The occurrence, behaviors and fate of 18 PAHs were investigated in a coking wastewater treatment plant in Songshan coking plant, located in Shaoguan, Guangdong Province of China. It was found that the target compounds occurred widely in raw coking wastewater, treated effluent, sludge and gas samples. In raw coking wastewater, high molecular weight (MW) PAHs were the dominant compounds, while 3-6 ring PAHs predominated in the final effluent. The dominant compounds in gas samples were phenathrene, fluoranthene and pyrene, while they were fluoranthene, pyrene, chrysene and benzo[k]fluoranthene for sludge. The process achieved over 97% removal for all the PAHs, 47-92% of eliminations of these target compounds in liquid phase were achieved in biological stage. Different behaviors of PAHs were observed in the primary tank, anaerobic tank, aerobic tank, hydrolytic tank and coagulation tank units, while heavier and lower ones were mainly removed in anaerobic tank and aerobic tanks, respectively. Regarding the fate of PAHs, calculated fractions of mass losses for low MW PAHs due to transformation and adsorption to sludge accounted for 15-50% and 24-49%, respectively, while the rest was less than 1%. For high MW PAHs, the mass losses were mainly due to adsorption to sludge and separation with tar (contributing 56-76% and 22-39%, respectively), and the removal through transformation was less. 相似文献
In the polydomous ant species Cataglyphis iberica, nests belonging to the same colony are completely separated during hibernation. In order to examine whether this separation
induces changes both in the hydrocarbon profile and in recognition ability between adult nestmates, we separated groups of
workers for several months under two different conditions: at hibernation temperature and at room temperature. At room temperature,
recognition remained unchanged but separation led to longer mutual antennations relative to non-separated controls. When half
of a colony was placed under hibernation conditions, antennal interactions also increased in duration and a few aggressive
interactions emerged between separated ants. This aggressiveness never reached the intercolonial level observed in this species.
In both cases, the hydrocarbon profiles showed differences between individuals after separation while remaining homogeneous
within each nest. This chemical modification may induce the longer antennations observed. After separated groups were reunited,
individuals recovered their previous antennation pattern and a convergence in hydrocarbon profiles was again observed. These
concurrent observations suggest that hydrocarbons are transferred between nestmates. In C. iberica, the formation of the colonial odor seems to follow the “Gestalt” model which allows all satellite nests of a colony to have a common colonial odor. In the field, temporary nest isolation
during hibernation may induce divergence between satellites. The role of adult transport in connecting nests during the active
season to obtain an efficient Gestalt odor is discussed.
Received: 16 June 1997 / Accepted after revision: 25 October 1997 相似文献
The aim of the current study was to measure polycyclic aromatic hydrocarbons (PAHs) in eight indoor (In both kitchen and living room) air sampling locations using a passive sampling method for collection. Passive outdoor air samples were also collected from 3 of the same sampling locations as the indoor air sampling sites. Sampling was conducted in three seasons. The summer season, when windows are generally open, was between 18th July and 01st September, 2014; the autumn and winter seasons, when windows are mostly closed, was between 18th October and 01st December, 2014, and 01st December, 2014, and 18th January, 2015, respectively.
Average PAH concentrations in summer were 22 ± 21 ng/m3 and 17 ± 12 ng/m3 in the living room and kitchen, respectively, whereas living room and kitchen average PAH concentrations were 23 ± 16 ng/m3 and 20 ± 9 ng/m3, respectively, in autumn and 23 ± 13 ng/m3 and 23 ± 24 ng/m3, respectively, in winter. Outdoor air PAH concentrations in summer, autumn and winter were 7 ± 0.4 ng/m3, 22 ± 13 ng/m3 and 209 ± 33 ng/m3, respectively. An increase in outdoor PAH concentrations was measured in winter compared to the concentrations in summer and autumn, which paralleled the lower outdoor air temperature. However, PAH concentrations in the indoor environment vary according to the household characteristics and personal habits. 相似文献
Sediment-associated hydrocarbons can pose a risk to wildlife that rely on benthic marine food webs. We measured hydrocarbons in sediments from the habitat of protected sea otters in coastal British Columbia, Canada. Alkane concentrations were dominated by higher odd-chain n-alkanes at all sites, indicating terrestrial plant inputs. While remote sites were dominated by petrogenic polycyclic aromatic hydrocarbons (PAHs), small harbour sites within sea otter habitat and sites from an urban reference area reflected weathered petroleum and biomass and fossil fuel combustion. The partitioning of hydrocarbons between sediments and adjacent food webs provides an important exposure route for sea otters, as they consume ∼25% of their body weight per day in benthic invertebrates. Thus, exceedences of PAH sediment quality guidelines designed to protect aquatic biota at 20% of the sites in sea otter habitat suggest that sea otters are vulnerable to hydrocarbon contamination even in the absence of catastrophic oil spills. 相似文献
The ambient air in Northern Italy is characterised by relatively high PAH and PM10 concentrations in relation to calm wind and intensive temperature inversions, especially during cold periods. These stagnant conditions are occasionally interrupted by North-Föhn events, which cause a drop in relative humidity and an increase in O3 levels, indicating the mixing of local and free troposphere air flows. In this study the influence of the North-Föhn on concentrations of tracer organic compounds, including polycyclic aromatic hydrocarbons (PAHs), PM10, O3 and black carbon (BC) was studied during a North-Föhn event in November 2007. Large fluctuations in the concentration of these compounds, as well as changes in PM10 composition due to daytime and night-time variations of local source emissions were observed. Although these events occur at low frequencies (6-10%) they can for short periods, strongly affect the regional air quality by quickly decreasing the concentrations of these tracer organic compounds. 相似文献
Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability. 相似文献
The in vivo conversion of dry olive mill residue (DOR) by wood- and dung-dwelling fungi − Auricularia auricula-judae, Bjerkandera adusta and Coprinellus radians − increases peroxidase secretion up to 3.2–3.5-fold (∼1.3, 3.5 and 7.0 U g−1 DOR for dye-decolorizing peroxidase, manganese peroxidase and aromatic peroxygenases, respectively). The incubation of DOR with these fungi produced a sharp decrease in total phenolic content (100% within 4 wk), a reduction in phytotoxicity as well as a certain degree of plant growth caused by the stimulating effect of fungal-treated DOR. These findings correlate with a characteristic shift in the fragmentation pattern of water-soluble aromatics (detected at 280 nm) from low (0.2, 1.5 and 2.2 kDa, respectively) to high molecular mass (35 to >200 kDa), which demonstrates the presence of a polymerization process. Phenol-rich agricultural residues are a useful tool for enzyme expression and production studies of peroxidase-producing Agaricomycetes which could make DOR a valuable organic fertilizer. 相似文献