nitrophenols and 2-6-dinitrophenol

A facile approach utilizing synthesis of cobalt nanoparticles in green polymers of chitosan (CS) coating layer on high surface area cellulose microfibers of filter paper (CFP) is described for the catalytic reduction of nitrophenol and an organic dye using NaBH

Topics: Adsorption; Catalysis; Cellulose; Cobalt; Filtration; Metal Nanoparticles; Models, Molecular; Molecular Conformation; Nitrophenols; Oxazines; Oxidation-Reduction; Paper

As promising in-situ chemical oxidation (ISCO) technologies, sulfate radical-based advanced oxidation processes (SR-AOPs) are applied in wastewater treatment and groundwater remediation in recent years. In this contribution, we report for the first time that, thermally activated persulfate oxidation of phenol in the presence of nitrite (NO

Topics: Groundwater; Nitrites; Nitrophenols; Oxidation-Reduction; Sulfates; Water Pollutants, Chemical

Although they are widely used as insecticides, acaricides and fungicides in the agriculture or as raw materials in the dye industry, dinitrophenols (DNPs) are extremely noxious, death cases having been registered. These compounds produce cataracts, lower leucocyte levels, disturb the general metabolism and can cause cancer. It is also assumed that DNPs hinder the proton translocation through the mitochondrial inner membrane and therefore inhibit oxidative phosphorylation. Their fluorescence quenching properties can help understand and explain their toxicity. Fluorescence quenching of tryptophan was tested using different dinitrophenols such as 2,4-dinitrophenol (2,4-DNP), 4,6-dinitro-orthocresol (DNOC), 2-[(2,4-dinitrophenyl)amino]acetic acid (GlyDNP), 2-(1-methyl-heptyl)-4.6-dinitrophenyl crotonate (Karathan), 2-amino-5-[(1-((carboxymethyl)amino)-3-((2,4-dinitrophenyl)thio)-1-oxopropan-2-yl)amino]-5-oxopentanoic acid (SDN GSH), 2,4-dinitroanisole (2,4-DNA) and 2,4-dinitrobenzoic acid (2,4-DNB). 2,4-DNP and DNOC showed the highest tryptophan fluorescence quenching constant values, these being also the most toxic compounds. The electronic chemical potential value of the most stable complex of 2,4-DNP-with tryptophan is higher than the values of the electronic chemical potentials of complexes corresponding to the derivatives.

Topics: 2,4-Dinitrophenol; Anisoles; Dinitrocresols; Ethers; Germination; Linear Models; Models, Molecular; Nitrophenols; Nonlinear Dynamics; Quantitative Structure-Activity Relationship; Seeds; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Thermodynamics; Triticum; Tryptophan

Four biodegradability tests (BOD(5)/COD ratio, production of carbon dioxide, relative oxygen uptake rate and relative enzymatic activity) were used to determine the aerobic biodegradability of 3-nitrophenol (3-NP), 2,4-dinitrophenol (2,4-DNP) and 2,6-dinitrophenol (2,6-DNP). Furthermore, biodegradation kinetics of the compounds was investigated in sequencing batch reactors both in the presence of glucose (co-substrate) and with nitrophenol as the sole carbon source. Among the three tested compounds, 3-NP showed the best biodegradability while 2,6-DNP was the most difficult to be biodegraded. The Haldane equation was applied to the kinetic test data of the nitrophenols. The kinetic constants are as follows: the maximum specific degradation rate (K(max)), the saturation constants (K(S)) and the inhibition constants (K(I)) were in the range of 0.005-2.98 mg(mgSS d)(-1), 1.5-51.9 mg L(-1) and 1.8-95.8 mg L(-1), respectively. The presence of glucose enhanced the degradation of the nitrophenols at low glucose concentrations. The degradation of 3-NP was found to be accelerated with the increasing of glucose concentrations from 0 to 660 mg L(-1). At high (1320-2000 mg L(-1)) glucose concentrations, the degradation rate of 3-NP was reduced and the K(max) of 3-NP was even lower than the value obtained in the absence of glucose, suggesting that high concentrations of co-substrate could inhibit 3-NP biodegradation. At 2,4-DNP concentration of 30 mg L(-1), the K(max) of 2,4-DNP with glucose as co-substrate was about 30 times the value with 2,4-DNP as sole substrate. 2,6-DNP preformed high toxicity in the case of sole carbon source degradation and the kinetic data was hardly obtained.

Topics: 2,4-Dinitrophenol; Aerobiosis; Biodegradation, Environmental; Biological Oxygen Demand Analysis; Glucose; Kinetics; Models, Theoretical; Nitrophenols; Wastewater; Water Pollutants, Chemical; Water Purification

A three-phase hollow fiber liquid-phase microextraction method coupled with CE was developed and used for the determination of partition coefficients and analysis of selected nitrophenols in water samples. The selected nitrophenols were extracted from 14 mL of aqueous solution (donor solution) with the pH adjusted to pH 3 into an organic phase (1-octanol) immobilized in the pores of the hollow fiber and finally backextracted into 40.0 microL of the acceptor phase (NaOH) at pH 12.0 located inside the lumen of the hollow fiber. The extractions were carried out under the following optimum conditions: donor solution, 0.05 M H(3)PO(4), pH 3.0; organic solvent, 1-octanol; acceptor solution, 40 microL of 0.1 M NaOH, pH 12.0; agitation rate, 1050 rpm; extraction time, 15 min. Under optimized conditions, the calibration curves for the analytes were linear in the range of 0.05-0.30 mg/L with r(2)>0.9900 and LODs were in the range of 0.01-0.04 mg/L with RSDs of 1.25-2.32%. Excellent enrichment factors of up to 398-folds were obtained. It was found that the partition coefficient (K(a/d)) values were high for 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol and 2,6-dinitrophenol and that the individual partition coefficients (K(org/d) and K(a/org)) promoted efficient simultaneous extraction from the donor through the organic phase and further into the acceptor phase. The developed method was successfully applied for the analysis of water samples.

Topics: 1-Octanol; 2,4-Dinitrophenol; Chromatography, Liquid; Electrophoresis, Capillary; Limit of Detection; Nitrophenols; Solvents; Uncoupling Agents; Water

The removal efficiencies of 3-nitrophenol (3-NP) and 2, 6-dinitrophnol (2, 6-DNP) were investigated in two lab-scale upflow anaerobic sludge bed (UASB) reactors using two different co-substrates. Initially, glucose was used as co-substrate and followed by sodium acetate. The results showed that glucose was found to be a better co-substrate for 3-NP degradation compared to sodium acetate. While for the degradation of 2,6-dinitrophenol, sodium acetate was better. For the study of 3-NP degradation, input COD concentration was kept as 2,500 mg/L and hydraulic retention time (HRT) was kept as 26 h with glucose as co-substrate. Maximum 3-NP concentration was 254.6 mg/L and 3-NP removal efficiencies were always more than 99.0%. While HRT was 30 h with sodium acetate as co-substrate, maximum 3-NP concentration was 71.6 mg/L and over 90.0% 3-NP removal efficiencies could be obtained. For the study of 2,6-DNP degradation, HRT was 35 h using the same input COD concentration as 3-NP degradation. The maximum 2,6-DNP concentration was 170.0 mg/L and 2,6-DNP removal efficiencies were always more than 98.0% using glucose as co-substrate. While HRT was 30 h with sodium acetate as co-substrate, maximum 2,6-DNP concentration was 189.5 mg/L and over 99.2% 2,6-DNP removal efficiencies could be obtained.

Topics: Bioreactors; Carbon; Chemical Precipitation; Glucose; Nitrophenols; Sewage; Sodium Acetate; Waste Disposal, Fluid

The distribution of chloride ion (Cl-) in the frog retinal pigment epithelium (RPE) was investigated histologically to determine the effects of various agents on the Cl- concentration in the intracellular spaces of the RPE. Fixation with osmium tetroxide containing silver acetate resulted in the deposit of silver chloride (AgCl) in the RPE, and this was confirmed by X-ray microanalysis. The Cl- concentration in the intercellular space decreased significantly after the fixation and washing with sucrose solution before Cl- deposition procedures, as well as after the 2,4-dinitrophenol treatment, which inhibits the active transport mechanism of the RPE. The intercellular Cl- concentration decreased after the cyclic AMP or cyclic GMP treatment which, respectively, decreases or might decrease Cl- transport from the apical to the basolateral side of the RPE. The Cl- concentration in the intercellular spaces did not change after the ouabain treatment. The results of the present study suggest that the changes in the Cl- concentration in the intercellular spaces of the RPE are related to the status of Cl- transport in the RPE.

Topics: Animals; Biological Transport, Active; Chlorides; Electron Probe Microanalysis; Extracellular Space; Fixatives; Nitrophenols; Nucleotides, Cyclic; Ouabain; Pigment Epithelium of Eye; Rana catesbeiana

We present data on the ionic strength dependence of the dissociation field effect (2nd Wien effect) of the protolytic reaction of 2,6-dinitrophenol in aqueous solution, monitored through optical absorption changes in high electric fields. The results are in very good agreement with the Onsager-Liu theory. We then investigate the field strength dependence of the acid-alkaline transition, i.e., the hydrolysis reaction of the water coordinated to the heme iron, in metmyoglobin and methemoglobin. The true field effect of the reaction is determined from measurements in buffers which exhibit no field effect. We conclude that negative charges on the protein influence the field effect in methemoglobin but not in metmyoglobin. The Onsager-Liu theory is applied to estimate the number of charges involved.

Topics: Azo Compounds; Coloring Agents; Electrochemistry; Hemeproteins; Hydrogen-Ion Concentration; Kinetics; Mathematics; Methemoglobin; Metmyoglobin; Nitrophenols; Osmolar Concentration

The ventilatory effects of the three mononitrophenols and six dinitrophenols have been examined in anaesthetized rats. The minute volume of ventilation increased in all the test groups, the increase reaching the 99% significance level with seven compounds (P<0.01), the 95% level with 3-nitrophenol (P<0.05), and the 90% level with 3,5-dinitrophenol (P<0.10). The effects of 4-nitrophenol, 3,4-dinitrophenol, 3-nitrophenol, and 2,5-dinitrophenol, in increasing carbon dioxide output relative to oxygen consumption, are not explicable on the basis of simple hyperventilation, and are attributed to a metabolic effect at the cellular level. The potency of the nitrophenols in stimulating respiration is related to their structure, nitro groups being most effective in the ortho position and least effective in the meta position, and 2,4-dinitrophenol being the most powerful respiratory stimulant of the group. 2,6-Dinitrophenol does not conform to this generalization; one unique feature of its structure is indicated, as a possible explanation for the discrepancy. The gradation of potency of the nitrophenols (except 2,6-dinitrophenol) parallels the gradation of acidic properties in the group; the more strongly acid compounds stimulate respiration more powerfully. This is not a direct effect on blood pH, since the compounds were administered in neutral or slightly alkaline solution. Methaemoglobin formation was found to occur with 2,5-dinitrophenol, and to a smaller inconstant extent with three other compounds. Further work is suggested, to explore whether peripheral-acting ventilatory stimulation by 2,4-dinitrophenol is necessarily associated with peripheral metabolic enhancement, or whether the two effects can be dissociated.

Topics: 2,4-Dinitrophenol; Animals; Cell Respiration; Dinitrophenols; Nitrophenols; Oxygen Consumption; Pulmonary Ventilation; Rats; Respiration

Topics: 2,4-Dinitrophenol; Animals; Death; Dinitrophenols; Lactic Acid; Muscles; Nitrophenols; Pyruvates; Pyruvic Acid; Rats; Rigor Mortis

Topics: 2,4-Dinitrophenol; Catalysis; Cell Respiration; Dinitrophenols; Humans; Metabolism; Naphthols; Nitrophenols; Phenol; Phenols