Phenol Inhibition and Restoration of the Bioactivity of Anaerobic Granular Sludge

Inhibition and restoration of different concentrations of phenol on the bioactivity of anaerobic granular sludge were investigated with laboratory-scale equipment. It indicated that phenol concentration lower than 50 mg/l show no inhibitory effect on bioactivities of granular sludge. However, methane productivity, extracellular polymeric substances (EPS) content, and coenzyme F(420) activity were decreased by varying degrees when phenol concentration adopted for inhibition ranged between 50 and 400 mg/l. Noticeably, methane productivity could be fully or partly restored in case the phenol was removed after 24 h of phenol inhibition.     

Cell biosensor for detection of phenol in aqueous solutions

A microbial sensor for concentration measurement of phenol in aqueous solutions has been developed. Phenol-utilizing cellsPseudomonas putida GFS-8 immobilized in poly(vinyl)alcohol cryogel were used as a biological transducer. Relationships between phenol concentration in the activating medium and endogenic cell respiration have been established. Cell respiration and phenol concentration in the assay solution positively correlated at a phenol concentration range of 0.1–2.0 mg/L and were linearly dependent in the range of 0.1–1.0 mg/L. A Clark membrane electrode was the physiochemical transducer. The assay may be completed within 5 min. The cells oxidize phenol, pyrocatechol, mesityl oxide, aniline, and do not react with a number of xenobiotics, sugars, and alcohol. With the exception of aniline, most components found in waste waters from phenol production affect neither the assay process nor the ability of these cells to use phenol as exogenic respiratory substrate. The immobilized cells retained their ability to utilize phenol as an exogenic respiratory substrate for up to 1 mo.     

The automatic determination of silicate-silicon in natural waters with special reference to sea water

An automatic method using a Technicon AutoAnalyzer is described for the determination of silicate in natural waters in the range 0–4 mg Si/l. It is based on the conversion of silicate to β-silicomolybdic acid which is reduced by means of a metolsulphite reagent to molybdenum blue. Interference of phosphate is prevented by oxalic acid. The relationship between silicate concentration and optical density is linear in both fresh waters and sea water. With sea water the salt error of the method is ca. 5% at a salinity of 35‰ A coefficient of variation of 0.8% was found at a silicate concentration of 1 mg Si/l with both fresh and sea waters.     

Novel photoreactors for heterogeneous photocatalytic wastewater treatment

Heterogeneous photocatalysis is an effective treatment method for removal of toxic pollutants from industrial wastewaters. A novel, thin film slurry photoreactor was evaluated in this work for its effectiveness in removing phenol. The efficiency of parameters, initial phenol and catalyst concentrations and the light intensity on phenol removal was studied. The reactor performed well giving near complete removal of phenol even at a higher concentration of 500 mg/l.     

Association of Am with humic substances isolated from river waters with different water quality

The association properties of Am with aquatic humic substances in a 0.01M NaClO₄ solution at pH 6-8 were studied on the basis of molecular size distribution. Ten humic substances isolated from river water with different water quality (pH 3.9-8.0 and dissolved organic carbon (DOC) concentration of 2-40 mg/l) were used for comparing their effects on the association of Am. The molecular size distribution of Am in the presence of humic substances from an uncolored river water (DOC 2 mg/l) was different from that at the experimental systems using humic substances from brownish and high DOC (14-40 mg/l) river waters.     

Absorption of phenol and methylene blue by activated carbon from pecan shells

Activated carbon is produced from pecan shells by chemical activation using phosphoric acid. This activation is followed by the treatment with sodium dodecyl sulfate to prepare the surface for the adsorption of phenol and methylene blue from aqueous solution. The results showed a great ability for methylene blue removal with sorption capacity of 410 mg/g at pH 9 and solution concentration of 35 mg/l, while moderate adsorption was obtained for phenol with a capacity of 18 mg/g at pH 11 and the same solution concentration. The increase or decrease in solution pH has a favorable effect on the sorption of both adsorbates. Langmuir and Freundlich models were used to fit the experimental data. The text was submitted by the authors in English.     

Preconcentration of trace amounts of manganese from natural waters by means of a macroreticular poly(dithiocarbamate) resin

A chelating poly(dithiocarbamate) resin (PDTC) with macroreticular support is characterized as effective collector for traces of manganese from natural waters. Using small PDTC columns preconcentration of manganese can be achieved even at high flow-rates (5-6 ml/min) and sample volumes (1500 ml). Accordingly, PDTC resin is used for the preconcentration of manganese from water samples prior to its determination by flame atomic-absorption spectrometry. A series of ions abundant in natural waters do not interfere. The sensitivity and detection limit were 2.5 and 0.5 mug/l., respectively. The relative standard deviations of the results for a manganese concentration of 40-400 mug/l. are in the range 1.1-6.2%. In mineral and tap waters analysed, the manganese concentration range was between 2.9 and 30.8 mug/l.     

Preparation,characterization and application of powdered activated carbon‐cellulose acetate phthalate mixed matrix membrane for treatment of steel plant effluent

Preparation, characterization and industrial application of a mixed matrix membrane (MMM) using powdered activated carbon (PAC) in cellulose acetate phthalate (CAP) have been reported in this study. The objective of this work is to fabricate a less energy intensive, highly selective (to phenolic compounds) adsorptive membrane with high throughput in a scalable platform for simultaneous removal of organic as well chemical oxygen demand (COD) from a steel plant effluent. The membrane with 25 wt% PAC has maximum adsorption capacity of phenol 35 mg/g at pH 5.5. Effluent with total phenolic compounds (23 mg/g) and COD of 5200 mg/l is treated in continuous cross‐flow configuration. Breakthrough time is 44 hr for a filtration area of 0.008 m² with total phenol concentration in permeate as per World Health Organization (WHO), 1 mg/l. Throughput of the system is high, 40 l/m² hr at transmembrane pressure drop 276 kPa and cross‐flow rate 20 l/hr. Maximum rejection of phenol is obtained at low pressure and cross‐flow rate. Removal of phenolic compounds is achieved by adsorption by PAC in CAP matrix and satisfactory reduction of COD and complete removal of non‐volatile solids are due of sieving mechanism. A simple chemical regeneration method is proposed to recover the permeate flux beyond 90%. Copyright © 2015 John Wiley & Sons, Ltd.     

The effect of surfactants,cations and complexing agents on the spectrophotometric determination of microgram amounts of uranium in waters

Summary Cationic, anionic and non-ionic detergents, phosphate, soap, citric acid, Alamine-336 and mineral oil at concentrations of 100 mg/l do not interfere in the bromo-PADAP method for uranium. Iron(III), nickel(II), copper(II), chromium(III) and vanadium(V) give additive errors, but do not interfere when present at the concentrations usual in waters. Vanadium(V) interference can be minimized by reducing vanadium(V) to (IV). Sodium tripolyphosphate (100 mg/l) and sodium pyrophosphate (20 mg/l) interfere badly, but the addition of 2 mg of thorium restores recovery to 97–98%. NTA and EDTA interfere slightly, giving recoveries of 96–97%. Provided that the water is not grossly contaminated by metals, uranium can be determined in fresh water at concentrations of 20g/l and in saline waters at 60g/l.

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Die Wirkung von Schaummitteln, Kationen und Komplexbildnern auf die spektrophotometrische Bestimmung von Mikrogrammengen Uran in Wässern

Zusammenfassung Kationische, anionische und nicht-ionisierbare Detergentien, Phosphate, Seifen, Zitronensäure, Alamin-336 und Mineralöl in Mengen von 100 mg/1 stören die Uranbestimmung mit 2-(5-Bromo-2-pyridylazo)-5-diäthylamino- phenol (Brom-PADAP) nicht. Eisen(III), Nickel(II), Kupfer(II), Chrom(III) und Vanadin(V) verursachen additive Fehler, stören aber in Konzentrationen, wie sie üblicherweise in Wässern auftreten, nicht. Die Störung durch Vanadin(V) kann durch dessen Reduktion zur 4wertigen Form minimalisiert werden. Natriumtripolyphosphat (100 mg/l) und Natriumpyrophosphat (20 mg/l) stören stark, aber der Zusatz von 2 mg Thorium gewährleistet Ergebnisse von 97–98%. NTA und ÄDTA stören geringfügig und führen zu Resultaten von 96–97%. Vorausgesetzt, das Wasser ist nicht sehr stark durch Metalle verunreinigt, läßt sich Uran in frischen Wasserproben in Mengen von 20 mg/l, in Salinenwässern in Mengen von 60 mg/l bestimmen.

     

Speciation of manganese in fresh water-I Use of EPR studies

The process of standardization of the use of electron paramagnetic resonance (EPR) spectrometry in the determination of Mn(II) species in aqueous solution by comparison with atomic absorption spectrometry (AAS) is discussed. It is shown that EPR signals obtained from standardized aqueous solutions of manganese(II) perchlorate and nitrate in the concentration range of 0.05-2 mg/l. do not vary significantly over the pH range 2.1-7.0. Study of the effect (on the manganese EPR signals) of the addition of inorganic ions commonly found in significant concentrations in natural waters, viz. chloride, sulphate and bicarbonate, has shown that such ions, at the levels reported to occur in surface fresh waters, will not complex manganese(II); however, evidence is obtained that humic acid/manganese complexes could be present in such waters. The EPR signals are not affected by ionic strengths of the levels found in fresh waters.     

电化学氧化法去除苯酚研究

利用氯碱厂报废的DSA电极电解苯酚,结果显示:此电极对一定浓度的苯酚溶液有较好的去除效果.按影响电解效果各主要因素进行筛选,最佳实验条件为:电流密度30mA/cm2,pH10,支持电解质浓度10mg/L,苯酚浓度10mg/L.电解2h后,CODcr的去除率为66.7%,吸光度去除率为90%.     

Detection of Natural Cr(VI) with Computer Screen Photo-assisted Technology

The combined use of a computer screen and a webcam has been demonstrated in several cases to provide a platform for measuring optical properties of liquid and solid samples. Here the method is utilized to measure the absorbance change in an analytical procedure aimed at determining the amount of hexavalent chromium (Cr(VI)) in water. The method calibrated on standard solutions was tested on-field on naturally contaminated spring waters. Results show a sufficient resolution to measure Cr(VI) concentration down to 5 ppb. World Health Organization recommends a maximum concentration of 0.05 mg/l (50 ppb) for chromium (as hexavalent) in drinking waters.     

Determination of bromide ion in raw and drinking waters by capillary zone electrophoresis.

A new capillary zone electrophoretic method was developed for the determination of bromide ion in raw and drinking waters. An NaCl-based low-pH buffer caused a reduction of electroosmotic flow (EOF) in the buffer zone, whereas injected water sample resulted in higher EOF in the sample zone thus pumping out the neutral water plug. Sample stacking was used for the preconcentration. The method was applicable for waters from low to intermediate ionic strengths, i.e., the concentration of chloride should preferably be less than 40 mg/l. The method had a limit of detection of 15 micrograms/l at a signal-to-noise ratio of three (S/N = 3) and a limit of quantitation of 20 micrograms/l. CZE results obtained with real samples were compared with ion chromatography--inductively coupled mass spectrometric results.     

Treatment of radioactive waste phenol with Fenton's oxidation

A new procedure was developed for the waste treatment of radioactive phenol on a laboratory scale. Waste phenol was dissolved in water (2% as phenol), and ferrous ion (10 mg/l as Fe2+) was added. Hydrogen peroxide (6% as H2O2) was added separately in three steps, 20, 30, and 50% of the volume, in order to avoid rapid reaction. The solution was heated at 80-90 degrees C for several hours in a beaker covered with a watch glass till the color of the solution changes from red purple to pale yellow. Then, the solution was neutralized with sodium hydroxide and heated for 1 h to decompose excess hydrogen peroxide. When the procedure is carried out with four 2 l beakers on a hot plate, 100 ml of phenol (1,200 ml of the aqueous solution saturated with phenol) can be oxidized simultaneously.     

Quantification of anions and cations in environmental water samples. Measurements with capillary electrophoresis and indirect-UV detection.

The aim of this study was to validate two separation methods for determination of inorganic anions and cations from natural waters with capillary electrophoresis (CE) by using indirect-UV detection. The research is related to method development for screening of groundwater samples obtained in site investigations for spent fuel of the Finnish nuclear industry. In CE analysis, anions were separated in pyromellitic acid (pH 7.7) in the order bromide, chloride, sulphate, nitrite, nitrate, fluoride and dihydrogenphosphate. Cations were separated at pH 3.6 after anions using an 18-crown-6-ether solution. In these analyses, ammonium migrated first followed by potassium, calcium, sodium and magnesium. The concentrations of the ions in the natural water samples were calculated by using two or three calibration curves made using reference solutions at concentration levels of 0.5-250 mg/l. The repeatabilities of the anion and cation methods were tested using laboratory-made reference sample mixtures with high and low salt concentrations. The limits of quantification in the analyses were between 0.02 and 0.1 mg/l, depending on the ion. Concentrations of ions tested in natural waters varied from a few milligrams to tens of grams per litre.     

Ion chromatographic determination of bromate in drinking water by post-column reaction with fuchsin.

Bromate deriving from ozonation treatment of bromide containing waters are analyzed by ion-exchange chromatography with spectrophotometric detection after post-column reaction with fuchsin in low pH medium. An anion-exchange column was used with 2.7 mM carbonate-0.3 mM hydrogencarbonate eluent. The eluent from the column was then allowed to react with a SO2-reduced fuchsin solution and then with a diluted HCl solution at 65 degrees C. The developed colour of the final product was measured spectrophotometrically at 530 nm. Linearity was checked up to 50 micrograms/l with a 200-microliter injection loop (r2 = 0.9997) and up to 100 micrograms/l of bromate with 100 microliters loop (r2 = 0.9939). Nitrate, sulfate, bromide, phosphate, fluoride did not interfere at 100 mg/l concentration level; only nitrite at concentration levels greater than 3 mg/l caused partial overlapping with bromate peak, but this value is not likely to occur in common drinking water. The detection limit (3 sigma) is 0.1 microgram/l (1 microgram/l propagation error approach).     

Separation and on-line concentration of bisphenol A and alkylphenols by micellar electrokinetic chromatography with cationic surfactant

The separation and on-line concentration of bisphenol A and three alkylphenols were investigated by micellar electrokinetic chromatography with cationic surfactant. Tetradecyltrimethylammonium bromide was used as surfactant and the separation conditions were optimized by the addition of the organic solvents and cyclodextrins to the running solution. The separation of hydrophobic analytes and 4-nonylphenol isomers was improved by the addition of 20% acetonitrile and 20 mM beta-cyclodextrin to the running solution. When the sweeping with the running solution used as the on-line concentration procedure, 56-, 67- and 29-fold increase in detection sensitivity of bisphenol A, 4-tert.-butylphenol and 4-(1,1,3,3-tetramethylbutyl)phenol, respectively. The detection limits were 0.030, 0.098 and 0.159 mg/l, respectively.     

毛细管气相色谱法测定香烟烟气中苯酚

建立毛细管气相色谱法(FID)测定香烟烟气中苯酚含量的方法。用5 mL磷酸三丁酯–三乙酸甘油酯混合液(体积比为1∶150)为吸收剂收集香烟烟气中苯酚,用毛细管气相色谱法(FID)测定烟气吸收液中苯酚含量。苯酚的质量浓度在1.6~160 mg/L的范围内与色谱峰峰面积呈良好的线性关系,线性相关系数r=0.999 5,方法的检出限为0.2 mg/L。加标回收率在91%~107%之间,测定结果的相对标准偏差为2.1%~4.3%(n=5)。该方法简单可行,可以满足烟气中苯酚含量的分析要求。     

Phenol Conversions during Electrochemical Generation of Active Chlorine

Data on the electrochemical oxidation of a model phenol solution (100 mg/l) in the presence of sodium chloride (10 g/l) are presented. It is shown that active chlorine yielded by the electrolysis is directly involved in the electrochemical oxidation of phenol, which proceeds with destruction of the aromatic ring. In the course of the oxidation of the model phenol solution on Pt/Pt, under the conditions of electrochemical generation of active chlorine, no dioxine structures form.     

Determination of phenols using simultaneous steam distillation-extraction

Simultaneous distillation-extraction was proposed as a preconcentration step for the determination of phenol and its derivatives in aqueous and soil samples. Detection limits of 0.01 mg l(-1) (water) and 0.1 mg kg(-1) (soil) were achieved by gas chromatography-flame ionization detection. The described preconcentration procedure was applied for the primary study of the adsorption equilibrium in a water-soil system serving as a model of phenol behaviors in the environment.