Fe^2＋／Mn^2＋／H2O2体系对含茜素红染料废水的脱色与降解处理

本义研究了过氧化氯在铁、锰两种金属离了共同作用下的催化体系对含有茜素红染料废水的脱色和降解作用。结果表明：Fe^2 ／Mn^2 ／H2O2体系在pH=5～6时对该染料废水的脱色和降解作用明显，脱色率和降解率均达到80％以上，COD去除率大于70％。处理后的废水值接近中性，可以直接排放。     

支持电解质对酸性大红染料废水电解的影响

通过静态试验对比研究了模拟酸性大红3R染料废水在NaCl和Na2SO4体系中的电化学氧化过程,考察了电流密度、电解质浓度和初始pH对色度去除效果的影响,比较了两种电解质对染料废水的处理效果。结果表明,在不同支持电解质体系中,电流密度、电解质浓度和初始pH对染料废水脱色作用的影响具有基本相同的规律;在不同支持电解质体系中,染料废水降解效果差别很大,以NaCl为支持电解质时的脱色率明显高于以Na2SO4作为支持电解质。     

CaO2/H+/FeSO4体系处理染料废水的研究

研究了CaO2/H+/FeSO4复合体系对以酸性黑10B为代表的4种水溶性染料模拟废水的处理,并以酸性黑10B为研究对象,研究了各种反应条件对脱色率的影响,结果表明当染料初始质量浓度为25 mg/L时,pH在2～3,CaO2为200 mg/L,FeSO4@7H2O为100～150 mg/L,反应时间为30 min的条件下,脱色率即可达到近100%,溶液无色透明.对高色度、高CODCr实际染料废水,采用以CaO2/H+/FeSO4复合体系催化氧化为主的稀释-催化氧化-絮凝-吸附综合处理工艺,也取得了很好的效果.说明该体系对水溶性染料具有很好的脱色效果,且脱色速率快,药品用量少,成本低,在废水处理上有较大的应用前景.     

UV-Fenton体系处理活性黑KNB染料废水的实验研究

采用UV-Fcnton体系处理活性黑KNB染料废水．研究了pH值、H2O2和FeSO4用量、反应温度和反应时间等对染料废水脱色率的影响。实验结果表明,当KNB的初始浓度为50mg／L时,在t=25℃、pHi5．4、[H2O2]=0．2ml/L,[FeSO4]=0．7mmol/L。使用30W的紫外灯光照射条件．反应1小时后,KNB染料废水脱色率几乎可达100%。通过比较反应前后染料废水的UV-Vis吸收光谱,初步探讨了KNB的降解机理。研究表明,UV-Fenton体系可以有效地处理活性黑KNB染料废水,为该工艺处理实际染料废水提供基础数据。     

多维电极法处理活性染料废水影响因子正交实验分析

以活性嫩黄K-4G染料模拟废水为处理对象(CODCr=4000mg／L，色度=13000，pH=6.5)采用多维电极法．选择了6个影响脱色率和CODCr降解率的因素，每个因素3个水平进行正交试验。实验结果表明：电解时间、电流密度和电导率对脱色率和CODCr降解率影响最大。最优水平组合为A3B3C3D1E1F3，在此条件下脱色率为81%，CODCr降解率为85％。     

光催化协同臭氧降解活性艳红X-3B

采用光催化协同臭氧技术降解蒽醌染料活性艳红X-3B。利用UV-vis光谱比较了X-3B在不同体系中的降解效果,并研究了光催化／爽氧法处理染料的主要影响参数。结果表明：光催化法和臭氧法之间存在明显的协同作用,经过60min的反应,初始浓度为100mg／L的X-3B溶液的脱色率达到99．95％。增加臭氧的流量有利于提高脱色率;溶液初始pH则对降解的影响较小：随着染料初始浓度的增加,脱色率逐渐下降,然而单位时间内X-3B的绝对去除祭却缓慢升高。在光催化／臭氧体系中,对降解起到主要作用的是·OH的氧化作用。     

强化日光／H2O2协同作用对酸性黑染料的降解脱色研究

在H2O2存在条件下．对酸性黑染料进行加强日光照射处理,系统地研究了染料初始浓度、pH值、光照强度、不同阴离子等因素对酸性黑染料废水的脱色效果的影响。结果表明,染料初始浓度越低,光降解速率越高：酸性媒介比碱性媒介更有利于酸性黑光解脱色;染料光解脱色速率随光照强度增加而增加,但在较高光强下时,降解速率增加并不明显。除SO4^2-离子外,试验范围内的其它Br^-、NO3^-、Cl^-和NO2^-等阴离子,均对降解脱色有抑制作用,其中NO2^-对脱色作用抑制最显著。处理前后的UV—Vis谱图分析表明酸性黑在H2O2／强化日光光解处理中脱色是因为染料发生氧化光降作用。     

Cu_2O/H_2O_2类芬顿工艺用于染料废水的脱色研究

采用类芬顿工艺处理印染废水,考察了自制Cu_2O催化剂对染料的降解性能。结果表明,当Cu_2O用量为0.5g/L、双氧水(H_2O_2质量分数30%)用量为5 m L/L,在75℃下反应4 min,对质量浓度为15 mg/L罗丹明B溶液脱色率达到100%。随着反应温度升高,染料的脱色速率和脱色率均增大,符合1级反应动力学方程,75℃下反应速率常数k为1.31 min~(-1),比室温条件(25℃)下提高了60倍。染料废水中的无机盐对Cu_2O催化降解染料有明显的促进作用,原因是催化过程中产生大量的活性氯基团有利于有机物降解。当NaCl浓度为0.2 mol/L时,可使染料在室温下,反应30 min脱色完全,且Cu~+的流失量小于0.6 mg/L,满足GB 25467-2010排放要求。该类球形Cu_2O在染料废水催化降解中具有较好的应用前景。     

活性染料染色废水的日光脱色降解

在太阳光照射条件下，使用铁(Ⅲ)-草酸盐络合物／H2O2对存在于水中三种中温型活性染料进行光催化降解研究，重点考察了太阳光的强度和活性染料的浓度对脱色降解反应的影响结果表明：太阳光的强度低于50001ux，染料的脱色率低于40％；在高于400001ux、照射60分钟脱色率高于98％，在高于900001ux时，照射10分钟，可使活性蓝MS脱色率接近100%，太阳光的强度越高，溶液中的染料浓度越低。     

杂多酸盐／聚苯胺／TiO2复合材料光催化降解甲基橙

以PW11Ti／PANI/TiO2为光催化剂,在太阳光照射下,研究了模拟染料废水甲基橙溶液的光催化降解的反应,讨论了甲基橙溶液的酸度、溶液的初始浓度以及催化剂投加量等对甲基橙溶液脱色效果的影响。结果表明：催化剂加入量为10mg,甲基橙的初始浓度为20mg／L,pH=4,脱色率达到85．62％。     

ION-EXCHANGE EQUILIBRIUM OF THE Cu2+/H+, Zn2+/H+ AND Pb2+/H+ IONS ON HYDRATED FERRIC OXIDE

ABSTRACT

The ion exchange of trace amounts of Cu²⁺, Zn²⁺ and Pb²⁺ with the hydrogen-form of hydrated ferric oxide as a function of nitric acid concentration has been studied at 25, 30,35 and 60^°C. Ion exchange of these cations increases with increasing temperature in the investigated temperature range. From these results, equilibrium constants for the Cu²⁺/H⁺, Zn²⁺/H⁺ and Pb²⁺/H⁺ ion exchange on hydrated ferric oxide and thermodynamic quantities for these reactions were calculated, and some predictions made for the exchange process taking place in this material. The selectivity series is Zn²⁺ > Cu²⁺ > Pb²⁺.     

Ca2+/Sr2+/Ba2+ dependent phase separation,nanocrystallization and photoluminescence in fluoroaluminosilicate glass

Fluoride phase separation is the initial stage of nanocrystallization in oxyfluoride glasses, and it is a key step in achieving transparent glass-ceramics with good luminescence. In this work, we combine molecular dynamics (MD) simulations and experimental studies to investigate the phase separation, nanocrystallization and photoluminescence in fluoroaluminosilicate glass and glass-ceramics containing alkali earth fluoride (MF₂). The results reveal different phase separation behaviors due to the field strength difference of M²⁺. The composition and size similarity between the fluoride-rich regions in the MD simulated glass and the fluoride nanocrystals in the experimental prepared glass-ceramics are observed, suggesting that the separated fluoride phase is the structural origin of the observed MF₂ nanocrystals. Besides, in order to understand the M²⁺ dependent glass structural features, the crystallization temperatures, the luminescent properties of Eu³⁺ and Eu²⁺ doped glass-ceramics, and the lasing performance of Er³⁺ doped glass-ceramics are discussed. Based on these comprehensions, some strategies are proposed to help to efficiently design oxyfluoride glass with desired luminescence performance.     

Electrochemical behaviour of Mn3+/Mn2+, Co3+/Co2+ and Ce4+/Ce4+ redox mediators in methanesulfonic acid

The redox behaviour of Mn³⁺/Mn²⁺, Co³⁺/Co²⁺ and Ce⁴⁺/Ce³⁺ mediators commonly used in indirect oxidation of organic compounds were evaluated in methane sulfonic acid on a glassy carbon working electrode employing cyclic voltammetry. Manganic methanesulfonate exhibits higher instability in dilute methanesulfonic acid. The solid MnO₂ formed during disproportionation on the glassy carbon electrode further affects the reproducibility. Cobaltic methanesulfonate formation occurs only at oxygen evolution region rendering the overall oxidation process less efficient. Ceric methane sulfonate formation is highly efficient over a wide acid concentration range. Ceric methanesulfonate can also be employed over a wide temperature range to oxidize different aromatic compounds.     

Fe2+/H2O2体系O2生成路径

掌握Fe²⁺/H₂O₂体系O₂的生成路径,可为避免H₂O₂无效分解,开发经济高效的Fe²⁺/H₂O₂体系利用技术指明方向。采用添加自由基捕获剂的方法,探究Fe²⁺/H₂O₂体系内各种自由基对O₂生成速率的影响,进而确定O₂的生成路径。结果表明:Fe²⁺/H₂O₂体系内不会产生大量O₂^-·,O₂^-·不是生成O₂的主要反应物质;O₂^-·被全部捕获后,体系中仍产生大量O₂^-·,但此时无O₂生成,证明生成O₂的反应由·OH和HO₂·两种自由基直接参与。分析认为反应·OH+HO₂·-H₂O+O₂是体系内O₂生成的主要路径。控制Fe²⁺/H₂O₂体系定向生成·OH,抑制HO₂·的产生,是提高Fe²⁺/H₂O₂体系中H₂O₂利用率的有效手段。     

Acceleration of the redox kinetics of VO2+/VO2 + and V3+/V2+ couples on carbon paper

The redox kinetics of VO²⁺/VO₂ ⁺ and V³⁺/V²⁺ couples on a carbon paper (CP, HCP030 N, Shanghai Hesen, Ltd., China) electrode were investigated in terms of their standard rate constant (k ₀) and reaction mechanism. The values determined for k ₀ for VO²⁺ ?? VO₂ ⁺ and V³⁺ ?? V²⁺ using the CP electrode are 1.0 × 10^?3 and 1.1 × 10^?3 cm s^?1, respectively. The value of k ₀ increases by one or two order(s) of magnitude compared with values obtained using electrodes composed of pyrolytic graphite and glassy carbon. The acceleration of the redox kinetics of vanadium ions is a result of the large surface area of the CP electrode. An inner-sphere mechanism for the reaction on the surface of the electrode is proposed. The kinetic features of vanadium redox reactions on the CP electrode reveal that CP is suitable for use as the electrodes in vanadium redox-flow batteries.     

Cu2+/ZnO-蒙脱石抗菌材料的制备及抑菌活性研究

以Cu(NO3)2、ZnCl2、NaOH为主要原料,蒙脱石(MMT)作为载体,制备Cu2+/ZnO-MMT抗菌材料,并对其结构、表面性质和抑菌性能进行表征.结果表明,Cu2+/ZnO-MMT对大肠杆菌和金黄色葡萄球菌均具有较强的抑菌活性.以大肠杆菌为试验菌种,研究了所制材料的杀菌机理,首先大肠杆菌被吸附到蒙脱石表面,然后细菌细胞质膜被所载的Cu2+和ZnO损伤,使胞内溶物外流,最终细菌死亡.     

Luminescence behavior of Nd3+/Zr4+/3+ Co-activated ZrP2O7 persistent phosphor

The bluish-green long persistent phosphor (LPP) materials ZrP₂O₇:Nd³⁺ were synthesized in a reducing atmosphere by a conventional high-temperature solid state reaction. The XRD patterns, XPS survey scan, excitation and emission spectra, decay curves and thermoluminescence (TL) curves were used for investigating the structure and luminescence properties and mechanism of the materials. The emission band between 400 and 600 nm exhibit the characteristics of blue emission from d-d transitions of Zr and the characteristics of green emission from f-f transitions of Nd³⁺. The TL curves showed that the formation of high-concentration trap level at 337 K (0.73 eV) was mainly responsible for the LPP phenomenon of ZrP₂O₇:Nd³⁺ at room temperature.     

Color-tunable up-conversion emission from Yb3+/Er3+/Tm3+/Ho3+ codoped KY(MoO4)2 microcrystals based on energy transfer

Tunable up-conversion luminescent material KY(MoO₄)₂: Yb³⁺, Ln³⁺ (Ln=Er, Tm, Ho) has been synthesized by a typical hydrothermal process. Under 980 nm laser diode (LD) excitation, the emission intensity and the corresponding luminescence colors of KY(MoO₄)₂: Yb³⁺, Ln³⁺ (Ln=Er, Tm, Ho) have been investigated in detail. The energy transfer from the Yb³⁺ sensitizer to Ho³⁺, Er³⁺ and Tm³⁺ activators plays an important role in the development of color-tunable single- phased phosphors. The emission intensity keep balance through control of the Ho³⁺ co-doping concentrations, white light was experimentally shown at KY(MoO₄)₂: 20 mol% Yb³⁺, 0.8 mol% Er³⁺, 0.5 mol% Tm³⁺, 1.0 mol% Ho³⁺ phosphor with further calcination at 800 °C for 4 h under 980 nm laser excitation. The color tunability, high quality of white light and high intensity of the emitted signal make these up-conversion (UC) phosphors excellent candidates for applications in solid-state lighting.     

Cu~(2+)/H_2O_2法降解高浓度偏二甲肼废水

采用Cu~(2+)/H_2O_2法降解高浓度偏二甲肼(UDMH)废水,以废水中UDMH的去除率作为检测指标,通过正交实验确定了该反应的主要影响因素及最佳工艺条件,考察了最佳工艺条件下的降解效果;针对化学需氧量(COD)去除率低的问题,探讨了降解中间产物甲醛和亚硝基二甲胺的变化规律。结果表明,H_2O_2摩尔投加量为UDMH完全矿化理论摩尔投加量的1.5倍(1.5Qth)、初始pH值为9、Cu~(2+)与H_2O_2摩尔比1∶10、反应温度为20℃、反应进行120min后,废水中UDMH的降解率达98.88%,COD去除率达92.59%。但Cu~(2+)/H_2O_2法处理时产生有毒中间产物亚硝基二甲胺和甲醛,反应后期甲醛迅速降解,而亚硝基二甲胺则难以去除。     

Fe2+/H2O2体系内各种自由基在氧化NO中的作用

Fe²⁺/H₂O₂体系可分解产生多种氧化性自由基, 主要包括O₂^-·、·OH和HO₂·。本文实验研究了O₂^-·、·OH及HO₂·在Fe²⁺/H₂O₂体系氧化NO气体过程中的作用。结果表明:在本实验条件下, O₂^-·对NO气体的氧化作用不明显;·OH及HO₂·是该体系氧化NO气体的主要活性物质, 其中·OH的氧化作用更大。加快自由基的生成速率可以增强Fe²⁺/H₂O₂体系对NO气体的氧化能力, 但O₂的生成速率同时加快。只有少量·OH及HO₂·参与NO的氧化, ·OH与HO₂·之间的快速反应是Fe²⁺/H₂O₂体系氧化NO过程中H₂O₂利用率低的主要原因。