An internal circulation iron-carbon micro-electrolysis reactor for aniline wastewater treatment:Parameter optimization,degradation pathways and mechanism

Aniline is a vital industrial raw material.However,highly-toxic aniline wastewater usually deteriorated effluent quality,posed a threat to human health and ecosystem safety.Therefore,this study reported a novel internal circulation iron-carbon micro-electrolysis(ICE)reactor to treat aniline wastewater.The effects of reaction time,pH,aeration rate and iron-carbon(Fe/C)ratio on the removal rate of aniline and the chemical oxygen demand were investigated using single-factor experiments.This process exhibited high aniline degradation performance of approximately 99.86% under optimal operating conditions(reaction time=20 min,pH=3,aeration rate=0.5 m3·h^(-1),and Fe/C=1:2).Based on the experimental results,the response surface method was applied to optimize the aniline removal rate.The Box–Behnken method was used to obtain the interaction effects of three main factors.The result showed that the reaction time had a dominant effect on the removal rate of aniline.The highest aniline removal rate was obtained at pH of 2,aeration rate of 0.5 m^(3)·h^(-1)and reaction time of 30 min.Under optional experimental conditions,the aniline content of effluent was reduced to 3 mg·L^(-1)and the removal rate was as high as 98.24%,within the 95% confidence interval(97.84%-99.32%)of the predicted values.The solution was treated and the reaction intermediates were identified by high-performance liquid chromatography,ultraviolet-visible spectroscopy,Fourier-transform infrared spectroscopy,gas chromatography-mass spectrometry,and ion chromatography.The main intermediates were phenol,benzoquinone,and carboxylic acid.These were used to propose the potential mechanism of aniline degradation in the ICE reactor.The results obtained in this study provide optimized conditions for the treatment of industrial wastewater containing aniline and can strengthen the understanding of the degradation mechanism of iron-carbon micro-electrolysis.

Can the Prediction of Intrauterine Insemination Results by Used Aniline Blue Stain (ABS) and Sperm Chromatin Dispersion (SCD) Levels?

Introduction: This study aimed to perform routine seminal fluid analysis, sperm DNA fragmentation, and sperm function tests at the chromatin maturation level and evaluate pregnancy in the patients passing intrauterine insemination before starting Intrauterine Insemination (IUI) method. Materials and Methods: In this prospective study, 111 couples who underwent Intrauterine Insemination (IUI) in unexplained infertility patients were admitted to Al-Farah IVF and assisted reproductive center in Baghdad, Iraq between November 2020 and February 2021 were evaluated. Semen fluid analysis was performed based on (WHO 4th) guiding rules. In addition, Sperm Chromatin Dispersion (halo test) and sperm maturation were performed with Aniline Blue Stain (ABS). Results: Sperm Chromatin Dispersion (SCD) groups were compared in terms of pregnancy outcome;the positive pregnancy rate was found to be above in the normal SCD groups (p = 0.0005). In addition, Aniline Blue Stain (ABS) groups were compared in the terms of pregnancy outcome;the positive pregnancy rate was found to be higher in the normal ABS group (p = 0.017). Conclusion: Our study showed that the use of DNA fragmentation (SCD) and sperm maturation tests (ABS) together with routine semen analysis in intrauterine insemination cases will make a significant contribution to the prediction of Intrauterine Insemination (IUI) increased results. So, these results indicate a defect in the effect of DNA fragmentation on the outcome of intrauterine insemination.

Electrochemical Synthesis of Three-Dimensional Polyaniline Network on 3-Aminobenzenesulfonic Acid Functionalized Glassy Carbon Electrode and Its Application

The electrochemical synthesis of three-dimensional (3D) polyaniline (PAN) network structure on 3-aminobenzenesulfonic acid (ABSA) functionalized glassy carbon electrode (GCE) and its electro-catalytic oxidation towards ascorbic acid (AA) had been studied. ABSA was first covalently grafted on GCE surface via the direct electrochemical oxidation of ABSA on GCE, which was followed by the electrochemical polymerization of aniline on the ABSA functionalized GCE. Then PAN-ABSA composite film modified GCE (PAN-ABSA/GCE) was obtained. Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and electrochemical techniques had been employed to characterize the obtained electrodes. Due to the effective doping of ABSA in PAN, the redox electro-activity of PAN had been extended to neutral and even the basic media, thus, the PAN-ABSA composite film modified GCE could be used for electro-catalytic oxidation of AA in 0.1 M phosphate buffer solution (PBS, pH 6.8). At PAN-ABSA/GCE the oxidation over-potential of AA shifted from 0.39 V at GCE to 0.17 V with a greatly enhanced current response. The electro-catalytic oxidation peak current of AA increased linearly with the increasing AA concentration over the range of 5.00 × 10-4-1.65 × 10-2 M with a correlation coefficient of 0.9973. The detection limit (S/N = 3) for AA was 1.16 × 10-6 M. Chronoamperometry had also been employed to investigate the electro-catalytic oxidation of AA at PAN-ABSA/GCE. The modified electrode had been used for detecting AA in real samples with satisfactory results.

Determination of aniline in environmental water samples by alternating-current oscillopolarographic titration

A new method for the determination of aniline in environmental water based on oscillopolarographic titration was presented in this paper. Several factors including the kind, concentration, and volume of acid, the dosage of potassium bromide, the temperature and concentration of concomitant substances were investigated in detail. The experimental results indicated that this method was simple, rapid, and sensitive. The linear range was 8.367×10-4 to 2.789×10-2 mol L-1, the relative standard deviation (R.S.D.) was lower than 0.96%, and the spiked recoveries of aniline in environmental water samples were in the range of 99.4-106.9% under the optimal conditions. The results indicated that the present method could be used as an alternative method for aniline determination in realworld water samples.

Recovery of Aniline from Wastewater by Nitrobenzene Extraction Enhanced with Salting-Out Effect

Objective Nitrobenzene extraction enhanced by salting-out effect was employed to recover aniline from wastewater at 25℃.Method Batchwise experiments were conducted to elucidate the influence of various operating variables on the extracting performance,including acidity of wastewater,initial aniline concentration,ratios of solvent to wastewater,extraction stages,concentrations and different types of inorganic salts,such as NaC1,KC1,Na_2SO_4,CaCl_2 and K_2SO_4.Results Nitrobenzene with a concentration of 20%and a pH value of 9.1 at the temperature of 25℃together with NaCl of a concentration of 14 wt.%realized nearly 100%aniline recovery at the fifth stage of wastewater treatment.Conclusions High pH values and volume ratios of nitrobenzene/wastewater are more suitable for recovery of aniline.In addition,recovery of aniline is significantly elevated with increase of the concentration of salts,whose promoting effects are in the following order: NaCl>Na_2SO_4>K_2SO_4>CaCl_2>KCl on the weight basis of wastewater.Furthermore,aniline in wastewater can be almost completely recovered by five-stage sequential nitrobenzene extraction,which is promoted continuously by the salting-out effect.

STUDIES ON THE INITIATION MECHANISM OF ORGANIC PEROXIDE AND N-METHACRYLOYLOXYETHYL-N-METHYL ANILINE IN METHYL METHACRYLATE POLYMERIZATION

The initiation mechanism of methyl methacrylate (MMA) polymerization by organic peroxide and polymerizable aromatic tertiary amine such as N-methacryloyloxyethyl-N-methyl aniline (MEMA) binary system has been studied. The kinetics of polymerization of MMA and the ESR spectra of organic peroxide/MEMA system were determined. Based on the ESR study and the end-group analysis by UV spectra of the polymer formed, the initiation mechanism is proposed.

Rapid Quantification of Bioactive Lentinan with an Aniline Blue Fluorescent Method

Lentinan is a clinically approved immune modulator and its anticancer and immunomodulatory bioactivity is found to be dependent on its triple helical conformation. Therefore, the development of rapid and convenient method for determination of bioactive lentinan with triple helical conformation holds great promise for the quality control of lentinan healthy products. In this work, an aniline blue fluorescent method was optimized and established to accurately and rapidly detect bioactive lentinan. In the presence of lentinan, the fluorescence intensity of aniline blue with 404 nm excitation and 492 nm emission dramatically enhanced within 15 min in pH 10 glycine-NaOH buffer solution, which allowed the analysis of lentinan in a very simple and fast manner. The method allowed for the sensitive determination of lentinan in the range of 1 to 60 μg/mL with a detection limit of 0.25 μg/mL. Notably, the protocol exhibited excellent selectivity for the determination of triple helical lentinan over other saccharides. The method was successfully applied to the detection of bioactive lentinan in health tonic solution, which demonstrated the method had great potential for quality control of lentinan contained products.

ELECTROCHEMICAL COPOLYMERIZATION OF ANILINE AND AZURE B

The electrochemical copolymerization of aniline and N,N,N'-trimethylthionin (azure B) in aqueous solutions has been carried out using the potential sweep method. The optimum conditions for the coelectrodeposition are that the pH value and the temperature of the electrolytic solution are controlled at 5.57 and 30℃, respectively, and the scan potential range is set between -0.25 and 1.10 V (versus SCE). The copolymerization rate of aniline and azure B is about 3 times larger than that of aniline in the absence of azure B. The copolymerization of aniline and azure B was verified from the results of visible spectra during electrolysis, FTIR spectra and the atomic force microscopy (AFM) images of the polymers. The in situ visible spectrum for the electrolysis of the solution containing aniline and azure B is different from that of the respective aniline and azure B. The FTIR spectrum of the copolymer is not a superposition of that of polyaniline and poly(azure B). The AFM image of the copolymer is different from those of polyaniline and poly(azure B) and is not a mixture of individual polymers. The conductivity of the copolymer synthesized at pH 5.57 is four orders of magnitude higher than that of polyaniline synthesized under the same conditions, but in the absence of azure B. The electrochemical properties of the copolymer are mainly attributed to polyaniline, but the copolymer has a better electrochemical reversibility and a much faster charge transfer than those of polyaniline.

STUDIES ON THE ELECTRICAL CONDUCTIVITY OF FREE-STANDING FILMS OF POLYANILINE

An insulate to metal transition was investigated based on the measurements of the dependence of the conductivity, activation energy on the protonation state of polyaniline (PANI). An isotropy in conductivity for stretched salt form of PANI was observed.For salt film of PANI, the Ⅰ-Ⅴcurve obeys Ohm’s law, which shows a typical metal behavior, however, for base film or film with low protonation state, it can be explained by Space Charge Limited Current (SCLC). It is also found that the Ⅰ-Ⅴcurve of base film of PANI is independent of the work function of electrodes and the polymerization temperature.

ELECTROCHEMICAL BEHAVIOURS OF CYANOETHENYL ANILINE DERIVATIVES

The redox behaviours of the donor-acceptor model compounds, cyanoethenyl aniline derivatives were investigated by cyclic voltammetry and the mechanism of the electrode reaction was studied in detail.

NONLINEAR OPTICAL PROPERTY OF para-DISUBSTITUTED BENZYLIDENE-ANILINE DERIVATIVES

Forty para-disubstituted benzylidene-aniline derivatives weresynthesized,and their second harmonic generation(SHG)efficiency was measuredby the Kurtz powder technique.The effect of the electronic property and theposition of the substituents on powder SHG efficiency was studied.

OXIDATIVE ETHOXYCARBONYLATION OF ANILINE TO ETHYL PHENYLCARBAMATE CATALYZED BY SILICA- SUPPORTED POLY-γ-AMINOPROPYLSILOXANEMETAL COMPLEXES

Several silica-supported poly-γ-aminopropylsiloxane-monometal and bimetal complexes （Si-NH2-M,M = Cu or Co ; Si-NH2-Cu-M’, M’ =Co, Sn, Mn, Ni or Fe） have been prepared. Their catalytic properties for oxidative ethoxycarbonylation of aniline to ethyl phenylcarbamate have been investigated.The catalytic reaction was carried out under relatively mild conditions. The catalyst Si-NH2-Cu-CO had high activity and selectivity, and the turn-over number （molar of aniline converted/molar of metal in Si-NH2-Cu-CO added） could amount to 450 under the conditions: 150℃, 4 MPa （CO/O2 =3） and 40 hours.The results of XPS and IR indicated that the coordination bonds were formed between nitrogen and metals in Si-NH2-Cu, Si-NH2-Co and Si-NH2-Cu-Co, and the coordination pattern was not single. In the oxidative ethoxycarbonylation of aniline to ethyl phenylcarbamate, the catalytic property of Si-NH2-Cu-CO bimetallic complex was better than Si-NH2-Cu or Si-NH2-Co monometatlic complex. This indicated that there was synergistic action between different metals in the bimetallic complex.

INVESTIGATION OF THE MIDDLE REDOX PEAK OF POLYANILINE ON THE CYCLIC VOLTAMMOGRAM

The middle peak which appeared frequently on the voltammetric curves has been interpreted as the degradation of the polymer, according to the results of anion effect. When α-CD (α-cyclodextrin) was added in the acidic solution of aniline to form aniline-α-CD complex, the middle peak became even higher during electrochemical polymorization. This suggests that the middle peak is mot originated from cross-link or ortho-polymerization in aqueous acidic solution.

ELECTROCHEMICAL AND SPECTROELECTROCHEMICAL CHARACTERIZATION OF p-TRICYANOETHENYL-N,N-DIMETHYL ANILINE

The redox behaviours of a donor-acceptor model compound. p-tricyano-ethenyl-N, N-dimethyl aniline was investigated by electrochemical and spectroelectrochemical methods. The results indicate that charge transfer between the donor(amino) and the acceptor(cyanoethenyl) groups takes place in the process of oxidation of this compound.

STUDY OH PHo_(12)O_(40)^(3-)-POLYANILINE MODIFIED ELECTRODE

Electrochemical Betted not only can obtain the conducting film of polyaniline on a glass carbon electrode, but also can imobilize PMo12O403- in the film to form a organic conducting film electrode modified by heteropolyanion.The paper here reports electrochemical changes in the preparation of PMo12O403--polyaniline modified electrode, the electrochemical reaction mechanism of the modified electrode was obtained from the study on its redox properties.Moreover, the above electrode showed marked electrocatalysis for the reduction reaction of CIO?-.

The Synthesis of Symmetrical Azobenzenes from Anilines by Phase Transfer Catalysis

Using galvinoxyl as catalyst. the phase transfer catalyzed method of oxidation of primary amines to symmetrical azobenzenes with a saturated solution of potassium ferricyanide in 2 mol/L aqueous potassium hydroxide and dichloromethane is described. The reaction has intimate relation with Hammett substituent constants. This report offers an efficient and rapid method to prepare azobenzenes and a possible mechanism is also suggested.

The Characteristic of Electrochemical Oxidation of Aniline on SnO_2/Ti Electrode

The characteristic of electrochemical oxidation of aniline on SnO 2/Ti electrode is studied. The results indicate that SnO 2/Ti electrode doped F plays a wonderful role in the oxidation of aniline comparing with Pt electrode. The kinetics factors that influence the oxidation rate of aniline on the SnO 2/Ti electrode are determined by the dissolving of the film on the electrode. The dissolving of the film consisted of intermediate products on the electrode is the slow step. The effects of aniline concentration, pH in aniline solution and the current density( i )on the rate of aniline oxidation, the complexity of intermediate products and the basic category of the intermediate products consisted of the film are introduced.

Kinetics study of the N-formylation of aniline with DMF catalyzed by temperature-controlled Brùnsted ionic liquids

A series of SO_(3)-functional Br?nsted acidic ionic liquids(SBAILs)were prepared to catalyze the Nformylation of aniline with DMF.The reaction conditions such as ionic liquid type,reaction temperature.catalyst loading and molar ratio of reactants were investigated.To the best of our knowledge,kinetic model for the N-formylation of aniline with DMF using SBAIL was firstly built and simulated.The studies on the reaction order of the reaction were evaluated by initial concentration method,and the kinetic parameters such as reaction rate constant and activation energy were proposed and used to explain the catalytic activities of the SBAILs catalysts.Accordingly,the recycling experiments showed that the SBAIL[Bsmim][HSO_(4)]can be easily recovered and reused with stable activity.Further,the temperature-controlled study emphasized that the ionic liquid was easy to be separated and environmentally friendly.

Flow Injection Determination of Oxalate Based on Its Catalytic Effect on the Oxidation of p-Chloride Aniline by Dichromate

In a sulfuric acid medium, oxalate exhibits a strong catalytic effect on the oxidation of p-chloride aniline (ClBN) by dichromate, and the red oxidation product of ClBN has a maximum absorbancy at 520 nm. Based on this founding, a new FI method for determining oxalate was developed. A calibration curve of oxalate in the range of 0. 40-17.0 tg/mL was obtained. The detection limit was 0. 10 μg/mL. Sampling rate was 103-samples/h. The possible interference by the co-existing substances or ions was examined. This new method was applied to the determination of micro amounts of oxalate in real samples with satisfactory results.

Synthesis,Crystal Structure and Photoluminescence Property of Ag(I)with N,N-dimethyl-4-(pyridine-4-yldiazenyl)aniline

A 2D plane coordination compound [Ag_2(Dpya)_2.(NO_3)_2]n was synthesized and characterized by FT-IR,elemental analysis and TG analysis.The red crystal was obtained via solvent diffusion method at room temperature and is slightly soluble in organic solvents.Its structure was determined by single-crystal X-ray diffraction analysis.It crystallizes in monoclinic,space group P1 with a = 10.7995(13),b = 7.4748(8),c = 18.364(2) ?,β = 98.916(4)o,V = 1464.5(3) ?~3,Z = 2,C_(26)H_(28)Ag_2N_(10)O_6,M_r = 792.32,Dc = 1.302 Mg/m^3,F(000) = 792,μ(Mo Ka) = 1.356 mm^(-1),R = 0.0575 and w R = 0.0826.The compound [Ag_2(Dpya)_2.(NO_3)_2]_n is a two-dimensional structure and there are two kinds of coordination configurations about the Ag atoms in the compound.The Ag(1) center is tetrahedrally coordinated with two O atoms of NO_3^-and two N atoms from the ligand Dpya.Meanwhile,the Ag(2) is five-coordinated by five O atoms from three NO_3^-anions.The Ag centers(Ag(1) and Ag(2)) connect to themselves as well as with each other by the bridging NO_3^-anions.And the coordination compound shows photoluminescence with an emission peak at 530 nm(λex = 450 nm) as the ligand Dpya.