Motor exhaust gas from an automobile motor, operated under stationary conditions with unleaded gasoline, was sampled with two different impinger bath methods. The samples were analyzed by gas chromatography /mass spectrometry (GC/MS) for phenol, cresols and nitrated phenols. Phenol and cresols were measured in the range of 80 -220 nmol/L of exhaust gas from a noncatalyst engine, and nitrated phenols were found in the range of 9 -36 nmol/L. A large reduction of total phenols down to 7% and less was observed when the engine was operated with a regulated three-way catalytic converter. The result of this study shows that exhaust gas sampling of phenols with alkaline aqueous impinger solutions leads to an underestimation of phenol emissions, since phenols are not stable under high-pH conditions.In order to better assess the environmental fate of nitrated phenols, laboratory experiments were conducted to measure the Henry's law constants of a series of nitrated phenols. For that purpose an apparatus for dynamic determination of the Henry's law constants was constructed and successfully used. Special emphasis was put on temperature dependence of the Henry's law constants.
The frequency and mass concentrations of 13 herbicide micropollutants (triazines, phenylureas, chloroacetanilides and trifluralin) were investigated during 2014 in surface, ground and drinking waters in the area of the city of Zagreb and its suburbs. Herbicide compounds were accumulated from water by solid-phase extraction using either octadecylsilica or styrene-divinylbenzene sorbent cartridges and analysed either by high-performance liquid chromatography with UV-diode array detector or gas chromatography with mass spectrometric detection. Atrazine was the most frequently detected herbicide in drinking (84 % of samples) and ground (61 % of samples) waters in mass concentrations of 5 to 68 ng L. It was followed by metolachlor and terbuthylazine, the former being detected in 54 % of drinking (up to 15 ng L) and 23 % of ground (up to 100 ng L) waters, and the latter in 45 % of drinking (up to 20 ng L) and 26 % of ground (up to 25 ng L) water samples. Acetochlor was the fourth most abundant herbicide in drinking waters, detected in 32 % of samples. Its mass concentrations of 107 to 117 ng L in three tap water samples were the highest of all herbicides measured in the drinking waters. The most frequently (62 % of samples) and highly (up to 887 ng L) detected herbicide in surface waters was metolachlor, followed by terbuthylazine detected in 49 % of samples in mass concentrations of up to 690 ng L, and atrazine detected in 30 % of samples in mass concentrations of up to 18 ng L. The seasonal variations in herbicide concentrations in surface waters were observed for terbuthylazine, metolachlor, acetochlor, chlortoluron and isoproturon with the highest concentrations measured from April to August.
Polychlorinated biphenyls (PCBs), organochlorine pesticides and chlorophenols were measured in samples of rain and snow collected at urban and suburbadsemi-rural locations in the Zagreb City area, Croatia. PCBs and organochlorine pesticides were extracted with hexane from filtered aqueous samples and from particulate matter isolated by filtration. Chlorophenols were accumulated from rain and snow water by C18 reversed-phase adsorption. All samples were analysed by capillary gas chromatography using an electron-capture detector. Polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs) in rain and snow water were checked by gas chromatographic-mass spectrometric analysis of combined hexane extracts. PCBs were detected in all water (4-203 ng 1-1) and particle (40-4155 ng g-1) samples. The only organochlorine pesticide present in all rain and snow water (1-36 ng 1-1) and in particle (7-512 ng g-1) samples was y-hexachlorocyclohexane as a consequence of the regular local usage of lindane. A positive correlation was found between its concentration in the water phase and the average air temperature during the sampling period. Compounds of the DDT-type, trace amounts of which were detected in only two rain water samples, were determined in most particle samples. The DDE : DDT median concentration ratio in particles was lower than unity and indicated a recent input of DDT into the atmosphere. The incidence and concentrations of di-, tri-, tetra-and pentachlorophenols were higher in snow (single compound concentration 11-527 ng 1-1) than in rain (single compound concentration 2-171 ng 1-1). A quadratic decrease in chlorophenol concentrations in snow and rain with increasing air temperature was observed. Trace amounts of PCDDs and PCDFs were detected in both rain and snow water samples and the highest concentrations were measured for octa-CDD (2 pg 1-1 in snow and 6 pg 1-1 in rain).
This article describes the sorption behavior of 3 hydrophobic ionizable chlorophenols-2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, and pentachlorophenol-in different types of natural sorbents. A series of experiments was carried out with 11 topsoil samples, 9 aquifer sediments, and 12 marine sediments differing in pH, organic-matter content, and mineral composition and presumably also in type of organic matter due to their differing origins. Ionized forms of chlorophenols dominated in almost all sorption experiments. Freundlich isotherm coefficients K(f) and 1/n, as well as organic-matter sorption coefficient (log K(om)) and free-energy change (DeltaG(o)), were calculated for all 3 compounds in all sorbents. The sorption intensity of predominantly ionized chlorophenols increased linearly with the increase of sorbent organic-matter content and decreased with the increasing sorbent pH. Different sorption behavior of all 3 compounds in marine sediments with respect to topsoils and aquifer sediments was indicated by significant differences in K(f) and 1/n coefficients as well as in log K(om) and DeltaG(o) values. The highest K(f) and log K(om) values were obtained for sorption of chlorophenolic compounds in topsoils and the lowest in marine sediments, although both groups of sorbents had similar organic-matter content. The 1/n coefficient, reflecting the isotherm nonlinearity, was considerably lower than unity for all compounds in almost all sorbents. The most significant deviation of sorption isotherms from linearity was observed in marine sediments. Only marine sediments showed a linear increase in sorption intensity of all 3 compounds with the increase in sorbent-specific surface area. These results pointed to a different mechanism of sorption in marine and terrestrial sorbents and confirmed that the capacity of sorption was related to amount as well as type and origin of organic matter.
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