Degradation Of Quinoline Research Articles

Degradation of pyridine and quinoline in aqueous solution by gamma radiation

In present work, the degradation of two N-heteroaromatic pollutants, i.e., pyridine and quinoline was investigated by gamma irradiation in the presence of TiO2 nanoparticle. The experimental results showed that quinoline has a higher degradation rate than pyridine. The removal efficiency of the pollutants, TOC and TN reached 93.0%, 11.9% and 12.0% for quinoline, 71.0%, 10.6% and 4.4% for pyridine, respectively at 7.0kGy and initial concentration of 50mg/L. Ammonium was detected for both pyridine and quinoline within the absorbed doses, suggesting that the organic nitrogen was transformed into ammonium. The degradation rate constant of pyridine and quinoline was increased by 1.1–1.5 times with addition of TiO2. TiO2 nanoparticles were especially effective to enhance the mineralization. The removal efficiency of TOC and TN was increased by 15–12% for pyridine and 23–25% for quinoline, respectively in the presence of 2.0g/L TiO2. Following gamma irradiation, 2-hydroxypyridine, 3-hydroxypyridine, oxalic acid and formic acid were identified for pyridine and the hydroxyl quinoline and formic acid were detected for quinoline. Accordingly, the degradation mechanism of pyridine and quinoline by gamma irradiation was tentatively proposed.

Carbon and hydrogen isotope fractionation during aerobic biodegradation of quinoline and 3-methylquinoline.

Compound-specific isotope analysis has been used extensively to investigate the biodegradation of various organic pollutants. To date, little isotope fractionation information is available for the biodegradation of quinolinic compounds. In this study, we report on the carbon and hydrogen isotope fractionation during quinoline and 3-methylquinoline aerobic microbial degradation by a Comamonas sp. strain Q10. Degradation of quinoline and 3-methylquinoline was accompanied by isotope fractionation. Large hydrogen and small carbon isotope fractionation was observed for quinoline while minor carbon and hydrogen isotope fractionation effects occurred for 3-methylquinoline. Bulk carbon and hydrogen enrichment factors (ε bulk) for quinoline biodegradation were -1.2±0.1 and -38±1‰, respectively, while -0.7±0.1 and -5±1‰ for 3-methylquinoline, respectively. This reveals a potential advantage for employing quinoline as the model compound and hydrogen isotope analysis for assessing aerobic biodegradation of quinolinic compounds. The apparent kinetic isotope effects (AKIEC) values of carbon were 1.008±0.0005 for quinoline and 1.0048±0.0005 for 3-methylquinoline while AKIEH values of hydrogen of 1.264±0.011 for quinoline and 1.0356±0.0103 for 3-methylquinoline were obtained. The combined evaluation of carbon and hydrogen isotope fractionation yields Λ values (Λ=Δδ2H/Δδ13C≈εHbulk/εCbulk) of 29±2 for quinoline and 8±2 for 3-methylquinoline. The results indicate that the substrate specificity may have a significant influence on the isotope fractionation for the biodegradation of quinolinic compounds. The substrate-specific isotope enrichment factors would be important for assessing the behavior and fate of quinolinic compounds in the environment.

Catalytic ozonation of quinoline using nano-MgO: Efficacy, pathways, mechanisms and its application to real biologically pretreated coal gasification wastewater

Nano-MgO was prepared by homogeneous precipitation method and applied for the degradation of quinoline. The characterization of the catalyst was determined by X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), Transmission Electron Microscope (TEM) and Energy Dispersive Spectrometer (EDS). The results showed that the presence of nano-MgO significantly improved the degradation and mineralization of quinoline. Nine intermediates were identified by liquid chromatograph–tandem mass spectrometer (LC–MS/MS), gas chromatograph and mass spectrometry (GC–MS) and ion chromatograph (IC) analysis. And a possible degradation pathway of quinoline in catalytic ozonation was proposed. The change of dissolved ozone concentration and the effect of tert butyl alcohol (TBA) and phosphate indicated that the prepared catalyst could enhance ozone decomposition into hydroxyl radicals, which was considered to be mainly responsible for the pollutants removal. In addition, catalytic ozonation pretreatment was applied for the treatment of biologically pretreated coal gasification wastewater. The results demonstrated that catalytic ozonation pre-treatment improved the biodegradability of wastewater containing quinoline in terms of BOD5/COD (B/C), toxicity and resazurin dehydrogenase activity (DHA), indicating the potential of catalytic ozonation integrated with biosystem for this type of wastewater. This study would assist in obtaining a better understanding of the application of catalytic ozonation pre-treatment in biologically pretreated coal gasification wastewater.

Aerobic Degradation Characteristics of the Quinoline-Degrading strain Ochrobactrum sp. and Its Bioaugmentation in Coking Wastewater

Quinoline is one of the common refractory organic pollutants in coking wastewater. An aerobic bacterial strain KDQ3 capable of utilizing quinoline as the sole source of carbon, nitrogen and energy was isolated from activated sludge of a coking wastewater treatment plant. The morphological properties and the 16S rDNA sequence identified KDQ3 as Ochrobactrum sp.. The optimized temperature and initial pH for quinoline degradation were 37℃ and 7.0-8.0, and the degradation kinetics fit with Haldane's model. KDQ3 could degrade 200 mg·L-1 quinoline in the presence of 10.4 mg·L-1 hexavalent chromium. In addition, KDQ3 was able to degrade quinoline in real coking wastewater of aerobic tank and improve the removal of COD, indicating that KDQ3 had the potential of bioaugmentation for removal of quinoline from coking wastewater.

Photo‐activated periodate in homogeneous degradation and mineralization of quinoline: Optimization, kinetic, and energy consumption

Aqueous solutions of quinoline (Qu) were treated with photo‐activated potassium periodate (UV/KPI) process. A low consumption, cylindrical photo‐reactor was employed for this purpose. Either KPI oxidant or UV irradiation alone had little effect in Qu degradation; however, the combined UV/KPI process leads to significant degradation and mineralization. Experiments were conducted based on central composite design (CCD) methodology. The established optimized conditions for treatment of 40 mg L−1 of the substrate were [KPI] = 695.5 mg L−1, pH = 4.3 and T = 35.6 °C. Under these conditions, 96.5% degradation and 71.5% mineralization were obtained after 70 min operations. A quadratic equation predicts the variation of degradation efficiency as a function of the influencing parameters. To investigate about the involved species, tert‐butyl alcohol was used as radical scavenger and it was found that the contribution of hydroxyl radical was about 73.1%. Kinetic study revealed that Qu degradation was a pseudo first‐order reaction and the corresponding activation energy was determined. Meanwhile, the required irradiation energy for one order of magnitude degradation was estimated as 3.13 kWh m−3. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1621–1627, 2017

Electrochemical oxidation of quinoline aqueous solution on β-PbO2 anode and the evolution of phytotoxicity on duckweed.

Electrochemical oxidation of quinoline on a β-PbO2 electrode modified with fluoride resin and the comprehensive toxicity of intermediates formed during oxidation on duckweed were investigated in detail. The results showed that quinoline was initially hydroxylated at the C-2 and C-8 positions by hydroxyl radicals (·OH) electro-generated on a β-PbO2 anode, yielding 2(1H)-quinolinone and 8-hydroxyquinoline, then undergoing ring cleavage to form pyridine, nicotinic acid, pyridine-2-carboxaldehyde and acetophenone, which were ultimately converted to biodegradable organic acids. NO3- was the final form of quinoline-N. The growth of duckweed exposed to the oxidized quinoline solution was gradually inhibited with the decrease in pH and the formation of intermediates. However, the growth inhibition of duckweed could be eliminated beyond 120 min of oxidation, indicating the comprehensive toxicity of the quinoline solution reduced when the amount of quinoline removed was above 80%. Additionally, the adjustment of the pH to 7.5 and the addition of nutrients to the treated quinoline solution before culturing duckweed could obviously alleviate the inhibition on duckweed. Thus, partial electrochemical degradation of quinoline offers a cost-effective and clean alternative for pretreatment of wastewater containing nitrogen-heterocyclic compounds before biological treatment. The duckweed test presents a simple method for assessing the comprehensive toxicity of intermediates.

Catalytic peroxidation of recalcitrant quinoline by ceria impregnated granular activated carbon

In this work, quinoline (a recalcitrant poly-nuclear aromatic compound) mineralization was studied by catalytic peroxidation process using ceria impregnated granular activated carbon. Various catalysts with different loading of ceria were prepared by wetness impregnation method and further characterized by liquid nitrogen adsorption–desorption technique, X-ray diffraction, scanning electron microscopy, thermo-gravimetric analysis and Fourier transform infrared spectroscopy. Effects of various parameters like ceria loading, pH, catalyst dose (Cw), H2O2/quinoline molar ratio, initial concentration (Co) of quinoline, reaction temperature (T) and time on quinoline degradation and chemical oxygen demand (COD) removal efficiencies were studied. Quinoline degradation of 81.6% and COD removal of 86.5% were observed at optimum operating condition of pH = 4, Co = 100 mg/L, Ce loading = 7.5 wt%, H2O2/quinoline molar ratio = 1, Cw = 0.5 g/L, T = 55 °C and reaction time = 4 h. The kinetics of the oxidation process was represented by the power law model.

Comparison of bacterial community characteristics between complete and shortcut denitrification systems for quinoline degradation.

For quinoline-denitrifying degradation, very few researches focused on shortcut denitrification process and its bacterial community characteristics. In this study, complete and shortcut denitrification systems were constructed simultaneously for quinoline degradation. By calculation, specific quinoline removal rates were 0.905 and 1.123g/(gVSSd), respectively, in the complete and shortcut systems, and the latter was 1.24 times of the former. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), high-throughput sequencing, and quantitative PCR (qPCR) techniques based on 16S rRNA were jointly applied to compare microbial community structures of two systems. Many denitrifying bacteria phyla, classes, and genera were detected in the two systems. Phylum Proteobacteria, Class Gammaproteobacteria, and Genus Alicycliphilus denitrificans were the dominant contributors for quinoline-denitrifying degradation. In the shortcut denitrification system, main and specific strains playing crucial roles were more; the species richness and the total abundance of functional genes (narG, nirS, nirK, and nosZ) were higher compared with the complete denitrification system. It could be supposed that inorganic-nitrogen reductase activity of bacterial community was stronger in the shortcut denitrification system, which was the intrinsic reason to result in higher denitrification rate.

Preparation of MWCNTs-TiO2 photocatalyst in thin liquid films under continuous flow conditions and their photocatalytic activities for quinoline degradation

Preparation of MWCNTs-TiO2 photocatalyst in thin liquid films under continuous flow conditions and their photocatalytic activities for quinoline degradation

Degradation of the Nitrogenous Heterocyclic Compound Quinoline by O3/UV

The influences of various factors including initial concentration of quionline solution, static duration after reaction, initial pH, HCO3-on the degradation of quinoline by O3/UV were analyzed in this study. In addition, the degradation mechanism and pathways were also analyzed. The results showed that reaction rate constants and removal rate of quinoline decreased with the increase of the initial concentration of quinoline. The best degradation efficiency of quinoline was achieved under the alkaline conditions (pH 7-9). Removal rate of quinoline was obviously influenced by HCO3-, and was reduced by 42.01% within 6 min when the concentration of HCO3- was 100 mg·L-1. There was neglected effect of static duration after reaction on the removal rate and mineralization rate of quinolone. The intermediate products of quinoline were mainly 8-hydroxyquinoline, 5-hydroxyquinoline, 2(1H)-quinoline ketone, 2-pyridinecarboxaldehyde and so on. The main degradation pathways of quinoline in the O3/UV system were addition reaction, substitution reaction and electrophilic substitution mediated by O3 and·OH.

Electrochemical oxidation of reverse osmosis concentrate using a novel electrode: Parameter optimization and kinetics study

Pharmaceutical wastewater is difficult to be treated efficiently by the conventional biological wastewater treatment plant and reverse osmosis is a solution for this kind of wastewater pollution control. One limitation for RO application in pharmaceutical wastewater treatment is the treatment of RO concentrate. This work prepared a Co doped PbO2 anode and assessed the treatment of reverse osmosis concentrates with electrochemical oxidation process using this Co doped PbO2 anode. The operational parameters which have an influence on the electrochemical oxidation of quinoline, including the current density, the initial concentration of quinoline and the initial value of pH, were studied. The results revealed that the electrochemical degradation of quinoline followed the pseudo-first-order kinetics and the optimal removals of quinoline and COD were 100% and 59.35% after 120min. The EE/O was calculated among all the experiments which showed that the Co doped electrode would greatly reduce the EE/O value. The degradation mechanism and kinetics were analyzed and the intermediates including kinds of organic acids generated during the process of electrolysis were analyzed. This paper can provide a technique reference for the reverse osmosis concentrate pollution control.

Enhancing quinoline and phenol removal by adding Comamonas testosteroni bdq06 in treatment of an accidental dye wastewater

Accidentally released dye wastewater, which contained high concentrations of quinoline, phenol and other phenolics, was successfully treated by adding Comamonas testosteroni bdq06 and supplementing with domestic wastewater. Higher efficiency of 85.1% TOC removal was achieved by the bioaugmentation comparing to the control and no significant shock was observed from increasing the organic loadings. For the control, the removal of TOC was 11.1% less and the recovery of the shock was about 12 days. The addition of C. testosteroni bdq06 enhanced complete degradation of quinoline, phenol and other refractory compounds in the wastewater. DGGE result demonstrated that the inoculated C. testosteroni bdq06 adapted and proliferated in the process and predominated in quinoline degradation. Adding C. testosteroni bdq06 was shown to be an effective method for the treatment of wastewater containing quinoline, phenol and other refractory compounds.

Quinoline-degrading strain Pseudomonas aeruginosa KDQ4 isolated from coking activated sludge is capable of the simultaneous removal of phenol in a dual substrate system

ABSTRACTQuinoline is a refractory organic compound in the treatment of coking wastewater. The isolation of high efficiency quinoline-degrading bacteria from activated sludge and the evaluation of their degradation characteristics in the presence of phenol or in the actual coking wastewater are important for the improvement of effluent quality. The novel bacterial strain Pseudomonas aeruginosa KDQ4 was isolated from a quinoline enrichment culture obtained from the activated sludge of a coking wastewater treatment plant. The optimum temperature and initial pH for quinoline degradation were 33–38°C and 8–9, respectively. KDQ4 completely degraded 400 mg/L of quinoline within 24 h and 800 mg/L of phenol within 30 h. In the dual-substrate system, the removal efficiencies of quinoline and phenol at the same initial concentration (200 mg/L) by KDQ4 were 89% and 100% within 24 h, respectively, indicating that KDQ4 could simultaneously and quickly degrade quinoline and phenol in a coexistence system. Moreover, KDQ4 was able to adapt to actual coking wastewater containing high quinoline and phenol concentrations and rapidly remove them. KDQ4 also exhibited heterotrophic nitrification and aerobic denitrification potential under aerobic conditions. These results suggested a potential bioaugmentation role for KDQ4 in the removal of nitrogen-heterocyclic compounds and phenolics from coking wastewater.

Facile synthesis of NiS/CdS nanocomposites for photocatalytic degradation of quinoline under visible-light irradiation

NiS/CdS nanocomposites with good visible-light-induced photocatalytic activity were successfully prepared via a facile two-step process.

HETEROGENEOUS PHOTO-FENTON DEGRADATION OF QUINOLINE WITH A NOVEL INTERNAL CIRCULATING FLUIDIZED-BED REACTOR

The removal of quinoline from synthetic wastewater by heterogeneous photo-Fenton in a novel internal circulating fluidized-bed reactor was investigated systematically. The flow field in the reactor was simulated by FLUENT software conjoined with tracer particles experiment, and the influence of reaction parameters such as initial quinoline concentration, catalysts dosage and H2O2 dosage were evaluated. Results indicated that the designed reactor was suitable for the heterogeneous photo-Fenton process, and the catalysts could be fully fluidized. Moreover, the quinoline degradation reactions were well described with pseudo first-order kinetics, the removal rate was negatively correlated with the initial concentration of quinoline, whereas properly increasing catalysts and H2O2 dosage showed a positive effect. The optimal dose of catalysts and H2O2 were 1.0 g/L and 14.70 mmol/L, respectively, and resulted in 94.2% removal efficiency after 120 min reaction. The results suggest that heterogeneous photo-Fenton in an internal circulating fluidized-bed reactor is potentially applicable for organic wastewater treatment.

Functional Identification of a Novel Gene, moaE, for 3-Succinoylpyridine Degradation in Pseudomonas putida S16.

Microbial degradation of N-heterocyclic compounds, including xanthine, quinoline, nicotinate, and nicotine, frequently requires molybdenum hydroxylases. The intramolecular electron transfer chain of molybdenum hydroxylases consists of a molybdenum cofactor, two distinct [2Fe-2S] clusters, and flavin adenine dinucleotide. 3-Succinoylpyridine monooxygenase (Spm), responsible for the transformation from 3-succinoylpyridine to 6-hydroxy-3-succinoylpyridine, is a crucial enzyme in the pyrrolidine pathway of nicotine degradation in Pseudomonas. Our previous work revealed that the heterotrimeric enzyme (SpmA, SpmB, and SpmC) requires molybdopterin cytosine dinucleotide as a cofactor for their activities. In this study, we knocked out four genes, including PPS_1556, PPS_2936, PPS_4063, and PPS_4397, and found that a novel gene, PPS_4397 encoding moaE, is necessary for molybdopterin cytosine dinucleotide biosynthesis. Resting cell reactions of the moaE deletion mutant incubated with 3 g l−1 nicotine at 30 °C resulted in accumulation of 3-succinoylpyridine, and the strain complemented by the moaE gene regained the ability to convert 3-succinoylpyridine. In addition, reverse transcription-quantitative polymerase chain reaction analysis indicated that the transcriptional levels of the genes of moaE, spmA, and spmC of Pseudomonas putida S16 were distinctly higher when grown in nicotine medium than in glycerol medium.

Oxidative Degradation of Quinoline Using Nanoscale Zero-Valent Iron Supported by Granular Activated Carbon

The nano zero-valent iron supported granular activated carbon (nFe0/GAC or 2.5%-nFe0/GAC) was synthesized by the liquid chemical reduction method and further used for the oxidative degradation of quinoline. The 2.5%-nFe0/GAC was characterized by various techniques such as Brunauer-Emmett-Teller (BET) surface area, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). It was ascertained that iron is of zero state and well dispersed on GAC. The 2.5%-nFe0/GAC exhibited an H4 type hysteresis loop with a surface area of ∼240 m2/g. The kinetic study reveals that quinoline degradation follows the pseudo–first order. At optimum conditions of pH=4, m=7.5 g/L, Co=100 mg/L, and T=303 K, it was observed that (1) ∼93% of quinoline and ∼63% of total organic carbon (TOC) removal is obtained, (2) iron leaching is within the permissible limit, and (3) it requires ∼63±5 min for completion of the half-life of quinoline. The activation energy is ∼22.4 kJ/mole, which indicates that quinoline removal is controlled by a chemical surface reaction. The degradation by-products of quinoline were analyzed. The mass fragments (of m/z=146 and 178) due to hydroxylation were obtained, which were further reduced into low m/z fragments, which may lead to mineralization of quinoline.

Novel porous polyethersulfone beads as matrix to immobilize Comamonas testosteroni sp. bdq06 in quinoline biodegradation

Novel matrix beads for the immobilization of strain Comamonas testosteroni sp. bdq06 to degrade quinoline were fabricated from polyethersulfone(PES). The beads have an average size of 3 mm and a surface dense layer of 20 microns. To help adhesion and proliferation of bacterial cells, the surfaces of the PES beads were etched, and numerous holes about 1.5 micrometers in diameter were generated as tunnels for cell colonizing in the larger internal cavities of about 5 micrometers in diameter. The quinoline degradation was remarkably enhanced by the cells immobilized in PES beads compared with that by the free cells at pH 5.0 or 10.0 and a temperature of 40 °C. The enhanced degradation of quinoline was contributed to the biofilm on the surface of PES beads, resulting in the significant reduction of retention time from 9 h to 2 h. Furthermore, the beads remain intact after the ultrasonic treatment of them for 30 min or recycling 50 times, indicating that they have excellent mechanical strength, flexibility and swelling capacity. Thus, PES beads have great potential to be matrix for the cell immobilization in bioaugmentation.

Biodegradation of quinoline by Streptomyces sp. N01 immobilized on bamboo carbon supported Fe3O4 nanoparticles

A novel immobilizing carrier, bamboo-carbon supported Fe3O4 nanoparticles (Fe3O4/BC), was developed and used for immobilization of cells of a quinoline-degrading, Streptomyces sp. N01. The performance of Fe3O4/BC immobilized cells in the degradation of quinoline was evaluated and compared with bamboo-carbon immobilized cells and the free cells. Experiments were performed at various quinoline concentrations (100–400mg/L), pH (5–10) and temperature (20–45°C). The results show that Fe3O4/BC immobilized cells could tolerate a higher quinoline concentration and protect the bacteria much more effectively against changes in temperature and pH. Reusability results revealed that quinoline removal was maintained 85.3% in the ninth cycle. These results demonstrated that Fe3O4/BC possesses a good application potential as a carrier in cell immobilization.

Biodegradation characterization and immobilized strains' potential for quinoline degradation by Brevundimonas sp. K4 isolated from activated sludge of coking wastewater.

A novel quinoline-degrading strain, named K4, was isolated from activated sludge of a coking wastewater treatment plant and identified as Brevundimonas sp. on the basis of its 16s rDNA gene sequence analysis. Its optimum temperature and pH for quinoline degradation were 30°C and pH 9.0, respectively, and during the biodegradation process, at 100mg/L initial quinoline concentration, an inoculation amount of 8% (OD600 of 0.23) was the optimal strain concentration. In addition, the kinetics of free K4 strains for quinoline degradation showed that it followed a zero-order equation. Furthermore, compared with free K4 strains, immobilized K4 strains' potential for quinoline degradation was investigated by adding both of them into SBR reactors for actual coking wastewater treatment on operation over 15days. The results showed that bioaugmentation by both free and immobilized K4 strains enhanced quinoline removal efficiency, and especially, the latter could reach its stable removal after a shorter accommodation period, with 94.8% of mean quinoline removal efficiency.