基于六偏磷酸钠-Fe^(2+)的铁盐脱氮反应器运行性能及微生物学特征研究

以实验室高效反硝化反应器中的反硝化污泥作为接种污泥,启动自养型六偏磷酸钠-Fe^(2+)脱氮反应器,试验采用模拟废水通过88 d的不间断运行,研究了铁盐脱氮工艺的脱氮效能及其微生物学特性。结果表明,当反应器硝态氮容积负荷为0.42 kg/(m^(3)·d)时,最高稳定氮去除负荷为0.41 kg/(m^(3)·d);当Fe^(2+)容积负荷为4.92 kg/(m^(3)·d)时,最大铁去除负荷为2.77 kg/(m^(3)·d)。反应器稳定运行时硝态氮、Fe^(2+)的去除率分别达94.6%、52.6%,最佳效能可维持28 d。反应器运行到第82天时,颗粒污泥由黄色变为灰褐色,颗粒解体,污泥比活性逐渐升高,比反硝化活性由0.71 mg[N]/(g[VSS]·h)升高到2.3 mg[N]/(g[VSS]·h),同比上升224%;比铁氧化活性由7.3 mg[Fe]/(g[VSS]·h)升高到15 mg[Fe]/(g[VSS]·h),同比上升105%。六偏磷酸钠-Fe^(2+)脱氮作为一种新型自养反硝化技术,不仅增强了活细菌的生物活性和反硝化活性,还延长了铁盐脱氮污泥反硝化的高效期。

STUDY OF SURFACE RESISTIVITY MODIFICATION IN Al_2O_3 CERAMIC IMPLANTED BY Fe^(2+)

The implanted ion range, the depth profile and the film sttucture of the implanted layer were studied; the carrier concentration and the mobility were measured; the conductivity mechanism of the film implanted Fe into Al_2O_3 ceramic was discussed. The conclusion is that the implanted Fe^(2+) ions move into Al_2O_3 lattice and replace Al^(3+) to form subs- titution impurities so that the ion implanted lat- tice, as compared with the original one, presents an effective negative charge which forms a negative charge center. A vacancy is bound arround it, and an acceptor is introduced in the forbidden band.

Study on Catalytic Wet Oxidation of H_2S into Sulfur on Fe/Cu Catalyst

A wet catalytic oxidation at room temperature was investigated with solution containing ferric, ferrous and cupric ions for H2S removal. The experiments were carried out in a two step process, and the results obtained show that the removal efficiency of H2S can always reach 100% in a 300 mm scrubbing column with four sieve plates, and the regeneration of ferric ions in 200 mm bubble column can match the consumed ferric species in absorption. Removal of H2S, production of elemental sulfur and regeneration of ferric, cupric ions can all be accomplished at the same time. No raw material is consumed except O2 in flue gas or air, the process has no secondary pollution and no problem of catalyst degradation and congestion.

Electrochemical synthesis of Ni doped carbon quantum dots for simultaneous fluorometric determination of Fe^(3+)and Cu^(2+)ion facilely

A novel Ni doped carbon quantum dots(Ni-CQDs)fluorescence probe was synthesized by facile electrolysis of monoatomic Ni dispersed porous carbon(Ni–N–C).The obtained Ni-CQDs showed a high quantum yield of 6.3%with the strongest excitation and emission peaks of 360 nm and 460 nm,and maintained over 90%of the maximum fluorescence intensity in a wide p H range of 3–12.The metal ions detectability of Ni-CQDs was enhanced by Ni doping and functional groups modification,and the rapid and selective detection of Fe^(3+)and Cu^(2+)ions was achieved with Ni-CQDs through dynamic and static quenching mechanism,respectively.On one hand,the energy band gap of Ni-CQDs was regulated by Ni doping,so that excited electrons in Ni-CQDs were able to transfer to Fe^(3+)easily.On the other hand,the abundant functional groups promoted the generation of static quenching complexation between Cu^(2+)and Ni-CQDs.In metal ions detection,the linear quantitation range of Fe^(3+)and Cu^(2+)were 100–1000μM(R^(2)=0.9955)and 300–900μM(R^(2)=0.9978),respectively.The limits of detection(LOD)were calculated as 10.17 and 7.88μM,respectively.Moreover,the fluorescence quenched by Cu^(2+)could be recovered by EDTA2-due to the destruction of the static quenching complexation.In this way,NiCQDs showed the ability to identify the two metal ions to a certain degree under the condition of Fe^(3+)and Cu^(2+)coexistent.This work paves the way of facile multiple metal ion detection with high sensitivity.

Fe(Ⅱ)/阳离子掺杂针铁矿矿物系统对2-NP的还原转化性能研究

制备了不同阳离子掺杂改性的针铁矿,并采用XRD、红外、热重差热分析以及TEM等手段对其进行了表征,结果显示,掺入Mn^(2+)、Cr^(3+)、Al^(3+)后并未明显改变α-FeOOH的晶体结构类型,说明部分阳离子掺杂进入α-FeOOH晶格,从而分别形成因Fe^(3+)被Mn^(2+)、Cr^(3+)、Al^(3+)部分取代的固溶体;红外分析也得到类似结果;热重和差热分析以及TEM观察结果均表明几种金属阳离子没有形成氧化物相,可以确定这些离子已经进入针铁矿的晶格;紫外-可见漫反射光谱分析发现Mn^(2+)、Cr^(3+)掺杂者的能带隙较之纯相针铁矿的稍小,依次为2.18 e V和2.24 e V;而Al^(3+)掺杂者的能带隙与纯相针铁矿相比有所提高,增加至2.34 e V。此外还考查了不同阳离子掺杂及纯相针铁矿与Fe(Ⅱ)构成的复合系统对邻硝基苯酚(2-NP)的还原效果,研究表明,在溶液pH=6和25℃等的条件下,上述还原转化反应符合准一级动力学方程。其中,Fe(Ⅱ)/Al^(3+)掺杂针铁矿复合系统对2-NP的降解效果最好,在120 min时就达到了100%去除率,在一定浓度范围内,随着2-NP浓度的升高,2-NP的还原速率降低。而且,Fe(Ⅱ)/Al^(3+)-针铁矿复合系统速率常数(k)随着溶液的pH值增大而升高。

Novel LaFe_(2)O_(4)spinel structure with a large oxygen reduction response towards protonic ceramic fuel cell cathode

Highly active and stable electrocatalysts are mandatory for developing high-performance and longlasting fuel cells.The current study demonstrates a high oxygen reduction reaction(ORR)electrocatalytic activity of a novel spinel-structured LaFe_(2)O_(4)via a self-doping strategy.The LaFe_(2)O_(4)demonstrates excellent ORR activity in a protonic ceramic fuel cell(PCFC)at temperature range of 350-500℃.The high ORR activity of LaFe_(2)O_(4)is mainly attributed to the facile release of oxide and proton ions,and improved synergistic incorporation abilities associated with interplay of multivalent Fe^(3+)/Fe^(2+)and La^(3+)ions.Using LaFe_(2)O_(4)as cathode over proton conducting BaZr_(0.4)Ce_(0.4)Y_(0.2)O_(3)(BZCY)electrolyte,the fuel cell has delivered a high-power density of 806 mW/cm^(2)operating at 500℃.Different spectroscopic and calculations methods such as UV-visible,Raman,X-ray photoelectron spectroscopy and density functional theory(DFT)calculations were performed to screen the potential application of LaFe_(2)O_(4)as cathode.This study would help in developing functional cobalt-free ORR electrocatalysts for low temperature-PCFCs(LT-PCFCs)and solid oxide fuel cells(SOFCs)applications.

One-step hydrothermal synthesis of Cit-NaYbF_(4):Er^(3+)nanocrystals with enhanced red upconversion emission for in vivo fluorescence molecular tomography

Fluorescence imaging techniques represent essential tools in in vitro,preclinical,and clinical studies.In this study,an improved one-step hydrothermal method to synthesize citric acid(CA)modifiedα-NaYbF_(4):2%Er^(3+)nanocrystals was proposed.The introduction of various doping ions into NaYbF_(4):2%Er^(3+)and the different valence states of the same ions affect both the crystal size and upconversion luminesce nce.There fore,we investigated the upconversion luminesce nce enha ncement of NaYbF_(4):2%Er^(3+)by ion doping and find that the upconversion luminescence intensity of the upconversion nanoparticles(UCNPs)co-doped with 5 mol%Fe^(2+)ions shows the greatest enhancement,especially for red emission at654 nm.Furthermore,HeLa cells incubated with UCNPs allow for imaging with strong red upconversion emission detectio n.Confocal laser scanning microscope(CLSM)fluorescent images of HeLa cells indicate that NaYbF_(4):2%Er/5%Fe^(2+)leads to a clear outline and improves visualization of the cell morphology.In addition,the CA coated NaYbF_(4):2%Er^(3+)/5%Fe^(2+)nanoparticles and NaYbF_(4):2%Er^(3+)/5%Fe^(2+)show low cytotoxicity in HeLa cells.Organ imaging reveals the efficiency of these UCNPs to analyze the lungs,liver,and spleen.Together,these results indicate that the Cit-NaYbF_(4):2%Er^(3+)/5%Fe^(2+)UCNPs are efficient nanoprobes for fluorescence molecular to mography.

A Fluorescent Chemosensor for Dihydrogen Phosphate Ion Based on 2-[2-Hydroxy-4-(diethylamino)phenyl]-1Himidazo[4,5-b]phenazine-Fe^(3+)Ensemble

A long wavelength emission fluorescent(612 nm)chemosensor with high selectivity for H_(2)PO_(4)^(−)ions was designed and synthesized according to the excited state intramolecular proton transfer(ESIPT).The sensor can exist in two tautomeric forms(‘keto’and‘enol’)in the presence of Fe^(3+)ion,Fe^(3+)may bind with the‘keto’form of the sensor.Furthermore,the in situ generated GY-Fe^(3+)ensemble could recover the quenched fluorescence upon the addition of H_(2)PO_(4)^(−)anion resulting in an off-on-type sensing with a detection limit of micromolar range in the same medium,and other anions,including F^(−),Cl^(−),Br^(−),I^(−),AcO^(−),HSO^(−)_(4),ClO^(−)_(4)and CN−had nearly no influence on the probing behavior.The test strips based on 2-[2-hydroxy-4-(diethylamino)phenyl]-1H-imidazo[4,5-b]phenazine and Fe^(3+)metal complex(GY-Fe^(3+))were fabricated,which could act as convenient and efficient H_(2)PO_(4)^(−)test kits.

不同种类绿茶提取物抗氧化活性研究

测定了3种绿茶的总多酚、黄酮和花青素含量,利用亚铁离子螯合能力、DPPH清除能力和铁还原力法对3种绿茶提取物的抗氧化活性进行分析,结果表明,绿茶中以黄山毛峰的总酚含量最高。黄酮含量基没有显著性差异。花青素的含量由大到小依次是信阳毛尖、黄山毛峰和营州芽峰。亚铁离子螯合能力,黄山毛峰>信阳毛尖>营州芽峰。在稀释倍数为2时,黄山毛峰的亚铁离子螯合能力分别是信阳毛尖和营州芽峰的1.32倍和1.38倍。在0.25～1mgDW/mL的浓度下,黄山毛峰的对DPPH的清除能力要显著高于信阳毛尖和营州芽峰,而信阳毛尖和营州芽峰之间无显著性差异。在稀释倍数为2时,黄山毛峰的铁还原力分别是信阳毛尖和营州芽峰的1.35和1.4倍。

聚合物在注聚管道中降解的模拟研究

实验聚合物溶液浓度 15 0 0mg/L ,用胜利标准盐水 (矿化度 5 72 5mg/L ,钙镁离子含量 10 8mg/L)配制 ,聚合物为分子量 9.5 6× 10 6,水解度 2 3%的工业品HPAM。聚合物溶液盛于内径 6cm、长 30cm、由不同材料制成的管子内 ,在不同条件下处理 1h和 3h ,测定溶液在实验温度下的粘度 (7s-1)和溶液中Fe3 + 浓度 ,根据测试结果讨论了造成注聚管道中聚合物溶液粘度损失的因素。按聚合物溶液粘度下降程度和溶液中Fe3 + 浓度 ,各测试条件的影响大小排序如下 :普通钢管 >渗氮钢管 >玻璃管 ;70℃ >室温 ;有氧环境 >充氮氛围 ;滚动条件 >静态条件。另外 ,在室温、有氧、、静态条件下 ,聚合物溶液粘度随Fe2 + 加入量增大和时间延长 (1h和 3h)而下降 ,Fe2 + 浓度为 10mg/L时 3h后粘度下降 5 0 %。得出结论 :在注聚管道中聚合物主要发生机械剪切降解和化学降解 ;前者受管壁材料和粗糙度影响 ;壁面钢材受溶解氧腐蚀而产生Fe2 + ,Fe2 + 被氧化成Fe3 + 并引起溶液中聚合物化学降解 ;温度升高时化学降解加剧。表 2参 2。

煅烧铝柱撑蒙脱石材料结合态Fe(Ⅱ)对邻硝基苯酚的还原转化研究

通过铝盐与蒙脱石（Na-Mt）反应制备了铝柱撑蒙脱石（Al-Mt）,同时采用X射线衍射（XRD）、红外光谱（FTIR）对在不同温度（200~600℃）下煅烧获得的铝柱撑蒙脱石产物（At-Mt-X）进行表征。探讨Fe（Ⅱ）与Al-Mt-X所形成的复合系统对邻硝基苯酚（2-NP）的吸附-还原降解行为,包括铝柱撑蒙脱石的煅烧温度、煅烧铝柱撑蒙脱石的表面酸位变化以及溶液pH值等条件对邻硝基苯酚还原转化的影响。结果表明,由于随着煅烧温度的升高,煅烧铝柱撑蒙脱石表面酸性位点会逐渐减少,使得其对Fe（Ⅱ）的还原性能增强;煅烧温度高于500℃时,煅烧改性产物与Fe（Ⅱ）形成的Fe（Ⅱ）/煅烧铝柱撑蒙脱石复合系统显著提高了Fe（Ⅱ）物种的还原活性,因而有效增强对2-NP的还原降解。此外,Fe（Ⅱ）/煅烧铝柱撑蒙脱石复合系统对2-NP的还原降解符合准一级反应动力学方程,表观速率常数（k）随pH值和铝柱撑蒙脱石煅烧温度的升高而增大。作为一种功能性矿物材料,煅烧铝柱撑蒙脱石在缺氧环境下能有效促进吸附态Fe（Ⅱ）物种对污染物的还原降解,煅烧温度与pH值是其中两个重要的制约因素。

高压微射流处理对原花青素平均聚合度和抗氧化性能的影响

为提高原花青素的生物利用度,本研究采用高压微射流技术处理原花青素溶液,探究其对原花青素平均聚合度及其抗氧化能力的影响。将原花青素在不同处理压力(100、140、180、220 MPa和260 MPa)下分别进行1、2、3、4次循环处理,结果表明:随着处理压力的升高,原花青素的平均聚合度基本不存在显著差异,220 MPa下平均聚合度相对较低;处理次数为4条件下的平均聚合度相对较小。固定处理次数为4,选择不同处理压力的样品进行抗氧化能力分析,抗氧化能力(包括铁还原力和清除1,1-二苯基-2-三硝基苯肼自由基能力)由大到小为:220 MPa>180 MPa>140 MPa>100 MPa>260 MPa>对照组>VC;半抑制浓度的变化趋势与抗氧化能力大小顺序相反,说明处理压力为220 MPa下的原花青素抗氧化能力最强。

利用Fe^0和Fe^(2+)在皂素废水中生成绿锈去除硫酸根

皂素废水中高浓度的SO_4^(2-)对环境危害大,厌氧环境下同时投加Fe^0和Fe^(2+)生成硫酸盐绿锈增强SO_4^(2-)的去除,实验研究了各因素对去除SO_4^(2-)的影响。结果表明,降低初始p H能快速提升SO_4^(2-)的去除率,25~35℃范围内提高温度有利于SO_4^(2-)的去除,Fe^(2+)浓度对去除效果影响显著,随着Fe^(2+)浓度的增加,SO_4^(2-)去除率快速上升。初始pH为2、温度为25℃的条件下,10 g·L^(-1)的Fe^0和1 000 mg·L^(-1)的Fe^(2+)能去除93.1%初始浓度为1 000 mg·L^(-1)的SO_4^(2-)。XRD和SEM表征结果显示,去除过程中铁粉表面有疏松多孔结构的Fe_3O_4生成,有利于SO_4^(2-)与Fe^0接触反应,促进硫酸盐绿锈的生成,进一步增强SO_4^(2-)的去除。动力学分析显示,去除过程拟合伪二级动力学模型,吸附SO_4^(2-)的过程以单分子层吸附为主。

Fruiting increases total content of flavonoids and antiproliferative effects of Cereus jamacaru D.C. cladodes in sarcoma 180 cells in vitro

Objective: To evaluate the influence of fruiting phenological stage on total flavonoid content, antioxidant activity, and antiproliferative effects of Cereus jamacaru(C. jamacaru)(mandacaru) cladodes and fruit. Methods: Fruit and cladodes at vegetative and fruiting stage of C. jamacaru were collected. The fruit was dissected and bark, pulp, and seeds were separated. Vegetative and fruiting cladodes, together with bark, pulp, and seeds were used to obtain five hydroalcoholic extracts. The extracts were investigated for total flavonoid content, using AlCl3 colorimetric method, antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging capacity and Fe^(2+) ion chelating activity, and in vitro antiproliferative effects(sarcoma 180 cells) by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2 H-tetrazolium bromide assay. Results: The extract of C. jamacaru cladodes at the fruiting stage showed higher flavonoid content compared to the other extracts. Seed extracts showed the highest antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) assays, and the extract of cladodes at vegetative stage showed better antioxidant activity in Fe^(2+) ion chelating activity. The extract of fruiting cladodes promoted higher antiproliferative effects compared to the other extracts. Conclusions: These findings suggest that fruiting increases the content of flavonoids and antiproliferative effects of C. jamacaru cladodes. Data reinforce the potential use of C. jamacaru cladodes and fruits as natural antioxidants and potent anticancer agent.

金纳米棒比色检测亚铁离子

实现亚铁离子的简单高效检测,在生化传感领域具有至关重要的作用。本文中,基于芬顿试剂(亚铁离子和过氧化氢的混合物)对金纳米棒的选择性氧化,实现了对亚铁离子的比色检测。伴随芬顿试剂的引入,金纳米棒溶胶颜色由红色逐渐演变为棕色、绿色、蓝色、紫色,乃至粉红色。基于此规律,实现了对亚铁离子的可视化检测。本文提出了一种相对Hg^(2+), Mg^(2+), Cu^(2+), Fe^(3+), Sn^(2+), Co^(2+), Cd^(2+), Cr^(3+), Zn^(2+), Ba^(2+), Ni^+等离子具有良好选择性的亚铁离子检测方法。

电冶金过程中熔融FeO中离子电化学输运模拟研究

介绍了在离子输运和电化学反应理论基础上,建立了二元对称电解质FeO电化学输运的数值模型,模型包括两个平行平板电极和熔融FeO电解质。采用有限体积法对无量纲Poisson-Nernst-Planck方程和非线性Butler-Volmer方程进行求解,模拟离子的电迁移和扩散行为。同时分析了稳态电解质内的离子浓度、电荷密度和电势的变化。研究表明:受外加电压的影响,O2-向阳极迁移。Fe^(2+)因参与法拉第反应,在阴极积累。当外加电压分别为0.1 V、0.2 V、0.3 V时,X=0.05 mm处的电势分别为-0.029 V、-0.016 V、-0.006 V。随着外加电压的增大,电极附近的电势梯度逐渐增大,阴极和阳极电荷密度差值也逐渐增大。

铁离子检测用自组装膜的光谱特性分析

以聚二烯丙基二甲基氯化铵(PDDA)和聚4-苯乙烯基磺酸钠(PSS)为前驱体,以1-亚硝基-2-萘酚-3,6-二磺酸二钠一水合物为铁离子指示剂,根据静电自组装原理,设计制备了对铁离子具有光学敏感性的自组装膜。采用紫外可见分光光度计考察了敏感膜的自组装制备过程,分析了不同指示剂含量的敏感膜与铁离子作用前后的光谱变化规律,并通过扫描探针显微镜对其微观形貌进行了观察,通过敏感膜与铁离子作用前后的特征峰分析,初步确定了敏感膜吸光度变化量与铁离子浓度间的对应关系。