scholarly journals Optimization parameters for Mycobacteria confluentis biodegradation of PAHs

2018 ◽  
Vol 150 ◽  
pp. 06035
Author(s):  
Muna Ibrahim ◽  
Essam A. Makky ◽  
Nina S. Azmi ◽  
Jamil Ismail
Keyword(s):  
Incubation Period ◽  
Process Parameters ◽  
Ph Value ◽  
Degradation Process ◽  
Inoculum Size ◽  
Bacterial Concentration ◽  
Maximum Percentage ◽  
Bacterial Inoculum ◽  
Initial Ph ◽  
Optimization Parameters

In this study, the effect of process parameters (incubation period, temperature, initial pH-value, concentration of PAHs in the medium, and bacterial inoculum size) on the biodegradation of PAHs using Mycobacteria confluentis was studied using One-Factor-At-a-Time (OFAT) method. From the results of the study, it was observed that the studied parameters had significant effects on the degradation process. The capability of Mycobacteria confluentis on the degradation of PAHs was found to be maximum when the initial pH of the PAH was 7, temperature 40 °, PAH concentration of 50 μL, bacterial concentration of 7.5 mL, and incubated for 3 to 5 days. This condition gave a PAH degradation percentage of 40 to 50 %, showing a similarity to most previous studies where the maximum percentage of degradation has been around 40 to 50 %. This study, therefore, concludes that Mycobacteria confluentis is a good PAHs degrader which can be of significant important in the management of oil polluted fields and environments.

Optimization of Degrading Poly-Containing Wastewater Conditions of Mixed Bacteria by Orthogonal Experiments

2012 ◽  
Vol 550-553 ◽  
pp. 2386-2390
Author(s):  
Jiang Hong Liu ◽  
Rui Dan Xu ◽  
Yang Pan ◽  
Yuan Ying Wang
Keyword(s):  
Ph Value ◽  
Nitrogen Sources ◽  
Inoculum Size ◽  
Optimum Process ◽  
Process Conditions ◽  
Activation Time ◽  
Orthogonal Experiments ◽  
Phosphorus Sources ◽  
Initial Ph ◽  
Mixed Bacteria

The factor influencing on the mixed bacteria to degrade wastewater containing poly-containing conditions were optimized. Crude oil as a source of carbon, the effects of nitrogen sources, phosphorus sources, time, inoculation amount, temperature, mineralization content, initial pH value and activation time on degrading poly-containing wastewater were investigated by experiment of single factor and orthogonal experiments. The optimum process conditions were as follows: polyacrylamide (HPAM) which comes from waste water as a source of nitrogen, without other nitrogen source, K2HPO4 was phosphorus sources, the microorganisms activation time was 2, incubation time was 3d, initial pH value was 7, the inoculum size was 5%(v/v), incubation temperature was 35°C, the mineralization degree was 4000 mg•L-1. The main factors affecting degradation rate was nitrogen sources, time, pH, activation time, inoculum size and mineralization content.

Photocatalytic Treatment of MO in Water with BiOBr Photocatalyst

2011 ◽  
Vol 694 ◽  
pp. 554-558 ◽  
Author(s):  
Xiao Xia Zhao ◽  
Yan Wang ◽  
Zhu Qing Shi ◽  
Cai Mei Fan
Keyword(s):  
Degradation Rate ◽  
Ph Value ◽  
Degradation Process ◽  
Xenon Lamp ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
X Ray ◽  
Hydrolysis Method ◽  
Methylene Orange ◽  
Initial Ph

The BiOBr catalyst prepared by the hydrolysis method was investigated with the X-ray diffractometry(XRD) and scanning electron microscope (SEM). The results show that the catalyst was the tetragonal primitive crystal structure and composed of homogeneous particles of fine ferrite plates. At the same time, the photocatalytic activity of BiOBr catalyst was evaluated by methylene orange (MO) in aqueous solution illuminated by Xenon lamp, and the degradation process parameters, such as initial concentration of MO, initial pH value and amount of BiOBr catalyst were discussed to the degradation rate of the MO. Under the following experimental conditions of C0=10mg/L, pH=8, m(BiOBr)=1.0g/L, MO can be entirely degraded after 2.5 hours.

KN-B removal from water by non-thermal plasma

2013 ◽  
Vol 68 (6) ◽  
pp. 1288-1292 ◽  
Author(s):  
Ya-nan Liu ◽  
Lu Tian ◽  
Rui Li ◽  
Shu-fang Mei ◽  
Gang Xue ◽  
...  
Keyword(s):  
Barrier Discharge ◽  
Ph Value ◽  
Degradation Process ◽  
Reactive Black 5 ◽  
Dielectric Barrier ◽  
Chromophore Group ◽  
Low Concentrations ◽  
Initial Ph ◽  
Non Thermal Plasma ◽  
High Concentrations

The degradation of Reactive Black 5 (KN-B) in water using double-dielectric barrier discharge (DDBD) was studied. Experimental results showed that the KN-B degradation rate increased as the initial pH decreased. Low concentrations of Fe2+ enhanced the degradation, whereas high concentrations of Fe2+ hindered the degradation. The results showed that DDBD did not noticeably reduce total organic carbon but did reduce the pH value and improve the biodegradability of the solution significantly. Furthermore, the UV–Vis spectra of the dye showed that the chromophore group was damaged and that the solution was decolorized after the 10-min degradation process.

scholarly journals Screening of Culture Conditions for Production of Xylanase from Landfill Soil Bacteria

2019 ◽  
Vol 19 (2) ◽  
pp. 470 ◽  
Author(s):  
Siti Nor Amira Rosli ◽  
Rohaida Che Man ◽  
Nasratun Masngut
Keyword(s):  
Carbon Source ◽  
Moisture Content ◽  
Nitrogen Source ◽  
Incubation Period ◽  
Xylanase Activity ◽  
Nitrogen Sources ◽  
Culture Conditions ◽  
Inoculum Size ◽  
Xylanase Production ◽  
Initial Ph

Culture conditions including initial pH media, incubation period, inoculum size, type of carbon source, type of nitrogen source and its concentration, which affect xylanase production were screened via the one-factor-at-a-time approach. The bacteria used in the production of xylanase was isolated from the landfill site at Sg. Ikan, Kuala Terengganu, Malaysia. Three characterizations of the landfill soil were investigated for their moisture content, ash content, and pH. The culture conditions range used in the experimental work were between 6–30 h for the incubation period, with initial pH between 5–9, inoculum size between 1–20% v/v, carbon, nitrogen sources, and nitrogen source concentration between 1–5% w/v. Xylanase activity was estimated using dinitrosalicylic acid (DNS) based on the release of xylose under standard assay conditions. The landfill soil was observed to have pH between pH 3.4–7.2 with a moisture content between 12.4–33.7% and ash ranged between 3.5–4.3%. Results showed that the highest xylanase activity within studied ranges was recorded at 25.91±0.0641 U/mL with 10% (v/v) inoculum size, 1% (w/v) xylose as sole carbon source, mixture of 1% (w/v) peptone and 0.25% (w/v) ammonium sulphate as nitrogen sources, which was carried out at initial pH of 8.0 for 24 h incubation.

Assessment of the Effects of Combined Fe/C Microelectrolysis–Electro-Fenton on the Acrylonitrile Removal from Analogue Wastewater

2012 ◽  
Vol 610-613 ◽  
pp. 2323-2327 ◽  
Author(s):  
Ming Zhong Hu ◽  
Zhong Hao Shen
Keyword(s):  
Reaction Time ◽  
Chemical Oxygen Demand ◽  
Process Parameters ◽  
Active Carbon ◽  
Ph Value ◽  
Electrochemical Reaction ◽  
Oxygen Demand ◽  
Optimal Conditions ◽  
Optimization Parameters ◽  
Percentage Removal

In the present work, acrylonitrile removal from analogue wastewater was investigated using the combined Fe/C microelectrolysis–electro-Fenton. The optimization parameters such as ratio of Fe/C, pH value, the reaction time, the dose of H2O2, the voltage, and the stir time on the acrylonitrile removal efficiency were determined by measuring the percentage removal of Chemical Oxygen Demand (CODcr) in the acrylonitrile analogue wastewater. In the Microelectrolysis section, the ratio of Fe/C was 1:1, the pH value was 3.0, and reaction time was 1h. In the electrolyzing Fenton, the optimal conditions of process parameters were the dose of H2O2 oxidant (5ml/L), the voltage (2.0 V), electrochemical reaction time (40min), and stir time (20min).Under the optimal conditions, the percentage removal of was 69% in first section and about 35% in the second section. Also, the dose of oxidant (H2O2) decreased from 11ml/L to 5ml/L compared with the using single active carbon method.

scholarly journals Biodegradation of Dimethyl Phthalate by Freshwater Unicellular Cyanobacteria

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaohui Zhang ◽  
Lincong Liu ◽  
Siping Zhang ◽  
Yan Pan ◽  
Jing Li ◽  
...  
Keyword(s):  
Degradation Product ◽  
Phthalic Acid ◽  
Ph Value ◽  
Degradation Process ◽  
Degradation Efficiency ◽  
Culture Solution ◽  
Optimum Temperature ◽  
Dimethyl Phthalate ◽  
Initial Ph ◽  
Unicellular Organisms

The biodegradation characteristics of dimethyl phthalate (DMP) by three freshwater unicellular organisms were investigated in this study. The findings revealed that all the organisms were capable of metabolizing DMP; among them, Cyanothece sp. PCC7822 achieved the highest degradation efficiency. Lower concentration of DMP supported the growth of the Cyanobacteria; however, with the increase of DMP concentration growth of Cyanobacteria was inhibited remarkably. Phthalic acid (PA) was detected to be an intermediate degradation product of DMP and accumulated in the culture solution. The optimal initial pH value for the degradation was detected to be 9.0, which mitigated the decrease of pH resulting from the production of PA. The optimum temperature for DMP degradation of the three species of organisms is 30°C. After 72 hours’ incubation, no more than 11.8% of the residual of DMP aggregated in Cyanobacteria cells while majority of DMP remained in the medium. Moreover, esterase was induced by DMP and the activity kept increasing during the degradation process. This suggested that esterase could assist in the degradation of DMP.

scholarly journals Hydrothermal Synthesis of Various Shape-Controlled Europium Hydroxides

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 529
Author(s):  
Hongjuan Zheng ◽  
Kongjun Zhu ◽  
Ayumu Onda ◽  
Kazumichi Yanagisawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ph Value ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Hydrothermal Reactions ◽  
Starting Solution ◽  
Initial Ph ◽  
Shape Controlled ◽  
Scanning Electron

Eu(OH)3 with various shape-controlled morphologies and size, such as plate, rod, tube, prism and nanoparticles was successfully synthesized through simple hydrothermal reactions. The products were characterized by XRD (X-Ray Powder Diffraction), FE-SEM (Field Emission- Scanning Electron Microscopy) and TG (Thermogravimetry). The influence of the initial pH value of the starting solution and reaction temperature on the crystalline phase and morphology of the hydrothermal products was investigated. A possible formation process to control morphologies and size of europium products by changing the hydrothermal temperature and initial pH value of the starting solution was proposed.

scholarly journals The sorption of inorganic arsenic on modified sepiolite: Effect of hydrated iron(III)-oxide

2014 ◽  
Vol 79 (7) ◽  
pp. 815-828 ◽  
Author(s):  
Nikola Ilic ◽  
Slavica Lazarevic ◽  
Vladana Rajakovic-Ognjanovic ◽  
Ljubinka Rajakovic ◽  
Djordje Janackovic ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Arsenic Removal ◽  
Ph Value ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Deionized Water ◽  
Order Kinetic ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of inorganic arsenic species, As(III) and As(V), from water by sepiolite modified with hydrated iron(III) oxide was investigated at 25 ?C through batch studies. The influence of the initial pH value, the initial As concentrations, the contact time and types of water on the sorption capacity was investigated. Two types of water were used, deionized and groundwater. The maximal sorption capacity for As(III) from deionized water was observed at initial and final pH value 7.0, while the bonding of As(V) was observed to be almost pH independent for pH value in the range from 2.0 to 7.0, and the significant decrease in the sorption capacity was observed at pH values above 7.0. The sorption capacity at initial pH 7.0 was about 10 mg g?1 for As(III) and 4.2 mg g?1 for As(V) in deionized water. The capacity in groundwater was decreased by 40 % for As(III) and by 20 % for As(V). The Langmuir model and pseudo-second order kinetic model revealed good agreement with the experimental results. The results show that Fe(III)-modified sepiolite exhibits significant affinity for arsenic removal and it has a potential for the application in water purification processes.

scholarly journals The Removal of Methylene Blue Dye from Aqueous Solutions Using Activated and Non-Activated Bentonites

2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah
Keyword(s):  
Methylene Blue ◽  
Ph Value ◽  
Sodium Dodecyl ◽  
Freundlich Isotherm ◽  
Blue Dye ◽  
Batch Adsorption ◽  
Ionic Surfactant ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Initial Ph

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.

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