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.

Photodegradation of Dimethyl Phthalate Induced by Photolysis of Fe(III)-Pyruvate Complex

2012 ◽  
Vol 518-523 ◽  
pp. 2653-2656
Author(s):  
Xiang Hua Feng ◽  
Liang Ding ◽  
Shi Min Ding
Keyword(s):  
Ph Value ◽  
Degradation Efficiency ◽  
Uv Disinfection ◽  
Light Sources ◽  
Dimethyl Phthalate ◽  
Initial Concentration ◽  
Photodegradation Efficiency ◽  
Optimum Ph ◽  
Initial Ph ◽  
Metal Halide Lamps

Photodegradation of dimethyl phthalate (DMP) in aqueous solutions by Fe(III)-pyruvate complex system was preliminarily investigated. The influences such as light sources, initial pH value, initial concentration of Fe(III), pyruvate and DMP on photodegradation efficiency of DMP were discussed in detail. The result indicates that DMP could be decomposed efficiently in Fe(III)-pyruvate system. The degradation efficiency of DMP are dependent on initial pH value, Fe (III) initial concentration and pyruvate initial concentration. The optimum pH for photodegration of DMP is 3.0. The degradation efficiency of DMP increases with increase of the initial concentrations of Fe(III) or pyruvate, whereas decreases with increase of the initial concentrations of DMP. Various light sources including metal halide lamps, daylight lamps, UV disinfection lamps and sunlight can be adopted in the system.

Photodegradation of Dimethyl Phthalate by Fe(III)/Oxalate/H2O2 System

2012 ◽  
Vol 550-553 ◽  
pp. 2412-2415 ◽  
Author(s):  
Xiang Hua Feng ◽  
Jun Zhou ◽  
Shi Min Ding
Keyword(s):  
Ph Value ◽  
Degradation Efficiency ◽  
Light Sources ◽  
Dimethyl Phthalate ◽  
Photochemical Process ◽  
Photodegradation Efficiency ◽  
Optimum Ph ◽  
Initial Ph ◽  
High Level ◽  
Metal Halide Lamps

Photodegradation of dimethyl phthalate (DMP) in aqueous solutions by Fe(III)/oxalate/H2O2 system was investigated using daylight lamps as main light source. The UV-Vis spectra of the system and the concentration of •OH generated during irradiation were detected. The influences such as light sources, initial pH value, initial concentration of reactants on photodegradation efficiency of DMP were discussed. This system has advantage in appling visible light to produce •OH. DMP degradation efficiency principally depend on the concentration of •OH produced from photochemical process of the system. Several light sources including daylight lamps, metal halide lamps, UV disinfecting lamp and sunlight can all be as the light sources to achieve DMP degradation. DMP degradation efficiency keeps on a high level over the range of pH 3.0 to 5.0 and the optimum pH is 3.0. The degradation rate of DMP increases with increase of the initial concentrations of Fe(III) and H2O2, whereas decreases with increase of the initial concentrations of oxalate.

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.

Optimum and Efficiency of Chloramphenicol Degradation by UV/H2O2 Process

2013 ◽  
Vol 838-841 ◽  
pp. 2677-2680 ◽  
Author(s):  
Yan Bo Li ◽  
Cui Ping Wang ◽  
Ming Yue Zheng ◽  
Kai Jun Wang
Keyword(s):  
Reaction Time ◽  
Advanced Oxidation Process ◽  
Oxidation Process ◽  
Ph Value ◽  
Advanced Oxidation ◽  
Degradation Efficiency ◽  
Complete Degradation ◽  
Initial Ph ◽  
Operation Parameters

Degradation of chloramphenicol (CAP) by an advanced oxidation process, UV/H2O2, was investigated. Firstly, effect of H2O2 concentration, initial pH value, K2S2O8 concentration and reaction time on chloramphenicol degradation by UV/H2O2 process was studied. In addition, all the operation parameters mentioned above were optimized. The results showed that the degradation efficiency of CAP can be obviously enhanced with increasing both H2O2 concentration and K2S2O8 concentration. Moreover, initial pH value had unapparent impact on the efficiency of chloramphenicol degradation. Nearly complete degradation of chloramphenicol was achieved under the conditions of H2O2 concentration 2mM, initial pH value 7.7, K2S2O8 concentration 1mM and reaction time 15min.

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.

Synthesis and Oxidizability Study on Mn3O4 Nanoparticles

2017 ◽  
Vol 48 ◽  
pp. 138-147 ◽  
Author(s):  
Xin Li Hao ◽  
Jing Zhe Zhao ◽  
Yue Hong Song ◽  
Zhi Fang Huang
Keyword(s):  
Crystal Growth ◽  
Rhodamine B ◽  
Ph Value ◽  
Reaction System ◽  
Degradation Process ◽  
Degradation Efficiency ◽  
Precipitation Method ◽  
Peg 6000 ◽  
Size And Shape ◽  
Major Factors

Sphere-like Mn3O4 nanoparticles were prepared by a simple aqueous precipitation method at 30 °C for 1.5 h with PEG 6000 involved. The as-prepared Mn3O4 nanoparticles extended sphere-like structures with sizes of around 80 nm. The size and shape could be manipulated by changing the species of alkali. Introduction of PEG6000 in the experiments caused the inhibition of crystal growth. The oxidiability of as-prepared Mn3O4 nanoparticles was evaluated by degradation of rhodamine B (RhB). The pH value of the reaction system was major factors to be assessed in the degradation process. After 120 minutes’ reaction, the degradation efficiency can reach 61.3 %.

scholarly journals Degradation of Norfloxacin in an Aqueous Solution by the Nanoscale Zero-Valent Iron-Activated Persulfate Process

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yanchang Zhang ◽  
Lin Zhao ◽  
Yongkui Yang ◽  
Peizhe Sun
Keyword(s):  
Degradation Process ◽  
High Reactivity ◽  
Degradation Efficiency ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
Paramagnetic Resonance ◽  
Promising Alternative ◽  
Quenching Effect ◽  
Nanoscale Zero Valent Iron ◽  
Initial Ph

In this study, nanoscale zero-valent iron (nZVI) was synthesized and used to activate persulfate (PS) for the degradation of norfloxacin (NOR). The nZVI/PS system exhibited a high reactivity towards NOR, and the degradation efficiency of NOR (100 mg/L) reached 93.8% with 0.1 g/L nZVI, 12 mM PS, and an initial pH of 7.0 within 7 min. The NOR degradation followed a pseudo-first-order kinetic model, and the effects of parameters such as nZVI dosage, PS concentration, initial pH, and temperature were investigated systematically. Overloading of nZVI lowered the degradation efficiency owing to the quenching effect of excessive Fe2+. The higher PS concentration and temperature favored the degradation of NOR. The influence of pH was not obvious, and the degradation was effective in a wide pH range. In addition, the radical quenching experiments and electron paramagnetic resonance (EPR) indicated that both sulfate radical (SO4⋅-) and hydroxyl radical (OH⋅) were the dominant radicals in the degradation process, in which the latter played a more important role. Finally, three degradation pathways were proposed based on the result of intermediates identified by liquid chromatography-mass spectrometry. Overall, this study indicated that the nZVI/PS system could provide a promising alternative for NOR wastewater treatment.

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.

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