scholarly journals Treatment of succinonitrile wastewater by immobilized high efficiency microorganism strains

2008 ◽  
Vol 58 (4) ◽  
pp. 911-918 ◽  
Author(s):  
X. F. Zhou ◽  
Y. L. Zhang ◽  
D. Q. Xu ◽  
W. H. Cao ◽  
C. M. Dai ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Sodium Alginate ◽  
High Efficiency ◽  
Treatment Plant ◽  
Optimal Growth ◽  
Sole Source ◽  
Growth Conditions ◽  
Experimental Conditions ◽  
J 13 ◽  
Rotary Speed

Using succinonitrile as a sole source of carbon and nitrogen, two bacterium strains named as J-1-3 and J-13-1 were isolated and screened out from the treatment facilities of Shanghai petrochemical wastewater treatment plant treating acrylic fiber production wastewater. The optimal growth conditions of the two strains in the degradation of succinonitrile with varied initial concentrations were determined through flask tests as follows: temperature 30°C, shaker rotary speed of 250 r/min, inoculum percentage 0.1%, and initial pH 6. Results indicate that the two strains, especially J-13-1, exhibited a high efficiency for succinonitrile degradation. Thereafter, the bacterium strains were immobilized separately by sodium alginate and polyvinyl alcohol 1750±50, and applied to succinonitrile degradation again. Results show that in a very broad range of the initial succinonitrile concentration, i.e., 30–5,000 mg/L, the sodium alginate immobilized grains could degrade more than 80% of succinonitrile after 24 h under the experimental conditions of 30°C, pH 6.5, and shaker rotary speed of 250 r/min. However, the polyvinyl alcohol immobilized grains tended to inflate and break down due to a weak mechanical strength.

scholarly journals Cultivation of Microalgae and Cyanobacteria: Effect of Operating Conditions on Growth and Biomass Composition

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2834 ◽  
Author(s):  
Alejandra Sánchez-Bayo ◽  
Victoria Morales ◽  
Rosalía Rodríguez ◽  
Gemma Vicente ◽  
Luis Fernando Bautista
Keyword(s):  
Cell Growth ◽  
Culture Media ◽  
Treatment Plant ◽  
Isochrysis Galbana ◽  
Volume Ratio ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Operating Conditions ◽  
Biomass Composition ◽  
Nannochloropsis Gaditana

The purpose of this work is to define optimal growth conditions to maximise biomass for batch culture of the cyanobacterium Arthrospira maxima and the microalgae Chlorella vulgaris, Isochrysis galbana and Nannochloropsis gaditana. Thus, we study the effect of three variables on cell growth: i.e., inoculum:culture medium volume ratio (5:45, 10:40, 15:35 and 20:30 mL:mL), light:dark photoperiod (8:16, 12:12 and 16:8 h) and type of culture medium, including both synthetic media (Guillard’s F/2 and Walne’s) and wastewaters. The results showed that the initial inoculum:culture medium volume ratio, within the range 5:45 to 20:30, did not affect the amount of biomass at the end of the growth (14 days), whereas high (18 h) or low (6 h) number of hours of daily light was important for cell growth. The contribution of nutrients from different culture media could increase the growth rate of the different species. A. maxima was favoured in seawater enriched with Guillard’s F/2 as well as C. vulgaris and N. gaditana, but in freshwater medium. I. galbana had the greatest growth in the marine environment enriched with Walne’s media. Nitrogen was the limiting nutrient for growth at the end of the exponential phase of growth for C. vulgaris and N. gaditana, while iron was for A. maxima and I. galbana. The growth in different synthetic culture media also determines the biochemical composition of each of the microalgae. All species demonstrated their capability to grow in effluents from a wastewater treatment plant and they efficiently consume nitrogen, especially the three microalga species.

Efficient biodegradation of naphthalene by a newly characterized indigenous Achromobacter sp. FBHYA2 isolated from Tehran Oil Refinery Complex

2012 ◽  
Vol 66 (3) ◽  
pp. 594-602 ◽  
Author(s):  
Sima Farjadfard ◽  
Seyyed Mehdi Borghei ◽  
Amir Hessam Hassani ◽  
Bagher Yakhchali ◽  
Mehdi Ardjmand ◽  
...  
Keyword(s):  
Aromatic Hydrocarbons ◽  
Optimal Growth ◽  
Sole Source ◽  
Growth Conditions ◽  
American Petroleum Institute ◽  
Oil Refinery ◽  
Rrna Gene ◽  
Significant Difference ◽  
Aliphatic And Aromatic Hydrocarbons ◽  
Achromobacter Sp

A bacterial strain, FBHYA2, capable of degrading naphthalene, was isolated from the American Petroleum Institute (API) separator of the Tehran Oil Refinery Complex (TORC). Strain FBHYA2 was identified as Achromobacter sp. based on physiological and biochemical characteristics and also phylogenetic similarity of 16S rRNA gene sequence. The optimal growth conditions for strain FBHYA2 were pH 6.0, 30 °C and 1.0% NaCl. Strain FBHYA2 can utilize naphthalene as the sole source of carbon and energy and was able to degrade naphthalene aerobically very fast, 48 h for 96% removal at 500 mg/L concentration. The physiological response of Achromobacter sp., FBHYA2 to several hydrophobic chemicals (aliphatic and aromatic hydrocarbons) was also investigated. No biosurfactant was detected during bacterial growth on any aliphatic/aromatic hydrocarbons. The results of hydrophobicity measurements showed no significant difference between naphthalene- and LB-grown cells. The capability of the strain FBHYA2 to degrade naphthalene completely and rapidly without the need to secrete biosurfactant may make it an ideal candidate to remediate polycyclic aromatic hydrocarbon (PAH)-contaminated sites.

Preparation of sodium alginate/polyvinyl alcohol composite nanofiber membranes for adsorption of dyes

2021 ◽  
pp. 004051752110536
Author(s):  
Xiaodong Jiang ◽  
Caixia Sang ◽  
Jiankun Wang ◽  
Jing Guo
Keyword(s):  
Polyvinyl Alcohol ◽  
Sodium Alginate ◽  
Fiber Diameter ◽  
Orthogonal Design ◽  
Langmuir Model ◽  
Experimental Conditions ◽  
Composite Nanofiber ◽  
Isotherm Of Adsorption ◽  
Nanofiber Membranes ◽  
Blend Ratios

In this research, electrospinning was used to prepare sodium alginate (SA)/polyvinyl alcohol (PVA) composite nanofiber membranes. Effects of electrospinning parameters on the morphology and fiber diameter were investigated, and an orthogonal design was chosen to optimize the parameters. The optimized nanofiber membranes were applied as an adsorbent for the removal of methylene blue (MB), basic fuchsin (BF), and methyl orange (MO). Kinetic and isotherm of adsorption and effects of different experimental conditions such as pH, contact time, and initial dye concentration on adsorption capacity were investigated. It was found that the optimum parameters for the nanofiber membranes were SA/PVA blend ratios (3:7), electric field strength (20 kV), flow rate (0.05 mL/h), and distance (12.5 cm) between the syringe needle and collector, and the mean fiber diameter of the optimized membranes was 99.58 nm. The adsorption of nanofiber membranes was well described by the pseudo-second-order adsorption kinetic model and the Langmuir model, indicating that the adsorption mechanism was chemisorption by a monolayer. Based on the Langmuir model, the adsorption capacities for MB, BF, and MO were 9.25 mg/g, 9.02 mg/g, and 7.35 mg/g, respectively.

scholarly journals Effect of Cultivation Variables on Biomass Composition and Growth of Microalgae and Cyanobacteria

2019 ◽  
Author(s):  
Alejandra Sánchez-Bayo ◽  
Victoria Morales ◽  
Rosalía Rodríguez ◽  
Gemma Vicente Crespo ◽  
Luis Fernando Bautista
Keyword(s):  
Culture Media ◽  
Treatment Plant ◽  
Isochrysis Galbana ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Biomass Composition ◽  
Water Medium ◽  
Nannochloropsis Gaditana ◽  
Initial Inoculum ◽  
Inoculum Volume

The purpose of this work is to define optimal growth conditions for batch culture of the cyanobacterium Arthrospira maxima and the microalgae Chlorella vulgaris, Isochrysis galbana and Nannochloropsis gaditana. Thus, we study the effect of three variables on algae growth: i.e., inoculum:culture medium ratio, light:darkness photoperiod and type of culture medium, including both synthetic media and wastewaters. The results showed that the initial inoculum volume did not affect the amount of biomass at the end of the growth (14 days), whereas an excess (18 h) or defect (6 h) in the number of hours of light is determinant for its development. The contribution of nutrients from different culture media modified the growth of the different species. A. maxima was favoured in seawater enriched with Guillard's F/2 as well as C. vulgaris and N. gaditana but in fresh water medium. I. galbana had the greatest growth in the marine environment enriched with Walne’s media. Nitrate was the limiting growth reagent at the end of the exponential phase of growth for C. vulgaris and N. gaditana, while iron was for A. maxima and I. galbana. All species demonstrated their capability to grow in effluents from a wastewater treatment plant and they efficiently consume nitrogen, especially the three microalgae species.

scholarly journals Preparation and application of embedded and immobilized Achromobacter sp. agent for effective removal of ammonia nitrogen from water

2021 ◽  
Author(s):  
Yao Xiao ◽  
Yongbing Huang ◽  
Weishan Wu ◽  
Yao Li ◽  
Zhipeng Li ◽  
...  
Keyword(s):  
High Efficiency ◽  
Storage Stability ◽  
Removal Rate ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Ammonia Nitrogen ◽  
Effective Removal ◽  
Wastewater Quality ◽  
Screening And Identification ◽  
Achromobacter Sp

Abstract A novel wastewater-quality-improver, Sodium Alginate Embedded Microbe-treated Zeolite (SAEMZ), was proposed. The strains used are screened from black-odorous water and have high-efficiency NH4+-N degradation performance. The Gram-positive bacteria, belong to Achromobacter sp., was determined through the screening and identification for this strain, whose removal rate of NH4+-N can reach 88.06%, to decrease the NH4+-N's concentration from 61.83 mg/L to 7.80 mg/L, and its optimal growth conditions are pH 7–8, rotation speed 150–210 r/min, temperature 25–35 °C. The SAEMZ's removal effect on NH4+-N were considered in this research from aspects of reusability, storage stability, and the effects of dosage, coexisting ions, and wastewater's concentration. The increase of the SAEMZ's dosage effectively improved NH4+-N's removal rate; Ca2+ in the solution promoted NH4+-N's removal rate, while Mg2+ and Mn2+ inhibited it. Also, NH4+-N's removal rate improved slightly with Fe2+ concentration's increase and then decreased significantly; With the increase of wastewater's dilution factor, NH4+-N's removal rate showed an upward trend and with the increase of the SAEMZ's reuse times, it decreased. Therefore, recycle times should be controlled less than 3 times in practical application; The SAEMZ still maintains its physiological stability, high mechanical strength, and good storage stability after stored at 4 °C for 120 days.

Biotransformation of 2,4,6-trinitrotoluene (TNT) by a Methanococcus sp. (strain B) isolated from a lake sediment

1994 ◽  
Vol 40 (4) ◽  
pp. 273-278 ◽  
Author(s):  
R. Boopathy ◽  
C. f. Kulpa
Keyword(s):  
Carbon Dioxide ◽  
Mineral Salt Medium ◽  
Optimal Growth ◽  
Sole Source ◽  
Growth Conditions ◽  
Salt Medium ◽  
Ph Range ◽  
The University ◽  
Optimal Ph ◽  
In Cells

A mesophilic, irregular coccoid methanogen, which shows close resemblance to Methanococcus sp., was isolated from a sediment sample of St. Joseph Lake located in the University of Notre Dame campus. Formate or hydrogen plus carbon dioxide served as substrate for methanogenesis in a mineral salt medium. This organism was studied for its ability to metabolize 2,4,6-trinitrotoluene (TNT). The result showed that this isolate could transform 100 ppm of TNT within 40–60 days of incubation at 30 °C. The main intermediate produced was 2,4-diamino-6-nitrotoluene. The TNT transformation rates were higher in cells grown in hydrogen plus carbon dioxide than in cells grown in formate. The isolate did not use acetate and methanol as sole source of carbon and energy. The organism had an optimal pH range of 6.8–7.2. The optimal growth conditions for this isolate are described.Key words: biotransformation, methanogens, bioremediation, nitroaromatics, TNT, anaerobic process.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

Improvement of Ti/RuO2–IrO2 Anode Lifetime and Electrocatalytical Properties by Using an Eco-Friendly Thermal Decomposition Method Using Polyvinyl Alcohol as Solvent

2019 ◽  
Author(s):  
Charlys Bezerra ◽  
Géssica Santos ◽  
Marilia Pupo ◽  
Maria Gomes ◽  
Ronaldo Silva ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Polyvinyl Alcohol ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Pechini Method ◽  
Low Cost ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Calcination Temperatures ◽  
Service Lifetime

<p>Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO<sub>2</sub> and IrO<sub>2</sub> have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes with improved properties that can be further extended to synthesise other MMO compositions.</p>

scholarly journals Naturally Occurring Ecdysteroids in Triticum aestivum L. and Evaluation of Fenarimol as a Potential Inhibitor of Their Biosynthesis in Plants

2021 ◽  
Vol 22 (6) ◽  
pp. 2855
Author(s):  
Anna Janeczko ◽  
Jana Oklestkova ◽  
Danuše Tarkowská ◽  
Barbara Drygaś
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Triticum Aestivum L ◽  
Growth Conditions ◽  
Animal Kingdom ◽  
Experimental Conditions ◽  
P450 Monooxygenase ◽  
Naturally Occurring ◽  
Regulatory Effects ◽  
Potential Use

Ecdysteroids (ECs) are steroid hormones originally found in the animal kingdom where they function as insect molting hormones. Interestingly, a relatively high number of these substances can also be formed in plant cells. Moreover, ECs have certain regulatory effects on plant physiology, but their role in plants still requires further study. One of the main aims of the present study was to verify a hypothesis that fenarimol, an inhibitor of the biosynthesis of ECs in the animal kingdom, also affects the content of endogenous ECs in plants using winter wheat Triticum aestivum L. as a model plant. The levels of endogenous ECs in winter wheat, including the estimation of their changes during a course of different temperature treatments, have been determined using a sensitive analytical method based on UHPLC-MS/MS. Under our experimental conditions, four substances of EC character were detected in the tissue of interest in amounts ranging from less than 1 to over 200 pg·g−1 FW: 20-hydroxyecdysone, polypodine B, turkesterone, and isovitexirone. Among them, turkesterone was observed to be the most abundant EC and accumulated mainly in the crowns and leaves of wheat. Importantly, the level of ECs was observed to be dependent on the age of the plants, as well as on growth conditions (especially temperature). Fenarimol, an inhibitor of a cytochrome P450 monooxygenase, was shown to significantly decrease the level of naturally occurring ECs in experimental plants, which may indicate its potential use in studies related to the biosynthesis and physiological function of these substances in plants.

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