Sorption of PAHs and PCBs to activated carbon: coal versus biomass-based quality

The addition of activated carbon (AC) is an increasingly popular method for pollutant immobilization, and the AC material can be made of biomass or coal/fossil feedstock. The aim of the present study was to investigate whether there are differences between pollutant sorption to biomass and coal-based AC in the presence and absence of sediment. Through N₂ and CO₂ adsorption to probe surface area and pore size it was shown that the biomass-based AC had a stronger dominance of narrow pores in the size range 3.5-15 Å than the anthracite-based material. In the absence of sediment, sorption isotherms for the probe compounds pyrene and PCB-101 showed stronger sorption for the biomass-based AC (logarithmic Freundlich coefficients 8.15 for pyrene; 9.91 for PCB-101) than for the anthracite-based one (logarithmic Freundlich coefficients 7.20 and 9.70, respectively). In the presence of sediment, the opposite trend was observed, with the stronger sorption for anthracite-based AC. Thus, the presence of competing and/or pore-blocking sediment constituents reduces sorption to a larger extent for biomass-derived AC (factor of 5 for pyrene to almost 100 for PCB-101) than for anthracite-based AC (no reduction for pyrene to factor of 5 for PCB-101). This difference is tentatively attributed to the difference in pore size distribution, narrow pores being more prone to clogging, and could have implications for remediation feasibility with AC from different sources.     

不同萃取方法对长江口边滩多环芳烃萃取效果的影响

选取索氏提取法和加速溶剂萃取仪(ASE)提取法,对长江口边滩样品进行多环芳烃萃取实验,并利用气相色谱/质谱仪对萃取出来的多环芳烃进行定量分析,研究了不同萃取方法以及不同溶剂条件下多环芳烃的总量、分布特征.结果表明,长江口边滩多环芳烃最高值出现在吴淞口;索氏提取法在多环芳烃萃取效果上优于加速溶剂萃取仪提取法;混合溶剂萃取...     

Optimization of analytical methods to improve detection of erythromycin from water and sediment

Analytical methods to improve the detection of erythromycin in water and sediment were developed to optimize for erythromycin's recovery of extractable and bound residues from the aquatic environment. The objective of this study was to determine optimal recovery of erythromycin from water and sediment to improve its detection in environmental samples through solid-phase extraction (SPE) and sediment-extraction methods. SPE methods examined included previously reported methods for macrolide and sulfonamide antibiotics with erythromycin recoveries ranging from 75.5 % to 94.7 %. Extraction of erythromycin was performed from sand employing various solvents and buffers to determine the best method for extraction from two sandy loam pond sediments. Various extraction times were also examined, and all extraction procedures were performed in duplicate. The greatest recovery of ¹⁴C-erythromycin in the Iowa sediment was 84 % using 0.3 M ammonium acetate at pH 4.2: acetonitrile (15:85, v/v) solution. The Oklahoma sediment yielded the greatest recovery of ¹⁴C-erythromycin at 86.7 % with 0.3 M ammonium acetate at pH 7: acetonitrile (30:70, v/v) with a 60-minute shake time. The present results demonstrate improved extraction methods for enhancing the accuracy of erythromycin detection from environmental samples.     

Application of surrogate methods for assessing the bioavailability of PAHs in sediments to a sediment ingesting bivalve

The usefulness of two surrogate methods for rapidly determining the bioavailability of PAHs in hydrocarbon-contaminated marine sediments was assessed. Comparisons are made between the PAHs accumulated by the benthic bivalve, Tellina deltoidalis, and the extractable-PAHs determined using a 6-h XAD-2 resin desorption method and a 4-h gut fluid mimic (GFM) extraction method. There were significant positive relationships between PAH bioaccumulation by the bivalves and sediment PAH concentrations. These relationships were not improved by normalising the sediment PAH concentrations to the organic carbon concentration. The average percentage lipid content of the bivalves was 1.47 ± 0.22% and BSAFs for total-PAHs ranged from 0.06 to 0.80 (kg OC/kg lipid). The XAD-2 and GFM methods both extracted varying amounts of PAHs from the sediments. Low concentrations of PAHs were extracted by the GFM method (0.2–3.6% of total-PAHs in sediments) and the GFM results were inadequate for generalising about the bioavailability of the PAHs in the sediments. The XAD-2 method extracted greater amounts of PAHs (3–34% of total-PAHs in sediments), however, the total-PAH concentrations in the sediments provided a better, or equally good, prediction of PAH bioaccumulation by T. deltoidalis. The results indicated that these methods required further development before they can be applied routinely as surrogate methods for assessing the bioavailability of PAHs in sediments. Future research should be directed towards lowering detection limits and obtaining comparative data for a greater range of sediment types, contaminant classes and concentrations, and organisms of different feeding guilds and with different gut chemistry.     

江苏盐城滩涂土壤中多环芳烃的测定

文中采用江苏盐城滩涂响水到滨海一带的滩涂土壤样品,利用索氏提取法提取、硅胶柱净化、高效液相色谱法分离检测土壤样品中的多环芳烃(PAHs),并用优化洗脱程序对滩涂土壤中PAHs的含量进行了测定。结果表明:11个滩涂土壤样品中检出萘、苊烯、菲、蒽、荧蒽、芘六种PAHs,其含量较低,说明该段滩涂土壤尚未受到多环芳烃的污染。     

Persistent organic pollutants in cork used for production of wine stoppers

Owing to the lipophilic character of some components of cork and the long periods in the open air (during growth and barks storage), there is a risk of the cork becoming environmentally polluted. Moreover, cork stoppers are in contact with wines for periods ranging from a few months to several years; so they must maintain high levels of hygiene. The present work aims to investigate the level of PCBs, organochlorine pesticides, and PAHs in cork from different countries, used for the manufacturing of one-piece wine stoppers. Samples of cork were analysed using a multi-residue method. PCBs were not detected in all the samples; only a few samples contained detectable amounts of DDE; phenanthrene and anthracene were found in all the samples and fluoranthene in fewer cases. It was not possible to find a significant correlation between POPs concentration and origin of cork. Globally, the detected amounts are consistent with values found in foods, so the investigated cork show a suitable hygienic quality.     

Sources of PCDD/Fs, non-ortho PCBs and PAHs in sediments of high and low impacted transboundary rivers (Belgium-France)

PAHs, PCDD/Fs and non-ortho PCBs have been assessed in Yser and Upper-Scheldt river sediments. Higher contamination levels were observed in the Upper-Scheldt sediments: maximum concentrations for the 16 US-EPA PAHs, PCDD/Fs and non-ortho PCBs respectively amount to 8.9 mg kg⁻¹, 12 ng TEQ kg⁻¹ and 5.1 ng TEQ kg⁻¹. Diagnostic PAH ratios in sediments and atmospheric samples suggest that the PAH compounds are from pyrolytic origin, more specifically combustion processes. The huge consumption of coal in cokes-ovens and smelters and its use for house-heating in Northern France, although decreasing during the last decades, are in support of that suggestion. PCDD/F fingerprints in sediments and deposition material indicate that OCDD is the dominant congener. In addition use of pentachlorophenol (PCP) in the past led to a minor contribution of PCDD/Fs in our sediment samples. Non-ortho PCBs form a substantial fraction of the total TEQ concentrations observed in the sediments. Since the 1980s and 1990s a substantial reduction of the PCDD/F sediment concentrations is observed, but this is not the case for the PAHs.     

Dry deposition and soil-air gas exchange of polychlorinated biphenyls (PCBs) in an industrial area

Ambient air and dry deposition, and soil samples were collected at the Aliaga industrial site in Izmir, Turkey. Atmospheric total (particle + gas) ∑₄₁-PCB concentrations were higher in summer (3370 ± 1617 pg m⁻³, average + SD) than in winter (1164 ± 618 pg m⁻³), probably due to increased volatilization with temperature. Average particulate ∑₄₁-PCBs dry deposition fluxes were 349 ± 183 and 469 ± 328 ng m⁻² day⁻¹ in summer and winter, respectively. Overall average particulate deposition velocity was 5.5 ± 3.5 cm s⁻¹. The spatial distribution of ∑₄₁-PCB soil concentrations (n = 48) showed that the iron-steel plants, ship dismantling facilities, refinery and petrochemicals complex are the major sources in the area. Calculated air-soil exchange fluxes indicated that the contaminated soil is a secondary source to the atmosphere for lighter PCBs and as a sink for heavier ones. Comparable magnitude of gas exchange and dry particle deposition fluxes indicated that both mechanisms are equally important for PCB movement between air and soil in Aliaga.     

Comparison of Microwave Assisted Extraction with Conventional (Homogenization,Vortexing) for the Determination of Incurred Salinomycin in Chicken Eggs and Tissues

Abstract

Incurred and fortified salinomycin residues were extracted from chicken tissues and eggs by homogenization, vortexing and by microwave assisted extraction. The salinomycin residues were quantitated by liquid chromatography following postcolumn derivatization with either vanillin or 4-dimethylamino-benzaldehyde and detected at 520 or 592 nm, respectively. Comparison of residue data indicated that microwave assisted extraction performed as well as the vortexing technique in extracting salinomycin residues in the tissues of laying chickens that were fed meal containing drugs at various level. In the present study, extracts from homogenizing could not be analyzed directly without clean up. Therefore, microwave assisted extraction appears to be a reliable, reproducible, and economical substitute for routinely used homogenization and vortexing extraction techniques.     

Meteorological and pedological influence on the PCBs distribution in mountain soils

Polychlorinated biphenyls (PCBs) are a threat to environmental and human health due to their persistence and toxicological effects. In this paper, we analyse some meteorological and organic-matter-related effects on their distribution in the soils of an Alpine environment that is not subject to direct contamination. We collected samples and measured the contamination of 12 selected congeners from three soil layers (O, A1 and A2) and from North-, plain- and South-facing slopes on six different dates spanning the entire snowless portion of the year. We recorded the hourly air and soil temperatures, humidity and rainfall in the study period. We found evidence that PCBs contamination in soils varies significantly, depending on sampling date, layer and aspect. The observed seasonal trend shows an early summer peak and a rapid decrease during June. The layer effect demonstrates higher dry-weight-based concentrations in the O layer, whereas the differences are much smaller for SOM-based concentrations. Different factors caused significantly higher concentrations in northern soils, with a N/S enrichment factor ranging from 1.8 to 1.5 during the season. The southern site has significantly more rapid early-summer re-volatilisation kinetics (half-time of 16 d for South, 25 d for North).     

Dechlorination of PCBs in the simulative transformer oil by microwave-hydrothermal reaction with zero-valent iron involved

The conventional hydrothermal reaction with iron powder, NaOH and H₂O as reactants was reported to occur at temperature above 423 K, and iron oxides (Fe₃O₄ and NaFeO₂) and hydrogen were produced. In this study, microwave heating was adopted to take the place of conventional heating to induce the hydrothermal reaction. Under microwave irradiation, NaOH and H₂O absorbed microwave energy by space charge polarization and dipolar polarization and instantly converted it into thermal energy, which initiated the hydrothermal reaction that involved with zero-valent iron. X-ray diffraction (XRD) analysis found Fe₃O₄/NaFeO₂ and confirmed the occurrence of microwave-induced hydrothermal reaction. The developed microwave-hydrothermal reaction was employed for the dechlorination of PCBs. Hexadecane containing 100 mg L⁻¹ of Aroclor1254 was used as simulative transformer oil, and the dechlorination of PCBs was evaluated by GC/ECD, GC/MS and ion chromatography. For PCBs in 10 mL simulative transformer oil, almost complete dechlorination was achieved by 750 W microwave irradiation for 10 min, with 0.3 g iron powder, 0.3 g NaOH and 0.6 mL H₂O added. The effects of important factors including microwave power and the amounts of reactants added, on the dechlorination degree were investigated, moreover, the dechlorination mechanism was suggested. Microwave irradiation combined with the common and cheap materials, iron powder, NaOH and H₂O, might provide a fast and cost-effective method for the treatment of PCBs-containing wastes.     

Polycyclic aromatic hydrocarbons (PAHs) and their oxygen-containing derivatives (OPAHs) in soils from the Angren industrial area, Uzbekistan

We measured the concentrations and depth distribution (0-10, 10-20 cm) of 31 PAHs and 12 OPAHs in soils at eleven equidistant sampling points along a 20-km transect in the Angren industrial region (coal mine, power plant, rubber factory, gold mine), Uzbekistan to gain an insight into their concentrations, sources, and fate. Concentrations of all compounds were mostly much higher in the 0-10 cm than in the 10-20 cm layer except in disturbed soil close to the coal mine. Proximity to one of the industrial emitters was the main determinant of PAH and OPAH concentrations. The ∑31PAHs concentrations correlated positively with the ∑7 carbonyl-OPAH (r = 0.98, p < 0.01), ∑5 hydroxyl-OPAH (r = 0.72, p < 0.05), and with industrially emitted trace metals in the topsoil, identifying industrial emissions as their common source. Concentrations of several OPAHs were higher than their parent PAHs, but their vertical distribution in soil suggested only little higher mobility of OPAHs than their corresponding parent PAHs.     

Polycyclic aromatic hydrocarbons in crude oil-contaminated soil: A two-step method for the isolation and characterization of PAHs

A two-step analytical method is developed for the isolation and characterization of polycyclic aromatic hydrocarbons (PAHs) in crude oil contaminated soil. In the first step, those crude oil components were isolated which are easily mobilized with water from the contaminated soil (determination of groundwater pollution potential). In the second step, the fraction containing the remaining crude oil compounds was extracted using toluene. After the cleanup of the fractions, both fractions were analyzed using high-performance liquid chromatography (HPLC). The HPLC of the toluene extracted fraction shows that along with the sixteen priority pollutants from the US-EPA list, many other polycyclic aromatic hydrocarbons (PAHs) are present as well. It is evident from the chromatograms that a significant amount of PAHs are present as is also the case in the fractions eluted by water. The described method allows the determination of total organic pollutants from crude oil, some of them being potential groundwater contaminants. The major part of the total pollutants could not be mobilized by water and therefore remains in the soil, which was extracted in the second step.     

PCDD/Fs and dioxin-like PCBs in sediment and biota from the Mondego estuary (Portugal)

The concentrations of 17 polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in sediment and key species as an initial investigation on PCDD/Fs and dl-PCBs contamination in the Mondego estuary (Portugal). The results demonstrated that the values of the total PCDD/Fs (∑PCDD/Fs) concentrations were considerably lower than those of the sum of dl-PCBs (∑dl-PCBs) in all the studied samples. Regarding the contribution of individual congeners, OCDD was the predominant PCDD/F and the mono-ortho PCB 118 and PCB 105 were the dominant PCBs in the majority of the samples. Our results suggest that PCDD/Fs and PCBs behave quite differently along the aquatic food web: ∑PCDD/Fs concentrations were lower in higher trophic-level organisms with fish presenting a distinct PCDD/Fs congeners profile; on the contrary, the higher ∑dl-PCBs values were found in upper-level biota, although not exclusively, and quite similar dl-PCBs congener profiles were observed in nearly all the studied species.     

Identification of carbonaceous geosorbents for PAHs by organic petrography in river floodplain soils

Organic petrographic analysis was applied to provide direct information on carbonaceous geosorbents for PAHs in river floodplain soils. The anthropogenic OM group (primarily coal and coal-derived particles) displayed large volume amounts for all the soil samples. Distinct PAH concentrations with similar PAH distribution patterns were determined in grain size and density fractions for each sample. Two-ring PAHs had stronger correlation to organic carbon (OC) than black carbon (BC) contents, while heavier PAHs showed correlation to BC, rather than OC. In this study, we combined grain size and density separation, PAH determinations, TOC and BC measurements, and organic petrographic identification, and concluded that two-ring PAHs in soils were associated to coal particles. Other heavier PAHs could be more controlled by black carbon (BC), which were mostly coal-derived particles from former coal mining and coal industrial activity.     

PCBs in sediments of the Great Lakes--distribution and trends, homolog and chlorine patterns, and in situ degradation

A region-wide data analysis on polychlorinated biphenyls (PCBs) in the sediment of the Great Lakes reveals a total accumulation of approximately 300 ± 50 tonnes, representing a >30% reduction from the 1980s. Evidence of in situ degradation of sediment PCB was found, with estimated t_1/2 of 11 and 17 years, at two open water locations in Lake Ontario. The relative abundance of heavy homologs as well as para-chlorines decreases with increasing depth, while the opposite is true for medium and light homologs and ortho-chlorines. In Lake Michigan, the vertical pattern features enrichment of heavier congeners and reduction of ortho-chlorines in deeper sediment layers, opposite to the trend in Lake Ontario. PCBs decrease log-linearly with increasing latitude and longitude. Air deposition of PCBs to lake sediment decreases at about 0.077 ng cm⁻² yr⁻¹ per degree latitude (N) for the geographic region extending from the Great Lakes to within the Arctic Circle.     

Trace elements, organochlorines, polycyclic aromatic hydrocarbons, dioxins, and furans in lesser scaup wintering on the Indiana Harbor Canal

During the winter of 1993-94, male lesser scaup (Aythya affinis) were collected on the heavily polluted Indiana Harbor Canal (IHC), East Chicago, IN, USA, and examined for tissue contaminant levels. Lesser scaup collected on the IHC had higher concentrations of cadmium (Cd), mercury (Hg), selenium (Se), polychlorinated biphenyls (PCBs), selected organchlorine pesticides, polychlorinated dibenzodioxins, polychlorinated dibenzofurans, polycyclic aromatic hydrocarbons, and aliphatic hydrocarbons than reference birds. Of the scaup collected on the IHC, 44% had Cd concentrations in the liver considered above background for freshwater waterfowl (>3 microg/g dry wt.), 50% had Se concentrations in the liver above a level possibly harmful to the health of young and adult birds (>33 microg/g dry wt.), and 88% of the scaup carcasses exceeded the PCB human consumption guidelines for edible poultry in the USA (>3.0 microg/g lipid wt.). The ratio of pristane:n-heptadecane concentrations in 47% of lesser scaup collected on IHC was elevated above 1.0, which is indicative of chronic exposure to petroleum hydrocarbons.     

Passive air monitoring of PCBs and PCNs across East Asia: a comprehensive congener evaluation for source characterization

A comprehensive congener specific evaluation of polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in the atmosphere was conducted across East Asia in spring 2008, applying polyurethane foam (PUF) disk passive air sampler (PAS) as monitoring device. Mean concentrations derived for Japan, China and Korea were 184 ± 24, 1100 ± 118, and 156 ± 20 pg m⁻³ for ∑₂₀₂ PCBs, and 9.5 ± 1.5, 61 ± 6, and 16 ± 2.4 pg m⁻³ for ∑₆₃ PCNs, respectively. Relative to reported data from 2004, the present results suggest that air PCBs concentrations have not changed much in Japan and Korea, while it has increased by one order of magnitude in China. From principal component analysis, combustion emerged highly culpable in contemporary emissions of both PCBs and PCNs across the East Asian sub-region. Another factor derived as important to air PCBs was re-emissions/volatilization. Signals from PCBs formulations were also picked, but their general importance was virtually consigned to the re-emissions/volatilization tendencies. On the contrary, counterpart PCNs formulations did not appear to contribute much to air PCNs.     

Levels of PCDDs, PCDFs and non-ortho PCBs in serum samples of non-exposed individuals living in Madrid (Spain)

In an attempt to evaluate the background levels of PCDDs, PCDFs and non-ortho PCBs in people living in Madrid (Spain), blood serum samples had been analyzed PCDD, PCDF and coplanar PCB levels from non exposed individuals are reported in this study. Average levels found were 515.29 ppt for total PCDDs, 66.73 ppt for total PCDFs and 85.47 ppt for non-ortho PCBs on a lipid weight basis Calculated I-TEQ values were 8.78 ppt for PCDDs, 6.96 for PCDFs and 7.03 for coplanar PCBs on a lipid weight basis.     

Levels and congener profiles of PCDD/Fs, PCBs and PBDEs in seafood from China

A nationwide investigation into polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in market seafood was conducted for the first time in this study. Total PCDD/F concentrations in fatty fish ranged from 0.13 to 8.64 pg g⁻¹ wet weight (mean 2.05 pg g⁻¹ wet weight), total PCB concentrations ranged from 38.9 to 3514 pg g⁻¹ wet weight (mean 1133 pg g⁻¹ wet weight), and total PBDE concentrations ranged from 42.8 to 913 pg g⁻¹ wet weight (mean 322 pg g⁻¹ wet weight). Corresponding mean toxicity equivalent (TEQ) values for total PCDD/F and dioxin-like PCB were 0.25 pg g⁻¹ wet weight (WHO 98-TEQ) and 0.32 pg g⁻¹ wet weight (WHO 98-TEQ), respectively. OCDD, PCB-138 and PBDE-47 were the dominant compounds according to their respective congeners. WHO 98-TEQ _{PCDD/PCDF/PCB} for fatty fish and shell fish were 0.60 and 0.070 pg g⁻¹ wet weight, respectively, lower than the standard set by the European Commission. The contamination levels and profiles were compared with those documented in previous publications.