic activity. XPS characterization indicated that as the addition of Ce increased, Pd species was easy to enrich on the surface of the catalyst.     

炭基催化法降解烟气中二噁英研究进展

综述了炭基催化法烟气处理工艺中二噁英的降解机理,以及催化剂特性、降解气氛、温度和时间等对二噁英降解影响的研究进展,指出由于缺乏足够多的二噁英降解机理研究数据,一方面可能使得工业应用中催化剂被过量使用,另一方面可能会导致催化剂在多污染物协同处理时引发处理效率或装置运行问题。最后从超低排放背景下该技术的推广和应用角度对今后的研究方向提出了建议。     

阻挡放电联合金属氧化物催化降解H2S的研究

采用介质阻挡放电联合金属氧化物催化降解气态H2S,考察了单组分及复合金属氧化物催化剂、催化剂与低温等离子体结合方式对H2S及副产物O3去除性能的影响,分析了等离子体联合Mn复合金属氧化物催化降解H2S机理。结果表明,金属负载量相同条件下,电压低于22kV时,Mn复合金属氧化物对H2S的催化活性高于单组分Mn金属氧化物,催化活性及对O3的分解能力从大到小依次为:Ag+Mn、Cu+Mn、Fe+Mn、Mn。当电压为18 kV时,Ag+Mn、Cu+Mn、Fe+Mn复合催化剂分别比单组分Mn催化剂对H2S的去除效率提高了近10%、6%、4%。等离子体后催化区域中Mn催化剂催化氧化H2S的效率明显低于等离子体催化区域。Mn催化剂在等离子体后催化区域中能有效催化分解O3。随着电压的升高,Mn金属氧化物在等离子体后催化区域对H2S催化作用逐渐增强。在电压22 kV时,等离子体联合后催化比单独等离子体作用时,H2S去除效率提高了近11%。     

高级氧化工艺降解水中磺胺甲基嘧啶研究

为有效去除水体污染物磺胺类抗生素(Sulfonamides antibiotics,SAs),采用高级氧化紫外/双氧水(UV/H_2O_2)和紫外/过硫酸盐(UV/PS)工艺降解磺胺甲基嘧啶(sulfamerazine,SM1)。研究表明,紫外与氧化剂(H_2O_2,PS)联用可显著提高去除率,其反应符合拟一级动力学模型。磺胺甲基嘧啶的去除率在一定范围随着氧化剂H_2O_2和PS的浓度升高而升高;磺胺甲基嘧啶初始质量浓度越大,反应速率越小。两种工艺降解磺胺甲基嘧啶最大去除率均发生在pH=3。NaCl会抑制两种工艺对目标污染物的降解,而适当的NaHCO_3可促进其降解反应的进行。腐植酸的存在对两种工艺降解污染物均会产生抑制作用。