Occurrence and Distribution of Organic Contaminants in the Aquatic System in Berlin.Part II: Substituted Phenols in Berlin Surface Water

In a surface water screening, 30 representative surface water samples collected from rivers, canals, and lakes in Berlin were investigated for the presence of 22 substituted phenols. The phenols selected include the 11 phenols considered as “priority pollutants” by the US Environmental Protection Agency (US-EPA). Surface water samples were extracted applying solid-phase extraction with styrenedivinylbenzene adsorbent. The recoveries, determined in spiking experiments, were between 80 % and 103 %. After derivatization with N-(tert-butyldimethylsilyl)-N-methyl-trifluoroacetamide (MTBSTFA) the samples were analyzed by capillary gas chromatography-mass spectrometry (GC-MS). Phenol, cresols, 2-ethylphenol, 2-chlorophenol, 4-chloro-3-methylphenol, pentachlorophenol, 2-nitrophenol, and 4-nitrophenol were detected in the surface water samples at concentrations between 0.02 μg/L and 7.8 μg/L, respectively. The distribution of these residues in the Berlin surface waters showed that the phenolic residues, with the exception of pentachlorophenol and 2-ethylphenol, do not originate primarily from municipal sewage treatment plants discharges. Some of the phenols are formed naturally or occur as ubiquitous anthropogenic contaminants in the aquatic system.     

Analysis of the distribution coefficients and mobility characteristics of phenols in different soil types

Adsorption studies were carried out on soil samples of high organic and low organic content to analyze the distribution coefficient and mobility of phenols. The results show that the amount of phenols adsorbed by the soil varies linearly with the fraction of organic carbon. Soils that are highly organic compared to those with low organic matter content retain the phenols to a greater extent. Adsorption studies on the different soil types indicated that the extent of adsorption of phenols by different kinds of soils is important, as a smaller amount of adsorption by the soil increases the risk of contamination of the groundwater supply.     

海水中酚类有机物在粘土或沉积物上吸附特性的模拟研究

研究了海水中７种酚类有机污染物在粘土矿物及海洋沉积物上的吸附特征;发现了酚在粘土或沉积物上的吸附平衡常数与其水溶解度之间的线性自由能关系,。     

Modeling the biodegradation of phenolic compounds by microalgae

Phenols represent a group of organic pollutants frequently found in many near-shore marine systems. The microbial degradation of phenols, mainly by bacteria and fungi, has been extensively studied both experimentally and theoretically, but only relatively recently the capabilities of some algae for phenols biodegradation gained interest. The biodegradation of phenols by microalgae occurs only under aerobic conditions. In this paper, a dynamic energy budget model is proposed for describing aerobic biodegradation of phenolic compounds by microalgae and qualitatively validated against experimental data. A microalgal cell has the ability to produce biomass via the autotrophic assimilation (uptake of light and dissolved inorganic carbon), the heterotrophic assimilation (uptake of dissolved organic carbon) and, to a lesser extend, via the biodegradation of phenols. The rules of synthesizing units are used for the uptake and interactions of substrates and for the merging of assimilates. The model is capable of making predictions under oxygen and carbon (inorganic and organic) limiting conditions. Model predictions cover a wide range of experimental evidence, but also give a possible explanation for the inhibition of bioremoval of phenols in the presence of glucose. The dissolved oxygen profiles numerically observed show low oxygen concentration during the intermediate phase of the biodegradation process and a rapid increase after the consumption of the phenolic compound, indicating that lack of oxygen could be a limiting factor for the biodegradation of phenols. The presence of glucose increases the specific growth rate but decreases the specific biodegradation rate of the phenolic compound. Model analysis suggests that this inhibition may be due to the competition for oxygen between glucose and phenol assimilation. In general, the balance between the benefits and costs of the different types of assimilation determines the microalgal growth rates as well as the phenol biodegradation rates. Being based on general assumptions, the model can be applied to the biodegradation of a wide variety of aromatic compounds.     

Coal mine workers' pneumoconiosis

 The fibrogenic and cytotoxic potential of coal mine dust is independent of the amount of quartz and other inorganic parameters. Results of coal petrographical and organic geochemical investigations of coals and coal mine dust from the Ruhr and Ibbenbüren Region of Germany demonstrate variations of organic dust amount possibly influencing these noxious properties. Coal mine dust of high rank coals is characterized by a pronounced fibrogenic risk. This risk, independent of the quantity of quartz, is probably based on shape variations of different coal macerals. With increasing coalification of the corresponding seam, the vitrinite is enriched in its dust; however, lower concentrations have been determined for inertinite. Vitrinite shows constant shapes and sizes independent of the rank of coal. Inertinite particles with elongated to fibrous shapes tend to larger sizes with increasing coalification. Strikingly, coal mine dust from miners' lungs with high degrees of coal mine workers' pneumoconiosis (CWP) is enriched in inertinite. In contrast, high cytotoxicities in cell tests are known for coal mine dust from low coalified coals. High concentrations of phenolic compounds can be extracted by dichloromethane from low coalified coal mine dust. These compounds, which are characterized by a high water solubility and therefore high bioavailability, explain the high cytotoxicities of coal mine dust. Contamination of dust by diesel emissions in the coal mine can act as additionally supporting parameters for extended cytotoxicities. Received: 18 August 1995 · Accepted: 15 October 1995     

活性碳纤维吸附水中酚及脱附条件实验研究

化工、医药等行业排出的含酚废水对环境造成的污染十分严重,其废水的处理日益受到重视。活性炭纤维(Activated Carbon Fibers,ACF)作为一种新型吸附材料,其具有的大比表面积、丰富微孔结构等特点,使其吸附过程效率高。并且其吸附操作设备具有简单、方便、能耗低等优点,从而使该吸附法成为近年来一种快速发展的废水处理方法。本研究通过静态条件下的吸脱附性能研究,研究了ACF吸附水中酚的规律,确定了最佳的吸附时间为4 h,水溶液pH为弱酸性及低温有利于吸附的结果,得到了准确的平衡吸附量;找到了合适的ACF脱附再生剂NaOH,并测试出其多次再生的利用率。     

Changes of Acute Toxicity of Organic Chemicals to Daphnia magna in the Presence of Dissolved Humic Material (DHM)

With a series of substituted anilines, a series of substituted phenols as well as diazinon and tetrabromobisphenol-A alterations of short-term acute toxicity to the waterflea Daphnia magna have been studied in the presence of dissolved humic material (DHM). The results may be categorised as follows: No alteration in acute toxicity occurred with: tetrabromobisphenol-A, o-toluidine, 3,4-dichloroaniline, and pentachlorophenol. Toxicity decreases significantly with: diazinon, 4-chloroaniline, and 4-nitrophenol. Significant toxicity increases were observed with 2,4-dichlorophenol and 2,4,5-trichlorophenol. As demonstrated for diazinon, our study reveals that in the presence of DHM and light the chemical speciation of this chemical is altered and daughter products are produced most likely via photoactive species of DHM. Most probably the toxicity of both the parent and daughter compounds is changed as well. Alterations in acute toxicity of organic chemicals may thus be attributed to the adsorption to DHM as well as to the photoactive species mediated production of daughter products with toxicity different from that of the parent compounds.     

Formation of Dibenzodioxins and Dibenzofurans in the Photochemical Transformation of Polychlorinated Phenols

It is shown that in the direct photolysis of polychlorinated phenols (2,4,5-TCP, PCP) in aqueous solution, under the action of solar light or UV-radiation from artificial sources, polychlorinated dibenzodioxins (PCDD) and dibenzofurans (PCDF) are found among the products of transformation. A mechanism is suggested of formation of these toxic compounds via the intermediate formation of free radicals. In the oxidation of chlorophenols by singlet oxygen, free radicals are not formed. Addition of fulvic acids prevents formation of PCDD and PCDF in solar light, possibly as a result of trapping of intermediate radicals.     

Anreicherung von Phenolen aus Wasser mit Hilfe von hochporösem,chemisch vernetztem Polystyrol

Solid Phase Extraction of Phenols from Water by Highly Porous Cross-linked Polystyrene The extraction of organic trace components from water by solid phase extraction has largely substituted liquid/liquid extraction. For the isolation of many underivatized phenols with significant water solubility however, the conventional surface-modified silicagels are unsuitable. In the following, results are reported of experiments with a novel, highly porous material of cross-linked polystyrene. Using columns with 0.2 g of the adsorbent, the isolation of more than 60 differently substituted phenols, including 6 pesticides and 31 metabolites, in the concentration range of 25 to 125 ng/L has been accomplished. After adsorption from 1 L of sample water, derivatization and gas chromatographic determination recoveries ranged from 70 to 100%.