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Bismuth is one of the most difficult impurities to remove in mining concentrates and low concentrations generate problems in silver and copper refineries. Therefore, financial penalties are established when concentrations exceed 0.05%. Some researchers had used arsenic to remove bismuth with results of up to 52% of extraction. Unfortunately, this mechanism is not yet fully understood. The objective of this research was to obtain the solubility parameters of amorphous mineral compounds, including bismuth-based compounds, through computational simulation using molecular dynamics. The composition of the mineral sample was determined by X-ray diffraction and the crystalline species were obtained and modeled using Materials Studio software. The nanostructures were optimized by an energy minimization methodology using the Broyden-Fletcher-Goldfarb-Shanno algorithm and were validated using the figure of merit equation and density. Simulations were performed using the Universal Force Field at constant pressure and temperature. The results of the minerals identified in the sample were compared with arsenic trioxide, indicating miscibility between As2O3and Bi2O3, possible miscibility with 10 other minerals, and immiscibility with the rest. The results indicate that As2O3 can be successfully used for the removal of Bi2O3 without a negative effect on the recovery of other minerals of higher commercial value.

Neonicotinoids (NNIs) are active substances used as insecticides mainly in plant protection products (PPPs) but also in veterinary applications. The increasing evidence of affecting non-targeted organisms led the European Commission to severely restrict or even ban outdoor uses. To evaluate their current use and their influence in the ecological status of freshwater ecosystem, a total of 19 river water samples were collected to determine the presence of 5 NNIs (acetamiprid, clothianidin, imidacloprid, thiamethoxam and thiacloprid) in the Tagus basin. At least one target analyte was quantified by HPLC-MS/MS analysis in 17 of the 19 water samples, with ∑NNIs ranging fromMDL to 16.8 ng/L. Imidacloprid (2.75 ng/L; mean) and acetamiprid (0.47 ng/L) were quantified in most of the samples. Source identification evidences imidacloprid agricultural use. Risk assessment for different trophic levels was conducted with the data obtained calculating Risk Characterization Ratios (RCR) by two approaches, predicted non effect concentrations (PEC/PNEC) and Toxic Units (TU). RCRs were derived for each NNI and for the mixture of all (RCRmix). Results showed risk for imidacloprid in freshwater organism (RCRfw1) and for the mix of NNIs (RCRmix (PEC/PNEC) 1). RCRmix(PEC/PNEC) and the sum of toxic units (STU) showed a risky situation for some locations with different organisms related to agriculture practices. This data arouses concern about NNis (legal or forbidden) use in Tagus basin, and manifest the need of monitoring their presence and effect on the aquatic ecosystem.

Presence of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) were evaluated in indoor domestic air from four European countries (Belgium, Italy, Spain and Portugal). The main pollutants were hexachlorohexanes (sum of α-, β- and γ-HCH; ΣHCHs) and ΣPCBs (sum of PCB-28, 52, 101, 118, 138, 153 and 180), with median concentrations of 366 and 306 pg/m3, respectively. By decreasing order came hexachlorobenzene (HCB; 130 pg/m3), ΣDDXs (sum of DDTs, DDEs and DDDs; 94.4 pg/m3), ΣPBDEs (sum of BDE-17, 28, 47, 66, 99, 100, 153, 154, 183, 206, 207 and 209; 6.08 pg/m3) and DP (0.30 pg/m3). Lower ΣPCBs and ΣDDXs levels were found at Portuguese homes compared to Belgian, Italian and Spanish households. Italian samples presented also lower ΣHCHs concentrations while Spanish homes revealed higher HCB and BDE-209 indoor air concentrations than those obtained in the other countries. ΣHCHs, ΣDDXs and ΣPBDE levels mirrored lindane, dicofol and Penta-, DecaBDE use, respectively. The influence of building characteristics, surroundings and inhabitants habits on pollutant air concentrations was investigated. Data generated were used to conduct a human exposure assessment for toddlers and adults with median (P50) and upper (P95) concentrations. Results indicated that health risk posed by inhalation of ΣPCBs, ΣHCHs, ΣDDXs, HCB, ΣPBDEs and DP were 2 to 5 orders of magnitude lower than oral Reference Dose (RfD) values, and 90 (PCB-28) and 12 (γ-HCH) times lower than Minimal Risk Levels (MRLs) for toddlers at the worst case scenario.

The whitemouth croaker (Micropogonias furnieri) is one of the most commercially important species along the Atlantic coast of South America. Moreover, some of its biological traits (long life span, inshore feeding, high trophic position) make this species a suitable sentinel of coastal pollution. Here, we investigated contamination by multiple legacy and emerging organic pollutants, such as brominated and chlorinated flame retardants, polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), in whitemouth croakers from two estuaries (Guanabara and Sepetiba Bays) located in industrialized and urbanized areas in Rio de Janeiro State, Southeastern Brazil. Furthermore, we assessed how biological and ecological features could explain the observed contamination patterns. Regarding brominated flame retardants, concentrations of polybrominated diphenyl ethers (PBDEs) varied from 7.6 to 879.7 pg g-1 wet weight (w.w.), with high contribution of tetra-, penta-, hexa- and deca-BDEs. The sum of chlorinated flame retardants (dechlorane-related compounds, ΣDRC) ranged from

52 pollutants including organophosphate flame retardants and plasticizers (OPs), polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs) were evaluated in household dust from Belgium, Italy and Spain. Pollutant pattern was dominated by ∑OPs (12.8 μg/g; median) followed in decreasing order by ∑PBDEs (229 ng/g), decabromodiphenyl ethane (DBDPE, 130 ng/g), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE, 1.35 ng/g), hexabromobenzene (HBB, 0.28 ng/g) and finally pentabromoethylbenzene (PBEB, 0.03 ng/g). Country differences and substitution of regulated chemicals by unregulated ones were explored. Results clearly reflected a decrease in c-penta and c-octaBDE commercial mixtures, which are mainly substituted by OPs, BTBPE and PBEB. On the other hand, c-decaBDE concentrations increased in Spanish case. However, positive correlations with its proposed substitute (DBDPE) and recent restricted policies make it possible to assume that this trend will change in the coming years. On the basis of the relationship between pollutants, house characteristics and inhabitant habits, potential sources were studied. Finally, data obtained were used to determine estimated daily intakes (EDI) via house dust ingestion and dermal absorption for toddlers and adults at central and upper percentiles. Calculated EDI levels even at worst case scenario were below available reference dose (RfD) values in all cases.

65 house dust samples from three European countries (Belgium, Italy and Spain) were evaluated for the presence of 20 polyflouroalkyl substances (PFASs) including perfluoroalkane sulfonic acids (PFSAs), perfluoroalkyl carboxylic acid (PFCAs) and perfluoroalkane sulfonamides (PFOSAs). The three countries presented similar PFAS levels ranging from 3.13 to 155 ng/g (12.9 ng/g; median), but in all cases PFCAs concentrations (6.92, 15.2 and 8.68 ng/g; median for Belgium, Italy and Spain) were higher than those obtained for PFSAs (2.30, 1.76 and 2.68 ng/g). Interestingly, in comparison to previously published data exhibited an increase in perfluorobutanesulfonate (PFBS) concentrations in Belgian house dust. On the other hand, levels of perfluorooctanesulfonate (PFOS) decreased in Spanish case. Data were examined for relationships between PFAS house dust levels, building and outdoor surrounding characteristics and occupant habits. Main findings revealed a positive association between PFOS concentrations and the building edification age, which could highlight a decrease in the use of this chemical in Europe. Similarly, perfluorohexanesulfonate (PFHxS) levels correlated with the percentage of the floor covered by textiles. Homes located in industrial sites showed higher PFCA levels compared to urban or agricultural locations, revealing the industrial processes as a potential source of these chemicals in Europe. Data obtained were used to perform human exposure assessment for dust intake via oral ingestion. Estimated daily intakes, calculated for toddlers and adults at median and worst case scenarios, were below oral Reference Dose (RfD) and tolerable daily intakes (TDI). However, in perfluorooctanoic acid (PFOA) case, dust ingestion significance to total dietary exposure reached values of 51% for toddlers in the worst case scenario.

Biosolid application is considered a sustainable management tool as it positively contributes to recycle nutrients and to improve soil properties and fertility. Nevertheless, this waste management technique involves an important input source of emerging organic pollutants in soil. To evaluate the environmental potential risk related to perfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs) due to the biosolid application to soil, a quantitative ecotoxicological risk assessment was conducted. The analyte concentrations were employed to perform an estimation of the exposure levels to contaminants in the receiving media, defining predicted environmental concentrations (PECs) for terrestrial and aquatic compartments (PECsoil, PECwater, PECsed) and for secondary poisoning via the terrestrial and aquatic food chain (PECoral, predator (T), PECoral, predator (Aq)). The risk characterization ratios (RCRs) were calculated based in the comparison of the PEC values obtained with concentrations with no effect (PNECs) on terrestrial and aquatic ecosystems. Based on the chosen scenarios and experimental conditions, no environmental risk of PFASs and HFRs released from biosolid amended soils to different environmental compartments was detected (RCRsoil, RCRoral, worm, RCRwater, RCRsed and RCRoral, fish were below 1 in all cases). Besides, the potential health risk of PFASs and HFRs to local people who live in the scenario studied and are fed on horticultural crops grown in biosolid amended soil was also below 1, indicating that the risk is not considered significant to human health in the conditions studied. This approach provides a first insight of the risks relative to biosolid amendments to further research based on fieldwork risk assessment.

Rivers can receive the input of treated or untreated sewage effluents from wastewater treatment plants, urban and industrial discharges and agricultural run-off, becoming an important pathway for the transport and mobilization of pollutants to the oceans. In the present study, the occurrence of 20 PFAAs was determined in the water of Tagus River basin (Spain). PFAAs were detected in 76 out of 92 water samples collected during 5 years (2013-2018), being perfluorooctanesulfonic acid (PFOS) the predominant compound (0.01-34 ng/L). The annual average PFOS concentrations (2.9-11 ng/L) detected in Tagus River were above the annual average environmental quality standards (AA-EQS) established in the Directive, 2013/39/EU (0.65 ng/L for inland surface waters) but below the maximum allowable concentration (MAC-EQS; 36000 ng/L). The levels of PFAAs detected in urban and industrial areas were statistically higher (p 0.01) than those at background or remote areas. The mass flow rates amounted to0.01-46 kg/y for PFOS and0.01-22 kg/y for perfluorooctanoic acid (PFOA). A quantitative ecotoxicological risk assessment was conducted to evaluate the environmental potential risk related to PFAAs in the aquatic ecosystem. Risk characterization ratios (RCR

The bioaccumulation behavior of perfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs) was examined in three horticultural crops and earthworms. Two species, spinach (Spinacia oleracea) and tomato (Solanum lycopersicum L.), were grown in field soil amended with a single application of biosolids (at agronomic rate for nitrogen), to represent the scenario using commercial biosolids as fertilizer, and the third crop, corn (Zea mays) was grown in spiked soil (~50 mg PFOS/kg soil, ~5 mg Deca-BDE/kg soil and a mixture of both, ~50 mg PFOS and ~5 mg Deca-BDE/kg soil) to represent a worst-case scenario. To examine the bioaccumulation in soil invertebrates, earthworms (Eisenia andrei) were exposed to the spiked soil where corn had been grown. PFASs and HFRs were detected in the three crops and earthworms. To evaluate the distribution of the compounds in the different plant tissues, transfer factors (TFs) were calculated, with TF values higher for PFASs than PBDEs in all crop plants from 2 to 9-fold in spinach, 2 to 34-fold in tomato and 11 to 309-fold in corn. Bioaccumulation factor (BAF) values in earthworms were also higher for PFASs (4.06±2.23) than PBDEs (0.02±0.02). © 2016 Elsevier Inc.

We describe the development of instrumental methodology for the simultaneous determination of hexabromocyclododecane (HBCD) diastereoisomers and tetrabromobisphenol A (TBBPA) and its derivatives by liquid chromatography/quadrupole linear ion trap mass spectrometry (LC-QqLIT-MS). Two different experiments were developed, optimized and compared. The first is based on a selected reaction monitoring (SRM) method in which the two most abundant transitions were selected for each analyte, as well as for the internal standards. In the second, the ion trap was used for the storage and subsequent fragmentation of precursor ions, obtaining an enhanced product ion (EPI) experiment. Both methods were validated by measuring quality parameters such as linearity, sensitivity, reproducibility and repeatability. Limits of detection (LODs) were in the range of 0.1-1.8 pg and 0.01-0.5 pg for SRM and EPI experiments, respectively, being lower than those published for the LC/QqQ-MS methods. Thus, LC-QqLIT-MS, used for quantification and confirmation, proved to be a powerful and very sensitive analytical tool.

In the present work, the bioaccumulation behavior of 49 target emerging organic compounds (20 perfluoroalkyl substances, PFASs, and 29 halogenated flame retardants, HFRs) was studied in soil invertebrates (Eisenia andrei). Multi species soil systems (MS·3) were used to assess the fate and the effects associated with the application of four biosolids in agricultural soil on terrestrial soil organisms. Biosolid amendment increased concentrations 1.5-14-fold for PFASs, 1.1-2.4-fold for polybrominated diphenyl ethers, PBDEs, and 1.1-3.6-fold for chlorinated flame retardants, CFRs. Perfluorooctanesulfonate, PFOS, (25%) and BDE-209 (60%) were the predominant PFAS and HFR compounds, respectively, in biosolids-amended soils. Total concentrations (ng/g dry weight) in earthworms from biosolid-amended soils ranged from 9.9 to 101 for PFASs, from 45 to 76 for PBDEs and 0.3-32 for CFRs. Bioaccumulation factors (BAFs) were calculated to evaluate the degree of exposure of pollutants in earthworms. The mean BAF ranged from 2.2 to 198 for PFASs, 0.6-17 for PBDEs and 0.5-20 for CFRs. The relationship of PFAS and PBDE BAFs in earthworms and their log Kow were compared PFAS BAFs increased while PBDE BAFs declined with increasing log Kow values. The effect of the aging (21 days) on the bioavailability of the pollutants in amended soils was also assessed the residence time affected differently to the compounds studied. © 2016 Elsevier Inc.

Passive air samplers consisting of polyurethane foam (PUF) disks were deployed in seven remote points and four urban locations to assess levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and some organochlorine pesticides including: 1,1'-(2,2,2-trichloroethane-1,1-diyl)bis(4-chlorobenzene) (DDT) and their metabolites (1,1-bis-(4-chlorophenyl)-2,2-dichloroethene (DDE) and 1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene (DDD)), hexaclorobenzene (HCB) and hexachlorocyclohexanes (HCHs), in the Spanish ambient air. Results revealed HCB (49 pg m(-3); median) as the major pollutant, followed in decreasing order by HCHs (21 pg m(-3)), ∑DDT/E/Ds (20 pg m(-3)), PCBs (20 pg m(-3)), PBDEs (3.3 pg m(-3)) and PCDD/Fs (0.04 pg m(-3)), when urban and remote locations are evaluated together. Urban areas presented statistically significant (p

Sewage sludge from 31 urban Spanish wastewater treatment plants (WWTP) was analyzed for the emerging halogenated flame retardant Dechlorane Plus (DP). Concentrations of the two major isomers in the technical mixture, syn and anti, ranged between 0.903-19.2 and 1.55-75.1ngg(-1) dry weight, respectively. Overall, concentrations of DP were lower than those of polybrominated diphenyl ethers (PBDEs) (9.10-995ngg(-1) dry weight) and this is likely related to the higher usage of brominated flame retardants. The average ratio of the syn isomer to total DP (f(syn)) was 0.28±0.05, which is similar to that of the commercial mixture. Comparing different wastewater treatment methods, we found lower concentrations in those using biological nitrogen and phosphorous elimination, suggesting that DP is susceptible to microbial degradation and that anti-DP is more so, given the enrichment of syn-DP in the sewage sludge. Principal components analysis revealed significant positive correlation (r=0.619, p

We describe the development of instrumental methodology for the simultaneous determination of hexabromocyclododecane (HBCD) diastereoisomers and tetrabromobisphenol A (TBBPA) and its derivatives by liquid chromatography/quadrupole linear ion trap mass spectrometry (LC-QqLIT-MS). Two different experiments were developed, optimized and compared. The first is based on a selected reaction monitoring (SRM) method in which the two most abundant transitions were selected for each analyte, as well as for the internal standards. In the second, the ion trap was used for the storage and subsequent fragmentation of precursor ions, obtaining an enhanced product ion (EPI) experiment. Both methods were validated by measuring quality parameters such as linearity, sensitivity, reproducibility and repeatability. Limits of detection (LODs) were in the range of 0.1-1.8 pg and 0.01-0.5 pg for SRM and EPI experiments, respectively, being lower than those published for the LC/QqQ-MS methods. Thus, LC-QqLIT-MS, used for quantification and confirmation, proved to be a powerful and very sensitive analytical tool.