nitrophenols and 4-chlorophenol

Topics: Arginine; Chlorophenols; Mixed Function Oxygenases; Molecular Docking Simulation; Nitrophenols; Phenols

A porous carbon aerogel (CA) was prepared to activate persulfate (PS) for the removal of phenol. The adsorption of phenol on CA and its removal in CA/PS system was fitted to a second-order model and first-order kinetic model, respectively. Influencing factors of CA/PS such as pH, CA dose, PS concentration, phenol concentration and temperature were investigated. CA/PS presented good performance on phenol removal over a pH range of 3-11 with the highest removal obtained at pH 7. Four kinds of organic pollutants including tetracycline, Rhodamine B, Safranine T and malachite green were investigated in the CA/PS system, proving that the adsorption of the contaminants benefitted their subsequent oxidation removal. The removal of aromatic compounds (phenol, p-diphenol, p-chlorophenol, and p-nitrophenol) in CA/PS system followed a decreasing order of hydroxyl > chlorine > nitro. The radical scavenging experiments suggested the removal of phenol was mainly through a non-radical pathway. The study presented the preparation and application of a green catalyst to activate PS, which is very promising for the development of the technology and the treatment of phenolic wastewater.

Topics: Adsorption; Carbon; Catalysis; Chlorophenols; Hydroxyl Radical; Kinetics; Nitrophenols; Oxidation-Reduction; Phenol; Porosity; Sulfates; Tetracycline; Wastewater; Water Pollutants, Chemical

Carbon spherules from ginkgo seed starch were prepared through stabilization and carbonization processes. The ginkgo seed starch was first stabilized at 195 °C for 18 h, then carbonized at 500 °C for 2 h under an N₂ atmosphere. The characterization results confirmed that carbon spherules were in the size range of 10-20 μm. Experimental data were also evaluated to find out the kinetic characteristics of phenols on the carbon spherules during the adsorption process. Adsorption processes for phenol,

Topics: Carbon; Chlorophenols; Environmental Pollutants; Ginkgo biloba; Microscopy, Electron, Scanning; Nitrophenols; Phenols; Seeds; Spectroscopy, Fourier Transform Infrared; Starch; Thermodynamics; X-Ray Diffraction

The determination and remediation of three phenolic compounds bisphenol A (BPA), ortho-nitrophenol (o-NTP), parachlorophenol (PCP) in wastewater is reported. The analysis of these molecules in wastewater was done using gas chromatography (GC) × GC time-of-flight mass spectrometry while activated carbon derived from maize tassel was used as an adsorbent. During the experimental procedures, the effect of various parameters such as initial concentration, pH of sample solution, eluent volume, and sample volume on the removal efficiency with respect to the three phenolic compounds was studied. The results showed that maize tassel produced activated carbon (MTAC) cartridge packed solid-phase extraction (SPE) system was able to remove the phenolic compounds effectively (90.84-98.49%, 80.75-97.11%, and 78.27-97.08% for BPA, o-NTP, and PCP, respectively). The MTAC cartridge packed SPE sorbent performance was compared to commercially produced C18 SPE cartridges and found to be comparable. All the parameters investigated were found to have a notable influence on the adsorption efficiency of the phenolic compounds from wastewaters at different magnitudes.

Topics: Adsorption; Benzhydryl Compounds; Charcoal; Chlorophenols; Gas Chromatography-Mass Spectrometry; Inflorescence; Nitrophenols; Phenols; Solid Phase Extraction; Wastewater; Water Pollutants, Chemical; Water Quality; Zea mays

A rapid and sensitive electrochemical sensor based on disulfides bridged β-cyclodextrin dimer-functionalized multi-walled carbon nanotube (DBβ-CD-MWCNT) nanohybrids with higher supramolecular recognition capability was successfully constructed for the first time. Simultaneous trace analysis of three phenols (4-aminophenol, 4-AP; 4-chlorophenol, 4-CP; 4-nitrophenol, 4-NP) in tap-water and wastewater samples was performed based on the constructed sensor. Cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy were utilized to characterize the properties of the modified electrode. The proposed DBβ-CD-MWCNT-modified electrode displayed electrochemical signal superior to those of β-CD-MWCNT and MWCNT towards 4-AP, 4-CP, and 4-NP. Under optimal conditions, differential pulse voltammetry was used to simultaneously quantify 4-AP, 4-CP, and 4-NP within the concentration range of 0.01-20, 0.1-200, and 0.1-200 µM, respectively. The detection limits (S/N=3) of the DBβ-CD-MWCNT nanohybrid electrode for 4-AP, 4-CP, and 4-NP were 0.0042, 0.028, and 0.048 µM, respectively. Satisfactory results revealed that this proposed electrochemical sensor can provide a promising candidate for the simultaneous trace analysis of 4-AP, 4-CP, and 4-NP in environmental monitoring of water and wastewater samples. The present work might broaden the channel toward the application of bridged CD in the electrochemical sensing or biosensing.

Topics: Aminophenols; beta-Cyclodextrins; Biosensing Techniques; Chlorophenols; Dielectric Spectroscopy; Environmental Monitoring; Limit of Detection; Nanotubes, Carbon; Nitrophenols

Montmorillonite (MMT) was converted to organoclays by intercalation of cationic surfactants into its interlayer space. Two types of organoclays were prepared from different surfactants (DDTMA and DDDMA) at different surfactant loadings, and the structural changes in the clays investigated using various techniques. The arrangements of surfactant molecules in the interlayer space was visually aided by molecular mechanical calculation (MM calculation), and the adsorption capacities of MMT and the organoclays for the removal of p-chlorophenol (PCP) and p-nitrophenol (PNP) from aqueous solutions were tested under different conditions. Two adsorption isotherm models (Langmuir and Freundlich isotherms) were used to determine the best fit model and the Freundlich isotherm was found to provide better fit for both PCP and PNP. Due to its hydrophobic properties, the adsorption is more favourable for PNP than PCP. Overall, the adsorption capacity of the organoclays was significantly improved by intercalation with large surfactant molecules as well as highly loaded surfactants as the intercalation with large surfactant molecules created the partitioning phase, which strongly attracted large amounts of organic pollutants. Possible mechanisms and the implications of the results for the use of these organoclays as adsorbents for the removal of phenols from the environment are discussed.

Topics: Adsorption; Aluminum Silicates; Bentonite; Chlorophenols; Clay; Nitrophenols; Phenols; Quaternary Ammonium Compounds; Surface-Active Agents; Water Pollutants, Chemical; X-Ray Diffraction

Modified montmorillonite was prepared at different surfactant (HDTMA) loadings through ion exchange. The conformational arrangement of the loaded surfactants within the interlayer space of MMT was obtained by computational modelling. The conformational change of surfactant molecules enhance the visual understanding of the results obtained from characterization methods such as XRD and surface analysis of the organoclays. Batch experiments were carried out for the adsorption of p-chlorophenol (PCP) and different conditions (pH and temperature) were used in order to determine the optimum sorption. For comparison purpose, the experiments were repeated under the same conditions for p-nitrophenol (PNP). Langmuir and Freundlich equations were applied to the adsorption isotherm of PCP and PNP. The Freundlich isotherm model was found to be the best fit for both of the phenolic compounds. This involved multilayer adsorptions in the adsorption process. In particular, the binding affinity value of PNP was higher than that of PCP and this is attributable to their hydrophobicities. The adsorption of the phenolic compounds by organoclays intercalated with highly loaded surfactants was markedly improved possibly due to the fact that the intercalated surfactant molecules within the interlayer space contribute to the partition phases, which result in greater adsorption of the organic pollutants.

Topics: Adsorption; Aluminum Silicates; Cetrimonium; Cetrimonium Compounds; Chlorophenols; Clay; Molecular Dynamics Simulation; Molecular Structure; Nitrophenols; Surface Properties; Surface-Active Agents

Coupling of long-chain ionic liquid (LCIL)-based sweeping and micelle to solvent stacking (MSS) in CZE for anionic compounds was proposed. N-Cetyl-N-methylpyrrolidinium bromide (C16MPYBr) was used as a novel cationic surfactant. The capillary column was conditioned with poly(1-vinyl-3-butylimidazolium) bromide, a kind of polymeric ionic liquid, to obtain the anodic electroosmotic flow (EOF). There is a micellar solution (MS) zone which is prepared with C16MPYBr before the sample zone. The micelles penetrated into the sample zone, swept and transported the analytes toward the micelle to solvent boundary (MSSB). Meanwhile, a sufficient amount of methanol in the background solution (BGS) resulted in the reversal of effective electrophoretic mobility of analytes and completed the MSS. Under optimal conditions, good linearity (0.9988–0.9999) was obtained for model analytes in a wide linear range with limits of detection (LODs) from 0.025 to 0.25 mg/L. The intraday and interday repeatabilities (%RSD, n=5, 10) were acceptable in the range from 2.12 to 7.29%. 34 and 25 times increases in peak area sensitivity for benzoic acid (BA) and 2-nitrophenol (2-NP) and 60 times increase in peak height sensitivity for 4-chlorophenol (4-CP) were obtained. The proposed method is applied to analyze two spiked environmental water samples obtaining satisfactory recoveries.

Topics: Benzoic Acid; Cations; Chlorophenols; Ionic Liquids; Micelles; Nitrophenols; Solvents; Surface-Active Agents; Water Pollutants, Chemical

Photochemical processes can decontaminate the aqueous environment from xenobiotics, but they also produce secondary pollutants. This paper presents field and laboratory evidence of the transformation of 4-chlorophenol (4CP) into 2-nitro-4-chlorophenol (2N4CP).. Field monitoring of 4CP and 2N4CP was carried out by solid phase extraction coupled with liquid chromatography-multiple reaction monitoring mass spectrometry. Laboratory irradiation experiments were carried out under a UV-Vis lamp, and the time evolution of the compounds of interest was followed by liquid chromatography.. The purpose of this study was elucidating the pathways leading to 2N4CP from 4CP in paddy field water.. The field monitoring results suggest that 4CP can be transformed into 2N4CP in the paddy field water of the Rhône delta (Southern France). The laboratory study indicates that the transformation can take place via photonitration by (*)NO(2). The nitration process is inhibited by bicarbonate, possibly due to basification that favours the occurrence of the 4-chlorophenolate. The latter could consume (*)NO(2) without being nitrated. Photonitration in the presence of bicarbonate could account for the observed transformation in the field.. Photonitration of 4CP to 2N4CP by (*)NO(2) could account for the observed interconversion of the two compounds in paddy fields. The results are of concern because 2N4CP is biorecalcitrant and toxic.. Bicarbonate can modulate the photonitration of 4CP into 2N4CP, which can be very significant in bicarbonate-poor waters.

Topics: Bicarbonates; Chlorophenols; Chromatography, Liquid; Environmental Monitoring; France; Mass Spectrometry; Nitrates; Nitrophenols; Pesticides; Photochemical Processes; Solid Phase Extraction; Time Factors; Water Pollutants, Chemical

We compared the Arthrobacter chlorophenolicus proteome during growth on 4-chlorophenol, 4-nitrophenol, or phenol at 5 and 28 degrees C, both for the wild-type and a mutant strain with mass spectrometry based proteomics. A label-free workflow employing spectral counting identified 3749 proteins across all growth conditions, representing over 70% of the predicted genome and 739 of these proteins form the core proteome. Statistically significant differences were found in the proteomes of cells grown under different conditions including differentiation of hundreds of unknown proteins. The 4-chlorophenol-degradation pathway was confirmed, but not that for phenol.

Topics: Arthrobacter; Bacterial Proteins; Chlorophenols; Chromatography, Liquid; Electrophoresis, Gel, Two-Dimensional; Nitrophenols; Phenols; Proteome; Tandem Mass Spectrometry; Temperature

The adsorption characteristics of phenol, p-chlorophenol and p-nitrophenol in wastewater by activated carbon fiber (ACF) were studied. The surface properties of ACF were characterized by scanning electron microscopy (SEM). The thermodynamic characteristics and mechanism of phenol, p-chlorophenol and p-nitrophenol adsorption on ACF were investigated by using the bottle-point technique. The results showed that the adsorption speed was fast, and ACF had good adsorption properties when pH < 7. On the same condition, the order of removal efficiency were: phenol (87%) < p-chlorophenol (96%) < p-nitrophenol (99%). All the adsorptions are physical adsorption, and the adsorption process were spontaneous exothermic reaction. All the adsorption isotherms can be well represented by Dubinin-Radushkevich equation and the sorption process were spontaneous exothermic reaction.

Topics: Adsorption; Charcoal; Chlorophenols; Nitrophenols; Phenol; Water Pollutants, Chemical

Quotation and calculation accuracy can play a key role in a scientific paper. This comment mainly presents the possible errors in an article by Akçay et al., including the questionable expression of Polanyi potential (epsilon) in the Dubinin-Radushkevich (DR) equation used by the authors and the discrepancies in adsorption thermodynamic parameters study.

Topics: Adsorption; Bentonite; Chlorophenols; Kinetics; Nitrophenols; Phenol; Solutions; Water

Arthrobacter chlorophenolicus is a previously described Gram-positive bacterium capable of degrading high concentrations of several phenolic compounds under optimal mesophilic (28 degrees C) as well as psychrophilic (5 degrees C) conditions. However, the exact mechanisms by which this organism is able to tolerate such extremes in temperature and high levels of toxic compounds are currently not known. In this study, we monitored changes in the fatty acid composition of the cell membrane under different extreme growth conditions. Arthrobacter chlorophenolicus adapts to differences in temperature and phenol concentrations by altering the anteiso/iso ratio of fatty acids in the cell membrane to different extents. According to the different physico-chemical properties of those two species of branched fatty acids, the bacteria showed an increased amount of anteiso fatty acids when grown under psychrophilic conditions to decrease the viscosity of their membranes. On the other hand, at higher growth temperatures as well as in the presence of toxic concentrations of phenol, 4-chlorophenol and 4-nitrophenol, the cells adapted their membrane by a dose-dependent decrease in the anteiso/iso ratio, leading to a more rigid membrane and counteracting the fluidity increase caused by the higher temperature and the organic solvents.

Topics: Adaptation, Physiological; Arthrobacter; Cell Membrane; Chlorophenols; Chromatography, Gas; Fatty Acids; Membrane Fluidity; Nitrophenols; Phenols; Temperature

The electrochemical oxidative removal of p-chlorophenol and p-nitrophenol was studied by cyclic voltammetry (CV) and constant current electrolysis on commercially available graphite and titanium substrate insoluble anodes (TSIA). The effect of cationic cetyl trimethylammonium bromide (CTAB), anionic sodium dodecyl sulphate (SDS) and non-ionic polyoxyethylene(23)lauryl ether (Brij-35) surfactants, which prevent adherent film formation on the electrode surface were also studied. CV experiments indicate that p-chlorophenol exhibits a relatively higher tendency for film formation on graphite and that sodium chloride is a better medium for the destruction of phenols. The electrochemical oxidation of phenols under galvanostatic conditions in chloride medium with CTAB enhanced the detoxification process with significantly lower fouling effects on TSIA. The surfactants, however, did not improve phenol removal on graphite under identical experimental conditions. A charge of 2.5F per mol was found to be sufficient to achieve 44-48% removal of phenol on both the electrodes in the absence of the surfactants. A 55-65% removal was achieved in the presence of the cationic surfactant on the TSIA electrode. Phenol was removed as a low molecular weight polymer (MW approximately 4450).

Topics: Chlorophenols; Electrochemistry; Electrodes; Nitrophenols; Surface-Active Agents

A bacterium named LZ-1 capable of utilizing high concentrations of p-nitrophenol (PNP) (up to 500 mg L(-1)) as the sole source of carbon, nitrogen and energy was isolated from an activated sludge. Based on the results of phenotypic features and phylogenetic similarity of 16S rRNA gene sequences, strain LZ-1 was identified as a Stenotrophomonas sp. Other p-substituted phenols such as 4-chlorophenol (4-CP) were also degraded by strain LZ-1, and both PNP and 4-CP were degraded via the hydroquinone pathway exclusively. Strain LZ-1 could degrade PNP and 4-CP simultaneously and the degradation of PNP was greatly accelerated due to the increased biomass supported by 4-CP. An indigenous plasmid was found to be responsible for phenols degradation. In soil samples, 100 mg kg(-1) of PNP and 4-CP in mixtures were removed by strain LZ-1 (10(6) cells g(-1)) within 14 and 16 days respectively, and degradation activity was maintained over a wide range of temperatures (4-35 degrees C). Therefore, strain LZ-1 can potentially be used in bioremediation of phenolic compounds either individually or as a mixture in the environment.

Topics: Biomass; Biotransformation; Chlorophenols; DNA, Bacterial; Genes, rRNA; Molecular Sequence Data; Nitrophenols; Phylogeny; Plasmids; RNA, Bacterial; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Sewage; Stenotrophomonas

The oxidation of phenol and two substituted species (4-nitrophenol and 4-chlorophenol) has been carried out by means of the O3, UV-vis, O3+UV-vis, TiO2+UV-vis, O(3)+UV-vis+TiO2 and O3+TiO2 systems. From UV-vis experiments, the quantum yield of these organics has been calculated (0.018, 0.005 and 0.017 mol per Einstein for phenol, 4-nitrophenol and 4-chlorophenol, respectively). Broadly speaking, the addition of titania powder results in a slight inhibition of the parent compound degradation rate, although a positive effect is experienced when measuring the chemical oxygen demand (COD) and total organic carbon (TOC) removals. Amongst the technologies investigated, those combining ozone and radiation show the best efficiency in terms of phenols elimination and also COD and TOC decay rates. A simple economy analysis of the processes illustrates how the combinations O3+UV-vis and O3+UV-vis+TiO2 are the most attractive technologies, although some additional considerations have to be taken into account.

Topics: Chlorophenols; Environmental Pollution; Nitrophenols; Oxidants, Photochemical; Oxidation-Reduction; Ozone; Photochemistry; Ultraviolet Rays

To elucidate the comparative susceptibility of newborn rats to chemicals, newborn and young animals were administered six industrial chemicals by gavage from postnatal days (PND) 4 to 21, and for 28 days starting at 5-6 weeks of age respectively, under the same experimental conditions as far as possible. As two new toxicity endpoints specific to this comparative analysis, presumed no-observed-adverse-effect-levels (pNOAELs) were estimated based on results of both main and dose-finding studies, and presumed unequivocally toxic levels (pUETLs) were also decided. pNOAELs for newborn and young rats were 40 and 200 for 2-chlorophenol, 100 and 100 for 4-chlorophenol, 30 and 100 for p-(alpha,alpha-dimethylbenzyl) phenol, 100 and 40 for (hydroxyphenyl)methyl phenol, 60 and 12 for trityl chloride, and 100 and 300 mg/kg/day for 1,3,5-trihydroxybenezene, respectively. To determine pUETLs, dose ranges were adopted in several cases because of the limited results of experimental doses. Values for newborn and young rats were thus estimated as 200-250 and 1000 for 2-chlorophenol, 300 and 500 for 4-chlorophenol, 300 and 700-800 for p-(alpha,alpha-dimethylbenzyl) phenol, 140-160 and 1000 for (hydroxyphenyl)methyl phenol, 400-500 and 300 for trityl chloride, and 500 and 1000 mg/kg/day for 1,3,5-trihydroxybenzene, respectively. In most cases, newborn rats were 2-5 times more susceptible than young rats in terms of both the pNOAEL and the pUETL. An exception was that young rats were clearly more susceptible than their newborn counterparts for trityl chloride.

Topics: Animals; Animals, Newborn; Benzene Derivatives; Body Weight; Chlorophenols; Dose-Response Relationship, Drug; Female; Kidney; Liver; Male; Nitrophenols; No-Observed-Adverse-Effect Level; Organ Size; Phenols; Rats; Rats, Sprague-Dawley; Stomach; Trityl Compounds

The adsorption of p-chlorophenol (p-CP) and p-nitrophenol (p-NP) on organophilic bentonite (dodecylammonium bentonite, DDAB) was studied as a function of solution concentration and temperature. The observed adsorption rates were found to be equal to the first-order kinetics. The rate constants were calculated for temperatures ranging between 25.0-35.0 degrees C at constant concentration. The adsorption energies, E and adsorption capacity, (qm), for phenolic compounds adsorbed to organophilic bentonite were estimated by using the Dubinin-Radushkevic equation. Thermodynamic parameters from the adsorption isotherms of p-CP and p-NP on organophilic bentonite were determined. These isotherms were modeled according to Freundlich and Dubinin-Radushkevic adsorption isotherms and followed the V-shaped isotherm category with two steps. The amount of adsorption was found to be dependent on the relative energies of adsorbent-adsorbate, adsorbate-solvent and adsorbate-adsorbate interaction.

Topics: Adsorption; Bentonite; Chlorophenols; Kinetics; Nitrophenols; Solutions; Water

Three polymers have been synthesised using 4-chlorophenol (4-CP) as the template, following different protocols (non-covalent and semi-covalent) and using different functional co-monomers, 4-vinylpyridine (4-VP) and methacrylic acid (MAA). The polymers were evaluated to check their selectivity as molecularly imprinted polymers (MIPs) in solid-phase extraction (SPE) coupled on-line to liquid chromatography. The solid-phase extraction procedure using MIPs (MISPE), including the clean-up step to remove any interferences, was optimised. The 4-VP non-covalent polymer was the only one which showed a clear imprint effect. This MIP also showed cross-reactivity for the 4-chloro-substituted phenols and for 4-nitrophenol (4-NP) from a mixture containing the 11 priority EPA (Environmental Protection Agency) phenolic compounds and 4-chlorophenol. The MIP was applied to selectively extract the 4-chloro-substituted compounds and 4-NP from river water samples.

Topics: Chlorophenols; Chromatography, Liquid; Nitrophenols; Water Pollutants, Chemical

Competitive inhibition by phenolic compounds of the ascorbic acid oxidation reaction catalyzed by ascorbate oxidase was investigated at pH 7.0 and 23.0 degrees C. Inhibition of p-nitrophenol is pH dependent over the range 5.0-8.0, with inhibitor binding favored at higher pH. Bulky substituents on the phenol nucleus reduce or prevent the inhibitory effect. The presence of phenol affects the binding characteristics of azide to the trinuclear cluster of the enzyme. In particular, binding of azide to type 2 copper is prevented, and the affinity of azide to type 3 copper is reduced. In addition, reduction of type 1 copper is observed upon prolonged incubation of ascorbate oxidase with excess phenol and azide, but not with phenol alone. It is proposed that binding of phenolic inhibitors occurs at or near the site where the substrate (ascorbate) binds. NMR relaxation measurements of the protons of phenols in the presence of ascorbate oxidase show paramagnetic effects due to the proximity of the bound inhibitor to a copper center, likely type 1 copper. Copper-proton distance estimates between this paramagnetic center and p-cresol or p-nitrophenol bound to ascorbate oxidase are between 4.4 and 5.9 A.

Topics: Ascorbate Oxidase; Binding, Competitive; Chlorophenols; Cresols; Electron Spin Resonance Spectroscopy; Enzyme Inhibitors; Hydrogen-Ion Concentration; Nitrophenols; Phenol; Phenols; Spectrophotometry, Ultraviolet

With and without p-chlorophenol as an activator, the rates of hydrolysis of p-nitrophenyl acetate catalyzed by alpha-chymotrypsin were measured at pressures up to 2 kbar at 25 degrees C. From the pressure dependence of the rate constant (kcat)A and (kcat)0 of the product formation with and without an activator, the activation volumes (delta V not equal to cat)A and (delta not equal to cat)0 were +2 and -6 +/- 1 cm3.mol-1. From the pressure dependence of the equilibrium constant (KA) of incorporation of p-chlorophenol into the enzyme, the volume change (delta VA) was -10 +/- 1 cm3.mol-1. The mechanisms of the substrate activation are discussed in terms of the activation and reaction volumes.

Topics: Atmospheric Pressure; Catalysis; Chlorophenols; Chymotrypsin; Enzyme Activation; Kinetics; Nitrophenols; Protein Conformation

The ability of subsurface microbial communities to adapt to the biodegradation of xenobiotic compounds was examined in aquifer solids samples from a pristine aquifer. An increase in the rates of mineralization of radiolabeled substrates with exposure was used as an indication of adaptation. For some compounds, such as chlorobenzene and 1,2,4-trichlorobenzene, slight mineralization was observed but no adaptation was apparent during incubations of over 8 months. Other compounds demonstrated three patterns of response. For m-cresol, m-aminophenol, and aniline intermediate rates of biodegradation and a linear increase in the percent mineralized with time were observed. Phenol, p-chlorophenol, and ethylene dibromide were rapidly metabolized initially, with a nonlinear increase in the percent mineralized with time, indicating that the community was already adapted to the biodegradation of these compounds. Only p-nitrophenol demonstrated a typical adaptation response. In different samples of soil from the same layer in the aquifer, the adaptation period to p-nitrophenol varied from a few days to as long as 6 weeks. In most cases the concentration of xenobiotic added, over the range from a few nanograms to micrograms per gram, made no difference in the response. Most-probable-number counts demonstrated that adaptation is accompanied by an increase in specific degrader numbers. This study has shown that diverse patterns of response occur in the subsurface microbial community.

Topics: Aminophenols; Aniline Compounds; Bacteria; Biodegradation, Environmental; Chlorobenzenes; Chlorophenols; Cresols; Ethylene Dibromide; Hydrocarbons, Halogenated; Nitrophenols; Phenols; Soil Microbiology; Water Microbiology

1. The metabolism of five phenols in zebra fish was studied after uptake from the medium. The results showed no qualitative differences to other Cyprinid fish species, only the oxidation rate seemed to be lower. 2. Phenyl glucuronide, phenyl sulphate, and quinol sulphate were identified as metabolites of phenol. 3. Identified metabolites of 2-cresol were 2-cresyl glucuronide, 2-cresyl sulphate, and 2-hydroxybenzoic acid in trace amounts. 4. Only the glucuronide and sulphate conjugates were detected as metabolites of 4-nitrophenol, 4-chlorophenol, and pentachlorophenol.

Topics: Animals; Chlorophenols; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Cresols; Cyprinidae; Female; Nitrophenols; Pentachlorophenol; Phenols; Zebrafish