International audience | Paris conurbation is a heavily urbanized but weakly industrialized catchment. Recently, it has been shown at the scale of Paris that alkylphenols (AP) and phthalates (PAE) are not rejected by the industry, but they originate from domestic wastewater at more than 95 %. However, the contribution of the different types of greywater to the pollution by alkylphenols and phthalates was not addressed. This work aims at providing new insights on this particular point. Hence, the concentration of four phthalates (diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), benzyl butyl phthalate (BBP), and di(2-ethylhexyl)phthalate (DEHP)) and two alkylphenols (octylphenols (OP) and isomers of nonylphenol (NP)) were followed in greywater. For each sample, analyses were carried out on both the dissolved and particulate phases. Moreover, water quality parameters were also monitored, in order to find out whether or not any correlation exists between the concentration of the investigated contaminants and the quality of water. Water quality parameters studied are pH, total suspended solids (TSS), dissolved and particular organic carbon (DOC and POC), chemical and biochemical oxygen demands (COD and BOD5), total Kjeldahl nitrogen (TKN), and anionic detergents (methylene blue active substance or MBAS). This paper presents the methodology used to monitor two greywater with the most important volumes: showers and washing machines. These greywater showed high variability with regard to water quality parameters. Moreover, AP and PAE concentrations are given for the first time for these two types of greywater. All compounds except OP were observed in almost all samples in at least one of the two monitored phases. The concentrations varied between limit of quantification for OP and 102 μg/l for DEHP. The levels measured in washing machines were higher than those for showers for all compounds. For instance, median NP concentration in washing machines was 3.59 μg/l against 1.09 μg/l in showers, DEHP was observed at 102 μg/l in washing machines against 16.6 μg/l in showers. Variability of the results was explained by habits of individuals (shower time, number of products used…) but also by differences in product composition. However, each type of water exhibited the same distribution. NP was the most abundant AP (about 85 % of the total amount) while DEHP represented the two thirds of the PAE compounds. The partition coefficients (Kd in l/kg) were evaluated. The results showed that log Kd ranged between 2.1 (DEP) and 4.8 (DEHP). Log Koc presented similar trends lying in the 2.4 (DEP)-5.0 (DEHP) range. Finally, with regard to greywater quality, the application for greywater reuse is discussed.

A characterization of the physical–chemical composition of the atmospheric PM adsorbed to airborne pollen was performed. Airborne pollen was sampled using a Hirst-type volumetric spore sampler and observed using a Field Emission Electron Probe Microanalyser for PM analysis. A secondary electron image was taken of each pollen grain and EDS spectra were obtained for individually adsorbed particles. All images were analysed and the size parameters of the particles adsorbed to pollen was determined. The measured particles’ equivalent diameter varied between 0.1 and 25.8 μm, mostly in the fine fraction. The dominant particulates identified were Si-rich, Organic-rich, SO-rich, Metals & Oxides and Cl-rich. Significant daily differences were observed in the physical–chemical characteristics of particles adsorbed to the airborne pollen wall. These differences were correlated with weather parameters and atmospheric PM concentration. Airborne pollen has the ability to adsorb fine particles that may enhance its allergenicity.

A new approach is proposed to quantify the evaporative vapor generation based on real parking activity data. As compared to the existing methods, two improvements are applied in this new approach to reduce the uncertainties: First, evaporative vapor generation from diurnal parking events is usually calculated based on estimated average parking duration for the whole fleet, while in this study, vapor generation rate is calculated based on parking activities distribution. Second, rather than using the daily temperature gradient, this study uses hourly temperature observations to derive the hourly incremental vapor generation rates. The parking distribution and hourly incremental vapor generation rates are then adopted with Wade–Reddy's equation to estimate the weighted average evaporative generation. We find that hourly incremental rates can better describe the temporal variations of vapor generation, and the weighted vapor generation rate is 5–8% less than calculation without considering parking activity.

Dry deposition fluxes of 12 neutral poly-/perfluoroalkyl substances (PFASs) were estimated at Büsum located in northern German coast, and their gas/particle partition coefficients were predicted by employing the polyparameter linear free energy relationships (PP-LFERs). The gas deposition flux, particle deposition flux and total (gas + particle) flux of the 12 PFASs during sampling periods were 1088 ± 611, 189 ± 75 and 1277 ± 627 pg/(m2 d), respectively. The gas deposition of PFASs played a key role during deposition to marine ecosystem. Sensitivity analysis showed that wind speed was the most sensitive parameter for gas deposition fluxes. Good agreements (within 1 log unit) were observed between the measured gas/particle partitioning data of PFASs and the predicted partition coefficients using PP-LFERs, indicating the model can reliably predict the gas/particle partitioning behaviors of atmospheric neutral PFASs.

Tieshanping catchment in southwest China was supposed to a large pool of atmospheric mercury. This work was aimed to examine THg (total mercury) concentrations, pools and influence factors in the acidic forest. THg concentrations were highly elevated in the study area, which was significantly depended on TOM (total organic matter) concentrations and altitudinal elevation, whereas negatively correlated with soil pH. The pools of mercury accumulated in soils were correlated strongly with the stocks of TOM and altitude, ranged from 5.9 to 32 mg m−2 and averaged 14.5 mg m−2, indicating that the acidic forest was a great sink of atmospheric mercury in southwest China. THg concentrations in stream waters decreased with altitude increasing and regression analyses showed that soil/air exchange flux would be increased with the decrease of altitude. Present results suggest that elevation increasing decreases THg losses as low THg concentrations in runoffs and volatilization from soils.

As the climate in California warms and wildfires become larger and more severe, satellite-based observational tools are frequently used for studying impact of those fires on air quality. However little objective work has been done to quantify the skill these satellite observations of smoke plumes have in predicting impacts to PM2.5 concentrations at ground level monitors, especially those monitors used to determine attainment values for air quality under the Clean Air Act. Using PM2.5 monitoring data from a suite of monitors throughout the Central California area, we found a significant, but weak relationship between satellite-observed smoke plumes and PM2.5 concentrations measured at the surface. However, when combined with an autoregressive statistical model that uses weather and seasonal factors to identify thresholds for flagging unusual events at these sites, we found that the presence of smoke plumes could reliably identify periods of wildfire influence with 95% accuracy.

Dissolution of silver nanoparticles (AgNP with carbonate or citrate coating, total Ag 1–5 μM) was examined in the presence of the ligands cysteine, chloride and fulvic acids and of the oxidant hydrogen peroxide (H2O2) at low concentrations at pH 7.5. Dissolved Ag was separated from AgNP by ultrafiltration. Cysteine in the concentration range 0.2–5 μM resulted in an initial increase of dissolved Ag within few hours. Chloride (up to 0.1 mM) and fulvic acids (up to 15 mg L−1) had little effect on the dissolution of AgNP within hours to days. In contrast, very rapid dissolution within 1–2 h of both carbonate and citrate coated AgNP was observed in the presence of H2O2 in the concentration range 0.1–10 μM, under dark or light conditions. The high efficiency of H2O2 in dissolving AgNP is likely to be of importance in toxic effects of AgNP to algae, as H2O2 is produced and released into solution by algae.

The complexation flocculation (CF) method was successfully employed to identify binding coefficients (Kdoc) of specific organic contaminants to dissolved organic matter (DOM, often indicated by dissolved organic carbon, DOC) in a multi-contaminant hydrophobic organic contaminant (HOC) system. Kdoc values were obtained for most of the evaluated 33 HOCs, indicating the feasibility and applicability of the CF method in a multi-contaminant system. Significant positive correlations were observed between binding coefficients and octanol–water partition coefficients (Kow) for organic halogen compounds, such as polybrominated diphenyl ethers (PBDEs) (R2 = 0.95, p < 0.05) and organic chlorine pesticides (OCPs) (methoxychlor excluded, R2 = 0.82, p < 0.05). The positive correlations identified between the lgKdoc and lgBCF (bioconcentration factor) for PBDEs and OCPs, as well as the negative correlation observed for polycyclic aromatic hydrocarbons (PAHs), indicated that different binding or partition mechanisms between PAHs and organic halogen compounds exist. These differences further result in discriminative competition partitions of HOCs between DOM and organisms. Assuming that only freely dissolved HOCs are bioconcentrative, the results of DOM-influenced bioconcentration factor (BCFDOM) and DOM-influenced lowest observed effect level (LOELDOM) indicate that the ecological risk of HOCs is decreased by DOM.

Concentrations of 13 perfluoroalkyl substances (PFASs) were quantified in 79 surface soil samples from 17 coastal cities in three provinces and one municipality along the Bohai and Yellow Seas. The ∑PFASs concentrations ranged from less than limitation of quantification (LOQ) to 13.97 ng/g dry weight (dw), with a mean of 0.98 ng/g dw. The highest concentration was observed along the Xiaoqing River from Shandong province, followed by that from the Haihe River in Tianjin (10.62 ng/g dw). Among four regions, ∑PFASs concentrations decreased in the order of Tianjin, Shandong, Liaoning and Hebei, which was consistent with levels of urbanization. Fluorine chemical industries allocated in Shandong and Liaoning played important roles in terms of point emission and contamination of PFASs, dominated by perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Intensive anthropogenic activities involved in urbanization possibly resulted in increasing releases of PFASs from industrial and domestic sources.