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The presence of 14 organophosphate esters (OPEs) in surface sediments from a typical fishing port agglomeration in Dalian, North China was investigated for the first time. Tris(2-ethylhexyl) phosphate (TEHP), triphenylphosphine oxide (TPPO), and tris(2-chloroethyl) phosphate (TCEP) dominated 12 detectable OPEs (∑OPEs), with concentrations ranging widely from 0.56 to 352 ng/g (dry weight basis). The ∑OPE levels in sediments varied significantly across fishing harbors of various grades, and within the same grade, highlighting uneven distribution of OPE sources and inputs to harbors. The first- and second-class fishing harbors had higher geometric mean of ∑OPE contents compared to center and natural harbors, reflecting higher OPE pollution in these areas. Although there were significant correlations among the OPE congeners with high detection frequencies, the composition patterns of sediment OPEs varied considerably among fishing ports. The sediments in the center and first-class harbors had higher abundance of non-chlorinated OPEs (non-Cl-OPEs), suggesting heterogeneity in source strength and pollution characteristics of Cl- and non-Cl-OPEs in fishing ports. The distribution of OPEs in sediments was weakly associated with sediment organic carbon, but not socioeconomic variables, indicating complex controlling factors of their distributions in port sediments. The ecological risks of sediment OPEs were evaluated, and while OPE accumulations ranged broadly (7–684 ng/cm2), exposure hazards were negligible. The sediments in first- and second-class fishing harbors, which had greater OPE accumulation, were identified as reservoirs of OPEs in port aquatic environments. [Display omitted] • TEHP and TCEP dominated non-Cl- and Cl-OPEs in fishing port sediments, respectively. • OPE levels and compositions varied irregularly with fishing port grades. • Sediment organic carbon partially controlled OPE distributions among fishing ports. • The sediments of first- and second-class fishing ports were reservoirs of OPEs. [ABSTRACT FROM AUTHOR]

Abstract Semi-permeable membrane devices (SPMDs) were applied to sample some Organochlorinated Pesticides (OCPs), Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs) from the seawater of 14 Chinese coastal areas. The total concentrations of OCPs (∑ 16 OCPs), PAHs (∑ 15 PAHs) and PCBs (∑ 35 PCBs) were in the ranges of 489.2–2174, 589.4–53,160, and 133.2–3658 ng/g lipid, respectively. The ∑ 15 PAHs varied significantly with the sampling locations, which were far higher in north Chinese coastal areas than in south areas, whereas ∑ 16 OCPs and ∑ 35 PCBs only slightly fluctuated along the entire coast line. Comparing SPMD to grab sampler, it was found that the distribution patterns of the PCBs and OCPs in seawater were generally similar. However, the compositional profiles of the PAHs, PCBs, DDTs and HCHs in SPMDs were slightly different to grab samplers and organisms. The SPMDs accumulated less lipotropic compounds, which are inclined to dissolve in water rather than in organisms. Graphical abstract In the present study, the concentrations of PAHs, PCBs and OCPs in the seawater of Chinese coastal areas using SPMDs were reported. This figure illustrated that OCPs and PCBs did not vary significantly along the whole coast line, while PAHs residual levels in the Yellow Sea and East China Sea were relatively higher than other coastal areas in Chinese coasts. Unlabelled Image Highlights • The PAHs, PCBs and OCPs in entire Chinese coastline seawater using SPMD were reported. • The concentrations of PAHs in north sea area were much higher than in south. • The spatial distribution presented by SPMD was basically consistent to grab sampler. • The OCs compositions and source diagnosis ratios in SPMDs were different to organisms. [ABSTRACT FROM AUTHOR]

Abstract Three cores collected in the area of 16th July 2010 oil spill by box crab in May 2013 and July 2014 at the Dalian Bay have been geochemically characterized to investigate the fate of chemical components in sediments. The total organic carbon, extractable organic matter contents and biomarker compositions have been applied for the differentiation of alien organic matters from in situ ones and evaluation of the biodegradation impact. Multivariate statistical analysis suggests four groups of sediments. Except a few samples at deepest part of BQ050, majority samples have certain affinity with the spilled oil. The most contaminated sediments occur at site BQ050 and the spilled oil has migrated to 8–12 cm depth. The degree of contamination can be ranked by the similarity of molecular compositions with spilled oil. Variable biomarker components in sediment extracts were also altered by ongoing biodegradation. Highlights • Oil spill contamination in Dalian Bay is controlled by wind direction. • Spilled oil has migrated downward to 16 cm in last 3 years. • Extractable Organic matter content indicates four ranks of contamination. • Biomarker similarity between sediments and oil is correlated to contamination levels. • Biomarker compositions are partially affected by ongoing biodegradation. [ABSTRACT FROM AUTHOR]

This study provides the first data on the distribution, sources, and transport dynamics of polycyclic aromatic hydrocarbons (PAHs) in Fildes Peninsula, Antarctica via summertime analyses of lakes, seawater, snow, and air in 2013. Relatively high PAH levels and similar composition profiles (dominance of two- and three-ring PAHs) in the investigated marine and terrestrial environmental matrices were found, indicating substantial primary emissions of petrogenic PAHs. This result was corroborated by nonequilibrium partitioning of atmospheric PAHs caused by release of anthropically-derived lighter PAHs and air mass movement trajectories mainly originated from the Antarctic marginal seas. Notable geographical disparities of PAH pollution in the various types of samples consistently suggested impacts of station-related activities, rather than long-range atmospheric transport, on PAHs in Fildes Peninsula. The lack for temperature dependence for gas-phase concentrations and various molecular diagnostic ratios of atmospheric PAHs demonstrated that the impact of local anthropogenic inputs on air PAH variability supersedes the re-emission effect. The derived air–water and air–snow exchanges of PAHs in this remote region indicated a disequilibrium state, partially associated with intense local emissions of PAHs. PAH outgassing from, and absorption into, lake and marine waters were both observed, probably due to differences in anthropogenic influences among sites, while the net deposition of gaseous PAHs into snow prevailed. The results of this study shed lights on the major importance of native anthropogenic sources in the footprint and fate of PAHs in the Fildes Peninsula, which merits further monitoring. [Display omitted] • Petrogenic emissions considerably contributed to PAH profiles in Fildes Peninsula. • Releases from research station as a remarkable point source underlie PAH pollution. • Exchange dynamics of PAHs between air-water/snow were related to human influence. [ABSTRACT FROM AUTHOR]

Highlights: [•] First report of distribution characteristics of ARGs and its main sources in coastal environment of the Northern Yellow Sea. [•] There is strong relationship between sulfonamide and ARGs in coastal environments. [•] The gene int I may facilitate ARGs propagation as a major transmission mode of ARGs in marine environment. [ABSTRACT FROM AUTHOR]

Highlights: [•] SCCPs pollution in the marine environment of Bohai Sea was relatively heavy. [•] C10-CPs and C11-CPs were the predominant homologue groups in all sediments and bivalves. [•] Bivalve is a good bio-indicator of SCCPs contamination in marine system. [•] The highly chlorinated SCCPs congeners were more prone to be accumulated in bivalves. [ABSTRACT FROM AUTHOR]

Highlights: [•] BDE-47 was the dominating congener in organisms of the Liaodong Bay. [•] The length of food chain played an important role on the TMFs. [•] PBDEs were steadily metabolized in the trophic transfer process along the food chain. [ABSTRACT FROM AUTHOR]

Abstract: Seawater, sediment, and aquatic organism samples were collected from 20 sampling sites in coastal environment of Dalian in August, 2011. The occurrence, distribution, and bioaccumulation of 20 antibiotics categorizing into three groups, including 14 sulfonamides (SAs), two chloramphenicols (CAPs) and four tetracyclines (TCs), were investigated. The results suggested that tetracyclines were the predominant antibiotics in the seawater (range: 2.11–9.23ngL−1), while sulfonamides were the dominant antibiotics in both sediments (range: 1.42–71.32μgkg−1) and aquatic organisms (range: 2.18–63.87μgkg−1). The sorption coefficient K d,s values revealed that sulfameter, sulfadiazine, sulfamethoxypyridazine, sulfamonomethoxine, chloramphenicol, and doxycycline presented higher sorption capacities than the other antibiotics. The average BAFs suggested that sulfamethazine, sulfamethiazole, sulfamonomethoxine, and doxycycline were potentially bioaccumulative, while sulfadiazine, sulfameter, sulfamethoxypyridazine, and chloramphenicol were bioaccumulative. [Copyright &y& Elsevier]

Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in soil, moss and reindeer dung collected at Ny-Ålesund of the Arctic were measured to investigate their accumulation trends and distribution in the three compartments. Compared with the other regions, the proportions of 2 + 3 ring PAHs to the total PAHs were higher, whereas the proportions of 5 + 6 ring PAHs were lower in the three compartments at Ny-Ålesund. Significant log/log-linear relationship was observed between the sub-cooled liquid vapor pressure and the soil/moss quotient (Q SM). The relation was similar to the relationship between the gas/particle partition coefficient (K P) and of PAHs, implying Q SM would be a “mirror image” of K P. Excellent log/log-linear relationships were observed between Q SM and K OA as well as between the moss/dung quotient (Q MD) and K OW. The results presented here indicate the physicochemical properties are suitable for characterizing the distribution of PAHs in soil, moss and reindeer dung. [Copyright &y& Elsevier]

This study investigated the occurrence and profile of 14 organophosphate esters (OPEs) in surface water and sediment of the whole Bohai Sea. A total of 53 pairs of surface water and sediment samples were collected and the contained OPEs were quantified using a gas chromatography–mass spectrometry (GC–MS). The average concentrations of OPEs in surface water and sediment were in the range of 0–92.9 ng/L and 0.001–8.58 ng/g dry weight (dw), respectively, with tri (2-chloroethyl) phosphate (TCEP) as the predominant congener in both compartments. The total concentrations of 14 OPEs (∑ 14 OPEs) in surface water and sediment were in the range of 10.9–516.4 ng/L and 1.42–52.9 ng/g dw, respectively. The inventories of ∑ 14 OPEs were calculated to be 179.3 tons in the water and 101.5 tons in the sediment. Based on the risk quotients (RQs), the ecological risks of OPEs to the aquatic organisms in the Bohai Sea were considered to be negligible. • TCEP was the dominant OPE in both surface water and sediment of the Bohai Sea. • Higher levels of OPEs were detected in Bohai Bay and Laizhou Bay. • The estimated loads of OPEs in water and sediment were 179 and 102 tons, respectively. • OPE contamination posed negligible risks to the aquatic organisms. [ABSTRACT FROM AUTHOR]

A better understanding of the sources of organophosphate esters (OPEs) is a prerequisite for OPE control and the establishment of related environmental policies. Sources of OPEs in 35 major inflow rivers to the Bohai Sea of China were quantitatively analyzed using three effective receptor models (principal component analysis-multiple linear regression (PCA-MLR), positive matrix factorization (PMF), and Unmix) in this paper. The similarities and differences in results from PCA-MLR, PMF, and Unmix were discussed in depth. All three models well predicted the spatial variability of the total concentrations of nine OPEs (triethyl phosphate, tri-n-butyl phosphate, triisobutyl phosphate, tri (2-ethylhexyl) phosphate, tri (2-chloroethyl) phosphate, tris(1-chloro-2-propyl) phosphate, tris(1,3-dichloro-2-propyl) phosphate, triphenyl phosphate, and triphenylphosphine oxide) (∑ 9 OPEs) (r2 = 0.90–0.96, p = 0.000) and explained 98.4%–101.2% of the observed ∑ 9 OPEs. The predicted ∑ 9 OPEs values from each pairwise model were significantly correlated (r2 = 0.88–0.91, p = 0.000). Three OPE sources were extracted by all three models: rigid and flexible polyurethane foam/coating, cellulosic/acrylic/vinyl polymer/unsaturated polyester, and polyvinyl chloride, contributing 49.9%, 29.7%, and 20.5% by PCA-MLR, 57.9%, 28.6%, and 13.5% by PMF, and 47.9%, 30.8%, and 22.4% by Unmix to the ∑ 9 OPEs, respectively. PMF was recommended as the preferred receptor model for analyzing OPE sources in water during the monitoring period because of its optimal performance. Image 1 • Receptor models were used to quantitatively identify organophosphate ester sources. • Overlapping conclusions from convergent results of multiple models were achieved. • Three source categories of organophosphate esters were apportioned consistently. [ABSTRACT FROM AUTHOR]

To study human-induced changes in sedimentation and carbon sequestration over the last 100 years in Dalian Bay (a typical coastal sea in North China), three sediment cores from different locations (C1, C2 and C3) were collected and the chronologies of their depths were evaluated from a radionuclides-based approach. Sedimentation rates (mass accumulation rates) over core depths were calculated based on 210Pb ex chronologies, with maximum values of 8.69 kg m−2·yr−1, 5.65 kg m−2·yr−1 and 8.47 kg m−2·yr−1 for C1, C2 and C3, all appearing at the top layer. Distinct increases in sedimentation rates since the 1980s were observed. Correlations between increasing sedimentation rates and decreasing sea areas of Dalian Bay after 1980 verified the influence of human activities on the sedimentary processes. The range of ratios on total organic carbon to total nitrogen (TOC/TN) and isotopic composition of carbon (δ13C) in the sediment was 9.44–17.9 and −22.81‰ to −24.46‰ respectively. Sedimentary organic carbon (SOC) in Dalian Bay showed characteristics of significant terrestrial input, while also being influenced by marine input. The carbon sequestration potential in Dalian Bay's sediment, based on the sequestration rate of SOC (SR-SOC), showed pronounced increase over time, especially since the 1980s. Primarily driven by sedimentation rate, the carbon sequestration potential was dominated by natural processes before 1980. Since then, it came under significant influence from human activities, and this trend grew more intense after the year 2000. Ecosystem service values from carbon sequestration were assessed, and the values' slower increase was the combined result of Dalian Bay's increased SR-SOC and decreased sea area. • Sediment chronology over depth for the last 100 years in Dalian Bay were investigated. • Sedimentation rate increased after 1980, which correlated with decreased sea area. • SOC presented characteristic of terrestrial input based on TOC/TN ratios and δ13C. • Driven by sedimentation rate, SR-SOC's increase since the 1980s recorded human-induced influence. • Ecosystem service value from carbon sequestration was a combined result of increasing SR-SOC and decreasing sea area. [ABSTRACT FROM AUTHOR]

In the present study, the contamination level and spatial distribution of PFASs in the water dissolved phase and suspended particulate matter (SPM) phase of the Dalian Bay, and the SPM-water partition behavior were investigated. The total concentrations of PFASs (∑PFASs) in the water dissolved phase ranged from 6.9 to 17.1 ng L −1 , with perfluorooctanoic acid (PFOA), perfluorobutanoic acid, and perfluorobutane sulfonate (PFBS) as the predominant PFASs, while ∑PFASs in SPM ranged from 1.7 to 27.5 ng g −1 dw with higher contributions from PFBS, perfluorooctane sulfonic acid and PFOA. As for the pollution distribution, the concentrations of PFASs inside the Dalian Bay were higher than those outside the bay. For perfluoroalkyl carboxylic acid (PFCAs) and perfluoroalkane sulfonic acids (PFSAs), the suspended particulate matter-water partition coefficient (log K d ) values ranged from 2.62 to 3.76, and from 3.39 to 3.56, respectively. The log K d values of PFASs generally increased with the increasing perfluorinated carbon chain length. Short-chain PFCAs were mostly detected in the water dissolved phase, while long-chain PFCAs and PFSAs appeared to bind more strongly to SPM phase. The contamination level of long-chain PFCAs and PFSAs could be underestimated if only the water dissolved phase were measured. Therefore, further investigations should consider the role of SPM on the environmental behavior and fate of PFASs in the aquatic environment. [ABSTRACT FROM AUTHOR]

To enrich knowledge concerning occurrence and behavior of novel brominated flame retardants (NBFRs) in the Chinese marine environment, a group of 11 NBFRs were measured in the atmosphere over the northern Bohai and Yellow Seas. Samples were taken downwind of the primary NBFR production and application areas in North China. The total NBFR air concentrations (ΣNBFRs) varied from 80.9 to 934 pg/m3, with decabromodiphenyl ethane (DBDPE) being the most abundant component. The high spatial variability of ΣNBFRs and relatively weak correlations among individual compounds indicated the diverse impact of anthropogenic activities in the coastal regions. The K OA-based absorption model predicted the distributions of low-mass NBFRs, while a steady state model was more applicable for heavier compounds such as DBDPE. The partitioning of NBFRs between the gas and particle phases were significantly related with octanal–air partition coefficient (K OA) only for the notable pollution locations, suggesting absorptive contribution to NBFR sorption. The resulting relationships characterized by event differences possibly pointed out the influences including the sources of NBFRs and aerosol particles, the continental impact, and the sorption kinetics on NBFR partitioning behaviors. Dry particle-bound deposition estimations indicated that the NBFR inputs to the sea from the air was significant. [Display omitted] • DBDPE dominated air NBFR profiles in consistence with land usage pattern. • Difference in nearby continental outflow underlies NBFR spatiality in marine air. • Sorption of low- and high-mass NBFRs to aerosols differed in sorptive process. • Significant dry particle-bound deposition of NBFRs into sea was observed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A high-performance gold capture material C-S-180 has been reported. • C-S-180 exhibits excellent gold selectivity in intricate wastewater. • Sulfur modulates the electronic structure of the skeleton to promote gold capture. • C-S optimized energy band gap for a more efficient gold reduction process. The efficient and selective recovery of gold from secondary sources is key to sustainable development. However, the complexity of the recovery environment can significantly complicate the compositions of utilized sorbents. Here, we report a straw-derived mesoporous carbon as an inexpensive support material. This mesoporous carbon is modified by anions (sulfur modulation, C-S-180) to improve its electron-transfer efficiency and tune the electronic structure of its skeleton toward enhanced gold reduction. The high surface area of C-S-180 (989.4 m2/g), as well as the presence of abundant C–S in the porous structure of the adsorbent, resulted in an outstanding Au3+-uptake capacity (3422.75 mg/g), excellent resistance to interference, and favorable Au3+ selectivity. Dissimilar to most existing carbon-based adsorbents, electrochemistry-based studies on the electron-transfer efficiencies of adsorbents reveal that sulfur modulation is crucial to optimizing their adsorption performances. Furthermore, the density functional theory reveals that the optimization mechanism is attributable to the adjustment of the electronic structure of the carbon skeleton by C–S, which optimizes the band-gap energy for enhanced Au3+ reduction. These findings offer a strategy for constructing green and efficient adsorbents, as well as a basis for extending the applications of inexpensive carbon materials in gold recovery from complex environments. [ABSTRACT FROM AUTHOR]

Abstract The concentrations and congener-specific profiles of polybrominated diphenyl ethers (PBDEs) were investigated in the atmosphere, soil and moss samples were collected from Ny–Ålesund, Svalbard in the Arctic and King Georgia Island (KGI), Fildes Peninsula in Antarctica, respectively. The congener profiles of PBDEs were symmetrical between gas and moss, as well as between particles and soil at Ny–Ålesund and KGI, respectively, similar to a "mirror image". The proportions of highly brominated congeners (for example, BDE–99, –153 and –183) in the particle phase and soil were higher than those in the gas phase and moss, while tri– and tetra–BDEs possessed higher proportions in the gas phase and moss at both sites. The slopes of log–log linear correlations between the gas–particle partition coefficient (K p) and sub–cooled liquid vapor pressures (p ° L) of PBDEs were observed at both sites compared with the values in the urban areas. Moreover, the slopes of log K p vs. log p ° L (−0.51 at Ny–Ålesund and − 0.29 at KGI) were notably close to the slopes of log–log linear correlations between the dimensionless soil–moss quotient (Q SM) and p ° L (−0.42 at Ny–Ålesund and −0.22 at KGI). Significant correlations between particle fraction (φ particle) and soil fraction (φ soil) at both sites indicated that the gas–particle partitioning of PBDEs is directly related to their distribution in moss and soil. Graphical abstract Unlabelled Image Highlights • The atmospheric residual level of PBDEs both in Arctic and Antarctic was much lower than that of low latitudes. • The proportions of highly brominated congeners in the particulate and soil were higher than those in the gas and moss. • The PBDE congener profiles were symmetrical between gas and moss, as well as between particles and soil at both sites. • The gas/particle partitioning of PBDEs is directly related to their distribution in moss and soil. [ABSTRACT FROM AUTHOR]

Abstract Sulfonamide antibiotics (SAs) are increasingly detected as aquatic contaminants and exist as different dissociated species depending on the pH of the water. Their removal in sunlit surface waters is governed by photochemical transformation. Here we report a detailed examination of the hydroxyl radical (•OH) and singlet oxygen (1O 2) mediated photooxidation of nine SAs: sulfamethoxazole, sulfisoxazole, sulfamethizole, sulfathiazole, sulfamethazine, sulfamerazine, sulfadiazine, sulfachloropyridazine and sulfadimethoxine. Both •OH and 1O 2 oxidation kinetics varied depending on the dominant protonated states of the SA in question (H 2 SAs+, HSAs0 and SAs−) as a function of pH. Based on competition kinetic experiments and matrix deconvolution calculations, HSAs0 or SAs− (pH ∼5–8) were observed to be more highly reactive towards •OH, while SAs− (pH ∼8) react the fastest with 1O 2 for most of the SAs tested. Using the empirically derived rates of reaction for the speciated forms at different pHs, the environmental half-lives were determined using typical 1O 2 and •OH concentrations observed in the environment. This approach suggests that photochemical 1O 2 oxidation contributes more than •OH oxidation and direct photolysis to the overall phototransformation of SAs in sunlit waters. Based on the identification of key photointermediates using tandem mass spectrometry, 1O 2 oxidation generally occurred at the amino moiety on the molecule, whereas •OH reaction experienced multi-site hydroxylation. Both these reactions preserve the basic parent structure of the compounds and raise concerns that the routes of phototransformation give rise to intermediates with similar antimicrobial potency as the parent SAs. We therefore recommend that these phototransformation pathways are included in risk assessments concerning the presence and fate of SAs in waste and surface waters. Graphical abstract Image 1 Highlights • Aquatic photooxidation of sulfonamides (SAs) via reactive oxygen species is important. • The kinetics depend on pH and separate reactivities of H 2 SAs+, HSAs0 and SAs−. • 1O 2 plays a key role in aquatic fate of SAs compared with •OH and direct photolysis • Different primary pathways and multiple intermediates occur for the three reactions. [ABSTRACT FROM AUTHOR]

Fluoroquinolone antibiotics (FQs) are ubiquitous and ionisable in surface waters. Here we investigate gatifloxacin (GAT) and balofloxacin (BAL), two widely used FQs, and determine the photochemical reactivity of their respective dissociation species that arise at different pH to understand the relevance and pathways of phototransformation reactions. Simulated-sunlight experiments and matrix calculations showed that neutral forms (HFQs 0 ) of the two antibiotics had the highest apparent photolytic efficiency and hydroxyl-radical oxidation reactivity. Based on the pH-dependent photochemical reactivities, the solar apparent photodegradation half-lives ( t 1/2 ) in sunlit surface waters ranged from 14.5–169 min and was 1–2 orders of magnitude faster than hydroxyl-radical induced oxidation ( t 1/2 = 20.9–29.8 h). The corresponding pathways were proposed based on the identification of key intermediates using HPLC-ESI-MS/MS. The apparent photodegradation induced defluorination, decarboxylation, and piperazinyl oxidation and rearrangement, whereas hydroxyl-radical oxidation caused hydroxylated defluorination and piperazinyl hydroxylation. The photomodified toxicity of GAT and BAL was examined using an Escherichia coli activity assay. E . coli activity was not affected by BAL, but was significantly affected by the photo-modified solutions of GAT, indicating that primary photo-degradates have a comparable or higher antibacterial activity than the parent GAT. In fresh water and seawater this antibacterial activity remained high for up to 24 h, even after GAT had undergone significant photodegradation (>1 half-life), indicating the potential impact of this chemical on microbial communities in aquatic systems. [ABSTRACT FROM AUTHOR]

Hydroxyl polycyclic aromatic hydrocarbons (OH-PAHs) are derived from hydroxylated PAHs as contaminants of emerging concern. They are ubiquitous in the aqueous and atmospheric environments and may exist in the polar snow and ice, which urges new insights into their environmental transformation, especially in ice. In present study the simulated-solar ( λ > 290 nm) photodegradation kinetics, products and pathways of four OH-PAHs (9-Hydroxyfluorene, 2-Hydroxyfluorene, 1-Hydroxypyrene and 9-Hydroxyphenanthrene) in ice were investigated, and the corresponding implications for the polar areas were explored. It was found that the kinetics followed the pseudo-first-order kinetics with the photolysis quantum yields ( Φ s ) ranging from 7.48 × 10 −3 (1-Hydroxypyrene) to 4.16 × 10 −2 (2-Hydroxyfluorene). These 4 OH-PAHs were proposed to undergo photoinduced hydroxylation, resulting in multiple hydroxylated intermediates, particularly for 9-Hydroxyfluorene. Extrapolation of the lab data to the real environment is expected to provide a reasonable estimate of OH-PAH photolytic half-lives ( t 1/2,E ) in mid-summer of the polar areas. The estimated t 1/2,E values ranged from 0.08 h for 1-OHPyr in the Arctic to 54.27 h for 9-OHFl in the Antarctic. In consideration of the lower temperature and less microorganisms in polar areas, the photodegradation can be a key factor in determining the fate of OH-PAHs in sunlit surface snow/ice. To the best of our knowledge, this is the first report on the photodegradation of OH-PAHs in polar areas. [ABSTRACT FROM AUTHOR]

Concentrations of 16 polybrominated diphenyl ether (PBDE) congeners were measured in river sediments, paddy soils and three species of paddy-field organisms (crab, loach and carp) collected from the Liaohe River Basin, northeastern China. The total contents of PBDEs (∑ 16 PBDEs) in sediments and paddy soils were in the ranges of 273.4–3246.3 pg/g dry weight (dw), and 192.1–1783.8 pg/g dw, respectively. BDE 209 was the dominant congener both in sediments and paddy soils. The concentrations of ∑ 16 PBDEs in sediments were significantly higher than those in the adjacent paddy soils, indicating a potential transport of PBDEs from river to paddy ecosystems via river water irrigation. The biota–soil accumulation factor (BSAF) was calculated as the ratio between the lipid-normalized concentration in paddy-field organisms and the total organic carbon-normalized concentration in paddy soil. The average BSAF values of ∑ 15 PBDEs followed the sequence of crab (3.6) > loach (3.3) > carp (2.1). BDE 154 had the highest BSAF value, and a parabolic trend between BSAF values of individual PBDE congeners and their log K OW values was observed. In view of the fact that crab had the larger BSAF value and higher lipid content, the ecological risk and health risk for crab cultivation in paddy fields should be of particular concern. [ABSTRACT FROM AUTHOR]

Hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) are contaminants of emerging concern in the aquatic environment, so it is of great significance to understand their environmental transformation and toxicity. This study investigated the aqueous photochemical behavior of four OH-PAHs, 9-Hydroxyfluorene (9-OHFL), 2-Hydroxyfluorene, 9-Hydroxyphenanthrene and 1-Hydroxypyrene, under simulated sunlight irradiation ( λ > 290 nm). It was observed that their photodegradation followed the pseudo-first-order kinetics. Based on the determined quantum yields, their calculated solar apparent photodegradation half-lives in surface waters at 45° N latitude ranged from 0.4 min for 9-Hydroxyphenanthrene to 7.5 × 10 3 min for 9-OHFL, indicating that the OH-PAHs would intrinsically photodegrade fast in sunlit surface waters. Furthermore, 9-OHFL as an example was found to undergo direct photolysis, and self-sensitized photooxidation via OH rather than 1 O 2 in pure water. The potential photoreactions involved photoinduced hydroxylation, dehydrogenation and isomerization based on product identification by GC–MS/MS. 9-OHFL photodegraded slower in natural waters than in pure water, which was attributed to the integrative effects of the most photoreactive species, such as Fe(III), NO 3 − , Cl − and humic acid. The photomodified toxicity was further examined using Vibrio fischeri , and it was found that the toxicity of photolyzed 9-OHFL did not decrease significantly ( p > 0.05) either in pure water or in seawater, implying the comparable or higher toxicity of some intermediates. These results are important for assessing the fate and risks of OH-PAHs in surface waters. [ABSTRACT FROM AUTHOR]

Distribution of 12 selected polybrominated diphenyl ethers (PBDEs) was characterized in soil, moss and reindeer dung samples collected simultaneously at Ny-Ålesund of the Arctic. The average PBDE concentrations were 42 pg/g (dry weight) in soil, 122 pg/g in moss and 72 pg/g in reindeer dung. Significant log/log-linear relationship was observed between the soil/moss quotients ( Q SM ) and the sub-cooled liquid vapor pressures of PBDEs ( r 2 = 0.80). Moreover, excellent log/log-linear relationships between Q SM and the octanol/air partition coefficients as well as between the moss/dung quotient ( Q MD ) and the octanol/water partition coefficients of PBDEs were also observed, indicating that the physicochemical properties of PBDEs are appropriate parameters for characterizing the distribution of PBDEs in soil, moss and reindeer dung at Ny-Ålesund. Capsule abstract : Significant log-linear correlations were observed between physicochemical properties of PBDEs and their soil/moss (moss/dung) quotients. [ABSTRACT FROM AUTHOR]

The ubiquity and photoreactivity of fluoroquinolone antibiotics (FQs) in surface waters urge new insights into their aqueous photochemical behavior. This study concerns the photochemistry of 6 FQs: ciprofloxacin, danofloxacin, levofloxacin, sarafloxacin, difloxacin and enrofloxacin. Methods were developed to calculate their solar direct photodegradation half-lives ( t d,E ) and hydroxyl-radical oxidation half-lives ( t OH,E ) in sunlit surface waters. The t d,E values range from 0.56 min to 28.8 min at 45° N latitude, whereas t OH,E ranges from 3.24 h to 33.6 h, suggesting that most FQs tend to undergo fast direct photolysis rather than hydroxyl-radical oxidation in surface waters. However, a case study for levofloxacin and sarafloxacin indicated that the hydroxyl-radical oxidation induced risky photochlorination and resulted in multi-degradation pathways, such as piperazinyl hydroxylation and clearage. Changes in the antibacterial activity of FQs caused by photodegradation in various waters were further examined using Escherichia coli , and it was found that the activity evolution depended on primary photodegradation pathways and products. Primary intermediates with intact FQ nuclei retained significant antibacterial activity. These results are important for assessing the fate and risk of FQs in surface waters. [ABSTRACT FROM AUTHOR]

With the exacerbating problem of antibiotic resistance, antibiotic resistance genes (ARGs) as emerging contaminants are found at elevated levels in inland aquatic environments, especially in regions of intensive agricultural and urban activity. However, little quantitative data exist on the migration and attenuation of ARGs in estuary ecosystem, which is central to predicting their fate after release into marine environment. Moreover, the relevance of multiple chemical contaminants and water quality constituents should be understood to amplify and attenuate antibiotic resistance levels. To determine the prevalence and examine the fate of sulfonamide ARGs ( sul -ARGs) in two estuaries under different effects of anthropogenic activities, we analyzed the sul -ARGs ( sul1 , sul2 , and sul3 ), class 1 integrons ( int1 ), and bacterial biomass in surface water samples from Daliaohe and Liaohe river estuaries. We also evaluated five types of antibiotics, heavy metals, and various bulk water quality constituents. Results showed that sul -ARGs were widespread in Daliaohe and Liaohe river estuaries, but the distribution did not correlate with the concentration of sulfonamides. Significant reduction in the abundance of sul -ARGs was also observed with increased salinity. Nevertheless, the trend in the change of concentrations of sul -ARGs was different in the two estuaries. Statistical analysis of the results indicated that several metals were significantly and positively correlated with sul -ARGs. Pearson's correlation coefficients were higher than those determined between antibiotic residues and sul -ARGs. Furthermore, the relative abundance of sul -ARGs was significantly and positively correlated with the relative abundance of int1 which suggested that the propagation of sul -ARGs was facilitated by class 1 integrons in estuaries. [ABSTRACT FROM AUTHOR]

Abstract: Gas- and particle-phase polycyclic aromatic hydrocarbons (PAHs) were collected in the atmosphere from the North Pacific to the Arctic Ocean to investigate their occurrence and gas/particle distribution. Significant linear correlations were observed between the gaseous concentrations of 9 PAHs and latitudes (r 2 = 0.69). The regression of gaseous PAHs and 1/T also gave a certain extent correlation (r 2 = 0.46). The gas/particle partition coefficients (K P) correlated well with the sub-cooled liquid vapor pressures (p o L) of PAHs with slopes higher than the theoretical value of −1, and the regressions of logK P–logp o L possessed a general tendency to intersect at a point (−2.52, −1.60). The non-linear regression of logp o L and the particle fraction displayed a more significant correlation (r 2 = 0.84) than the linear relation of logK P–logp o L (r 2 = 0.69). The influence of soot on K P was investigated, and it was found that the predicted values derived from the soot-air model agreed relatively better with the field measurements than those calculated based on the Junge–Pankow model and the K OA-based model. The results indicated that soot played an important role on the partitioning of PAHs to aerosols, and the partitioning of PAHs is more sensitive to presence of elemental carbon compared to organic matter of the aerosol. [Copyright &y& Elsevier]

Congener specific distributions of polybrominated diphenyl ethers (PBDEs) were investigated in sediment and mussel (Mytilus edulis) collected from the coast of Bo Sea, China. The median values of BDE-209 and ΣPBDEs (including BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183 and -190) were 2.29 and 0.16ngg−1 dry weight in sediment, and 2.43 and 0.68ngg−1 dry weight in mussel, respectively. BDE-209 was the predominant congener (61–99% in mussel and 75–99% in sediment except for one sample with 17%). Different congener patterns (excluding BDE-209) were observed between sediment and mussel, which were attributed to individual congener’s bioaccumulation potential and/or the ability to metabolize. The four most abundant congeners were BDE-47 (40.3%), -99 (22.5%), -71 (8.9%) and -28 (5.8%) in sediment, and -47 (36.4%), -28 (14.5%), -154 (8.6%) and -71 (8.6%) in mussel, respectively. The ratios of BDE-47/BDE-99 and BDE-100/BDE-99 in sediment were lower than those in mussel, indicating higher transformation and uptake rate of BDE-99 in mussel. The biota-sediment accumulation factor (BSAF) of individual PBDE congeners declined with the increase of their logarithm of octanol–water partition coefficients (log K OW) except for BDE-154, indicating congeners with higher log K OW were more likely to retain in sediment. These can be explained with a high affinity of these compounds for carbonaceous geosorbents, and molecular steric hindrance that limits large, very hydrophobic organic compounds from penetrating the cellular membranes. [Copyright &y& Elsevier]

To date, the impact of air-sea exchange on spatial distribution of atmospheric methane (CH 4 hereafter) remains less understood in the coastal areas of China. Here we measured the dissolved and atmospheric CH 4 in the Dalian Bay and adjacent area in July and August 2014, respectively. Results showed that the study area was a net significant source of atmospheric CH 4 , with a mean sea-to-air CH 4 flux of 170.6 ± 149.5 μmol/(m2·day). We optimized a method to accurately quantify the elevated atmospheric CH 4 mole fraction (△CH 4 hereafter) caused by air-sea exchange. The calculated △CH 4 in the study area ranged from 15.4 to 102.1 nmol/mol, 1.5–10.2 nmol/mol, and 0.03–0.22 nmol/mol at the mixing height of 1, 10, and 471 m, respectively. The △CH 4 mole fractions caused by air-sea exchange were positive with sea-to-air CH 4 flux and in situ observed atmospheric CH 4 mole fraction, while negative with altitude. Under the standard conditions, we defined 50.8 μmol/(m2·day) as the criteria value of sea-to-air CH 4 flux which could result in a detectable elevation atmospheric CH 4 mole fraction at a height of 10 m. Image 106245 • Coastline is an intensive ventilated area for CH 4 in the study area. • A method was improved for quantifying the impact of air-sea exchange on atmospheric CH 4. • Air-sea exchange induced atmospheric CH 4 mole fraction decreasing with increasing altitude. • A criterion flux value was defined for studying the impact of air-sea CH 4 exchange. [ABSTRACT FROM AUTHOR]