Reaction Of Potassium Permanganate Research Articles

Synergetic Adsorption of Dyes in Water by Three-Dimensional Graphene and Manganese Dioxide (PU@RGO@MnO2) Structures for Efficient Wastewater Purification

The improper discharge of industrial wastewater causes severe environmental pollution and the textile industry’s dye usage contributes significantly to industrial wastewater pollution. Hence, an effective method for removing the harmful substance methylene blue (MB) from dye wastewater is proposed. This method adopts a three-dimensional graphene composite material based on manganese dioxide (MnO2), named polyurethane@ reduced graphene oxide@ MnO2 (PU@RGO@MnO2). First, graphene is prepared with hydrazine hydrate as a reducing agent and polyurethane as a framework. MnO2 nanoparticles are synthesized by the reaction of potassium permanganate (KMnO4) with carbon. These nanoparticles are then loaded onto the three-dimensional framework to create the composite material. Finally, adsorption and removal experiments for MB are conducted to compare the performance of the composite material. The results indicate that the graphene based on the polyurethane framework exhibits favorable mechanical properties. The unique three-dimensional lattice structure provides abundant active sites for loading MnO2 nanoparticles, significantly increasing the contact area between the adsorbent and MB solution and thus improving the adsorbent utilization rate (reaching 94%). The nanoparticles synthesized through the reaction of KMnO4 with carbon effectively suppress the agglomeration phenomenon. Additionally, the introduction of dynamic adsorption and dynamic removal modes, aided by a water pump, substantially enhances the adsorption and removal rates, showcasing excellent performance. The research on a multi-porous three-dimensional structure holds significant practical value in water treatment, offering a new research direction for dye wastewater treatment.

Synthesis and evaluation of manganese dioxide with layered structure as an adsorbent for selective removal of strontium ions from aqueous solution

The selective removal of 90Sr from natural waters and technological effluents is an important issue to ensure radiation safety. Manganese dioxide with layered structure was prepared through the reaction of potassium permanganate with manganese chloride in alkaline medium at room temperature. The results of X-ray diffraction method and Fourier transform infrared spectroscopy confirmed the formation of c-disordered hexagonal birnessite. Scanning electron microscopy revealed that the synthesized birnessite is formed as agglomerated microspheres. Scanning electron microscopy and adsorption–desorption method revealed that birnessite is formed as agglomerated microspheres with mesoporous texture and external surface area of 207 m2/g. To determine the efficiency of the synthesized birnessite in selective removal of strontium ions from multicomponent solutions, the effect of contact time, competitive ions (Na, K, Ca) and pH on strontium ions adsorption was investigated in detail. Strontium ions adsorption has demonstrated a fast initial adsorption followed by a much slower sorption process. It was found that the synthesized birnessite can effectively remove strontium ions from monocomponent solution. The presence of alkaline metals ions in the model solutions (up to ~ 0.3 mol/l) had little effect on strontium ions adsorption; however, calcium ions caused considerable decrease in the adsorption parameters. However, taking into account a relatively high adsorption parameters obtained in the model solutions characterized by a high concentration of calcium ions and a significant excess of calcium over strontium ions, the synthesized birnessite can be considered as an adsorbent with a rather high selectivity toward strontium ions. It can be effectively applied for the removal of strontium ions from multicomponent solutions with a high salt content. The alkaline medium is preferable for selective removal of strontium ions. The synthesized birnessite has lots of additional advantages, such as its simple fabrication process, low-cost raw materials and the ease of desorption.

Analisis Kandungan Mikroba, Formalin, dan Timbal (Pb) pada Tahu Sumedang yang Dijual Di Daerah Macet Cicurug, Ciawi, dan Cisarua Jawa Barat

Sumedang tofu is one of favorite foods for Indonesian society. But many sellers or producers are not aware to the food safety of sumedang tofu. The aims of this study were to analyze the microbial, formalin, and lead (Pb) contents in ready-to-eat sumedang tofu which were sold in traffic jams area in Cicurug, Ciawi, and Cisarua. The analysis were carried out by Total Plate Count (TPC) testing for microbial analysis, potassium permanganate reaction (KMnO4) testing for formaldehyde analysis, and atomic absorption spectrophotometry (AAS) method for lead content analysis in the samples. The results obtained for the microbial analysis were sumedang tofu that were sold in the traffic jam areas of Cicurug, Ciawi, and Cisarua contained contaminant above the treshold (1.4 x 105 colonies / gram to 2.2 x 105 colonies / gram of microbes). All of the samples of sumedang tofu were positive containing formaldehyde. Otherwise, there were no lead (Pb) content in all samples regarding to AAS analysis. This study concluded that the ready-to-eat sumedang tofu those were sold in traffic jam area in the Cicurug, Ciawi, and Cisarua were not suitable for consumption because it contained exceed microbial contamination and formalin which are harmful for human health.Keywords : formalin, microbes, sumedang tofu, lead, traffic jam

Covalent bonding of MnO2 onto graphene aerogel forwards: Efficiently catalytic degradation of organic wastewater

Graphene/α-MnO2 nanocrystals hybrid aerogel (GMA) was designed for catalytic ozonation of rhodamine B (RhB) solution in this study. A novel method was proposed to synthesize this hybrid aerogel in an isopropanol-water system, in contrast to the conventional reaction of potassium permanganate with graphene aerogel, which destroyed the desired structure of graphene. Characterization of the synthesized GMA was carried out by XRD, SEM, TEM, Raman, and BET. It was found that GMA had a porous structure and the needle-like α-MnO2 nanocrystals were doped in the graphene aerogel uniformly. Based on the FTIR and XPS analysis, the α-MnO2 was found to covalently bond with graphene aerogel. The removal efficiency of both RhB and COD was found to be in the following order of Blank< GA < SMA (silica wool with nano MnO2 deposited on it) < GMA(I) < GMA(II) < GMA(III). The degradation rate constant (k) of RhB ozonation catalyzed by GMA was determined to be 1.2–2.3 times higher as compared with that by UV/Ozone. The enhanced catalytic activity of GMA could be attributed to the high dispersibility of the α-MnO2 nanocrystals on graphene and the abundant mesopores (r < 40 nm) in GMA. The higher electron cloud density of the Mn atoms, when supported by graphene aerogel, promoted the generation of HO radicals, thereby resulting in better decomposition performance of GMA than UV/Ozone systems.

Lansoprazole Determination in Pharmaceutical Formulations by Flow Injection Coupled with Acidic KMnO4-Quinine Chemiluminescence System.

A simple and rapid flow injection chemiluminescence (FI-CL) method based on the reaction of potassium permanganate (KMnO4) and quinine was established for the determination of lansoprazole in pharmaceutical formulations. A linear calibration curve was achieved over the range from 0.01 to 20.0 mg L-1 LNP (R2 = 0.9997 (n = 8); RSD = 1.1 - 3.7% (n = 4)) with a limit of detection of 3.0 × 10-3 mg L-1 (S/N = 3) and injection throughput of 150 h-1. By applying the Student t-test (calculated t-test value: t = 1.059907664, and tabulated t-distributed (95%) = 2.200985) it was found that the proposed method and reported spectrophotometric method were not significantly different. The LNP was efficiently extracted and the recovery of LNP from the spiked pharmaceutical formulations was in the range of 91.0 - 105.9% (%RSD = 1.6 - 3.6, n = 4). No significant interference activity was detected from the excipients commonly found in the drug samples analyzed. The possible chemiluminescence emission mechanism is discussed briefly.

A NEW MODIFIED EXFOLIATED GRAPHENE OXIDE FOR REMOVAL OF COPPER(II), LEAD(II) AND NICKEL(II) IONS FROM AQUEOUS SOLUTIONS

An effective and facial method for removal of lead(II), copper(II) and Nickel(II) ions from aqueous solutions, is based on investigating a new modified graphene oxide, by appealing interaction between graphene oxide GO and 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one (4-aminoantipyrine). The adsorbent is fully characterized by FT-IR, XRD, SEM, EDX, TEM, and Raman spectroscopy. The GO was prepared using a modified Hummers method by the reaction of potassium permanganate with graphite in presence of a mixture of sulfuric and phosphoric acids. This novel solid phase adsorbent 4-aminoantipyrine-GO was utilized to adsorb Pb(II), Cu(II) and Ni(II) ions from aqueous solutions because of amide functional group, is resulting an efficient adsorption. Also the abundant oxygen-containing functional groups on the surfaces of graphene oxide GO play an important role in metal ions sorption. The adsorption isotherms data were well fitted with Langmuir isotherm for Pb(II), Cu(II) and Freundlich isotherm for Ni(II) ions respectively. The kinetics of Pb(II), Cu(II) and Ni(II) ions adsorption were well fitted with pseudo second-order equation. The results of thermodynamic parameters referred to chemical adsorption. Also the positive values of standard heat of adsorption (ΔHo) and negative values of (ΔGo) indicated that the adsorption process was endothermic and spontaneous.

Development of a Student Experiment Concerning the Reaction of Potassium Permanganate and Copper Plates

Development of a Student Experiment Concerning the Reaction of Potassium Permanganate and Copper Plates

Preparation of graphene oxides with different sheet sizes by temperature control**Project supported by the National Natural Science Foundation of China (Grant Nos. 41473090, 41430644, 11675098, 41373098, 41430644, and 21490585).

The sheet size of a graphene oxide (GO) can greatly influence its electrical, optical, mechanical, electrochemical and catalytic property. It is a key challenge to how to control the sheet size during its preparation in different application fields. According to our previous theoretical calculations of the effect of temperature on the oxidation process of graphene, we use Hummers method to prepare GOs with different sheet sizes by simply controlling the temperature condition in the process of the oxidation reaction of potassium permanganate (KMnO4) with graphene and the dilution process with deionized water. The results detected by transmission electron microscopy (TEM) and atomic force microscopy (AFM) show that the average sizes of GO sheets prepared at different temperatures are about 1 μm and 7 μm respectively. The ultraviolet–visible spectroscopy (UV-vis) shows that lower temperature can lead to smaller oxidation degrees of GO and less oxygen functional groups on the surface. In addition, we prepare GO membranes to test their mechanical strengths by ultrasonic waves, and we find that the strengths of the GO membranes prepared under low temperatures are considerably higher than those prepared under high temperatures, showing the high mechanical strengths of larger GO sheets. Our experimental results testify our previous theoretical calculations. Compared with the traditional centrifugal separation and chemical cutting method, the preparation process of GO by temperature control is simple and low-cost and also enables large-size synthesis. These findings develop a new method to control GO sheet sizes for large-scale potential applications.

Synthesis of manganese dioxide by homogeneous hydrolysis in the presence of melamine

A new selective method for the synthesis of nanocrystalline manganese dioxide (α-, β-, and γ-MnO2) based on the reaction of potassium permanganate with 2,4,6-triamino-1,3,5-triazine (melamine) under hydrothermal conditions has been proposed. Effect of synthesis conditions on the phase composition of the products has been revealed. A new manganese-containing phase with layered structure has been prepared.

Electro-synthesis, characterization and photoconducting performance of ITO/polybithiophene–MnO2 composite

Manganese dioxide is synthesized by reduction reaction of potassium permanganate with hydrogen peroxide. The as-synthesized α-MnO2 is characterized by powder X-ray diffraction and infrared spectroscopy. The MnO2 particles are used to prepare composite films containing polybithophene (PBTh) on indium tin oxide (ITO) glass substrates. The composite films ITO/PBTh–MnO2 are obtained by electro-polymerization of bithiophene in the presence the α-MnO2 particles dispersed in the electrolytic solution. The XRD and SEM analyses show that the α-MnO2 particles of size in the range 100–300nm are incorporated in the polymer. The films are characterized by cyclic voltammetry impedance spectroscopy, UV–vis spectroscopy and scanning electron microscopy. As a result, the electrochemical gap and the optical gap are shifted by the incorporation of MnO2 from 2.15eV for ITO/PBTh to 1.88eV for ITO/PBTh–MnO2, while the electrical conductivity decreases from 195.35S/cm for ITO/PBTh down to 0.047S/cm for ITO/PBTh–MnO2 at the highest MnO2 investigated. The photo-electrochemical measurements also indicate that the ITO/PBTh–MnO2 films show a photocurrent that is three times higher than that of ITO/PBTh substrate to reach 20.6μAcm−2, so that such a composite can be used as a new active material in solar cells.

A sensitive kinetic spectrophotometric determination of traces of tungsten in solution based on its inhibitory effect on the decolorization reaction of potassium permanganate

The present work describes a rapid and sensitive method for the determination of ultra micro amounts of tungsten (VI) based on its inhibitory effect on the oxidation of 4-hidroxycoumarine by potassium permanganate in the presence of hydrochloric acid. The sensitivity of the method is 20 ng/cm3. The probable relative error is -4.8-13 % for the W(VI) concentration range 250 to 20 ng/cm3, respectively. Kinetic equations for the investigated process which determine the order of the reactions regarding to each reaction parameter under certain experimental conditions were proposed, and they allowed quantification of the unknown concentrations W(VI) in solution. The detection and quantification limit of the method are 4.5 and 15.1 ng/cm3. The effects of certain foreign ions upon the reaction rate were determined for the assessing the selectivity of the method.

Room-Temperature Oxidation of Formaldehyde by Layered Manganese Oxide: Effect of Water

Layered manganese oxide, i.e., birnessite was prepared via the reaction of potassium permanganate with ammonium oxalate. The water content in the birnessite was adjusted by drying/calcining the samples at various temperatures (30 °C, 100 °C, 200 °C, 300 °C, and 500 °C). Thermogravimetry-mass spectroscopy showed three types of water released from birnessite, which can be ascribed to physically adsorbed H2O, interlayer H2O and hydroxyl, respectively. The activity of birnessite for formaldehyde oxidation was positively associated with its water content, i.e., the higher the water content, the better activity it has. In-situ DRIFTS and step scanning XRD analysis indicate that adsorbed formaldehyde, which is promoted by bonded water via hydrogen bonding, is transformed into formate and carbonate with the consumption of hydroxyl and bonded water. Both bonded water and water in air can compensate the consumed hydroxyl groups to sustain the mineralization of formaldehyde at room temperature. In addition, water in air stimulates the desorption of carbonate via water competitive adsorption, and accordingly the birnessite recovers its activity. This investigation elucidated the role of water in oxidizing formaldehyde by layered manganese oxides at room temperature, which may be helpful for the development of more efficient materials.

Kinetics and mechanism study on adsorption of cadmium by freshly synthesized hydrous manganese dioxide

Hydrous manganese dioxide (HMO) was synthesized by redox reaction of potassium permanganate (KMnO4) and hydrogen peroxide (H2O2), and then freshly synthesized HMO (FSHMO) was used for cadmium (Cd(I...

Hierarchical porous carbon/MnO2 hybrids as supercapacitor electrodes.

Hybrid electrodes of hierarchical porous carbon (HPC) and manganese oxide (MnO2) were synthesized using a fast surface redox reaction of potassium permanganate under facile immersion methods. The HPC/MnO2 hybrids had a number of micropores and macropores and the MnO2 nanoparticles acted as a pseudocapacitive material. The synergistic effects of electric double-layer capacitor (EDLC)-induced capacitance and pseudocapacitance brought about a better electrochemical performance of the HPC/MnO2 hybrid electrodes compared to that obtained with a single component. The hybrids showed a specific capacitance of 228 F g(-1) and good cycle stability over 1000 cycles.

Template-free synthesis of mesoporous MnO2 under ultrasound irradiation for supercapacitor electrode

Mesoporous MnO2 with high specific surface area (192m2g−1) and narrow pore distribution (10nm) was synthesized by a simple method through the reaction of potassium permanganate and ethanol under ultrasound irradiation. The obtained material was characterized with XRD, XPS, nitrogen sorption, TEM and FE-SEM. The electrochemical properties of synthesized material were determined with cyclic voltammetry (CV) and galvanostatic charge–discharge cycle tests. The specific capacitances of 229Fg−1 and the specific capacitance retention of 97.3% after 2000 cycles were obtained. The excellent electrochemical property of this mesoporous MnO2 can be ascribed to its mesoporous structure and high specific surface area caused by the cavitation effect of the ultrasound during synthesis.

Capacitance behavior of nanostructured ϵ-MnO2/C composite electrode using different carbons matrix

In this work nanostructured ϵ-MnO2/C composite electrode was synthesized via the reduction reaction of potassium permanganate. A wide range of carbons such as mesoporous carbon (MC), graphite (GC), super P carbon (super P) and Vulcan carbon (VC) were used in order to enhance the interfacial electrical conductivity and the electrochemical capacitance of the composite electrodes. Physical properties, structure and specific surface area of electrode materials were investigated by scanning electron microscopy (SEM), x-ray diffraction and nitrogen adsorption measurements. The capacitance behavior of MnO2/C materials was studied in aqueous and non-aqueous solution using cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy measurements. The composite electrode exhibits the highest capacitance at 30 wt% activated carbon. Among different carbons used, the maximum capacitance of MnO2/super P electrode is as high as 205 F g−1 at 50 mV s−1 and retains 98% after 300 cycles.

SYNTHESIS AND CHARACTERIZATION OF GRAPHENE OXIDE IN SUSPENSION AND POWDER FORMS BY CHEMICAL EXFOLIATION METHOD

In this study, an efficient and facile technique for preparing graphene oxide in suspension and powder forms was presented based on a modification on Hummers' method followed by an additional ultrasonic process. The method involved the provision of graphene oxide from graphite by reaction of potassium permanganate and sulfuric acid with stabilizing the medium complex. Furthermore, this study evaluated the functionality of graphene oxide in powder form in comparison with suspension using Fourier transform infrared spectroscopy. In addition, prepared graphene oxide powder was characterized using X-ray diffraction method for investigating the exfoliation of graphite to graphene nanosheets. Moreover, transmission electron microscopy and atomic force microscopy techniques were employed to demonstrate the structure of resulting graphene oxide in suspension form. The presence of graphene oxide nanosheets including an average thickness of about 2-4 nm was proved via microscopy observation of the prepared nanosheets.

Degradation of progestagens by oxidation with potassium permanganate in wastewater effluents

BackgroundThis study investigated the oxidation of selected progestagenic steroid hormones by potassium permanganate at pH 6.0 and 8.0 in ultrapure water and wastewater effluents, using bench-scale assays. Second order rate constants for the reaction of potassium permanganate with progestagens (levonorgestrel, medroxyprogesterone, norethindrone and progesterone) was determined as a function of pH, presence of natural organic matter and temperature. This work also illustrates the advantages of using a novel analytical method, the laser diode thermal desorption (LDTD-APCI) interface coupled to tandem mass spectrometry apparatus, allowing for the quick determination of oxidation rate constants and increasing sample throughput.ResultsThe second-order rate constants for progestagens with permanganate determined in bench-scale experiments ranged from 23 to 368 M-1 sec-1 in both wastewater and ultrapure waters with pH values of 6.0 and 8.0. Two pairs of progestagens exhibited similar reaction rate constants, i.e. progesterone and medroxyprogesterone (23 to 80 M-1 sec-1 in ultrapure water and 26 to 149 M-1 sec-1 in wastewaters, at pH 6.0 and 8.0) and levonorgestrel and norethindrone (179 to 224 M-1 sec-1 in ultrapure water and 180 to 368 M-1 sec-1 in wastewaters, at pH 6.0 and 8.0). The presence of dissolved natural organic matter and the pH conditions improved the oxidation rate constants for progestagens with potassium permanganate only at alkaline pH. Reaction rates measured in Milli-Q water could therefore be used to provide conservative estimates for the oxidation rates of the four selected progestagens in wastewaters when exposed to potassium permanganate. The progestagen removal efficiencies was lower for progesterone and medroxyprogesterone (48 to 87 %) than for levonorgestrel and norethindrone (78 to 97%) in Milli-Q and wastewaters at pH 6.0-8.2 using potassium permanganate dosages of 1 to 5 mg L-1 after contact times of 10 to 60 min.ConclusionThis work presents the first results on the permanganate-promoted oxidation of progestagens, as a function of pH, temperature as well as NOM. Progestagen concentrations used to determine rate constants were analyzed using an ultrafast laser diode thermal desorption interface coupled to tandem mass spectrometry for the analysis of water sample for progestagens.

Flow injection–chemiluminescence determination of dopamine using potassium permanganate and formaldehyde system

A simple and sensitive flow injection–chemiluminescence method for the determination of dopamine has been proposed. The method is based on the enhancing effect of dopamine on the chemiluminescence emission generated by the reaction of potassium permanganate with formaldehyde in an acidic medium. The proposed procedure allows the determination of dopamine over the concentration range of 3.1×10−8–1.7×10−5mol/L and with a detection limit of 1.0×10−8mol/L. The linear regression equation was F=44.4912+1.07×109∗C (correlation coefficient, r2=0.9998). The relative standard deviation is 2.1% for the determination of 1.0×10−8mol/L dopamine (n=11). The method was successfully applied to the determination of dopamine in pharmaceutical preparation with satisfactory results. The recoveries were found in the range of 96.5–101.3%.

Mesoporous manganese oxide for warfare agents degradation

Manganese(IV) oxides were prepared by homogeneous hydrolysis of potassium permanganate with 2-chloroacetamide and direct reaction of potassium permanganate with manganese(II) sulfate in aqueous solutions. Synthesized manganese(IV) oxides were characterized using Brunauer–Emmett–Teller (BET) surface area and Barrett–Joiner–Halenda porosity (BJH), X-ray diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscopy (SEM). These oxides were taken for an experimental evaluation of their reactivity with sulfur mustard (HD or bis(2-Chloroethyl)sulfide), soman (GD or (3,3′-dimethylbutan-2-yl)-) and VX agent (S-[-(diisopropylamino)ethyl]-O-ethyl-methylphosphonothionate). The degree of conversion for sulfur mustard and agent VX is very good for both samples and come up to 95% and 99%, respectively. In the contrast to sulfur mustard and agent VX, degradation of soman was only 56% of the cryptomelane-type MnO2 and 18% of the birnessite-type MnO2.