scholarly journals Removal of Sulphate and Manganese on Synthetic Wastewater in Sulphate Reducing Bioreactor Using Indonesian Natural Zeolite

2017 ◽  
Vol 17 (2) ◽  
pp. 203 ◽  
Author(s):  
Endah Retnaningrum ◽  
Wahyu Wilopo
Keyword(s):  
Natural Zeolite ◽  
Fluidized Bed Reactor ◽  
Synthetic Wastewater ◽  
Particle Analysis ◽  
Support Material ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Manganese Removal ◽  
Ph Values ◽  
Reducing Bacteria

The present research was conducted to investigate sulphate and manganese removal from synthetic wastewater. The continuous laboratory scale of down-flow fluidized-bed reactor (DFBR) using sulphate reducing bacteria (SRB) consortium and Indonesian natural zeolite as a bacterial support material was designed. At 9 days operation, maximum sulphate and manganese removal was observed to be 23% and 15.4%, respectively. The pH values were also changed to neutral. The population of SRB increased which effect on the raising of their activity for removing sulphate and manganese. Using the scanning electronic microscopy (SEM), it was observed that natural zeolite possesses excellent physical characteristics as a bacterial support material in DFBR. The imaging SEM result of SRB consortium on zeolite surface clearly showed the developed SRB biofilm on that particle. Analysis result of EDX confirmed that manganese was precipitated as manganese–sulfides.

scholarly journals Studies on Synthetic and Natural Melanin and Its Affinity for Fe(III) Ion

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
T. G. Costa ◽  
R. Younger ◽  
C. Poe ◽  
P. J. Farmer ◽  
B. Szpoganicz
Keyword(s):  
Metal Binding ◽  
Binding Sites ◽  
Quinone Imine ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Metal Binding Sites ◽  
Ph Values ◽  
Eds Analysis ◽  
New Interactions

In this work, we measured the metal-binding sites of natural and synthetic dihydroxyindole (DHI) melanins and their respective interactions with Fe(III) ions. Besides the two acid groups detected for the DHI system: catechol (Cat) and quinone-imine (QI), acetate groups were detected in the natural oligomer by potentiometric titrations. At acidic pH values, Fe(III) complexation with synthetic melanin was detected in an Fe(OH)(CatH2Cat) interaction. With an increase of pH, three new interactions occurred: dihydroxide diprotonated catechol, Fe(OH)2(CatH2Cat)−, dihydroxide monoprotonated catechol, [Fe(OH)2(CatHCat)]2−, and an interaction resulting from the association of one quinone-imine and a catechol group, [Fe(OH)2(Qi−)(CatHCat)]3−. In the natural melanin system, we detected the same interactions involving catechol and quinone-imine groups but also the metal interacts with acetate group at pH values lower than 4.0. Furthermore, interactions in the synthetic system were also characterized by infrared spectroscopy by using the characteristic vibrations of catechol and quinone-imine groups. Finally, scanning electronic microscopy (SEM) and energy-dispersive X-ray (EDS) analysis were used to examine the differences in morphology of these two systems in the absence and presence of Fe(III) ions. The mole ratio of metal and donor atoms was obtained by the EDS analysis.

Characterization of Badinsk Zeolite and its Use for Removal of Phosphorus and Nitrogen Compounds from Wastewater

2019 ◽  
Vol 970 ◽  
pp. 7-16
Author(s):  
Anastasiya Novikova ◽  
Olga B. Nazarenko ◽  
Anna N. Vtorushina ◽  
Tatiyana A. Zadorozhnaya
Keyword(s):  
Natural Zeolite ◽  
X Ray Diffraction ◽  
Ammonium Ions ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Purification Efficiency ◽  
Calcium Cations ◽  
Insoluble Compounds

The characterization of natural zeolite from Badinsk deposit was carried out by means of X-ray diffraction, scanning electronic microscopy, thermal analysis, Fourier transform infrared spectroscopy. The possibility of water purification from phosphates in dynamic conditions using of natural zeolite as a filtering bed was studied. The effect of the filtration rate of phosphates solution on purification efficiency is investigated. The mechanism of phosphates and ammonium removal with the participation of the zeolite is discussed: in case of phosphates it is the formation of insoluble compounds by reacting of calcium cations and phosphate anions; in case of ammonium ions it is ion exchange.

Removal of lead by sulfate-reducing bacteria in anaerobic continuous stirred tank reactors

2016 ◽  
Vol 14 (3) ◽  
pp. 557-561
Author(s):  
Nguyễn Thị Yên ◽  
Kiều Thị Quỳnh Hoa
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Stirred Tank ◽  
Synthetic Wastewater ◽  
Terminal Electron Acceptor ◽  
Stirred Tank Reactors ◽  
Sulfate Reducing ◽  
Sulfide Production ◽  
Continuous Stirred Tank ◽  
Continuous Stirred Tank Reactors ◽  
Reducing Bacteria

Lead contaminated wastewater negatively impacts to living organisms as well as humans. In recent years, a highly promising biological process using the anaerobic production of sulfide ions by sulfate-reducing bacteria has presented itself as an alternative option for the removal of lead. This process is based on microbial utilization of electron donors, such as organic compounds (carbon sources), and sulfate as the terminal electron acceptor for sulfide production. The biogenic hydrogen sulfide reacts with dissolved heavy metals to form insoluble metal sulfide precipitates Removal of lead by an enriched consortium of sulfate-reducing bacteria (DM10) was evaluated sulfate reduction, sulfide production and lead precipitation. Four parallel anaerobic continuous stirred tank reactors (CSTR, V = 2L) (referred as R1 - R4) were fed with synthetic wastewater containing Pb2+ in the concentrations of 0, 100, 150 and 200 mg L-1 of lead and operated with a hydraulic retention time of 5 days for 40 days. The loading rates of each metal in R1- R4 were 0, 20, 30 and 40 mg L-1 d-1, respectively. The results showed that there was no inhibition of SRB growth and that lead removal efficiencies of 99-100% for Pb2+ were achieved in R2 (100 mg L-1) and R3 (150 mg L-1) throughout the experiment. For the highest lead concentration of  200 mg L-1, a decrease in efficiency of removal (from 100 to 96%) was observed at the end of the experiment. The obtained result of this study might help for a better control operation and performance improvements of reactors.

Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

1989 ◽  
Vol 21 (4-5) ◽  
pp. 157-165 ◽  
Author(s):  
F. Ehlinger ◽  
J. M. Audic ◽  
G. M. Faup
Keyword(s):  
Fluidized Bed ◽  
Future Development ◽  
Protein Concentration ◽  
Specific Activity ◽  
Fluidized Bed Reactor ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Biofilm Development ◽  
Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

scholarly journals Tribological Performance of CoCrMo Alloys with Boron Additions in As-Cast and Heat-Treated Conditions

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 355
Author(s):  
Marco A. L. Hernandez-Rodriguez ◽  
Diego E. Lozano ◽  
Gabriela M. Martinez-Cazares ◽  
Yaneth Bedolla-Gil
Keyword(s):  
Boron Content ◽  
Tribological Performance ◽  
Secondary Phases ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Hardness Tests ◽  
Heat Treated ◽  
Cocrmo Alloys ◽  
Cast Condition ◽  
Ball On Disc

The present study evaluates the effect of boron additions on the tribological performance of CoCrMo alloys. The alloys were prepared with boron ranging from 0.06 to 1 wt%. The materials were characterized using metallographic techniques, scanning electronic microscopy, and roughness and hardness tests. Tribological evaluation was made by means of ball-on-disc tests for sliding distances of 4, 8 and 12 km. The samples were in the as-cast condition and after a heat treatment at 1200 °C for 1 h, finished by water quenching. The results showed that wear resistance was influenced by the microstructure and the number of secondary phases. The volume loss decreased as the boron content increased. Due to hard phases, abrasion wear was observed. Delamination fatigue was also detected after long sliding distances. Both wear mechanisms diminished in higher boron content alloys.

scholarly journals IMPROVEMENT OF MICROMERITIC, COMPRESSIBILITY AND SOLUBILITY CHARACTERISTICS OF LINEZOLID BY CRYSTALLO-CO-AGGLOMERATION TECHNIQUE

2017 ◽  
Vol 9 (4) ◽  
pp. 47 ◽  
Author(s):  
Atul M. Kadam ◽  
Shitalkumar S. Patil
Keyword(s):  
Drug Release ◽  
Methyl Cellulose ◽  
Mechanical Deformation ◽  
Angle Of Repose ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Time Required ◽  
Good Flow

Objective: The purpose of current study was to improve physicochemical properties such as micrometric, compressibility and solubility of linezolid (LNZ) by preparing crystallo-co-agglomerates (CCA) in the presence of polymer for the enhancement of overall physicochemical performance.Methods: The process of agglomeration involves the use of dichloromethane (DCM) as a good solvent and chloroform as bridging liquid were used to prepare agglomerates. Agglomerates were characterised in the solid state using several techniques such as Scanning electronic microscopy(SEM), Fourier transformation infrared spectroscopy (FTIR), X-ray powder diffraction analysis (XRPD) The agglomerates obtained were evaluated for micrometric, mechanical, deformation, compressibility and drug release properties.Results: It was found that micrometric properties and dissolution characteristics of agglomerates were significantly improved than that of pure linezolid. Solubility was found to be increased than pure linezolid. The solubility of crystallo co-agglomerates was found an increase in 5 fold 3 fold and 3.7 fold for PVPK30 (0.5%), PVPK30 (0.25%) and PVPK30 (0.75%) respectively. The angle of repose for all batches was found between 22 ° to 30 °Carrs index was between 12.27±0.6 to 18.73±0.4 and Hausners ratio Near to 1, indicated good flow ability of agglomerates. The time required for drug release over a period of 60 min, is as LA1>LA2>LA3. LA3 shows fast drug release than LA1 and LA2, due to solubilization of drug due to more concentration of PVPK30 and less concentration of talc.Conclusion: Based on the above results, it was revealed that CCA of linezolid prepared with DCM and HPMC (Hydroxypropyl methyl cellulose)/PEG (Polyethylene glycol)/PVP (Polyvinylpyrrolidone) K30 exhibited improved micrometric properties, compressibility and in addition to improving solubility and dissolution rate.

scholarly journals Analysis of the properties of a Cu-Al2-O3 sintered system based on ultra fine and nanocomposite powders

2007 ◽  
Vol 39 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Z. Andjic ◽  
M. Korac ◽  
Z. Kamberovic ◽  
A. Vujovic ◽  
M. Tasic
Keyword(s):  
Mechanical Properties ◽  
Chemical Method ◽  
Elevated Temperatures ◽  
Hydrogen Atmosphere ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Composite Powders ◽  
Nanocomposite Powders ◽  
Final Composition

In this paper synthesis of a composite based on Cu-Al2O3 by a thermo-chemical method is shown along with a comparative analysis of the properties of the obtained nanocomposite sintered samples, which are characterized by a good combination of electric-mechanical properties, suitable for work at elevated temperatures. Ultra fine and nanocrystal powder Cu-Al2O3 is obtained by a chemical method, starting from water solutions of nitrates up to achieving the requested composition with 3 and 5% of Al2O3. Synthesis of composite powders has been developed through several stages: drying by spraying, oxidation of the obtained powder of precursor and then reduction by hydrogen until the final composition of nanocomposite powder is achieved. After characterization of the obtained powders, which comprised examination by the Scanning Electronic Microscopy (SEM) method and X-ray-structure analysis (RDA), the powders were compacted with compacting pressure of 500 MPa. Sintering of the obtained samples was performed in the hydrogen atmosphere in isothermal conditions at temperatures of 800 and 900oC for 30, 60, 90 and 120 minutes. Characterization of the obtained Cu-Al2O3 of the nanocomposite sintered system comprised examination of microstructure by the Scanning Electronic Microscopy (SEM), as well as examining of electric mechanical properties. The obtained results show a homogenous distribution of dispersoides in the structure, as well as good mechanical and electric properties. .

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