The determination of phenols in aqueous effluents
ABSTRACT A method is described for the determination of monohydric and dihydric phenols in aqueous effluents. The phenols were extracted into methyl isobutyl ketone, the trimethylsilyl ethers prepared, separated by gas—liquid chromatography and detected by a flame ionization detector. Complete separation of phenol, cresols, xylenols, ethylphenols and dihydric phenols was achieved using dual stainless steel columns packed with Chromosorb W (AW-DCMS) coated with 5 per cent tri-2,4-xylenyl phosphate and by linear temperature programming from 75° to 125°C at 1.5°C min−1; concentrations down to 0.1 mg l−1 of each phenol in the original sample could be determined. The results obtained by the gas chromatographic method were compared with those using standard colorimetric methods of analysis for carbonization effluents arising from different sources. The method is generally applicable to wastes containing phenols.
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ABSTRACT: Upflow anaerobic sludge blanket (UASB) process has been successfully applied in the treatment of municipal and industrial wastewaters. Several researchers have investigated the suitability of the process for the treatment of phenols and phenolic wastewaters. The anaerobic treatment of phenols is still at an investigative stage. With increasing recognition of the UASB process, feasibility studies on the treatment of wastewater containing phenol and cresols (o-, m- and p- isomers) in UASB have been reviewed. It is reported that phenol concentration up to a range of 500-750 mg/L is generally not inhibitory to the UASB process. Phenol concentrations greater than 500 mg/L can be effectively treated with acclimatization of inocula, recirculation of the treated effluent and/or supplementing with co-substrates such as glucose, VFA and dilute molasses. The degradability of phenol is more than p-cresol, which in turn is more than m- and o-cresol.Water Research 02/2005; 39(1):154-70. · 4.66 Impact Factor
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ABSTRACT: The effect of COD/O3−-N ratio on the biodegradation of complex phenolic mixture was studied in bench scale hybrid upflow anaerobic sludge blanket (HUASB) reactors. HUASB reactor is a combination of a UASB unit at the lower part and an anaerobic fixed film at the upper end. The aim of this study was to evaluate the biodegradability of phenolic mixture (from synthetic coal wastewater) as the only carbon and energy source in continuous experiments using nitrate as the final electron acceptor. Synthetic coal wastewater contained phenol (490 mg/L); m-,o-,p-cresols (123.0 mg/L, 58.6 mg/L, 42 mg/L); 2,4-, 2,5-, 3,4- and 3,5 dimethyl phenols (6.3 mg/L, 6.3 mg/L, 4.4 mg/L and 21.3 mg/L) as major phenolic compounds representing the complex phenolic mixture. Nitrate nitrogen loading was increased from 0.11 g/m3/d to 0.5 g/m3/d in order to keep COD/NO3−-N ratio as 20.1, 14.85, 9.9, 6.36 and 4.45. An input phenolics concentration of 752 mg/L and hydraulic retention time (HRT) of 24 h was maintained through out the study. Removal of phenolic mixture was found to increase with the lowering of COD/NO3−-N ratio. Maximum phenolics removal of 98% was achieved at a COD/NO3−-N ratio of 6.36. However, phenolics removal got adversely affected when COD/NO3−-N ratio was reduced below 6.36. A nitrogen production efficiency of 78% was obtained according to nitrate consumption. Simultaneous denitrification and methanogenesis was observed in all the reactors throughout the study, demonstrating that denitrification is a feasible alternative for the treatment of coal wastewater. Granules degrading complex phenolic mixture were of diameter 1.6–2.25 mm.Desalination. 01/2008; 232(1):128-138.