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BFC biofuel cell is a new advanced wastewater treatment technology that is environmentally friendly and economical in energy production. To increase the output current, the choice of configuration of the anodic and cathodic chambers of the bioreactor is important. In this study, we investigated the improvement of power generation in BFC. For this purpose, studies were carried out in the cathode chamber using compounds K3Fe(CN)6, KMnO4, and K2CrO7 as acceptors. In the biofuel cell, when using a mixed culture with KMnO4, YX No. 1 with K3Fe(CN)6 and AN No. 1 with K3Fe(CN)6, voltages of 720 mV, 515 mV, 486 mV were observed, respectively. Among the acceptors-KMnO4, energy was generated with a maximum voltage density of 460.80 mW/m3 and a current density of 116 A/m3. Keywords: Biofuel cell, Microorganism, Electron acceptor, Current density, voltage densit
The Tavantolgoi coal deposit used in our study is one of the largest deposits and belongs to coking coal of the Permian age. Technical properties of each layer of coal in Ukhaa Khudag of the Tavantolgoi deposit were determined and compared. This study was carried out by selecting coal from layer 4C, which has the lowest calorific value of economically important layers. Sieve analysis of the coal samples was carried out to select the ultra-fine or ˂0.25 mm particle size fraction, and three different methods of flotation enrichment were conducted and compared. In this, conventional flotation, flotation after interplay of ultrasonic vibration and flotation after interplay combined with ultrasonic with electrolysis were carried out, respectively. As a result of the experiment, the best result was the coal concentrate with 6078k Cal/kg calorific value and 25.65% ash content of flotation after interplay of ultrasonic vibration combined with electrolysis. Therefore, we have determined the suitable experimental conditions for the further application of ultrasonic vibration in combination with electrolysis. We determined that the ultrasonic vibration time of 20 minutes, the amount of ethanol of 30 ml, and the electrolysis power of 1.5 A are suitable condition because the ash content of the floating concentration is the lowest, 24.1%, and the caloric content was the highest (6264kCal/kg).
Oxidation of copper concentrate changes the phase of copper and iron, and the content of copper decreases. This has a significant negative impact on the economy. Therefore, we aimed to study the interactions between the factors affecting oxidation (temperature and humidity). Artificial oxidation in laboratory conditions was carried out in a «Temperature Humidity Chamber» at temperatures of 10°C, 30°C, 50°C, and humidity was adjusted to 10 %, 30 %, and 60 %,
n this study, the microorganisms used to obtain the bioelement were studied; they were isolated at the central wastewater treatment plant in Ulaanbaatar, i.e. samples of industrial waste water IWW), domestic waste water (DW) and sludge (S). We obtained 79 bacteria from wastewater and 4 bacteria were selected by measuring their oxidation potential with a µStat-I 400 device (bipotentiostat/galvanostat). The bioMérieux VITEK® 2 GN identification card was used to determine the taxonomy and morphological characteristics of the isolated bacteria. It was confirmed that the DW1 strain is 98 % closely related to E. coli, that the IWW1 strain is 99 % closely related to Morganella morganii, and the DW29 strain is 93 % closely related to Serratia liquefaciens, respectively
The commercial application of copper bioleaching, an environmentally-friendly approach for low-grade and secondary mineral resources recycling, has increased worldwide. In this paper is considered the application of iron oxidizing bacteria in biological treatment of resource from mining of copper. The major bacterial species involved in the bioleaching of sulfide ore were isolated from acid mine drainage. The leaching experiments were carried out in shake flasks in mineral salts media inoculated with iron oxidizing bacteria at 10⁰C and 30⁰C. The bioleaching tests yielded Cu recoveries are 19.22 and 56.14 respectively.
Ухаа худаг ордын давхарга бүрийн техникийн үзүүлэлтүүдийг тодорхойлж, харьцуулан судлаад 4С давхаргын нүүрсийг сонгон авч энэхүү судалгааг явуулав. Сонгосон дээжинд шигшүүрийн анализ хийж хэт нарийн буюу <0.25мм ширхэглэлтэй фракцыг нь хоёр ялгаатай арга зүйгээр хөвүүлэн баяжуулалт хийв. Үүнд, ердийн хөвүүлэн баяжуулалт болон хэт авиан чичиргээг электролизтой хослуулан үйлчилсэний дараа хөвүүлэн баяжуулалт явуулав. Туршилтын үр дүнд хэт авиан чичиргээт электролизоор үйлчилсэний дараа хөвүүлэн баяжуулалтын үр дүн сайн байсан учир цаашид хэт авиан чичиргээг электролизтой хослуулан үйлчлэх туршилтын тохиромжтой нөхцлийг тогтоосон болно. Хэт авиан чичиргээн хугацааг 20 минут, этанолын хэмжээг 30мл, электролизийн хүчийг 1.5А байхад хөвүүлэн баяжуулалтаар гарган авсан баяжмалын үнслэгийн хэмжээ хамгийн бага буюу 24,1%, илчлэгийн хэмжээ хамгийн их буюу 6264кКал/кг бүхий баяжмал гарч байсан.
Ухаа худаг ордын давхарга бүрийн техникийн үзүүлэлтүүдийг тодорхойлж, харьцуулан судлаад 4С давхаргын нүүрсийг сонгон авч энэхүү судалгааг явуулав. Сонгосон дээжинд шигшүүрийн анализ хийж хэт нарийн буюу <0.25мм ширхэглэлтэй фракцыг нь хоёр ялгаатай арга зүйгээр хөвүүлэн баяжуулалт хийв. Үүнд, ердийн хөвүүлэн баяжуулалт болон хэт авиан чичиргээг электролизтой хослуулан үйлчилсэний дараа хөвүүлэн баяжуулалт явуулав. Туршилтын үр дүнд хэт авиан чичиргээт электролизоор үйлчилсэний дараа хөвүүлэн баяжуулалтын үр дүн сайн байсан учир цаашид хэт авиан чичиргээг электролизтой хослуулан үйлчлэх туршилтын тохиромжтой нөхцлийг тогтоосон болно. Хэт авиан чичиргээн хугацааг 20 минут, этанолын хэмжээг 30мл, электролизийн хүчийг 1.5А байхад хөвүүлэн баяжуулалтаар гарган авсан баяжмалын үнслэгийн хэмжээ хамгийн бага буюу 24,1%, илчлэгийн хэмжээ хамгийн их буюу 6264кКал/кг бүхий баяжмал гарч байсан.
Although Castellaniella species are crucial for denitrification, there is no report on their capacity to carry out denitrification and anode respiration simultaneously in a bioelectrochemical system (BES). Herein, the ability of a mixed inoculum of electricigenic Castellaniella species to perform simultaneous denitrification and anode respiration coupled with cathodic metals recovery was investigated in a BES. Results showed that 500 mg/L NO3-N significantly decreased power generation, whereas 100 and 250 mg/L NO3-N had a lesser impact. The single-chamber MFCs (SCMFCs) fed with 100 and 250 mg/L NO3-N concentrations achieved a removal efficiency higher than 90% in all cycles. In contrast, the removal efficiency in the SCMFCs declined dramatically at 500 mg/ L NO3-N, which might be attributable to decreased microbial viability as revealed by SEM and CLSM. EPS protein content and enzymatic activities of the biofilms decreased significantly at this concentration. Cyclic voltammetry results revealed that the 500 mg/L NO3-N concentration decreased the redox activities of anodic biofilms, while electrochemical impedance spectroscopy showed that the internal resistance of the SCMFCs at this concentration increased significantly. In addition, BES inoculated with the Castellaniella species was able to simultaneously perform heterotrophic anodic denitrification and cathodic metals recovery from real wastewater. The BES attained Cu2+, Hg2+, Pb2+, and Zn2+removal efficiencies of 99.86 ±0.10%, 99.98 ±0.014%, 99.98 ± 0.01%, and 99.17 ±0.30%, respectively, from the real wastewater. Cu2+was bio-electrochemically reduced to Cu0 and Cu2O, whereas Hg0 and HgO constituted the Hg species recovered via bioelectrochemical reduction and chemical deposition, respectively. Furthermore, Pb2+and Zn2+were bio-electrochemically reduced to Pb0 and Zn0, respectively. Over 89% of NO3-N was removed from the BES anolyte during the recovery of the metals. This research reveals promising denitrifying exoelectrogens for enhanced power generation, NO3-N removal, and heavy metals recovery in BES.
Abstract: Acid mine drainage (AMD) has become a widespread environmental issue and its toxicity can cause permanent damage to the ecosystem. However, there are few studies focusing on the formation of AMD under moderately thermophilic conditions, hence we employed X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and 16S rRNA sequencing to study the dissolution of pyrite and bornite by a moderate thermophilic consortium, and explored the role of free and attached microorganisms in the formation of AMD. The consortium mainly comprised Acidithiobacillus caldus, Leptospirillum ferriphilum and Sulfobacillus thermosulfidooxidans. The results indicated that total iron in pyrite solution system reached 33.45 g/L on the 12th day, and the copper dissolution rate of bornite dissolution reached 91.8% on the 24th day. SEM results indicated that the surfaces of pyrite and bornite were significantly corroded by microorganisms. XRD and XPS results showed that ore residues contained jarosite, and the dissolving residue of bornite contained elemental sulfur. The dominant bacterial genus in pyrite dissolution was A. caldus, and L. ferriphilum in bornite dissolution. To sum up, microbes significantly accelerated the mineral dissolution process and promoted the formation of AMD.
The impact of nickel (Ni2+) on the performance of anodic electroactive biofilms (EABs) in the bioelectrochemical system (BES) was investigated in this study. Although it has been reported that Ni2+influences microorganisms in a number of ways, it is unknown how its presence in the anode of a BES affects extracellular electron transfer (EET) of EABs, microbial viability, and the bacterial community. Results revealed that the addition of Ni2+ decreased power output from 673.24 ±12.40 mW/m2 at 0 mg/L to 179.26 ±9.05 mW/m2 at 80 mg/L. The metal and chemical oxygen demand removal efficiencies of the microbial fuel cells (MFCs) declined as Ni2+ concentration increased, which could be attributed to decreased microbial viability as revealed by SEM and CLSM. FTIR analysis revealed the involvement of various microbial biofilm functional groups, including hy droxyl, amides, methyl, amine, and carboxyl, in the uptake of Ni2+. The presence of Ni2+on the anodic biofilms was confirmed by SEM-EDS and XPS analyses. CV demonstrated that the electron transfer performance of the anodic biofilms was negatively correlated with the various Ni2+concentrations. EIS showed that the internal resistance of the MFCs increased with increasing Ni2+concentration, resulting in a decrease in power output. High-throughput sequencing results revealed a decrease in Geobacter and an increase in Desulfovibrio in response to Ni2+ concentrations of 10, 20, 40, and 80 mg/L. Furthermore, the various Ni2+ concentrations decreased the expression of EET-related genes. The Ni2+-fed MFCs had a higher abundance of the nikR gene than the control group, which was important for Ni2+ resistance. This work advances our understanding of Ni2+ inhibition on EABs, as well as the concurrent removal of organic matter and Ni2+ from wastewater.
Water pollution is a global issue that has drastically increased in recent years due to rapid 40 industrial development. Different technologies have been designed for the removal of pollutants 41 from wastewater. However, most of these techniques are expensive, generate new waste, and focus 42 solely on metal removal instead of metal recovery. In this study, novel facultative exoelectrogenic 43 strains designated Castellaniella sp. A5, Castellaniella sp. B3, and Castellaniella sp. A3 were 44 isolated from a microbial fuel cell (MFC). These isolates were utilized as pure and mixed culture 45 inoculums in a bioelectrochemical system (BES) to produce bioelectricity and treat simulated 46 industrial wastewater. A single-chamber MFC inoculated with the mixed culture attained the 47 highest electricity generation (i.e., 320 mW/m2 power density and 3.19 A/m2 current density), 48 chemical oxygen demand removal efficiency (91.15 ± 0.05%), and coulombic efficiency (54.81 ± 49 4.18%). In addition, the BES containing biofilms of the mixed culture achieved the highest Cu, 50 Cr, and Cd removal efficiencies of 99.89 ± 0.07%, 99.59 ± 0.53%, and 99.91 ± 0.04%, respectively. 51 The Cr6+ and Cu2+ in the simulated industrial wastewater were recovered via microbial 52 electrochemical reduction as Cr3+ and Cu0, respectively. However, Cd2+ precipitated as Cd (OH)2 53 or CdCO3 on the surface of the cathodes. These results suggest that a mixed culture inoculum of 54 Castellaniella sp. A5, Castellaniella sp. B3, and Castellaniella sp. A3 has great potential as a 55 biocatalyst in BES for heavy metals recovery from industrial wastewater.
Chalcopyrite is the most abundant copper mineral in the world, and its bioleaching suffers from low dissolution rates, which is often attributed to passivating layers. Hence, these passivating layers must be overcome to use bioleaching technology to its full potential to process chalcopyrite. Leaching must occur at a low oxidation/reduction potential (ORP) to prevent these passivating layers from forming, but chemical redox control in bioleaching heaps is difficult and costly. As an alternative, selected weak iron-oxidizers could be employed that are incapable of scavenging exceedingly low concentrations of iron and, therefore, raise the ORP just above the onset of bioleaching but not high enough to allow for the occurrence of passivation. This study isolated four bacterial strains from acid mine drainage in one of Mongolia’s most significant copper mining sites. Three of these strains were identified based on their partial sequence of the 16S rRNA gene. Also, we studied the electrochemical properties of the bioleaching process of sulfide ore by one of the isolates obtained from the acid mine drainage. Our results show that strains ER-1a and ER-1c are closely related to Candidate division OP10 bacterium P488 (AM749768), and ER-1d is closely related to Fimbriimonas ginsengisoli Gsoil 348 (GQ339893). Bioleaching of copper concentrate was monitored by the electrochemical method. During 18 days of oxidation, only three types of oxidations were observed. The solubility of copper reached 615 mg/L and 53.37%, while 83.7% of ferrous ions were converted to iron (III). The CV-cyclic voltammetry oxidation current peak intensity gradually increased until day 15 and then decreased on day 18 during the bioleaching experiment
In this work, the effects of a functionalization method involving different conditions and milling processes on the dispersion and thermal and electrical conductivity of multiwalled carbon nanotubes were studied. The surfaces of MWCNTs were modified using a mixture of sulfuric and nitric acid as an acid treatment and potassium persulfate and sodium hydroxide as an alkaline treatment to achieve more hydrophilic MWCNTs. The morphological and structural investigations were carried out using transmission electron microscopy and Fourier transform infrared spectroscopy. Furthermore, the dispersion characteristics and thermal and electrical conductivity of the as-prepared water-based nanofluids were measured. As a result, the dispersion characteristics revealed that the best dispersion and stability results were obtained for alkaline-treated MWCNTs using potassium persulfate and sodium hydroxide. The thermophysical study using a thermal conductivity analyzer exhibited that the thermal conductivity of the pristine MWCNT nanofluid (0.1 wt%) was enhanced from 603.5 to 610.4 mW/m·K and the electrical conductivity of the raw MWCNT nanofluid was increased from 16.2 to 125.8 µS/cm at 25 ◦C after alkaline treatment and milling processes, which were performed using planetary ball milling. Regarding the overall results, the milling process and mild alkaline oxidation process are more environmentally friendly, effective, and convenient for the functionalization of CNTs, without requiring any organic solvents or strong acids
Recently, applications for lithium-ion batteries (LIBs) have expanded to include electric vehicles and electric energy storage systems, extending beyond power sources for portable electronic devices. The power sources of these flexible electronic devices require the creation of thin, light, and flexible power supply devices such as flexile electrolytes/insulators, electrode materials, current collectors, and batteries that play an important role in packaging. Demand will require the progress of modern electrode materials with high capacity, rate capability, cycle stability, electrical conductivity, and mechanical flexibility for the time to come. The integration of high electrical conductivity and flexible buckypaper (oxidized Multi-walled carbon nanotubes (MWCNTs) film) and high theoretical capacity silicon materials are effective for obtaining superior high-energy-density and flexible electrode materials. Therefore, this study focuses on improving the high-capacity, capability-cycling stability of the thin-film Si buckypaper free-standing electrodes for lightweight and flexible energy-supply devices. First, buckypaper (oxidized MWCNTs) was prepared by assembling a free stand-alone electrode, and electrical conductivity tests confirmed that the buckypaper has sufficient electrical conductivity (10−4(S m−1) in LIBs) to operate simultaneously with a current collector. Subsequently, silicon was deposited on the buckypaper via magnetron sputtering. Next, the thin-film Si buckypaper freestanding electrodes were heat-treated at 600 ◦C in a vacuum, which improved their electrochemical performance significantly. Electrochemical results demonstrated that the electrode capacity can be increased by 27/26 and 95/93 µAh in unheated and heated buckypaper current collectors, respectively. The measured discharge/charge capacities of the USi_HBP electrode were 108/106 µAh after 100 cycles, corresponding to a Coulombic efficiency of 98.1%, whereas the HSi_HBP electrode indicated a discharge/charge capacity of 193/192 µAh at the 100th cycle, corresponding to a capacity retention of 99.5%. In particular, the HSi_HBP electrode can decrease the capacity by less than 1.5% compared with the value of the first cycle after 100 cycles, demonstrating excellent electrochemical stability.
There exists a high market demand for small, thin, lightweight, and bendable batteries to power flexible, portable electronic equipment. Therefore, it is necessary to develop materials capable of being used in flexible, lightweight, high-capacity, low-cost, and eco-friendly electronic devices. This study aims to replace heavy-duty metal current collectors with lighter, flexible, and highly conductive buckypaper (oxidized multi-walled carbon nanotubes (MWCNTs)) to improve the electrochemical performance of Si and increase the electrode energy density. We prepared chemically modified MWCNTs using a strong oxidizer (1:3 mixture of nitric and sulfuric acid) and extracted the MWCNT thin sheets (or buckypaper) to assemble a free, stand-alone electrode with no binder or current collector. Si was deposited on the buckypaper and a Cu foil by magnetron sputtering to produce Si/buckypaper and Si/Cu electrodes, respectively, and their electrochemical performances were compared. The morphology of the buckypapers and the Si thin film was studied using the field scanning electron microscopy, and the crystal structures of the deposited Si film were investigated by X-ray diffraction. The electrical conductivity of the electrodes was measured using the two probe technique measurement system. The electrochemical performance of the buckypaper, Si/buckypaper, and Si/Cu electrodes was examined by performing the galvanostatic charge-discharge tests and a cycle voltammetry test. The Si/buckypaper electrode showed high discharge and charge capacities of 89 μAh and 86 μAh, respectively, after 100 cycles corresponding to 97% Coulombic efficiency, which was 9 times higher than that of the Si/Cu electrode. The bending test revealed a battery performance similar to that of a conventional cell, and a sufficiently high electrical conductivity (104 S m− 1 ) was obtained. Therefore, the heavy-metal current collector can be replaced with a light-weight (4 times lighter than Si/Cu electrode), thin, flexible MWCNT thin sheet. This provides an innovative solution for the nextgeneration thin, light-weight, and flexible lithium-ion batteries.
Biohydrometallurgical / Bioleaching is economic-efficiently and environment-friendly technology that is convenient to process low-grade, fine and complex distributed ore and now this technology research is developing rapidly. We selected the ore which is hard to process by the cyanide method and studied the ore structure and chemical composition to use in bioleaching research. The selected primary ore is sulfide ore that is containing 2.88ppm Au, 1.67ppm Ag, 0.13% Cu, 1.03% S and identified as containing minerals as pyrite, goethite, covellite, chalcopyrite, and arsenopyrite.
The multi-walled carbon nanotubes (MWCNTs) and Alumina (Al2O3) (CNT/Alumina) have been synthesized by two different simple methods including mechanical and chemical fabrication. The effect of the weight ratio of MWCNTs to Alumina on dispersion characteristic and thermal conductivity has been studied. To confirm that it is the success process, the morphological and structural investigations were carried out using transmission electron microscopy (TEM), Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Raman spectroscopy. The whole results indicated that the chemical synthesized CNT/Al2O3 (c-CNT/Al2O3) were possessed good dispersion as compared to mechanical synthesized CNT/Al2O3 (m-CNT/Al2O3). However, for the dispersion stability, although c-CNT has higher value than m-CNT, m-CNT/Al2O3 were higher than c-CNT/Al2O3 for the nanofluid. The highest thermal conductivity enhancement was revealed when the weight ratio of (1:1) for the nanocomposite. The results were indicated that the synthesis methods were simple, environmentally-friendly and it has very effective characteristics than other chemical treatment
Pyrethrum pulchrum Ledeb. has been a phytochemically unexplored Mongolian medicinal folklore plant. In this study, its total flavonoid content was determined and fourteen flavonoids (1-14) were isolated from the aerial parts of P. pulchrum. Their structures were elucidated on the basis of spectroscopic data. The compounds 12-14, methoxyflavones, were tested for antiproliferative and cytotoxic activity against A549, HeLa, K-562, THP-1 and HUVEC cell lines. This is the first report on the effects of 5,7,4'-trihydroxy-3,6,3'-trimethoxyflavone (13) against all tested cell lines and it exhibited potent activity against chronic myeloid leukemia K-562 and acute monocytic leukemia THP-1 cells, each with GI50 value at 2.0 μg/mL. The 5,4'-dihydroxy-3,6,7,3'-tetramethoxyflavone (14) showed the most potent activity against THP-1 (GI50 = 1.1 μg/mL) and the highest cytotoxicity (5.6 μg/mL). In addition, acute toxicity of plant ethanol extract was evaluated and the lethal dose (LD50) was estimated at 1048 mg/kg.
The anti-corrosion performance of fatty acid-coated mild steel samples is studied. Samples of structural steel coated with collector reagents deposited from surfactant in an ethanol solution and overcoated with an epoxy barrier paint. A quantitative corrosion rate was determined by the linear polarization resistance method using bio-potentiostat/galvanostat 400. A coating morphology was determined by scanning electronic microscopy. A test for the hydrophobic surface of steel by surfactant was done. Prior to measuring the corrosion rate, mechanical and chemical treatments were performed to prepare the test specimens. Overcoating the metal samples with epoxy barrier paint after exposing them to surfactant the corrosion rate can be inhibited by 34-35µm/year
The anti-corrosion performance of fatty acid coated mild steel samples is studied. Samples of structural steel coated with collector reagents deposited from surfactant in ethanol solution, and over coated with an epoxy barrier paint. A quantitative corrosion rate was determined by linear polarization resistance method using biopotentiostat/galvanostat 400. A coating morphology was determined by scanning electronic microscopy. A test for hydrophobic surface of steel by surfactant was done. Prior to measuring the corrosion rate, mechanical and chemical treatments were performed to prepare the test specimens. Over coating the metal samples with epoxy barrier paint after exposing them with surfactant the corrosion rate can be inhibited by 34-35µm/year
Abstract—The anti-corrosion performance of fatty acid coated mild steel samples is studied. Samples of structural steel coated with collector reagents deposited from surfactant in ethanol solution and overcoated with an epoxy barrier paint. A quantitative corrosion rate was determined by linear polarization resistance method using biopotentiostat/galvanostat 400. Coating morphology was determined by scanning electronic microscopy. A test for hydrophobic surface of steel by surfactant was done. From the samples, the main component or high content iron was determined by chemical method and other metal contents were determined by Inductively Coupled PlasmaOptical Emission Spectrometry (ICP-OES) method. Prior to measuring the corrosion rate, mechanical and chemical treatments were performed to prepare the test specimens. Overcoating the metal samples with epoxy barrier paint after exposing them with surfactant the corrosion rate can be inhibited by 34-35 µm/year.
INVESTIGATION OF SOME FLAVONOIDS AND ACUTE TOXICITY OF PYRETHRUM PULCHRUM E. Uugangerel1,2, G. Choijamts, D. Erdenechimeg2 , D. Enkhmaa1 1School of Bio-Medicine, Mongolian National University of Medicinal Sciences, Mongolia, 14210, Ulaanbaatar, str. Zorig, e-mail: uugangerel@mnums.edu.mn 2School of Engineering and Applied Sciences, National University of Mongolia, Mongolia, 14201, Ulaanbaatar, str. University, 1 Plants have played a significant role in maintaining human health and improving the quality of human life for thousands of years. Pyrethrum was a genus of several old world plants now classified as Chrysanthenum or Tanacetum is one of the largest genera in the Asteraceae family, and reputed to have excellent medicinal value. There are four species of Pyrethrum grown in Mongolia of which P. lanuginosum, P. alatavicum, P. pulchrum and P. changaicum [1] are widely used in traditional medicine as fever, inflammatory conditions, bone fracture, carcinoma and anthrax [2]. Pyrethrum pulchrum L. is recognized as an ingredient of 401 Traditional Mongolian medicines and that it is native to many regions of Mongolia. The aim of the present study was to determine of total flavonoid contents and purify of some flavonoids in the aerial parts of P. pulchrum. In addition, the acute toxicity effect is investigating for ethanolic extract of this plant. There is considerable interest in the health promoting effect of flavonoids from dietary sources e.g from major crops, herbs and medicinal plants. The air-dried and grounded aerial parts of P. pulchrum were extracted with ethanol (96%) and acid hydrolysis. This was carried out by heating in the presence of acid. The total flavonoids were determined by UV-visible spectrophotometry and the result of total flavonoids was 0.68% quercetin equivalents. Rapid extraction (SPE and preparative HPLC) methods were used, in order to reduce degradation prior to LC/MS and NMR analysis. Apigenin (fig.1) and their derivatives (Ap-7-Gls and isovitexin) were obtained from P. pulchrum. From 1H NMR parameters of apigenin in methanol solution, the apparent doublets at δ=6.93 and δ=7.85 derive from AA′XX′ spin system formed by H-2′, H-3′, H-5′ and H-6′. The singlet at δ=6.59 is assigned to H-3, and the doublets at δ=6.21 and δ=6.46 to H-6 or H-8. It has also been compared by Piet Van loo et al and other references [3,4,5,6]. Fig.1. Structure of Apigenin An acute toxicity study was conducted according to the guidelines of Organization for Economic Cooperation and Development (OECD). Animals used in this study were BALB/c white mice weighing 33-39 g. The animals were randomly allocated into three groups of three animals each. Effects of the administration of different concentrations of previously prepared ethanolic extract were investigated in mice. For the acute toxicity effect, it was observed values with LD of 1048 mg/g. We measured the body mass of the mice after 7 days and 14 days. After 14 days we measured the organs of the mice separately (liver, heart, kidney, lungs). Statistical analysis carried out showed no significant variation (p>0.05) during the period of study. References 1. Grubov V.I. Key to the Vascular plants of Mongolia. Leningrad, 1982. P. 243-244 2. Volodya Ts. Methods for using medicinal plants in Mongolia, Ulaanbaatar, 2014. P.143-144 3. Piet Van Loo., Anre De Bruyn. Magnetic resonance in chem. 1986. V. 24, P. 879-882 4. Vanda S., Richard N., et al. Phytochemistry. 2004. V.65, P.2323-2332 5. Darcy C. B., David A.E., et al. Magnetic resonance in Chem. 2007. V. 45, P. 835-845 6. Yun-Lian-Lin et al J. of the Chinese Chem. Society. 2000. V. 47, P. 253-256 7. Pooja S., Prashanth S., et al. World J. of Pharmacy and Pharmaceutical Sciences. 2016. V. 5, P.703-713
OXIDATION MECHANISM OF THE COPPER CONCENTRATE
There is still high need for removal of heavy metals from industrial wastewater with easily and quickly at low-cost. In addition, it is desirable to recover the heavy metals which become the valuable materials. As prior studies, foam separation has received considerable interest due to its simplicity, rapidity, high efficiency and costeffective for the solid-liquid separation [1]–[3]. The role of surface active substance is the most important in the foam separation process. Besides, milk casein, one of the eco-friendly surface-active proteins, has unique characteristics such as high foaming capacity and adsorbed to ferric and aluminum hydroxides as collector for removal of suspended substances [1]. However, there is no study about attachment of casein for the removal of heavy metals by the foam separation. In this study, the removal and recovery of heavy metals from artificial wastewater using dispersed bubbles and milk casein were tested with pre-precipitation. In addition, to prove the effectiveness for the actual condition, precipitation and foam separation was applied to the mining tailing water collected from the mining industry in Mongolia. Lime (Ca(OH)2) was used as an alkaline agent for heavy metal precipitation. To simulate the optimum pH for precipitation, jar tests were performed under different conditions. After the precipitation process, casein was added to the precipitated wastewater, and foam separation was performed subsequently. Milk casein functioned as a collector and frother for foam separation. The removal efficiencies of heavy metals were determined via inductively coupled plasma spectrometry. Under the optimum alkaline condition at pH9, where the pH was adjusted by lime addition and a casein dosage of 15 mg/L, 96% of Cr, Cu, Cd, and Pb were removed from the wastewater and recovered in the foam; however, Mo remained in the water. When the pH of the treated water was readjusted at 5.3 and the water was reprocessed by foam separation, 76% of Mo was removed from the treated water. To demonstrate the effectiveness of the proposed precipitation and foam separation method under actual conditions, it was applied to mining tailing water collected from an ore mining facility in Mongolia. The removal efficiencies of heavy metals, such as Mn, Fe, and Cu, included in the mining tailing water were greater than 85%. Furthermore, more than 90% of the suspended solids were also removed from the tailing water. The casein enabled the collection and recovery of the precipitation components of heavy metals within a total processing time of 10 min. Precipitation and foam separation using lime and casein is an effective and adaptable method for treating industrial effluents that contain heavy metals.
Plants have played a significant role in maintaining human health and improving the quality of human life for thousands of years. Pyrethrum was a genus of several old world plants now classified as Chrysanthenum or Tanacetum is one of the largest genera in the Asteraceae family, and reputed to have excellent medicinal value. There are four species of Pyrethrum grown in Mongolia of which P. lanuginosum, P. alatavicum, P. pulchrum and P. changaicum [1] are widely used in traditional medicine as fever, inflammatory conditions, bone fracture, carcinoma and anthrax [2]. Pyrethrum pulchrum L. is recognized as an ingredient of 401 Traditional Mongolian medicines and that it is native to many regions of Mongolia. The aim of the present study was to determine of total flavonoid contents and purify of some flavonoids in the aerial parts of P. pulchrum. In addition, the acute toxicity effect is investigating for ethanolic extract of this plant. There is considerable interest in the health promoting effect of flavonoids from dietary sources e.g from major crops, herbs and medicinal plants. The air-dried and grounded aerial parts of P. pulchrum were extracted with ethanol (96%) and acid hydrolysis. This was carried out by heating in the presence of acid. The total flavonoids were determined by UV-visible spectrophotometry and the result of total flavonoids was 0.68% quercetin equivalents. Rapid extraction (SPE and preparative HPLC) methods were used, in order to reduce degradation prior to LC/MS and NMR analysis. Apigenin (fig.1) and their derivatives (Ap-7-Gls and isovitexin) were obtained from P. pulchrum. From 1H NMR parameters of apigenin in methanol solution, the apparent doublets at δ=6.93 and δ=7.85 derive from AA′XX′ spin system formed by H-2′, H-3′, H-5′ and H-6′. The singlet at δ=6.59 is assigned to H-3, and the doublets at δ=6.21 and δ=6.46 to H-6 or H-8. It has also been compared by Piet Van loo et al and other references.
In this study, mechanism and effect of oxidation process was studied in order to find cause of mass difference and decreasing of copper content in copper concentrate. Main components of copper concentrate were determined by chemical analysis using Mongolian National Standard methods MNS2078:1984 and MNS2071:1981 and main phase components were determined based on differential solubility in thiourea according to MNS4594:1998 and MNS4594:1998 standard methodologies by phase analysis and XRD analysis. According to comparison of wet concentrates (sample 1) are sampled from the concentrates that are kept at the Oyu-Tolgoi mining open site for few months, dry concentrates (sample 2) are sampled from concentrates that is exported to China by chemical analysis, the amounts of total copper and iron were decreased by about 1%. According to phase analysis, primary sulfide components was decreased and secondary sulfide components was increased. Furthermore, copper sulfate components were formed due to oxidation. The main factors that can be affects for oxidation are O2, Fe3+, humidity and temperature. The oxidation of sulfide minerals is straight-forward, non-return process which means O2 adsorption is very important to control oxidation process.
The present study conducted on chemical treatment of multi-walled carbon nanotubes (MWCNTs) to investigate the dispersion characteristics and thermal conductivity of MWCNTs in aqueous with ball milling effect. The surface of MWCNTs was modified by chemical oxidation with potassium persulfate/sodium hydroxide(K2S2O8/NaOH) to achieve more hydrophilic MWCNTs. As result, the best dispersion and stability of MWCNTs obtained for ground treated MWCNTs.
С помощью метода циклической вольтамперометрии было изучено влияние реагенга EDTA (этлендиаминтеграуксусная к-та ) на электрохимическое поведение медных и железных электродов в растворе сульфида натрия Очистка рабочих электродов определяется рентгеновской флуоресценцией. На вольтамперной кривой измеренной на медных электродах имеются 3 анодных и 3 катодных пика, которые соответствуют (аналогичны ) Cu2S ,CuS и Cu2O на кривой железных электродов имеется один анодный пик который соответсвует Fe2S при отсутствии катодного пика. С другой стороны, образовавшийся при окислении сульфида металла удалялся с использованием ЭДТА.
Abstract Background and Objective: Even today, a strong need exists for the quick and easy removal and recovery of heavy metals from industrial wastewater at low cost. In this study, recovery of heavy metals from artificial wastewater containing Cr, Cu, Cd, Pb and Mo (each concentration, 10 mg L–1) by precipitation and foam separation using lime and milk casein was investigated. In addition, the performance of foam separation was tested using mining tailing water collected from a mining plant. Materials and Methods: Lime was used as an alkaline agent for heavy-metal precipitation. Milk casein functioned as both a collector and a frother for foam separation. After the precipitation process, casein was added to the precipitated wastewater and foam separation was carried out. The removal efficiencies of heavy metals were determined by inductively plasma spectrometry. Results: Under the optimum alkaline condition at pH 9, where the pH was adjusted by lime addition and a casein dosage of 15 mg L–1, 96% of Cr, Cu, Cd and Pb were removed from the wastewater and recovered in the foam, however, Mo remained in the water. When the pH of the treated water was re-adjusted at 5.3 and the water was reprocessed by foam separation, 76% of Mo was removed from the treated water. To demonstrate the effectiveness of the proposed precipitation and foam separation method under actual conditions, it was applied to mining tailing water collected from an ore-mining facility in Mongolia. The removal efficiencies of heavy metals such as Mn, Fe and Cu included in the mining tailing water were greater than 85%. Furthermore, more than 90% of the suspended solids were also removed from the tailing water. Conclusion: The casein enabled the collection and recovery of the precipitation components of heavy metals within a total processing time of 10 min. Precipitation and foam separation using lime and casein is an effective and adaptable method for treating industrial effluents that contain heavy metals.
