Lab-Scale Study on Removal of Phenol from Contaminated Groundwater by Chlorine Dioxide Oxidation Technology

2012 ◽  
Vol 599 ◽  
pp. 363-366
Author(s):  
Qi Shan Wang ◽  
Ze Xu ◽  
You Wen Zeng ◽  
Shang Chao Yue ◽  
Yi Ran Zhang
Keyword(s):  
Chlorine Dioxide ◽  
Removal Rate ◽  
Contaminated Groundwater ◽  
Phenol Removal ◽  
Reaction Conditions ◽  
Technical Parameters ◽  
Oxidation Technology ◽  
Series Of Experiments ◽  
High Level ◽  
Optimal Reaction

A series of experiments were conducted to investigate the optimal technical parameters for phenol removal by chlorine dioxide (ClO2) oxidation. Results demonstrated that ClO2 could removal phenol effectively, both for simulated phenol contaminated groundwater and practical phenol contaminated groundwater. ClO2 dosage and reaction time were found to have a significant impact on phenol removal, while pH only affected slightly between 6.5 to 7.0 . Under optimal reaction conditions, the removal rate could reach an extremely high level of 97.5% within 30 min at a ClO2 dosage of 0.6 mg/L for the simulated phenol contaminated groundwater with initial phenol concentration of 0.2 mg/L. For the practical phenol contaminated groundwater the removal rate could reach 96% within 60 min at a ClO2 dosage 1.0 mg/L. This study provides a feasible chemical method to removal phenol from contaminated groundwater.

Treatment of cyanide wastewater by bulk liquid membrane using tricaprylamine as a carrier

2016 ◽  
Vol 73 (12) ◽  
pp. 2888-2895 ◽  
Author(s):  
Guoping Li ◽  
Juanqin Xue ◽  
Nina Liu ◽  
Lihua Yu
Keyword(s):  
Organic Phase ◽  
Liquid Membrane ◽  
Removal Rate ◽  
Feed Solution ◽  
Bulk Liquid ◽  
Complexation Reaction ◽  
Bulk Liquid Membrane ◽  
Reaction Conditions ◽  
Optimal Reaction ◽  
Removal And Recovery

Abstract The transport of cyanide from wastewater through a bulk liquid membrane (BLM) containing tricaprylamine (TOA) as a carrier was studied. The effect of cyanide concentration in the feed solution, TOA concentration in the organic phase, the stirring speed, NaOH concentration in the stripping solution and temperature on cyanide transport was determined through BLM. Mass transfer of cyanide through BLM was analyzed by following the kinetic laws of two consecutive irreversible first-order reactions, and the kinetic parameters (k1, k2, Rmmax, tmax, Jamax, Jdmax) were also calculated. Apparently, increase in membrane entrance (k1) and exit rate (k2) constants was accompanied by a rise in temperature. The values of activation energies were obtained as 35.6 kJ/mol and 18.2 kJ/mol for removal and recovery, respectively. These values showed that both removal and recovery steps in cyanide transport is controlled by the rate of the chemical complexation reaction. The optimal reaction conditions were determined by BLM using trioctylamine as the carrier: feed phase: pH 4, carrier TOA possession ratio in organic phase: 2% (V/V), stripping phase concentration of NaOH: 1% (W/V), reaction time: 60 min, stirring speed: 250 r/min. Under the above conditions, the removal rate was up to 92.96%. The experiments demonstrated that TOA was a good carrier for cyanide transport through BLM in this study.

Study on Catalyst of Catalytic Wet Oxidation of High-concentration Industrial Organic Wastewater

2011 ◽  
Vol 233-235 ◽  
pp. 2994-2999 ◽  
Author(s):  
Qing Lin Peng ◽  
Jing Zeng
Keyword(s):  
Removal Rate ◽  
Space Velocity ◽  
Preparation Condition ◽  
Bubble Columns ◽  
Catalytic Wet Oxidation ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
High Concentration ◽  
Reaction Conditions ◽  
Oxidation Technology

A kind of compound catalyst containing the main activate component CuO, the second activate component ZrO2 and electronic promoter La2O3 was prepared. It was applicable to treat with high-concentration dimethyl acetylsuccinate (DMAS) production wastewater with catalytic wet air oxidation technology which was used in continuous bubble columns reactor. In this article the influences of concentration of soaked liquid of every component and the second activate component were studied, and the best preparation condition has been determined. The experimental results indicated that the catalyst of CuO-ZrO2-La2O3/ZSM-5 had a higher activity when handling high-concentration DMAS production wastewater. With this catalyst the CODcr removal rate could get 98.7% while non-catalyst only 35.8％ at the reaction conditions as follows: reaction temperature 240°C, reaction pressure 3.5MPa, liquor space velocity＝2.0 h-1, V (oxygen): V（wastewater）＝250:1 and influent wastewater pH=7.

Reducing the formation of adsorbable organic halides using an ammonium thiosulfate chlorine dioxide bleaching process

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8677-8688
Author(s):  
Yan Li ◽  
Liming Cao ◽  
Kaiqi Gu ◽  
Xinyue Wang ◽  
Yunbiao Pang ◽  
...  
Keyword(s):  
Chlorine Dioxide ◽  
Gas Chromatography Mass Spectrometry ◽  
Bleaching Agent ◽  
Reaction Conditions ◽  
Bleaching Process ◽  
Ammonium Thiosulfate ◽  
Adsorbable Organic Halides ◽  
Organic Halides ◽  
Effective Reduction ◽  
Optimal Reaction

Reducing the formation of adsorbable organic halides during chlorine dioxide bleaching (the first stage chlorine dioxide bleaching, D0) is necessary to obtain clean bleaching processes. A new bleaching agent, ammonium thiosulfate (AT), was investigated to determine its potential for reducing the amount of adsorbable organic halides (AOX). Upon investigating the optimal reaction conditions for an effective reduction in AOX, the authors determined that adding 0.20% of AT 10 min after the beginning of the bleaching reaction, while maintaining a pH of 4 and a temperature of 70°C, yielded the best results. Under these conditions, AOX formation decreased by 22.0%. The bleaching effluent after the addition of AT was analyzed via gas chromatography-mass spectrometry, which showed an inhibited production rate of chlorobenzene and chlorophenol, which are both highly toxic and difficult-to-degrade compounds. Therefore, AT not only reduces AOX formation during the bleaching process, but also minimizes the difficulty of treating bleaching effluent. The results of this study provided a new, clean method for reducing AOX formation during chlorine dioxide bleaching.

Phenol Degradation in the System of H2O2/Porous Tourmaline Composite Materials

2010 ◽  
Vol 178 ◽  
pp. 196-201
Author(s):  
Can Li ◽  
Yan Ding ◽  
Jun Ping Meng ◽  
Li Fang Zhao
Keyword(s):  
Activation Energy ◽  
Hydrogen Peroxide ◽  
Removal Rate ◽  
Phenol Degradation ◽  
Good Effect ◽  
Phenol Removal ◽  
Reaction Conditions ◽  
Optimum Reaction ◽  
Initial Phenol Concentration ◽  
Reaction Activation Energy

Porous tourmaline composite material (PTCM) was prepared mainly by schorl and used to catalyze hydrogen peroxide for the removal of phenol. The optimum reaction conditions were determined by testing the phenol removal rate under the conditions of different initial phenol concentration, hydrogen peroxide dosage, PTCM dosage and temperature. The reaction activation energy was calculated to be 32.148KJ/mol, indicating that PTCM showed good effect on catalyzing hydrogen peroxide, phenol could be degraded quickly and the removal rate could reach 97%. The mechanism of the system was the Fenton-like reaction

Shear Loss Characteristics of an Aerobic Biofilm

1992 ◽  
Vol 26 (3-4) ◽  
pp. 595-600 ◽  
Author(s):  
S. M. Rao Bhamidimarri ◽  
T. T. See
Keyword(s):  
Growth Rate ◽  
Shear Stress ◽  
Film Thickness ◽  
Removal Rate ◽  
Surface Growth ◽  
Phenol Removal ◽  
Concentric Cylinder ◽  
Substrate Utilisation ◽  
Utilisation Rate ◽  
Net Growth Rate

Growth and shear loss characteristics of phenol utilizing biofilm were studied in a concentric cylinder bioreactor. The net accumulation of the biofilm and the substrate utilisation were measured as a function of torque. Uniform biofilms were obtained up to a thickness of around 300 microns, beyond which the surface growth was non-uniform. The substrate utilisation rate, however, reached a constant value beyond film thickness of 50 to 100 microns depending on the operational torque. The maximum phenol removal rate was achieved at a shear stress of 3.5 Nm-2. The effect of shear stress on net growth rate was found to be described byand a zero net growth was obtained at a shear stress of 18.7 Nm-2.

Accelerated Phenol Removal by Amplifying the Metabolic Pathway with a Recombinant Plasmid Encoding Catechol 2, 3 Oxygenase

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2191-2194 ◽  
Author(s):  
M. Fujita ◽  
M. Ike ◽  
T. Kamiya
Keyword(s):  
Metabolic Pathway ◽  
Recombinant Plasmid ◽  
Removal Rate ◽  
Phenol Degradation ◽  
Wild Strain ◽  
Phenol Concentration ◽  
Phenol Removal

The metabolic pathway of the phenol degradation in Pseudomonasputida BH was amplified by introducing the recombinant plasmid containing catechol 2,3 oxygenase gene isolated fron the chromosome of BH. This strain could degrade phenol and grow much faster than the wild strain at the phenol concentration of 100mg/L. This strain seems to accelerate the phenol removal rate if it is applied to the treatment of wastewater containing phenol.

Relations between carbon removal rates, biofilm size and density of a novel anaerobic reactor: the inverse turbulent bed

2000 ◽  
Vol 41 (4-5) ◽  
pp. 253-260 ◽  
Author(s):  
P. Buffière ◽  
R. Moletta
Keyword(s):  
Removal Rate ◽  
Removal Rates ◽  
Carbon Removal ◽  
Biofilm Growth ◽  
Loading Rates ◽  
Biomass Activity ◽  
High Turbulence ◽  
The One ◽  
High Level ◽  
Very High

An anaerobic inverse turbulent bed, in which the biogas only ensures fluidisation of floating carrier particles, was investigated for carbon removal kinetics and for biofilm growth and detachment. The range of operation of the reactor was kept within 5 and 30 kgCOD· m−3· d−1, with Hydraulic Retention Times between 0.28 and 1 day. The carbon removal efficiency remained between 70 and 85%. Biofilm size were rather low (between 5 and 30 μm) while biofilm density reached very high values (over 80 kgVS· m−3). The biofilm size and density varied with increasing carbon removal rates with opposite trends; as biofilm size increases, its density decreases. On the one hand, biomass activity within the reactor was kept at a high level, (between 0.23 and 0.75 kgTOC· kgVS· d−1, i.e. between 0.6 and 1.85 kgCOD·kgVS · d−1).This result indicates that high turbulence and shear may favour growth of thin, dense and active biofilms. It is thus an interesting tool for biomass control. On the other hand, volatile solid detachment increases quasi linearly with carbon removal rate and the total amount of solid in the reactor levels off at high OLR. This means that detachment could be a limit of the process at higher organic loading rates.

Synthesis of Phosphonates via Michaelis-Arbuzov Reaction

2017 ◽  
Vol 14 (6) ◽  
pp. 883-903 ◽  
Author(s):  
Boppudi Hari Babu ◽  
Gandavaram Syam Prasad ◽  
Chamarthi Naga Raju ◽  
Mandava Venkata Basaveswara Rao
Keyword(s):  
Reaction Times ◽  
Biologically Active ◽  
Fine Tuning ◽  
Arbuzov Reaction ◽  
Reaction Conditions ◽  
Solvent Type ◽  
Potential Applications ◽  
Synthetic Methodologies ◽  
Optimal Reaction ◽  
The Arbuzov Reaction

Background: Michaelis–Arbuzov reaction has played a key role for the synthesis of dialkyl or diaryl phosphonates by reacting various alkyl or aryl halides with trialkyl or triaryl phosphite. This reaction is very versatile in the formation of P-C bond from the reaction of aliphatic halides with phosphinites or phosphites to yield phosphonates, phosphinates, phosphine oxides. The Arbuzov reaction developed some methodologies, possible mechanistic pathways, selectivity, potential applications and biologically active various phosphonates. Objective: The synthesis of phosphonates via Michaelis–Arbuzov reaction with many new and fascinating methodologies were developed and disclosed in the literature, and these are explored in this review. Conclusion: This review has discussed past developments and vast potential applications of Arbuzov reaction in the synthesis of organophosphonates. As presented in this review, various synthetic methodologies were developed to prepare a large variety of phosphonates. Improvements in the reaction conditions of Lewis-acid mediated Arbuzov rearrangement as well as the development of MW-assisted Arbuzov rearrangement were discussed. Finally, to achieve high selectivities and yields, fine-tuning of reaction conditions including solvent type, temperature, and optimal reaction times to be considered.

Amperometric assay of vitamin C using an ascorbate oxidase enzyme electrode

1979 ◽  
Vol 44 (11) ◽  
pp. 3395-3404 ◽  
Author(s):  
Pavel Posádka ◽  
Lumír Macholán
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Oxygen Electrode ◽  
Ascorbate Oxidase ◽  
Current Response ◽  
Reaction Conditions ◽  
Long Term Storage ◽  
Oxidase Enzyme ◽  
Optimal Reaction

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.

scholarly journals A Novel Pseudomonas geniculata AGE Family Epimerase/Isomerase and Its Application in d-Mannose Synthesis

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1809
Author(s):  
Zhanzhi Liu ◽  
Ying Li ◽  
Jing Wu ◽  
Sheng Chen
Keyword(s):  
3D Structure ◽  
Three Dimensional ◽  
Optimal Temperature ◽  
Reaction Conditions ◽  
Enzymatic Production ◽  
Physiological Properties ◽  
Potential Applications ◽  
Kinetics Of ◽  
Optimal Reaction ◽  
Gene Age

d-mannose has exhibited excellent physiological properties in the food, pharmaceutical, and feed industries. Therefore, emerging attention has been applied to enzymatic production of d-mannose due to its advantage over chemical synthesis. The gene age of N-acetyl-d-glucosamine 2-epimerase family epimerase/isomerase (AGEase) derived from Pseudomonas geniculata was amplified, and the recombinant P. geniculata AGEase was characterized. The optimal temperature and pH of P. geniculata AGEase were 60 °C and 7.5, respectively. The Km, kcat, and kcat/Km of P. geniculata AGEase for d-mannose were 49.2 ± 8.5 mM, 476.3 ± 4.0 s−1, and 9.7 ± 0.5 s−1·mM−1, respectively. The recombinant P. geniculata AGEase was classified into the YihS enzyme subfamily in the AGE enzyme family by analyzing its substrate specificity and active center of the three-dimensional (3D) structure. Further studies on the kinetics of different substrates showed that the P. geniculata AGEase belongs to the d-mannose isomerase of the YihS enzyme. The P. geniculata AGEase catalyzed the synthesis of d-mannose with d-fructose as a substrate, and the conversion rate was as high as 39.3% with the d-mannose yield of 78.6 g·L−1 under optimal reaction conditions of 200 g·L−1d-fructose and 2.5 U·mL−1P. geniculata AGEase. This novel P. geniculata AGEase has potential applications in the industrial production of d-mannose.

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