Several clay-organic complexes were synthesized by placing quaternary ammonium cations on smectite by cation exchange. They were then examined for their ability to adsorb phenol and several of its chlorinated congeners. The organic cations used were: hexadecylpyridinium (HDPY+), hexadecyltri-methyl ammonium (HDTMA+), trimethylphenyl ammonium (TMPA), and tetramethylammonium (TMA+). The complexes containing long-chain alkyl (hexadecyl) groups were the most hydrophobic and adsorbed the phenols from water in proportion to their hydrophobicities, which increase with chlorine addition (phenol < chlorophenol < dichloropohenol < trichlorophenol). With n-hexane as the solvent, different adsorption was found which depended on the type and degree of solvent interactions with the compound and the clay-organic complex. Thus, the amount of adsorption of these phenols on clay-organic complexes was dependent on the relative energies of adsorbent-adsorbate and adsorbate-solvent interactions.

The rate and extent of oxidation of dihydroxybenzenes (DHB) to quinones in acetate-buffered suspensions of synthetic birnessite were studied using Mn dissolution to monitor reaction progress. Concentration of free Mn2+ in the aqueous phase was continuously monitored by electron spin resonance, and ultraviolet-visible (UV-VIS) spectroscopy was utilized to quantify dihydroxybenzene and quinone concentrations. Although dissolution of the oxide and release of Mn2+ to solution generally accompanied phenol oxidation, a threshold oxidation level had to be exceeded before Mn2+ appeared in solution. Once this threshold was surpassed, the mole quantity of Mn2+ dissolved equaled the mole quantity of organic oxidized for 1,4-DHB, but exceeded the quantity of organic oxidized for 1,2-DHB. Thus, the latter phenol was more efficient in dissolving the oxide. Soluble phosphate suppressed Mn2+ release without influencing the degree of organic oxidation, suggesting that phosphate chemically interacted with reduced Mn to hinder its dissolution. UV spectra provided tentative evidence for the transitory existence of Mn3+-1,4-DHB complexes in the solution phase.

Infrared spectra of the birnessite after reaction with 1,4-DHB indicated some new features, which may have been a result of the reduction of surface Mn atoms to the 3+ oxidation state. These features were not present after reaction with 1,2-DHB, confirming that the latter phenol efficiently dissolved the oxide to release Mn2+. Although the initial Mn dissolution was very rapid and was attributed to a surface reaction, further slow Mn release accompanied by more complete oxidation of the phenols suggests a process limited by the rate of dissolution of the solid.

Air-dried samples of homoionic Na-, Ca-, Al-, and Fe-smectite were equilibrated with 2,6-dimethylphenol vapor for 24 hr. Infrared spectra of the complexes formed indicated that a portion of the sorbed phenol was transformed into quinone-type compounds. Both sorption and transformation were greatly influenced by the nature of the exchangeable cation and followed the order Fe ≫ Al > Ca > Na. Changes in the electron spin resonance spectra of the clays following interaction with the phenol followed the same order, indicating that these reactions are enhanced by a transition metal cation, such as Fe3+, on the exchange complex. The reaction products from the clay complexes were extracted with methanol and identified using ultraviolet/visible spectrophotometry, high-pressure liquid chromatography (HPLC), and mass spectrometry. The extracts contained mixtures of products including the parent phenol, di-, tri-, and tetramers of the phenol, as well as quinone and quinone dimers. The identities of these compounds were further confirmed by the coincidence of the retention times of HPLC peaks obtained from extracts of the clays with those from compounds produced by oxidation of 2,6-dimethylphenol with Ag2O.

The catalytic power of Ca-nontronite (0.2–2 μm) for the polycondensation of phenols and glycine and the associated reactions that involve the ring cleavage of phenols and the decarboxylation and deamination of glycine was studied in systems free of microbial activity. At the end of a 90-hr reaction period, the amount of CO2 released from the Ca-nontronite-glycine-pyrogallol, Ca-nontronite-glycine-eatechol, and Ca-nontronite-glycine-hydroquinone systems were 5.1, 8.7, and 11.6 times higher, respectively, than those from the respective nontronite-free systems, showing the catalytic role of Ca-nontronite in the ring cleavage of phenols and the decarboxylation of glycine. The release of CO2 and NH3 from the Ca-nontronite-glycine system revealed that Ca-nontronite can catalyze decarboxylation and deamination of glycine. The ability of Ca-nontronite to catalyze the deamination of glycine was substantially enhanced by the presence of a phenol. The visible absorbances at both 472 and 664 nm of the supernatants, the total yields of N-containing humic polymers, and the fractions of glycine converted to nitrogenous polymers indicated that polycondensation of glycine and phenol was greatly catalyzed by Ca-nontronite. The total N-containing humic polymers formed in the systems decreased in the order: Ca-nontronite-glycine-pyrogallol > Ca-nontronite-glycine-cateehol > Ca-nontronite-glycine-hydroquinone > glycine-pyrogallol > glycine-hydroquinone > glycine-catechol. The infrared and electron spin resonance spectra of humic acid (HA) and fulvic acid (FA) formed in the supernatants of the reaction systems were quite similar to those of soil HA and FA. The catalytic power of Ca-nontronite in affecting the ring cleavage of phenols, deamination and decarboxylation of amino acids, and formation of humic substances derived from phenols with amino acids in soils and the related environments thus merits attention.

Phenol (benzenol) oxidation by three synthetic manganese oxides (buserite, manganite, and feitknechtite) has been studied in aerated, aqueous, acidified suspensions. The rate of reaction was pH dependent. Oxidation was greatly enhanced below pH 4, when diphenoquinone and p-benzoquinone were identified as the first products. Initial reaction rate was correlated with standard reduction potential (E°) of the oxides following the order: feitknechtite > manganite > buserite. A more gradual process of phenol oxidation after the initial reaction was influenced by electrochemical properties of the solution. High soluble manganese activity and increase in pH adversely affected reaction rates. Thus, the reactivity of the oxides was related to their stability and possibly the ability to readsorb Mn(II), following the order: buserite > manganite > feitknechtite. The results indicate that thermodynamic and electrochemical data for oxides and phenols are useful in predicting under which conditions phenols can be oxidized by a given system.

An iron catalyst supported on the modified Tamazert kaolin has been prepared and tested in catalytic wet peroxide oxidation using phenol and 4-chlorophenol (4-CP) as target compounds (100 mg/L initial concentration). Kaolin is not usually employed as a catalytic support due to its low developed porous structure, but its textural properties may be improved upon calcination and acid and basic treatment. The catalyst was characterized by N2 adsorption–desorption and chemical analysis by total-reflection X-ray fluorescence spectroscopy. The catalytic tests were carried out in a batch reactor with a stoichiometric amount of H2O2. The catalytic efficiency was studied within the temperature range of 25–55°C at an initial pH of 3.3 and 1 g/L catalyst. Complete phenol and 4-CP removal was achieved with no significant differences in phenol and 4-CP conversions within the temperature range tested. Meanwhile, total organic carbon (TOC) reduction was greatly favoured by increasing the temperature, which may be partially attributed to a probable contribution of a homogeneous reaction associated with iron leaching. However, this effect might be of limited significance because the highest concentrations of iron in the liquid phase were below 4.5 and 8.5 mg/L in the experiments with phenol and 4-CP, respectively. At 55°C, TOC was reduced by ~70% after 4 h reaction time, with the remaining by-products corresponding almost completely to low-molecular-weight carboxylic acids of very low ecotoxicity.

Composite hydrogels based on hydroxypropyl cellulose (HPC) and graphene oxide (GO) were developed and used for adsorption of phenol. The single network composite hydrogel (SNCH) was first prepared by crosslinking of HPC and GO by epichlorohydrin; then the SNCH was treated with polyethyleneimine solution, forming the double network composite hydrogel (DNCH). The DNCH exhibited better adsorption capacity than the SNCH due to larger surface area and more functional groups. The possible adsorption mechanism of the composite hydrogels toward phenol involved electrostatic, hydrogen bonding, and π–π interactions. Study on dynamic adsorption behavior of phenol by SNCH and DNCH indicated that the breakthrough time increased when the initial concentration and feed flow rate of phenol decreased. Furthermore, the breakthrough time of DNCH was longer than that of SNCH at all operating conditions due to the relatively higher adsorption capacity of DNCH. The SNCH and DNCH could be repeatedly used without significant loss in the initial binding affinity after six adsorption–desorption cycles, which indicated that the composite hydrogels were qualified for practical application.

The influence of young, mature and senescent leaves of bitter gourd Momordica charantia L. (Cucurbitaceae) on the feeding, growth and reproduction of Epilachna dodecastigma (Weid.) (Coleoptera: Coccinellidae) were studied under laboratory conditions (27 ± 0.5 °C, 12 h light: 12 h dark photoperiod, 65 ± 5% RH). Larval developmental time of E. dodecastigma was longest on senescent leaves followed by young and mature leaves, whereas the pupal period was shortest on young and mature leaves. The longevity of females was generally higher than males. Male and female longevity were highest on mature leaves and lowest on senescent leaves. Fecundity was highest on mature leaves followed by young and senescent leaves. The growth and development of E. dodecastigma were related with nutrient and phenol content of three types of bitter gourd leaves. Carbohydrate content was higher in young and mature leaves, whereas protein, nitrogen, amino acid and lipid content were in greater quantities in mature leaves followed by young and senescent leaves. Phenol content was greatest in senescent leaves and least in mature leaves. Higher level of carbohydrates, proteins, lipids, nitrogen and amino acids including water content and lower phenol content of mature leaves had influenced higher growth rate and fecundity of E. dodecastigma.

Fresh buckwheat (Fagopyrum esculentum) and chicory (Cichorium intybus) had been shown to have the potential to improve certain milk quality traits when fed as forages to dairy cows. However, the process of ensiling might alter these properties. In the present study, two silages, prepared from mixtures of buckwheat or chicory and ryegrass, were compared with pure ryegrass silage (Lolium multiflorum) by feeding to 3 × 6 late-lactating cows. The dietary dry matter proportions realised for buckwheat and chicory were 0·46 and 0·34 accounting also for 2 kg/d of concentrate. Data and samples were collected from days 10 to 15 of treatment feeding. Buckwheat silage was richest in condensed tannins. Proportions of polyunsaturated fatty acids (PUFA) and α-linoleic acid in total fatty acids (FA) were highest in the ryegrass silage. Feed intake, milk yield and milk gross composition did not differ among the groups. Feeding buckwheat resulted in the highest milk fat concentrations (g/kg) of linoleic acid (15·7) and total PUFA (40·5; both P < 0·05 compared with ryegrass). The concentration of α-linolenic acid in milk fat was similar across treatments, but its apparent recovery in milk relative to the amounts ingested was highest with buckwheat. The same was true for the occurrence of FA biohydrogenation products in milk relative to α-linolenic acid intake. Recovery of dietary linoleic acid in milk remained unaffected. Feeding buckwheat silage shortened rennet coagulation time by 26% and tended (P < 0·1) to increase curd firmness by 29%. In conclusion, particularly buckwheat silage seems to have a certain potential to modify the transfer of FA from feed to milk and to contribute to improved cheese-making properties.

Two studies were performed to determine whether topical phenol is a safe and well tolerated local anaesthetic for grommet insertion. Study 1 was a retrospective examination of audiological outcomes and complications. Data were obtained regarding 71 procedures in 57 patients. One late infection and nine early extrusions were noted. No statistically significant changes between pre- and post-operative bone conduction thresholds were found. Study 2 was a prospective analysis of patients' perceptions of the procedure. Data from 17 patient questionnaires were analysed as follows: pain rating – not painful, three patients; slightly painful, 14 patients. Overall experience rating – pleasant, four patients; slightly unpleasant, 10; unpleasant, three. All patients stated that they would undergo the procedure again. In conclusion, we found no evidence of phenol-induced hearing loss. The complication rate was within normal limits and patients were satisfied with the procedure. Grommet insertion using phenol as a local anaesthetic is safe and acceptable to patients.

Five volatile organic compounds were identified throughout 1991 in the hypolimnion of Organic Lake. These were dimethylsulphide (DMS), dimethyldisulphide (DM2S), dimethyltrisulphide (DM3S), dimethyltetrasulphide (DM4S) and phenol. The concentration of these compounds increased with lake depth. The concentration of DMS and DM2S was higher in the sediment than in the water column. Carbon disulphide occurred only in the sediment. DMS was the only volatile organic compound detected in the epilimnion of the lake, where its concentration increased from winter onwards. The source of DMS was not dimethylsulphoniopropionate (DMSP). This was determined by hydroxylation of the sample with NaOH. There was no change in the concentration of DMS but the concentration of DM2S increased dramatically while the concentrations of DM3S and DM4S decreased concomitantly. This has important implications in the estimation of DMS derived from DMSP by hydroxylation when organic polysulphides are also present. The stability of the hypolimnion of Organic Lake was reflected by the lack of change in temperature, density, redox potential and the relatively constant concentration of volatile organic compounds throughout the year. Potential sources of the volatile organic compounds are discussed in relation to the isolated nature of the lake.

Prolonged nerve conduction blockade has been proposed to result from the summed effects of charged and neutral local anaesthetics. Thirty-seven patients were randomly allocated to receive intravenous patient-controlled analgesia alone or combined with intercostal blockade (T7–T11) with a mixture of 0.45% bupivacaine and 0.6% phenol for post-cholecystectomy analgesia. Adequacy of pain relief was measured by patient scores on a 10-cm visual analogue scale and by dose–demand ratio, amounts of loading dose and total consumption of morphine and also the duration of patient-controlled analgesia in each group. No differences were found between groups in post-operative scores, dose–demand ratios and loading doses of morphine. However, in the combined treatment group, a significantly lower total consumption of morphine (P<0.05), associated with a shorter duration of patient-controlled analgesia (P<0.02) and a decreased mean number of unsuccessful demands (P<0.001) were recorded. Intercostal blockade with bupivacaine–phenol supplements intravenous patient-controlled analgesia for post-cholecystectomy pain relief.