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Fullerenes are carbon based nanoparticles that may enter the environment as a consequence of both natural processes and human activities. Although little is known about the presence of these chemicals in the environment, recent studies suggested that soil may act as a sink. The aim of the present work was to investigate the presence of fullerenes in soils collected in The Netherlands. Samples (n = 91) were taken from 6 locations and analyzed using a new developed LC-QTOF-MS method. The locations included highly trafficked and industrialized as well as urban and natural areas. In general, C60 was the most abundant fullerene found in the environment, detected in almost a half of the samples and at concentrations in the range of ng/kg. Other fullerenes such as C70 and an unknown structure containing a C60 cage were detected to a lower extent. The highest concentrations were found in the proximity of combustion sites such as a coal power plant and an incinerator, suggesting that the nanoparticles were unintentionally produced during combustions processes and reached the soil through atmospheric deposition. Consistent with other recent studies, these results show that fullerenes are widely present in the environment and that the main route for their entrance may be due to human activities. These data will be helpful in the understanding of the distribution of fullerenes in the environment and for the study of their behavior and fate in soil.

Soil food webs are traditionally considered to have distinct energy channels through which resources flow belowground. Resources enter the soil food web either from roots or from detrital inputs. Compared to this traditional view we are now much more aware of the flow of carbon, nitrogen and other resources through the microbes in the soil food web. Currently, the function of some groups of bacteria and fungi is known. The lowering of the costs of high throughput sequencing methods enables us to acquire more data on who is around, when and where in the soil food web. For soil fauna, gut content analyses in combination with sequencing can reveal feeding preferences, which enables establishing real trophic links based on observations, which can then be visualised as networks of feeding interactions. The fate of carbon flow through the soil food web can be traced by using stable isotopes combined with sequence based techniques. This provides insight into trophic connections and interaction strength. As the sequencing costs decrease rapidly, the level of detail in soil food web knowledge will similarly increase rapidly and enhance the feasibility of combined techniques. Using these techniques to broaden our insight into soil subsystems and their soil food webs will lead to more targeted decisions on management practices.

The presence of certain pharmaceutical compounds in ground- and surface waters may constitute a serious environmental problem, even at low concentrations. The occurrence of pharmaceuticals in the environment indicates incomplete removal of these pharmaceuticals from municipal wastewater treatment plants (WWTPs). In this study four representative pharmaceutical compounds were identified and quantified in influent and effluent of WWTPs around the Region of Murcia. In addition, the removal efficiencies of the five different treatment systems employed by these WWTPs were evaluated for the four pharmaceutical compounds. Influent and effluent wastewaters were sampled on a weekly basis during four consecutive weeks and compound concentrations were quantitatively determined by HPLC-DAD. Pharmaceuticals were detected at μg/L levels (0.34–26.52 μg/L) in influent and effluent samples from all five different systems of the twelve WWTPs sampled in this work. The two most abundant pharmaceutical compounds were carbamazepine and naproxen. WWTPs that worked with extended aeration activated sludge processes, coagulation-flocculation, sand filtration and as tertiary treatment processes are used ultraviolet and chlorination systems (EAAS + C-F + SF + UV + Cl) removed better carbamazepine and ketoprofen than conventional activated sludge system with a double aeration tank, sand filtration, lamination, coagulation-flocculation and as tertiary treatment processes are used ultraviolet systems (CAS-DS + L + C-F + SF + UV) that removed better naproxen and diclofenac.

The Uddelermeer is a unique lake for The Netherlands, containing a sediment record that continuously registered environmental and climatic change from the late Pleistocene on to the present. A 15.6-m-long sediment record was retrieved from the deepest part of the sedimentary basin and an age–depth model was developed using radiocarbon dating, 210Pb dating, and Bayesian modeling. Lake-level change was reconstructed using a novel combination of high-resolution palaeoecological proxies (e.g. pollen, non-pollen palynomorphs, chironomids), quantitative determinations of lake-level change (ground-penetrating radar), and estimates of changes in precipitation (lipid biomarker stable isotopes). We conclude that lake levels were at least as high as present-day water levels from the late glacial to 3150 cal. yr BP, with the exception of at least one lake-level lowstand during the Preboreal period. Lake levels were ca. 2.5 m lower than at present between 3150 and 2800 cal. yr BP, which might have been the result of a change in moisture source region prior to the so-called 2.8-kyr event. Increasing precipitation amounts around 2800 cal. yr BP resulted in a lake-level rise of about 3.5–4 m to levels that were 1–1.5 m higher than at present, in line with increased precipitation levels as inferred for the 2.8-kyr event from nearby raised bog areas as well as with reconstructions of higher lake levels in the French Alps, all of which have been previously attributed to a phase of decreased solar activity. Lake levels decreased to their present level only during recent times, although the exact timing of the drop in lake levels is unclear.

Plaggic Anthrosols are the result of historical forms of land management in cultural landscapes on chemically poor sandy substrates. Application of plaggic manure was responsible for the development of the plaggic horizons of these agricultural soils. Pollen diagrams reflect aspects of the environmental development but the interpretation of the pollen spectra is complicated due to the mix of the aeolian pollen influx of crop species and species in the surroundings, and of pollen occurring in the used stable fillings. Pollen diagrams and radiocarbon dates of plaggic Anthrosols suggested a development period of more than a millennium. Calluna is present in almost all the pollen spectra, indicating the presence of heath in the landscape during the whole period of soil development. Optically stimulated luminescence dating of the plaggic horizon made clear that the deposition of plaggic covers started in the 16th century and accelerated in the 18th century. The stable fillings, used for the production of plaggic manure and responsible for the rise of the soil surface, cannot be identified with pollen diagrams alone. Biomarker analyses provide more evidence about the sources of stable fillings. The oldest biomarker spectra of the plaggic horizons of three typical plaggic Anthrosols examined in this study were dominated by biomarkers of forest species such as Quercus and Betula while the spectra of middle part of the plaggic horizons were dominated by biomarkers of stem tissue of crop species such as Secale and Avena. Only the youngest spectra of the plaggic horizons were dominated by biomarkers of Calluna. This indicates that the use of heath sods as stable filling was most likely introduced very late in the development of the Anthrosols. Before the 19th century the mineral component in plaggic manure cannot be explained by the use of heath sods. We conclude that other sources of materials, containing mineral grains must have been responsible for the raise of the plaggic horizon.

Brominated flame retardants account for about 21% of the total production of flame retardants and many of these have been identified as persistent, bioaccumulative and toxic. Nevertheless, debromination of these chemicals under anaerobic conditions is well established, although this can increase their toxicity. Consequently, the production and use of these chemicals has been restricted and alternative products have been developed. Many of these are brominated compounds and share some of the disadvantages of the chemicals they are meant to replace. Therefore, other, nonbrominated, flame retardants such as organophosphorus compounds are also being used in increasing quantities, despite the fact that knowledge of their biodegradation and environmental fate is often lacking.

Few methods are available for comprehensive organophosphate flame retardants (PFRs) detection in water and wastewater. Gas chromatography has been employed previously, but this approach is less selective, not amenable for use with deuterated standards and can suffer unfavorable fragmentation. Ultra-high-pressure liquid chromatography tandem mass spectrometry (UHPLC-QqQ-MS/MS) has become the most promising platform, already applied successfully for analysis of selected PFRs in some environmental matrices like water and wastewater. However, the presence of some interferences from the dissolvent, the equipment and the used materials should be taken into account. The procedure involves: The first determination of PFRs by UHPLC-QqQ-MS/MS using a trap column to distinguish the interferences coming from the instrument and mobile phases.The optimization of the LC separation to distinguish all target compounds and their interferences.This method coupled to a solid-phase extraction (SPE) improve the detection and quantification of PFRs., This work has been supported by the Spanish Ministry of Economy and Competitiveness through the projects GCL2011-29703-C02-02 (http://mefturia.es) and GCL2015-64454-C2-1-R (ECO2risk-dds) and the University of Valencia through the project (UV-INV-AE15-348995). María Lorenzo also acknowledges to the Foundation “Tatiana Pérez de Guzmán el Bueno” for the grant to get the PhD.

Invasive exotic plant species often have fewer natural enemies and suffer less damage from herbivores in their new range than genetically or functionally related species that are native to that area. Although we might expect that having fewer enemies would promote the invasiveness of the introduced exotic plant species due to reduced enemy exposure, few studies have actually analyzed the ecological consequences of this situation in the field. Here, we examined how exposure to aboveground herbivores influences shifts in dominance among exotic and phylogenetically related native plant species in a riparian ecosystem during early establishment of invaded communities. We planted ten plant communities each consisting of three individuals of each of six exotic plant species as well as six phylogenetically related natives. Exotic plant species were selected based on a rapid recent increase in regional abundance, the presence of a congeneric native species, and their co-occurrence in the riparian ecosystem. All plant communities were covered by tents with insect mesh. Five tents were open on the leeward side to allow herbivory. The other five tents were completely closed in order to exclude insects and vertebrates. Herbivory reduced aboveground biomass by half and influenced which of the plant species dominated the establishing communities. Exposure to herbivory did not reduce the total biomass of natives more than that of exotics, so aboveground herbivory did not selectively enhance exotics during this early stage of plant community development. Effects of herbivores on plant biomass depended on plant species or genus but not on plant status (i.e., exotic vs native). Thus, aboveground herbivory did not promote the dominance of exotic plant species during early establishment of the phylogenetically balanced plant communities. Electronic supplementary material The online version of this article (doi:10.1007/s00442-015-3472-6) contains supplementary material, which is available to authorized users.

The increasing production of fullerenes likely means a release of these chemicals in the environment. Since soils and sediments are expected to act as a sink, analytical tools are needed to assess the presence of fullerenes in these matrices. In the present work, a method was developed for the determination of fullerenes at environmental relevant levels employing Ultra High Performance Liquid Chromatograph coupled with High Resolution Mass Spectrometry (UHPLC-HRMS). Chromatographic separation was achieved with a core–shell biphenyl stationary phase that provided fast analysis with complete baseline separation. Ion Booster Electro Spray Ionization (IB-ESI) resulted in higher ionization efficiency and was much less susceptible to adduct formation in comparison with standard ESI, whereas Quadrupole Time of Flight (QTOF) MS granted high resolution mass spectra used for accurate identification. The Instrumental method limits of detection (ILoD) and quantification (ILoQ) were 6 and 20 fg, respectively, for C60 and 12 and 39 fg, respectively, for C70. Matrix effects related to co-extractants were systematically investigated in soil and sediments extracts through standard addition method (SAM) and monitoring the signal response during the chromatographic run of these samples. Consequently, minor chromatographic modifications were necessary for the analysis of matrices with high organic carbon content. The method limit of detection (MLoD)ranged from 84 pg/kg to 335 pg/kg, whereas limit of quantification (MLoQ) ranged from 279 pg/kg to 1.1 ng/kg. Furthermore, the method was successfully applied for the analysis of functionalized fullerenes (i.e. methanofullerenes). To the best of our knowledge, this is the first analytical method for the analysis of fullerenes in soils and sediments that employ core–shell biphenyl stationary phase as well as IB-ESI-QTOF MS hyphenated with UHPLC.

The effects of land use changes on soil carbon stocks are a matter of concern stated in international policy agendas on the mitigation of greenhouse emissions. Afforestation is increasingly viewed as an environmental restorative land use change prescription and is considered one of the most efficient carbon sequestration strategies currently available. Given the large quantity of CO2 that soils release annually, it is important to understand disturbances in vegetation and soil resulting from land use changes. The main objective of this study is to assess the effects of land abandonment, land use change and afforestation practices on soil organic carbon (SOC) dynamics. For this aim, five different land covers (bare soil, permanent pastureland, secondary succession, Pinus sylvestris (PS) and Pinus nigra (PN) afforestation), in the Central Spanish Pyrenees, were analysed. SOC dynamics have been studied in the bulk soil, and in the fractions separated according to two methodologies: (i) aggregate size distribution, and (ii) density fractionation, and rates of carbon mineralization have been determined by measuring CO2 evolution using an automated respirometer. The results showed that: (i) SOC contents were higher in the PN sites in the topsoil (10 cm), (ii) when all the profiles were considered no significant differences were observed between pastureland and PN, (iii) SOC accumulation under secondary succession is a slow process, and (iv) pastureland should also be considered due to the relative importance in SOC stocks. The first step of SOC stabilization after afforestation is the formation of macro-aggregates promoted by large inputs of SOC, with a high contribution of labile organic matter. However, our respiration experiments did not show evidence of SOC stabilization. SOC mineralization was higher in the top layers and values decreased with depth. These results gain insights into which type of land management is most appropriate after land abandonment for SOC.

Bacteria and fungi are important micro-organisms in the soil, but may differ in their impact on net N-mineralization. The hypothesis was tested that fungi are characterized by low microbial activity, but also low immobilization, and bacteria by high activity and high immobilization. A one-month laboratory incubation experiment with selective inhibition of fungi (cycloheximide) or bacteria (streptomycin) was conducted with samples of organic layer and mineral topsoil (0-10. cm) from neutral, bacteria-dominated and acidic, fungi-dominated Luxembourg beech forests. In the control treatment, respiration was higher in neutral than in acidic soil, but net N-mineralization was lower, due to higher immobilization. In the antibiotic treatments, differences in nitrification suggest that selective inhibition indeed occurred; in all soils and horizons, nitrification was especially limited by bactericide. Besides as inhibitor of the target group, antibiotics may also serve as source of C and N for the non-target group. For both bactericide and fungicide, acidic soils showed higher net recovery of C and N from antibiotics than neutral soil, which suggests that uptake or sorption of antibiotics is higher in the latter. Clear differences between neutral and acidic soils arose when the main micro-organisms were stimulated. In bacteria-dominated neutral soil, application of fungicide led to increased microbial respiration. In fungi-dominated acidic soil, however, application of bactericide did not lead to higher respiration, but to increased net N-mineralization per unit respiration, which supports a lower immobilization. Differences between antibiotics were consistent for organic layer and mineral topsoil, with increase in activity with fungicide, and lower immobilization with bactericide. The results provide correlative and experimental evidence that reduced immobilization by fungi compensates for their lower rates of activity with respect to N-availability to the vegetation.

Microorganisms capable of degrading herbicides are essential to minimize the amount of chemical compounds that may leach into other environments. This work aimed to study the potential of sandy-loam soil fungi to tolerate the herbicide Herburon (50% diuron) and to degrade the active ingredient diuron. Verticillium sp. F04, Trichoderma virens F28, and Cunninghamella elegans B06 showed the highest growth in the presence of the herbicide. The evaluation of biotransformation showed that Aspergillus brasiliensis G08, Aspergillus sp. G25, and Cunninghamella elegans B06 had the greatest potential to degrade diuron. Statistical analysis demonstrated that glucose positively influences the potential of the microorganism to degrade diuron, indicating a cometabolic process. Due to metabolites founded by diuron biotransformation, it is indicated that the fungi are relevant in reducing the herbicide concentration in runoff, minimizing the environmental impact on surrounding ecosystems.

Venlafaxine, gemfibrozil, ibuprofen, irbesartan and ofloxacin are highly-consumed pharmaceuticals that show considerable removal efficiencies (between 40 and 98%) in wastewater treatment plants (WWTPs). Consequently, they are expected to generate transformation products (TPs) during wastewater treatment and in surface water (SW) receiving WWTP effluent. In this work, degradation experiments for these five pharmaceuticals have been carried out with SW and WWTP activated sludge under laboratory-controlled aerobic conditions to identify their transformation products by liquid chromatography coupled to time-of-flight mass spectrometry (LC-QTOF MS). Initially, 22 pharmaceutical TPs were tentatively identified. A retrospective analysis was performed in effluent wastewater (EWW) and SW samples. All parent compounds as well as several TPs were found in some of the selected EWW and SW samples. Additionally, valsartan and 3 TPs were also detected by searching for common fragments in these waters. It is important to highlight that some TPs, such as O-desmethyl-venlafaxine and an oxidized gemfibrozil TP, were more frequently found than their corresponding parent compounds. On the basis of these results, it would be recommendable to include these TPs (at least those found in EWW and SW samples analyzed) in monitoring programs in order to gain a more realistic understanding of the impact of pharmaceuticals on water quality.

Soil studies commonly comprise the uppermost meter for tracing, e.g., soil development. However, the maximum rooting depth of various plants significantly exceeds this depth. We hypothesized that deeper parts of the soil, soil parent material and especially paleosols provide beneficial conditions in terms of, e.g., nutrient contents, thus supporting their utilization and exploitation by deep roots. We aimed to decipher the different phases of soil formation in Dutch drift sands and cover sands. The study site is located at Bedafse Bergen (southeastern Netherlands) in a 200-year-old oak stand. A recent Podzol developed on drift sand covering a Plaggic Anthrosol that was piled up on a relict Podzol on Late Glacial eolian cover sand. Root-free soil and sediment samples, collected in 10–15 cm depth increments, were subjected to a multi-proxy physical and geochemical approach. The Plaggic Anthrosol revealed low bulk density and high phosphorous and organic carbon contents, whereas the relict Podzol was characterized by high iron and aluminum contents. Frequencies of fine (diameter ≤ 2 mm) and medium roots (2–5 mm) were determined on horizontal levels and the profile wall for a detailed pseudo-three-dimensional insight. On horizontal levels, living roots were most abundant in the uppermost part of the relict Podzol with ca. 4450 and 220 m−2, significantly exceeding topsoil root abundances. Roots of oak trees thus benefited from the favorable growth conditions in the nutrient-rich Plaggic Anthrosol, whereas increased compactness and high aluminum contents of the relict Podzol caused a strong decrease of roots. The approach demonstrated the benefit of comprehensive root investigation to support interpretation of soil profiles, as fine roots can be significantly underestimated when quantified at the profile wall. The possible rooting of soil parent material and paleosols long after their burial confirmed recent studies on the potential influence of rooting to overprint sediment–(paleo)soil sequences of various ages, sedimentary and climatic settings. Potential consequences of deep rooting for terrestrial deep carbon stocks, located to a relevant part in paleosols, remain largely unknown and require further investigation.

Background and aims: In the last decades, large areas undergo a revegetation process as a result of land abandonment, producing significant environmental and landscape impacts. In this paper, revegetation impacts are identified. We present the solutions proposed by scientists to control the negative impacts of revegetation, from a literature review from studies carried out in Europe. Results: Some scientists suggest letting the revegetation process continued to contribute to the naturalisation of the landscape, reduce soil erosion, increase carbon sequestration and encourage recreational use of the territory. Other scientists, however, suggest the need to control the revegetation processes and retrieve abandoned land with productive purposes (extensive livestock and leisure), environmental objectives (reduction of fires and increasing biodiversity) and preserve cultural landscapes. Conclusion: The scrubland clearing and extensive livestock is an appropriate strategy to manage abandoned lands, combining environmental, landscape and socio-economic benefits. © 2015 Elsevier Ltd., This paper has received support from research projects: INDICA (CGL2011-27753-CO2-01 and 02) and HIDROCAES (CGL2011-27574-CO2-01 and 02), financed by the Ministry of the Economy and Competitiveness. E. Nadal-Romero was the recipient of a Marie Curie Intra-European Fellowship (Project “MED-AFFOREST”, PIEF-GA-2013-624974) (Seventh EU Framework Programme).

Monomeric organic nitrogen (N) compounds such as free amino acids (FAAs) are an important resource for both plants and soil microorganisms and a source of ammonium (NH4+) via microbial FAA mineralization. We compared gross FAA dynamics with gross N mineralization in a Dutch heathland soil using a 15N tracing technique. A special focus was made on the effects of climate change factors warming and drought, followed by rewetting. Our aims were to (1) compare FAA mineralization (NH4+ production from FAAs) with gross N mineralization, (2) assess gross FAA production rate (depolymerization) and turnover time relative to gross N mineralization rate, and (3) assess the effects of a 14 years of warming and drought treatment on these rates. The turnover of FAA in the soil was ca. 3 h, which is almost 2 orders of magnitude faster than that of NH4+ (i.e. ca. 4 days). This suggests that FAA is an extensively used resource by soil microorganisms. In control soil (i.e. no climatic treatment), the gross N mineralization rate (10 ± 2.9 μg N g−1 day−1) was 8 times smaller than the total gross FAA production rate of five AAs (alanine, valine, leucine, isoleucine, proline: 127.4 to 25.0 μg N g−1 day−1). Gross FAA mineralization (3.4 ± 0.2 μg N g−1 day−1) contributed 34% to the gross N mineralization rate and is therefore an important component of N mineralization. In the drought treatment, a 6–29% reduction in annual precipitation caused a decrease of gross FAA production by 65% and of gross FAA mineralization by 41% compared to control. On the other hand, gross N mineralization was unaffected by drought, indicating an increased mineralization of other soil organic nitrogen (SON) components. A 0.5–1.5 °C warming did not significantly affect N transformations, even though gross FAA production declined. Overall our results suggest that in heathland soil exposed to droughts a different type of SON pool is mineralized. Furthermore, compared to agricultural soils, FAA mineralization was relatively less important in the investigated heathland. This indicates more complex mineralization dynamics in semi-natural ecosystems.

In our study we investigated the clay fraction composition of Pliocene clay deposits in the Sohag area, Egypt. Our goal was to obtain insights into the origin of the deposits, and to assess their potential for use in inexpensive wastewater purification. The rationale for the latter was that in Egypt both industrial wastewater and irrigation water are often polluted with heavy metals (HMs), the load of which can be significantly reduced using the Pliocene clay. We combined physico-chemical analyses with detailed X-ray diffraction (XRD) mineralogical investigations and Specific Surface Area (SSA) measurements of samples from 16 locations in four areas containing Pliocene clay deposits. The grain size distribution of the studied samples was dominated by silt (75–89%) with lower quantities of clay (6–20%) and sand (2–15%). Neither grain size distribution nor the distribution of individual clay minerals varied between the tested samples, suggesting that they all originate from a single source area. The effect of differential cation saturation (K + and Mg 2 + ) and differential heat treatments (25°C, 300°C, and 550°C) on the XRD patterns of oriented aggregates of the clay-sized fractions revealed 4 different clay mineral groups in the tested samples. The relative abundances of the clay minerals were semi-quantified and revealed a dominance of smectite (69–91% on average) with relatively low contents of kaolinite (9–29% on average) and minor amounts of illite (1–7% on average) and chlorite (0 ≤ 1%). This mineral assemblage suggests chemical weathering and indicates warm climatic conditions of the source area during the period of deposition. The higher CEC values of the Pliocene clay deposits (32.3–65.4 cmol c /kg) also pointed to the occurrence of smectite in the soils. The SSA of the Pliocene clay fractions (26.25–128.97 m 2 /g) correlated well with their exchangeable cation contents (K + and Ca 2 + , R 2 = 0.96 and 1.0 respectively) and micropore volumes (R 2 = 1.0). Micropore volumes and SSA of the studied samples increased with the size of the exchanged cation: K + > Ca 2 + > Na + . The mineralogical composition suggests that Pliocene smectite-rich deposits in the studied area have great potential to be used as raw material for inexpensive, local purification of wastewater polluted with HMs.

Evidence is presented that the oxygen demand associated with photochemical processes in the surface layer of oceans and seas worldwide is of the same order of magnitude as the amount of oxygen released by photosynthesis of the world's marine phytoplankton. Both estimates are of necessity quite rough and therefore the agreement between oxygen loss and production, earlier found only locally in the Atlantic Ocean and the North Sea, came as a surprise. The heavy photochemical oxygen demand of the world's oceans must be explored further in oxygen budget studies by biogeochemical modelling in which special attention is paid to regional and temporal-differences in the vertical stratification regime at the surface. Indeed, stratification is the candid() sine qua non for photochemical processes that are driven by ultraviolet radiation. Oxygen cannot be expected to be released from the sea to the atmosphere in the permanently stratified open ocean when year-round the oxygen loss associated with photochemistry is so high. In the upper layer of sea and ocean regions of the temperate zone vertical stratification is only pronounced during spring, summer and early autumn, so photochemical oxygen demand there is restricted to those months. We argue that the constancy of the oxygen concentration observed at the surface of the oceans in the tropics and subtropics (80% of Earth's marine regions) is the consequence of the balance between three processes that influence oxygen dissolved in seawater: loss due to photochemical processes and to the activity of microheterotrophs on the one hand, photosynthetic oxygen production by phytoplankton on the other. (C) 2015 Elsevier B.V. All rights reserved

10 páginas.-- 3 figuras.-- 70 referencias.-- Ortega Calvo, J. J. et al.., The bioavailability of organic chemicals in soil and sediment is an important area of scientific investigation for environmental scientists, although this area of study remains only partially recognized by regulators and industries working in the environmental sector. Regulators have recently started to consider bioavailability within retrospective risk assessment frameworks for organic chemicals; by doing so, realistic decision-making with regard to polluted environments can be achieved, rather than relying on the traditional approach of using total-extractable concentrations. However, implementation remains difficult because scientific developments on bioavailability are not always translated into ready-to-use approaches for regulators. Similarly, bioavailability remains largely unexplored within prospective regulatory frameworks that address the approval and regulation of organic chemicals. This article discusses bioavailability concepts and methods, as well as possible pathways for the implementation of bioavailability into risk assessment and regulation; in addition, this article offers a simple, pragmatic and justifiable approach for use within retrospective and prospective risk assessment., All authors participated at the SETAC Europe SESSS10 symposium on bioavailability (http://sesss10.setac.eu/). They utilized of the presentations and the discussions at the symposium to write this paper. During the preparation of the symposium and this manuscript, J.-J.O.-C. was supported by the Spanish Ministry of Science and Innovation (CGL2013-44554-R). The support given by ECETOC for open access publication of this article is gratefully acknowledged.

Nadal-Romero...[et.al.], Precipitation has been recognized as one of the main factors driving soil erosion and sediment yield (SY), and its spatial and temporal variability is recognized as one of the main reasons for spatial and temporal analyses of soil erosion variability. The weather types (WTs) approach classifies the continuum of atmospheric circulation into a small number of categories or types and has been proven a good indicator of the spatial and temporal variability of precipitation. Thus, the main objective of this study is to analyze the relationship between WTs, runoff, soil erosion (measured in plots), and sediment yield (measured in catchments) in different areas of the Iberian Peninsula (IP) with the aim of detecting spatial variations in these relationships. To this end, hydrological and sediment information covering the IP from several Spanish research teams has been combined, and related with daily WTs estimated by using the NMC/NCAR 40-Year Reanalysis Project. The results show that, in general, a few WTs (particularly westerly, southwesterly and cyclonic) provide the largest amounts of precipitation; and southwesterly, northwesterly and westerly WTs play an important role in runoff generation, erosion and sediment yield as they coincide with the wettest WTs. However, this study highlights the spatial variability of erosion and sediment yield in the IP according to WT, differentiating (1) areas under the influence of north and/or north-westerly flows (the north coast of Cantabria and inland central areas), (2) areas under the influence of westerly, southwesterly and cyclonic WTs (western and southwestern IP), (3) areas in which erosion and sediment yield are controlled by easterly flows (Mediterranean coastland), and (4) lastly, a transitional zone in the inland northeast Ebro catchment, where we detected a high variability in the effects of WTs on erosion. Overall results suggest that the use of WTs derived from observed atmospheric pressure patterns could be a useful tool for inclusion in future projections of the spatial variability of erosion and sediment yield, as models capture pressure fields reliably. © 2014 Elsevier B.V., Support for this research was provided by the projects: HIDROCAES (CGL2011-27574-C02-01 and 02), INDICA (CGL2011-27753-CO2-01 and 02), and CGL2010-21754-C02-01 of the Spanish Ministry of Science and Technology funded by the Spanish Ministry of Economy and Competition and FSE. Thanks to the AEMeT for the rainfall data, and to Roberto Serrano for his helpful assistance in the precipitation analysis. Thanks to the reviewers and the editor for their detailed work to improve this article. E. Nadal-Romero was the recipient of a research contract (Spanish Ministry of Economy and Competition, Programme Juan de la Cierva), and now she is a Marie Curie postdoctoral researcher supported by the UE (project “MED-AFFOREST” PIEF-GA-2013-624974).

Erosion and deposition redistribute large quantities of sediment and soil organic carbon (SOC) in agricultural landscapes. In the perspective of global carbon cycling, the coupling between erosion processes and the fate of SOC is of particular interest. However, different concepts have been proposed to assess the impact of erosion-induced lateral and vertical carbon fluxes. On landscape scale, this resulted in contrasting conclusions if agricultural soils represent either a carbon sink or source. The large global area of arable soil and generally high erosion rates, make these insights important. In this review, we aim to give an overview of the different conceptual relations described governing C dynamics at sites of erosion, along the transport pathway and at depositional sites and the current state of knowledge on the fate of SOC upon erosion, transport and deposition in agricultural landscapes. The impact of erosion on SOC dynamics differs for sites of erosion, deposition and during transport, with further influences by agricultural practices (e.g. tillage and fertilisation). Controlling processes are the detachment of sediment and SOC, net primary production resulting in dynamic replacement and changes in mineralisation upon transport and deposition due to aggregate breakdown and deep burial, respectively. However, the exact magnitude and dominance of these processes are debated, resulting in a controversy whether arable land functions as a sink or source for atmospheric CO2. Global estimations range between a net sink strength of 0.06–1 versus a source of 0.27–1.14 Gt C yr− 1 for agricultural soils. An eco-geomorphologic approach, which encompasses physical- and biological-driven factors (e.g. spatio-temporal variation in biological, geomorphological and biological processes, environmental conditions, mineralisation, and net primary production) is of importance to balance the carbon budget and ascertain sink or source formation at landscape scale. High spatio-temporal variability on process-scale imposes constrains, to measure and model the fate of SOC upon erosion, with limited quantitative data available. Prospective research across the landscape (eroding sites, transport pathway, and depositional sites) should include all relevant processes at broad temporal and spatial scales. Definitive resolution of the sink/source controversy lies in further eco-geomorphologic research on the fate of SOC, focussing on long-term and spatial extensive monitoring studies, combined with advanced measuring, modelling and extrapolation techniques to cover broad spatio-temporal SOC dynamics. Ascertainment of carbon dynamics in agricultural landscapes provides important insights to balance the carbon budget and finally holds the answer on sink/source formation.

Many wetlands are heavily modified and identifying the environmental drivers of indicator groups like aquatic insects is complicated by multiple stressors and co-varying environmental factors. Yet, incorporating data from other biological groups, such as microbial communities, potentially reveals which environmental factors are underpinning insect community composition. In the present study we investigated the application of benthic microbial community composition, as determined by phospholipid fatty acid (PLFA) analysis, alongside aquatic insect data in 25 peatland ditches in the province of North Holland, The Netherlands. We applied clustering and principal component analysis to a matrix of 26 PLFAs to group ditches by the microbial community. Generalized linear models were used to examine correlations between microbial PLFAs, insects, vegetation (emergent and submerged) and abiotic factors. The ratio of heterotrophic (e.g. sulphate reducing bacteria) to autotrophic (e.g. algae and cyanobacteria) derived PLFAs could be estimated as the ratio between saturated and branched to monounsaturated and polyunsaturated fatty acids (SB/MP). SB/MP was correlated with insect community composition, differences in water chemistry (in particular bicarbonate, sulphate and nutrients) and vegetation cover in the ditches. Moreover, ditches distinguished by their microbial communities differed in the number of insects they supported with differences most pronounced for Odonata, Trichoptera and Chironomus larvae. This study demonstrates that integrating microbial and aquatic insect community data provides insight into key environmental drivers in modified aquatic ecosystems and may facilitate the development of remediation strategies for degraded wetlands.

Cropland abandonment and subsequent revegetation processes (due to secondary succession and afforestation practices) are global issues with important implications in Mediterranean mountain areas. Several publications have reviewed the impact of cropland abandonment and revegetation on the soil properties dynamics but, so far, limited attention has been paid to Mediterranean humid mountain areas. This paper examines six neighbouring land covers, in the Central Spanish Pyrenees to determine the effects of land covers, cropland abandonment and consequently secondary succession and afforestation practices on soil properties. For this purpose, a total of 85 samples from 6 land covers and from two soil depths were analysed. We observed that changes in soil properties after cropland abandonment were limited, even if afforestation practices were carried out, and no differences were observed between natural succession and afforestation. Land cover and depth had a significant effect on the physical and chemical variables, being larger in the uppermost 0–10 cm depth. The organic and inorganic carbon and N concentration, SOC and TN stocks, CN ratio, organic matter, and bulk density showed significant differences. Afforestation improved soil properties, aggregate stability and carbon concentration and stocks when compared to neighbouring bare soils. A soil quality index −based on statistical analysis- suggested that natural forests and Pinus nigra areas developed a higher soil quality rating. Our general results also demonstrated that the impact of disturbance by afforestation techniques (microsites) is difficult to discern. The differences found with respect to the native forest appear to indicate that the afforested soils have not yet reached their maximum soil quality and maximum potential as soil organic carbon sink. As there was no difference found between the soil improvement by natural succession in comparison to afforestation, these results put the question forward which type of forest and landscape management is most appropriate to decide for the best practices after cropland abandonment for soil recovery and erosion control.

In this short communication we report on the technical implementations of coupling an asymmetric flow field-flow fractionation (AF4) instrument to a high resolution mass spectrometer (Orbitrap) using an atmospheric photoionisation interface. This will allow for the first time online identification of different fullerenes in aqueous samples after their aggregates have been fractionated in the FFF channel. Quality parameters such as limits of detection (LODs), limits of quantification (LOQs) or linear range were evaluated and they were in the range of hundreds ng/L for LODs and LOQs and the detector response was linear in the range tested (up to ∼20μg/L). The low detection and quantification limits make this technique useful for future environmental or ecotoxicology studies in which low concentration levels are expected for fullerenes and common on-line detectors such as UV or MALS do not have enough sensitivity and selectivity.

Halogen-free flame retardants (HFFRs), such as the aromatic organophosphorus flame retardants (OPFRs) triphenyl phosphate (TPHP), resorcinol bis(diphenylphosphate) (PBDPP) and bisphenol A bis(diphenylphosphate) (BPA-BDPP) have been proposed as potential replacements for brominated flame retardants in polymers and textiles. Although these OPFRs are already marketed, their environmental fate and effects are poorly characterised. The aim of this study was therefore to determine the mineralisation and primary biodegradation of these OPFRs by activated sludge. Mineralisation was monitored by measuring CO2 production by means of GC analysis, whereas primary biodegradation was monitored by LC-MS/MS analysis of the OPFRs and their potential metabolites. TPHP was biodegraded and mineralised most rapidly and achieved the requirement for ready biodegradability (60% of theoretical maximum mineralisation). Primary biodegradation was also rapid for PBDPP, but 60% mineralisation was not achieved within the time of the test, suggesting that transformation products of PBDPP may accumulate. Primary degradation of BPA-BDPP was very slow and very low CO2 production was also observed. Based on these results, TPHP and to a lesser extent PBDPP appear to be suitable replacements for the more environmentally persistent brominated flame retardants.

AimsTo discuss the need to develop ethical guidelines for researchers using sewage epidemiology to monitor drug use in the general population and specific precincts, including prisons, schools and workplaces.MethodDescribe current applications of sewage epidemiology, identify potential ethical risks associated with this science, and identify key means by which these risks may be mitigated through proportionate ethical guidance that allows this science to be fully developed.ResultsA rapidly advancing field of research is sewage epidemiology (SE) — the analysis of wastewater samples to monitor illicit drug use and other substances. Typically this research involves low ethical risks because individual participants cannot be identified and, consequently, review has been waived by human research ethics committees. In the absence of such oversight, ethical research guidelines are recommended for SE teams, peer reviewers and journal editors; guidelines will assist them to mitigate any risks in general population studies and studies of prisons, schools and workplaces. Potential harms include the stigmatisation of participants and, in the prison setting, austere policy responses to SE data that impact negatively upon inmate-participants. The risk of harm can be managed through research planning, awareness of the socio-political context in which results will be interpreted (or, in the case of media, sensationalised) and careful relations with industry partners. Ethical guidelines should be developed in consultation with SE scholars and be periodically amended. They should include publication processes that safeguard scientific rigour and be promulgated through existing research governance structures.ConclusionsGuidelines will assist to promote an ethical research culture among SE teams and scholars involved in the publication process and this will work to protect the reputation of the field.

In oktober 2012 beschreef Jan van Mourik in Geografie hoe de ‘mythe van de heideplag’ ontmaskerd werd door archiefonderzoek en nieuwe luminescentiedatering. De allernieuwste techniek met biomarkers maakt het mogelijk nog preciezer te bepalen hoe de boeren op de arme zandgronden aan hun stalmest kwamen.

The combination of in vitro bioassays and chemical screening can provide a powerful toolbox to determine biologically relevant compounds in water extracts. In this study, a sample preparation method is evaluated for the suitability for both chemical analysis and in vitro bioassays. A set of 39 chemicals were spiked to surface water, which were extracted using Oasis MCX cartridges. The extracts were chemically analyzed by liquid chromatography linear ion trap Orbitrap analysis and recoveries appeared to be on average 61% Compounds with log Kow values in the range between 0 and 4 are recovered well using this method. In a next step, the same extracts were tested for genotoxic activity using the Comet assay and Ames fluctuation test and for specific endocrine receptor activation using a panel of CALUX assays, for estrogenic (ER), androgenic (AR), glucocorticoid (GR), progestagenic (PR), and thyroidogenic (TR) agonistic activities. The results of the genotoxicity assays indicated that spiked genotoxic compounds were preserved during sample preparation. The measured responses of the GR CALUX and ER CALUX assays were similar to the predicted responses. The measured responses in the AR CALUX and PR CALUX assays were much lower than expected from the analytical concentration, probably due to antagonistic effects of some spiked compounds. Overall, the presented sample preparation method seems to be suitable for both chemical analysis and specific in vitro bioassay applications.

The efficiency of water treatment systems in removing emerging (chemical) substances is often unknown. Consequently, the prediction of the removal of contaminants in the treatment and supply chain of drinking water is of great interest. By collecting and processing existing chemical properties of contaminants, QSARs (quantitative structure-activity relationships) for typical removal parameters can be constructed. Depending on the definition of the predicted endpoint, QSARs are (1) embedded in a process model suite, where they serve to predict a model parameter and the total, hybrid model predicts a removal rate or (2) used to directly predict, e.g., the removal rate, or a rejection coefficient for membrane systems. The different types of resulting prediction models, ranging from mechanistic (causal) to empirical (data-based), allow for hypothesis testing of current physico-chemical mechanisms and interactions between the contaminant, the type of water and the materials or energy (e.g. UV light) of the removal barrier. Two case studies illustrate this viewpoint and also pinpoint that, firstly, QSAR development, validation and residual analysis stress the linkage between the QSAR endpoints and process model predictions, and secondly, they lay bare the need to share data, algorithms and models.

Background and aimsWe studied the response of lignin oxidation in soils of a beech/oak forest to changes in litter fall. Additionally we considered possible factors in lignin oxidation, including altered (i) input of fresh organic matter and (ii) fungi-to-bacteria ratios.MethodsThe field-based experiment included (i) doubling and (ii) exclusion of litter fall and (iii) controls with ambient litter fall. Soil (0-20 cm depth) was sampled after 8 years. We analyzed (i) lignin using the CuO oxidation method, (ii) stocks of free and mineral-bound organic carbon (OC), (iii) the response of soil organic matter (SOM) decomposition to addition of labile organic compounds in laboratory incubations, and (iv) ratios of fungal- vs. bacterial-derived amino sugars (F/B ratios).ResultsLitter exclusion increased stocks of free-light fraction OC, F/B ratios, the ability of the microbial community to use labile compounds for SOM decomposition, as well as acid-to-aldehyde ratios of vanillyl-type lignin phenols in A horizons. Litter addition had no such effects. We assume that litter exclusion caused enhanced transport of organic debris from lower forest floor horizons with rainwater into the A horizon. Enhanced input of organic debris might have increased (i) the availability of labile compounds and (ii) F/B ratios. Consequently, lignin oxidation increased.ConclusionsEnhanced input of organic debris from forest floors can increase lignin oxidation in mineral topsoils of the studied forest. The expected gradual changes in litter fall due to climate change likely will cause no such effects.

This work illustrates the potential of liquid chromatography coupled to a hybrid linear ion trap Fourier Transform Orbitrap mass spectrometer for the simultaneous identification and quantification of 24 drugs of abuse and relevant metabolites in sewage water. The developed methodology consisted of automatic solid-phase extraction using Oasis HLB cartridges, chromatographic separation of the targeted drugs, full-scan accurate mass data acquisition under positive electrospray ionization mode over an m/z range of 50-600 Da at a resolution of 30,000 FWHM and simultaneous MSn measurements to obtain information of fragment ions generated in the linear ion trap. Accurate mass of the protonated molecule, together with at least one nominal mass product ion and retention time allowed the confident identification of the compounds detected in these complex matrices. In addition to the highly reliable qualitative analysis, Orbitrap analyzer also proved to have satisfactory potential for quantification at sub-ppb analyte levels, a possibility that has been very little explored in the literature until now. The limits of quantification ranged from 4 to 68 ng L−1 in influent sewage water, and from 2 to 35 ng L−1 in effluent, with the exception of MDA, morphine and THC that presented higher values as a consequence of the high ionization suppression in this type of samples. Satisfactory recoveries (70-120%) and precision (

Erosion and deposition processes in badland areas are usually estimated using traditional observations of topographic changes, measured by erosion pins or profile metres (invasive techniques). In recent times, remote-sensing techniques (non-invasive) have been routinely applied in geomorphology studies, especially in erosion studies. These techniques provide the opportunity to build high-resolution topographic models at centimetre accuracy. By comparing different 3-D point clouds of the same area, obtained at different time intervals, the variations in the terrain and temporal dynamics can be analysed. The aim of this study is to assess and compare the functioning of terrestrial laser scanner (TLS, RIEGL LPM-321) and structure-from-motion photogrammetry (SfM) techniques (Camera FUJIFILM, Finepix x100 and software PhotoScan by AgiSoft) to evaluate erosion and deposition processes in two opposite slopes in a humid badlands area in the central Spanish Pyrenees. Results showed that TLS data sets and SfM photogrammetry techniques provide new opportunities in geomorphological erosion studies. The data we recorded over 1 year demonstrated that north-facing slopes experienced more intense and faster changing geomorphological dynamics than south-facing slopes as well as the highest erosion rates. Different seasonal processes were observed, with the highest topographic differences observed during winter periods and the high-intensity rainfalls in summer. While TLS provided the highest accuracy models, SfM photogrammetry was still a faster methodology in the field and precise at short distances. Both techniques present advantages and disadvantages, and do not require direct contact with the soil and thus prevent the usual surface disturbance of traditional and invasive methods.

The effects of afforestation on water resources are still controversial. The aim of this paper is to (i) analyze the hydrological response of an afforested area in the Central Pyrenees, and (ii) compare the hydrological response of an afforested area with the response observed in a natural undisturbed forest. The Araguás catchment was cultivated until the 1950s, and then afforested with pines in an effort to control the active degradation processes. The hydrological response was variable and complex, because the discharge was generated by a combination of distinct runoff processes. The hydrological response showed that: (i) afforestation produced moderate peak discharges, stormflows and recession limbs, and long rising limbs; (ii) no one single variable was able to explain the hydrological response: rainfall volume and intensity did not explain the hydrological response and antecedent rainfall and initial discharge (indicating antecedent moisture conditions) did play an important role, (iii) seasonal differences were observed suggesting different runoff generating processes, and (iv) the effect of forest cover on peak discharges became less important as the size of the hydrological event increased. The stormflow coefficient showed a clear seasonal pattern with an alternation between a wet period, when the catchment was hydrologically responsive, and a dry summer period when the catchment rarely responded to any event, and two transitional periods (wetting and drying). Compared to a natural forest, the afforested area recorded greater flows and peak discharges, faster response times and shorter recession limbs. Afforestation reduces the water yield and the number of floods compared to non-vegetated areas and abandoned lands.

As engineered nanoparticles of zinc oxide, titanium dioxide and silver, are increasingly used in consumer products, they will most probably enter the natural environment via wastewater, atmospheric deposition and other routes. The aim of this study is to predict the concentrations of these nanoparticles via wastewater emissions in a typical river system by means of a numerical model. The calculations rely on estimates of the use of nanomaterials in consumer products and the removal efficiency in wastewater treatment plants as well as model calculations of the fate and transport of nanoparticles in a riverine system. The river Rhine was chosen for this work as it is one of the major and best studied rivers in Europe. The study gives insight in the concentrations that can be expected and, by comparing the model results with measurements of the total metal concentrations, of the relative contribution of these emerging contaminants.Six scenarios were examined. Two scenarios concerned the total emission: in the first it was assumed that nanoparticles are only released via wastewater (treated or untreated) and in the second it was assumed that in addition nanoparticles can enter the river system via runoff from the application of sludge as a fertilizer. In both cases the assumption was that the nanoparticles enter the river system as free, unattached particles. Four additional scenarios, based on the total emissions from the second scenario, were examined to highlight the consequences of the assumption of free nanoparticles and the uncertainties about the aggregation processes.If all nanoparticles enter as free particles, roughly a third would end up attached to suspended particulate matter due to the aggregation processes nanoparticles are subject to. For the other scenarios the contribution varies from 20 to 45%. Since the Rhine is a fast flowing river, sedimentation is unlikely to occur, except at the floodplains and the lakes in the downstream regions, as in fact shown by the sediment mass balance. Nanoparticles will therefore be transported along the whole river until they enter the North Sea.For the first scenario, the concentrations predicted for zinc oxide and titanium dioxide nanoparticles are in the order of 0.5 μg/l, for silver nanoparticles in the order of 5 ng/l. For zinc and titanium compounds this amounts to 5-10% of the measured total metal concentrations, for silver to 2%. For the other scenarios, the predicted nanoparticle concentrations are two to three times higher.While there are still considerable uncertainties in the inputs and consequently the model results, this study predicts that nanoparticles are capable of being transported over long distances, in much the same way as suspended particulate matter.

Besides many benefits, nanotechnology brings us a new type of contaminant to worry about: nanoparticles - particles smaller than 100 nm. Silver nanoparticles are used in medical textile, because they kill bacteria. Titanium dioxide and zinc oxide nanoparticles are used as UV filters in sunscreens, and in wastewater treatment to break down organic micropollutants.However, the properties that make them useful in personal care products and water treatment, may make them harmful for organisms in the aquatic environment. Modeling the release and the subsequent transport helps to understand the risks posed by the use of nanoparticles now and in the future. This was applied to the river Rhine. First, the release of nanoparticles from consumer products was estimated using literature data. Then a mathematical model for the fate of nanoparticles in the aquatic environment was set up, based on data and input parameters collected from published laboratory experiments. This knowledge together with information concerning the hydrology of the Rhine and the wastewater treatment plants in the Rhine basin was used to predict the nanoparticle concentrations under various release scenarios. The model results suggest that nanoparticles are mostly attached to suspended matter – so-called heteroaggregation being the most important process. Therefore they are transported along with suspended matter and will settle in the sediment if the circumstances allow. To examine the environmental risk of nanoparticles one needs to be able to estimate the release of nanoparticles but also to understand the behaviour of suspended matter.

Volcanic ash soil contains large stocks of organic matter per unit area. A large proportion of organic matter is stored in the subsoil; therefore, a thorough understanding of its vertical distribution is needed to predict the effects of change in climate and land use. Faunal bioturbation is often cited as the dominant process that affects the vertical distribution of organic matter. An additional but often overlooked process is change in the volume of the soil. Such change might affect the vertical distribution of organic matter by changing the position of the soil surface, which can affect the soil-forming processes related to depth, such as weathering, decomposition, bioturbation and rooting. We calculated the change in volume with geochemical mass balance equations, and showed the effect of change in soil volume on the vertical distribution of organic matter using a dynamic model. Then we evaluated the plausibility of the model concept with an independent model for parameter identification and through a model sensitivity analysis. Results show that volume change is a major soil-forming process that determines the vertical distribution of organic matter in volcanic ash soil as the active bioturbation zone moves upwards in response to soil thickening.

© 2016, National Academy of Sciences. All rights reserved. The respiratory release of carbon dioxide (CO2) from soil is a major yet poorly understood flux in the global carbon cycle. Climatic warming is hypothesized to increase rates of soil respiration, potentially fueling further increases in global temperatures. However, despite considerable scientific attention in recent decades, the overall response of soil respiration to anticipated climatic warming remains unclear. We synthesize the largest global dataset to date of soil respiration, moisture, and temperature measurements, totaling >3,800 observations representing 27 temperature manipulation studies, spanning nine biomes and over 2 decades of warming. Our analysis reveals no significant differences in the temperature sensitivity of soil respiration between control and warmed plots in all biomes, with the exception of deserts and boreal forests. Thus, our data provide limited evidence of acclimation of soil respiration to experimental warming in several major biome types, contrary to the results from multiple single-site studies. Moreover, across all nondesert biomes, respiration rates with and without experimental warming follow a Gaussian response, increasing with soil temperature up to a threshold of ∼25 °C, above which respiration rates decrease with further increases in temperature. This consistent decrease in temperature sensitivity at higher temperatures demonstrates that rising global temperatures may result in regionally variable responses in soil respiration, with colder climates being considerably more responsive to increased ambient temperatures compared with warmer regions. Our analysis adds a unique cross-biome perspective on the temperature response of soil respiration, information critical to improving our mechanistic understanding of how soil carbon dynamics change with climatic warming.

The aim of this revision was to build an updated collection of information focused on the mechanisms and elements involved in metabolic pathways of aromatic hydrocarbons by bacteria. Enzymes as an expression of the genetic load and the type of electron acceptor available, as an environmental factor, were highlighted. In general, the review showed that both aerobic routes and anaerobic routes for the degradation of aromatic hydrocarbons are divided into two pathways. The first, named the upper pathways, from the original compound to central intermediate compounds still containing the aromatic ring but with the benzene nucleus chemically destabilized. The second, named the lower pathway, begins with ring de-aromatização and subsequent cleavage, resulting in metabolites that can be used by bacteria in the production of biomass. Under anaerobic conditions the five mechanisms of activation of the benzene ring described show the diversity of chemical reactions that take place. Obtaining carbon and energy from an aromatic hydrocarbon molecule is a process that exhibits the high complexity level of the metabolic apparatus of anaerobic microorganisms. The ability of these bacteria to express enzymes that catalyze reactions, known only in non-biological conditions, using final electron acceptors with a low redox potential, is a most interesting topic. The discovery of phylogenetic and functional characteristics of cultivable and non-cultivable hydrocarbon degrading bacteria has been made possible by improvements in molecular research techniques such as SIP (stable isotope probing) making trace of 13C, 15N and 18O into nucleic acids and proteins.

In this forum paper we discuss how soil scientists can help to reach the recently adopted UN Sustainable Development Goals (SDGs) in the most effective manner. Soil science, as a land-related discipline, has important links to several of the SDGs, which are demonstrated through the functions of soils and the ecosystem services that are linked to those functions (see graphical abstract in the Supplement). We explore and discuss how soil scientists can rise to the challenge both internally, in terms of our procedures and practices, and externally, in terms of our relations with colleague scientists in other disciplines, diverse groups of stakeholders and the policy arena. To meet these goals we recommend the following steps to be taken by the soil science community as a whole: (i) embrace the UN SDGs, as they provide a platform that allows soil science to demonstrate its relevance for realizing a sustainable society by 2030; (ii) show the specific value of soil science: research should explicitly show how using modern soil information can improve the results of inter- and transdisciplinary studies on SDGs related to food security, water scarcity, climate change, biodiversity loss and health threats; (iii) take leadership in overarching system analysis of ecosystems, as soils and soil scientists have an integrated nature and this places soil scientists in a unique position; (iii) raise awareness of soil organic matter as a key attribute of soils to illustrate its importance for soil functions and ecosystem services; (iv) improve the transfer of knowledge through knowledge brokers with a soil background; (v) start at the basis: educational programmes are needed at all levels, starting in primary schools, and emphasizing practical, down-to-earth examples; (vi) facilitate communication with the policy arena by framing research in terms that resonate with politicians in terms of the policy cycle or by considering drivers, pressures and responses affecting impacts of land use change; and finally (vii) all this is only possible if researchers, with soil scientists in the front lines, look over the hedge towards other disciplines, to the world at large and to the policy arena, reaching over to listen first, as a basis for genuine collaboration.

The main aim of this study was to investigate the potential of using clay minerals abundant in local soils in Egypt as low cost materials to reduce Cu, Ni and Zn pollution of soil and groundwater originating from polluted wastewater; specifically focusing on the influence of the interaction of clay minerals and heavy metals with OM already present in the soil, or in the wastewater itself. To achieve this aim, the following specific objectives were formulated: • To identify and characterize the different clay mineral types in the context of their application in local wastewater treatment in Egypt. • To investigate the influence of the presence of DOM and the timing of its application (before or concurrently with the HMs) on the mobility of Cu, Ni and Zn in clay-rich deposits using a static batch approach. • To unravel the effect of the timing of the addition of DOM on the competitive adsorption of Cu, Ni and Zn onto different sorbent compositions in a kinetic system using a dynamic column approach. • To investigate the role of the presence and timing of addition of DOM during loading of clay mineral-based wastewater treatment columns on the subsequent removal of the HMs from the columns, focusing both on regenerating clay minerals used in wastewater treatment, and (re)mobilization of HMs previously immobilized in clay rich soils.

Background and aims Environmental factors such as climate and atmospheric CO2 control inputs of plant-derived matter into soils, which then determines properties and decomposition of soil organic matter. We studied how dissolved organic matter (DOM) in forest floors responded to six years of litter fall manipulation at a spruce site. Methods Experimental treatments included (i) ambient litter fall, as well as (ii) reduction or (iii) increase of litter fall, each by 80%. Results Reduced litter input did not change fluxes of dissolved organic carbon (DOC), which suggests that much of the mobile DOM in forest floors is not from recent litter but older, partly degraded material. Litter addition increased DOC fluxes over 6 years by 68% (Oi), 23% (Oe) and 12% (Oa). This was mainly due to excessive DOM production in Oi horizons, while net DOM production in Oe and Oa horizons decreased. Upon litter addition, aromaticity and molecule complexity of DOM released from the Oi horizon increased, but decreased for DOM leaving Oa horizons. The results suggest that DOM production by lignin degradation was enhanced in Oi but reduced in Oe and Oa horizons upon litter addition. Conclusions Recent litter is not an important source for DOM entering mineral soils, but increased litter input changes organic matter decomposition, thus affecting fluxes and properties of DOM within forest floors.

A wide variety of environmental compounds of concern, e.g. pharmaceuticals or illicit drugs, are acids or bases that may predominantly be present as charged species in drinking water sources. These charged micropollutants may prove difficult to remove by currently used water treatment steps (e.g. UV/H2O2, activated carbon (AC) or membranes). We studied the sorption affinity of some ionic organic compounds to both AC and different charged polymeric materials. Ion-exchange polymers may be effective as additional extraction phases in water treatment, because sorption of all charged compounds to oppositely charged polymers was stronger than to AC, especially for the double-charged cation metformin. Tested below 1% of the polymer ion-exchange capacity, the sorption affinity of charged micropollutants is nonlinear and depends on the composition of the aqueous medium. Whereas oppositely charged electrolytes do not impact sorption of organic ions, equally charged electrolytes do influence sorption indicating ion-exchange (IE) to be the main sorption mechanism. For the tested polymers, a tenfold increased salt concentration lowered the IE-sorption affinity by a factor two. Different electrolytes affect IE with organic ions in a similar way as inorganic ions on IE-resins, and no clear differences in this trend were observed between the sulphonated and the carboxylated cation-exchanger. Sorption of organic cations is five fold less in Ca2+ solutions compared to similar concentrations of Na+, while that of anionic compounds is three fold weaker in SO42- solutions compared to equal concentrations of Cl-. (C) 2012 Elsevier Ltd. All rights reserved.

Environmental contextPerfluorinated compounds are synthetic chemicals shown to be present in the blood of humans. To study how these contaminants get into our blood requires a good understanding of their physicochemical properties. We describe an alternative way to obtain values for how perfluorinated compounds distribute between water and fatty phases (mimicking e.g. gut content and gut wall), which is essential information for modelling and understanding the environmental fate of these chemicals. AbstractCapacity factors of perfluorinated alkylated substances were obtained from isocratic reversed-phase high-performance liquid chromatography–mass spectrometry experiments at different organic modifier strengths of the mobile phase. The resulting capacity factor v. modifier strengths plots were extrapolated to obtain capacity factors at 100% water (k0) that can serve as indicators of the hydrophobicity of the perfluorinated acids. Values of log k0 were shown to increase linearly with the number of CF2 units in the fluorinated alkyl chain.

Effects of anthropogenic nitrogen (N) deposition and the ability of terrestrial ecosystems to store carbon (C) depend in part on the amount of N retained in the system and its partitioning among plant and soil pools. We conducted a meta-analysis of studies at 48 sites across four continents that used enriched 15N isotope tracers in order to synthesize information about total ecosystem N retention (i.e., total ecosystem 15N recovery in plant and soil pools) across natural systems and N partitioning among ecosystem pools. The greatest recoveries of ecosystem 15N tracer occurred in shrublands (mean, 89.5%) and wetlands (84.8%) followed by forests (74.9%) and grasslands (51.8%). In the short term (< 1 week after 15N tracer application), total ecosystem 15N recovery was negatively correlated with fine-root and soil 15N natural abundance, and organic soil C and N concentration but was positively correlated with mean annual temperature and mineral soil C:N. In the longer term (3-18 months after 15N tracer application), total ecosystem 15N retention was negatively correlated with foliar natural-abundance 15N but was positively correlated with mineral soil C and N concentration and C:N, showing that plant and soil natural-abundance 15N and soil C:N are good indicators of total ecosystem N retention. Foliar N concentration was not significantly related to ecosystem 15N tracer recovery, suggesting that plant N status is not a good predictor of total ecosystem N retention. Because the largest ecosystem sinks for 15N tracer were below ground in forests, shrublands, and grasslands, we conclude that growth enhancement and potential for increased C storage in aboveground biomass from atmospheric N deposition is likely to be modest in these ecosystems. Total ecosystem 15N recovery decreased with N fertilization, with an apparent threshold fertilization rate of 46 kg N x ha(-1) x yr(-1) above which most ecosystems showed net losses of applied 15N tracer in response to N fertilizer addition.

During the last decade, compound-specific hydrogen isotope analysis of plant leaf-wax and sedimentary n -alkyl lipids has become a promising tool for paleohydrological reconstructions. However, with the exception of several previous studies, there is a lack of knowledge regarding possible effects of early diagenesis on the δD values of n -alkanes. We therefore investigated the n -alkane patterns and δD values of long-chain n -alkanes from three different C3 higher plant species ( Acer pseudoplatanus L., Fagus sylvatica L. and Sorbus aucuparia L.) that have been degraded in a field leaf litterbag experiment for 27 months. We found that after an initial increase of long-chain n -alkane masses (up to ∼50%), decomposition took place with mean turnover times of 11.7 months. Intermittently, the masses of mid-chain n -alkanes increased significantly during periods of highest total mass losses. Furthermore, initially high odd-over-even predominances (OEP) declined and long-chain n -alkane ratios like n -C 31 /C 27 and n -C 31 /C 29 started to converge to the value of 1. While bulk leaf litter became systematically D-enriched especially during summer seasons (by ∼8‰ on average over 27 months), the δD values of long-chain n -alkanes reveal no systematic overall shifts, but seasonal variations of up to 25‰ ( Fagus , n -C 27 , average ∼13‰). Although a partly contribution by leaf-wax n -alkanes by throughfall cannot be excluded, these findings suggest that a microbial n- alkane pool sensitive to seasonal variations of soil water δD rapidly builds up. We propose a conceptual model based on an isotope mass balance calculation that accounts for the decomposition of plant-derived n -alkanes and the build-up of microbial n -alkanes. Model results are in good agreement with measured n -alkane δD results. Since microbial ‘contamination’ is not necessarily discernible from n -alkane concentration patterns alone, care may have to be taken not to over-interpret δD values of sedimentary n -alkanes. Furthermore, since leaf-water is generally D-enriched compared to soil and lake waters, soil and water microbial n -alkane pools may help explain why soil and sediment n -alkanes are D-depleted compared to leaves.

Lignin is a main component of plant litter. Its degradation is thought to be critical for litter decomposition rates and the build-up of soil organic matter. We studied the relationships between lignin degradation and the production of dissolved organic carbon (DOC) and of CO2 during litter decomposition. Needle or leaf litter of five species (Norway spruce, Scots pine, mountain ash, European beech, sycamore maple) and of different decomposition stage (freshly fallen and up to 27 months of field exposure) was incubated in the laboratory for two years. Lignin degradation was followed with the CuO method. Strong lignin degradation occurred during the first 200 incubation days, as revealed by decreasing yields of lignin-derived phenols. Thereafter lignin degradation leveled off. This pattern was similar for fresh and decomposed litter, and it stands in contrast to the common view of limited lignin degradation in fresh litter. Dissolved organic carbon and CO2 also peaked in thefirst period of the incubation but were not interrelated. In the later phase of incubation, CO2 production was positively correlated with DOC amounts, suggesting that bioavailable, soluble compounds became a limiting factor for CO2 production. Lignin degradation occurred only when CO2 production was high, and not limited by bioavailable carbon. Thus carbon availability was the most important control on lignin degradation. In turn, lignin degradation could not explain differences in DOC and CO2 production over the study period. Our results challenge the traditional view regarding the fate and role of lignin during litter decomposition. Lignin degradation is controlled by the availability of easily decomposable carbon sources. Consequently, it occurs particularly in the initial phase of litter decomposition and is hampered at later stages if easily decomposable resources decline.

The primary aim of this article is to provide an overview of perfluoroalkyl and polyfluoroalkyl substances (PFASs) detected in the environment, wildlife, and humans, and recommend clear, specific, and descriptive terminology, names, and acronyms for PFASs. The overarching objective is to unify and harmonize communication on PFASs by offering terminology for use by the global scientific, regulatory, and industrial communities. A particular emphasis is placed on long-chain perfluoroalkyl acids, substances related to the long-chain perfluoroalkyl acids, and substances intended as alternatives to the use of the long-chain perfluoroalkyl acids or their precursors. First, we define PFASs, classify them into various families, and recommend a pragmatic set of common names and acronyms for both the families and their individual members. Terminology related to fluorinated polymers is an important aspect of our classification. Second, we provide a brief description of the 2 main production processes, electrochemical fluorination and telomerization, used for introducing perfluoroalkyl moieties into organic compounds, and we specify the types of byproducts (isomers and homologues) likely to arise in these processes. Third, we show how the principal families of PFASs are interrelated as industrial, environmental, or metabolic precursors or transformation products of one another. We pay particular attention to those PFASs that have the potential to be converted, by abiotic or biotic environmental processes or by human metabolism, into long-chain perfluoroalkyl carboxylic or sulfonic acids, which are currently the focus of regulatory action. The Supplemental Data lists 42 families and subfamilies of PFASs and 268 selected individual compounds, providing recommended names and acronyms, and structural formulas, as well as Chemical Abstracts Service registry numbers. Integr Environ Assess Manag 2011;7:513–541. © 2011 SETAC

The effect of salinity induced by CaCl2, MgCl2, NaCl and Na2SO4 on the mobility of Cu, Cd, Pb and Zn was studied. An increase of ionic strength by any salts promoted a higher release of Cd than the others metals. When CaCl2 and NaCl were applied, Cd and Pb showed the highest degree of mobilization. When MgCl2 was applied, Cd and Cu were mobilized the most. Finally, an increase of Na2SO4 also promoted the strongest mobilization of Cd and Cu.As the total heavy metal content was higher, the percentage of Pb and Cu released upon salinization decreased, indicating that these metals are strongly bound to soil constituents. An increase of carbonates in the soil promoted a higher release of Pb for all used salts and for Zn when MgCl2 and NaCl were used. This indicates that Pb and Zn are adsorbed on the surface of carbonate crystals. An increase of fine particles promoted a decrease of percentage of released Cd for all salts, indicating that Cd is strongly retained in the fine fractions.The main mechanism regulating Pb and Cd mobility was competition with Ca2+ for sorption sites followed for metal chloro-complexation, association between the Cd/Pb-sulfates and competition with Mg2+. The main mechanism regulating Cu mobility was the formation of Cu-sulfate, followed by competition with cations (Mg > Ca) and chloride. For Zn, competition with Ca2+ for sorption sites was the most important process for its mobility; followed by Zn-sulfate association and, finally, chloride and competition with Mg with the same effect.

Differences in molecular properties between linear and branched alkanes as well as between compounds with branched alkyl groups is of relevance due to the large number of branched isomers of environmentally relevant compounds (e.g. fuels, fuel additives, surfactants). For branched alkane vapor pressures, the McGowan specific volume is a poor predictor. Therefore, in this study a correction on the McGowan specific volume is derived in terms of the number of branches and the number of pairs of vicinal branches to improve the prediction of branched alkane vapor pressures. This branching correction also brought branched /alkane solvent accessible volumes, octanol/water partition coefficients, air/hexadecane partition coefficients, and aqueous solubilities as well as alkyl-branched substituted aliphatic hydrocarbon air/hexadecane partition coefficients more in line with corresponding linear hydrocarbon properties when compared on a McGowan specific volume basis. Even for air–hexadecane partition coefficients of substituted aliphatic hydrocarbons with substituents at non-terminal carbons, application of the branching correction to the carbon bearing the substituent caused these partition coefficients to be more in line with those for linear compounds. Values for the Abraham A and B solvation parameters for nonlinear aliphatic ethers, amines, and alcohols, recalculated using branching corrected McGowan specific volumes, turned out to be closer to chemical expectations based on linear aliphatic ether, amine and alcohol values compared to previously reported experimental values obtained using uncorrected McGowan specific volumes. A comparison of alkylbenzene and alkene partition coefficient estimates from two different linear solvation energy relations, one containing a McGowan specific volume term and one without such a term, suggests that no branching correction is needed for alkyl groups at sp2 carbons. The main advantage of using branching corrected McGowan specific volumes is that the values of other solvation parameters become chemically more consistent.

Extracellular polymeric substances (EPS) are continuously produced by bacteria during their growth and metabolism. In soils, EPS are bound to cell surfaces, associated with biofilms, or released into solution where they can react with other solutes and soil particle surfaces. If such reaction results in a decrease in EPS bioaccessibility, it may contribute to stabilization of microbial-derived organic carbon (OC) in soil. Here we examined: (i) the chemical fractionation of EPS produced by a common Gram positive soil bacterial strain (Bacillus subtilis) during reaction with dissolved and colloidal Al species and (ii) the resulting stabilization against desorption and microbial decay by the respective coprecipitation (with dissolved Al) and adsorption (with Al(OH)3(am)) processes. Coprecipitates and adsorption complexes obtained following EPS-Al reaction as a function of pH and ionic strength were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The stability of adsorbed and coprecipitated EPS against biodegradation was assessed by mineralizationexperiments for 1100 h. Up to 60% of the initial 100 mg/L EPS-C was adsorbed at the highest initial molar Al:C ratio (1.86), but this still resulted only in a moderate OC mass fraction in the solid phase (17 mg/g Al(OH)3(am)). In contrast, while coprecipitation by Al was less efficient in removing EPS from solution (maximum values of 33% at molar Al:C ratios of 0.1-0.2), the OC mass fraction in the solid product was substantially larger than that in adsorption complexes. Organic Pcompounds were preferentially bound during both adsorption and coprecipitation. Data are consistent with strong ligand exchange of EPS phosphoryl groups during adsorption to Al(OH)3(am), whereas for coprecipitation weaker sorption mechanismsare also involved. X-ray photoelectron analyses indicate an intimate mixing of EPS with Al in the coprecipitates, which is not observed in the case of EPS adsorption complexes. The incubation experiments showed that both processes result in overall stabilization of EPS against microbial decay. Stabilization of adsorbed or coprecipitated EPS increased with increasing molar Al:C ratio and biodegradation was correlated with EPS desorption, implying that detachment of EPS from surface sites is a prerequisite for microbial utilization. Results indicate that the mechanisms transferring EPS into Al-organic associations may significantly affect the composition and stability of biomolecular C, N and P in soils. The observed efficient stabilization of EPS might explain the strong microbial character of organic matter in subsoils.