The objective of the present study was to investigate the short-term effects of benzo(a)pyrene (BaP) on juvenile sea bass (Dicentrarchus labrax L.) using a multiparameter approach. At the end of the 96 h of exposure to a range of BaP concentrations (2–256 μg l⁻¹) in laboratorial conditions, a suite of biomarkers involved in biotransformation pathways, oxidative stress and damage, neurotransmission and energetic metabolism were analysed. Levels of BaP metabolites in bile and BaP-type compounds in tissues were also included as biomarkers of exposure, and the post-exposure swimming velocity was used as a toxicity endpoint at a higher level of biological organisation. In addition, a time-series experiment on the levels of bile BaP metabolites was also performed. Increased levels of BaP metabolites in bile and BaP-type compounds in liver and brain of exposed fish were found, indicating BaP uptake, metabolisation and distribution by different tissues. BaP induced oxidative stress and damage, but no significant effects on the post-exposure swimming velocity, neurotransmission and energetic pathways were found. An increase in the levels of BaP metabolites in bile over time was also observed, reaching a threshold similar at all the concentrations tested. Overall, this integrative multiparameter study reflecting different biological responses of D. labrax was suitable to assess the effects caused by the short-term exposure to BaP and may be useful in the marine environmental risk assessment of polycyclic aromatic hydrocarbons pollution. The observed toxic effects also highlight the relevance of short-term exposure to relatively high concentrations of chemicals, as can occur in the case of punctual heavy chemical releases, such as oil spills in the marine environment.

This study focuses on a detailed analysis of the errors introduced by two quasi-analytical approaches based on either Fick’s first law or a combination of Fick’s and Darcy’s laws to evaluate the vapour flux of chlorinated solvents from a source zone located in the unsaturated zone towards the atmosphere. A coupled one-dimensional numerical flow and transport model was developed and applied to three case studies characterised by different water content profiles in the vadose zone and under different levels of maximum dense nonaqueous-phase liquid vapour concentrations and vapour pressure conditions of the source zone. The steady-state concentration and pressure profiles obtained were then used in the two quasi-analytical approaches to estimate the flux towards the atmosphere. When mass fluxes due to density-driven advection become dominant and the vertical advective mass fluxes are increased due to strong pressure gradients in the soil air, the error was observed to increase when using the pure diffusion approach in the quantification of the surface flux calculated by the numerical model with increasing dimensionless Rayleigh numbers. Without taking into account the advective transport in the approach, the relative error calculated with only Fick’s law overestimates the real vapour flux when density-driven advection is dominant and underestimates it when pressure-gradient-driven advection dominates. The more advanced advective–diffusive quasi-analytical approach fits reasonably well with the numerically obtained mass fluxes except near soil layer discontinuities, where the evaluation of both the concentration gradient and pressure gradient in the porous media as well as the determination of the average effective diffusion coefficients are rendered more difficult.

In order to observe the variation in land use changes, satellite images from the Landsat Thematic Mapper (TM) and the Enhanced Thematic Mapper (ETM) for 1991, 2000, 2005, and 2008 were used to compare the differences between selected water quality parameters, including heavy metal (Cd, Pb, and Zn) content in both water and green mussels or Perna viridis (Linnaeus.) before and after the increase in land use activities beginning from 2006. The samples were collected at 11 points for water and 4 points for green mussels between the Second Link and the Causeway Link at the Johor Strait in 2009 and were analyzed for pH, temperature degrees Celsius), dissolved oxygen, ammoniacal nitrogen, and heavy metal (Cd, Pb, and Zn) content.

A contamination by petroleum hydrocarbons was detected in a sandy aquifer below a petrochemical plant in Southern Italy. The site is located near the coastline and bordered by canals which, together with pumping wells, control submarine groundwater discharge toward the sea and seawater intrusion (SWI) inland. In this study, a three-dimensional flow and transport model was developed using SEAWAT-4.0 to simulate the density-dependent groundwater flow system. Equivalent freshwater heads from 246 piezometers were employed to calibrate the flow simulation, while salinity in 193 piezometers was used to calibrate the conservative transport. A second dissolved species, total petroleum hydrocarbons (TPH), was included in the numerical model to simulate the plumes originating from light non-aqueous-phase liquid. A detailed field investigation was performed in order to determine the fate of dissolved hydrocarbons. Fifteen depth profiles obtained from multilevel samplers (MLS) were used to improve the conceptual model, originally built using a standard monitoring technique with integrated depth sampling (IDS) of salinity and TPH concentrations. The calibrated simulation emphasises that density-dependent flow has a great influence on the migration pattern of the hydrocarbons plume. This study confirms that calibration of density-dependent models in sites affected by SWI can be successfully reached only with MLS data, while standard IDS data can lead to misleading results. Thus, it is recommended to include MLS in the characterization protocols of contaminated sites affected by SWI, in order to properly manage environmental pollution problems of coastal zones.

The objective of this study was to determine the efficiency of a portable total mercury analyzer (OhioLumex RA-915+) in comparison with traditional analytical methods, such as inductively coupled plasma atomic emission spectrometry and cold vapor atomic absorption. The quick mercury analytical procedure with the direct mercury analyzer without sample pretreatment (such as sample digestion) was optimized for a variety of environmental samples, including contaminated soil and plant samples. The efficiency was evaluated using practical parameters, such as time required for analysis, sample amount, mercury species, accuracy, and precision/reproducibility, as well as using statistical analysis. Our results demonstrate that these three instrumental methods yielded similar mercury concentration values and statistical data, while the mercury direct analyzer had the advantages of not requiring for sample digestion and only requiring a small quantity of samples for distribution of mercury in a single root, a single root hair, and sub-regions of a single leaf of plants. These factors are used to justify use of the portable direct mercury analyzer under field conditions and validation of the results.

In this study, the role of Cyperus sp. was evaluated for removal of pollutants from swine wastewater. Vertical-flow pilot scale constructed wetlands (CWs) operating with a hydraulic retention time (HRT) of 72 h were monitored in a greenhouse, located in Viçosa, Brazil. Significant differences were observed for the following parameters: Kjeldahl nitrogen, total phosphorus, alkalinity and electric conductivity, with averages removals of 37.5 and 28.5%, 55.9 and 44.4%, 30.2 and 25.6 and 26.1% and 22.9% (for planted and unplanted CWs, respectively). The rate of dry matter yield from Cyperus sp. was 7.5 g m−2 day−1, and the nutrient uptake capacities were 21.8, 2.1, 14.0 and 0.9 g m−2 of N, P, K and Na, respectively. Evapotranspiration (2.7 mm day−1) was statistically higher in the planted CWs. Plants in the CWs are important for achieving high nutrient removal.

A polyaniline-modified quartz crystal microbalance (QCM) sensor was obtained through immobilizing the polyaniline film on the silver electrode surface of quartz crystal resonator by an electrochemical method. The sensor was studied for detecting the formic acid gas of different concentrations, and the results showed that the resonant frequency of QCM decreased quickly in the beginning and tended to be constant in the end when exposed to formic acid gas. The frequency shifts decreased faster as the concentration of formic acid gas increased. And the frequency shifts of the QCM sensors were found to be linearly related to the concentration of formic acid gas, which might be used to estimate the concentration level of the formic acid gas within the range of experimental concentrations. The result of on-line monitoring test fully indicated that the QCM sensor responded effectively to the increasing concentration of formic acid and had important practical significance and broad application prospect in real-time detection of antique conservation environment in the museum.

Odors, such as the malodorous and toxic hydrogen sulfide (H₂S), are released during leachate collection, storage, and treatment. A full-scale biofilter was applied to treat H₂S emitted from a leachate equalization basin in a sanitary landfill site. The inlet concentration of H₂S was 26.3–213.0 mg m⁻³. In steady state, total removal efficiency was over 90 % in summer and over 80 % in winter. The maximum elimination capacity achieved 9.1 g m⁻³ h⁻¹ at a loading rate of 10.5 g m⁻³ h⁻¹. The biofilter was effective at reducing H₂S. Factors on the level of H₂S inlet concentration and performance of the biofilter were investigated. The H₂S inlet load and removal efficiency relied on ambient and biofilter temperature, respectively. The water containing rate and relative humidity presented seasonal variation, according to which the interval period of irrigation could be optimized. The main product of H₂S degradation was sulfate, and sulfur also could be observed from the biofilter. Spatial and temporal shifts in bacterial community composition in the biofilter were determined by polymerase chain reaction-denaturing gradient gel electrophoresis followed by DNA sequence analysis. The present study revealed a correlation between biofilter performance and bacterial community structure, especially in a real application case.

A batch sorption method was used to study the removal of few toxic metals onto the Late Cretaceous clays of Aleg formation (Coniacian–Lower Campanian system), Tunisia, in single, binary and multi-component systems. The collected clay samples were used as adsorbents for the removal of Pb(II), Cd(II), Cu(II) and Zn(II) from aqueous solutions. Results show that the natural clay samples were mainly composed of silica, alumina, iron and magnesium oxides. N2-adsorption measurements indicated mesoporous materials with modest specific surface area of <71 m2/g. Carbonate minerals were the most influencing parameters for heavy metal removal by natural clays in both single and multi-element systems. The affinity sequence was Pb(II)>Cu(II)>Zn(II)>Cd(II) due to the variable physical properties of the studied metals. The maximum adsorption capacity reached 131.58 mg/g in single systems, but decreased to <50.10 mg/g in mixed systems. In single, binary and muti-element systems, the studied clay samples removed substantial amounts of heavy metals, showing better effectiveness than the relevant previous studies. These results suggest that the studied clay samples of the Late Cretaceous clays from Tunisia can be effectively used as natural adsorbents for the removal of toxic heavy metals in aqueous systems.

Incidental losses of dissolved reactive phosphorus (DRP) to a surface waterbody originate from direct losses during land application of fertilizer, or where a rainfall event occurs immediately thereafter. Another source is the soil. One way of immobilising DRP in runoff before discharge to a surface waterbody, is to amend soil within the edge of field area with a high phosphorus (P) sequestration material. One such amendment is iron ochre, a by-product of acid mine drainage. Batch experiments utilising two grassland soils at two depths (topsoil and sub-soil), six ochre amendment rates (0, 0.15, 1.5, 7.5, 15 and 30 g kg−1 mass per dry weight of soil) and five P concentrations (0, 5, 10, 20 and 40 mg L−1) were carried out. A proportional equation, which incorporated P sources and losses, was developed and used to form a statistical model. Back calculation identified optimal rates of ochre amendment to soil to ameliorate a specific DRP concentration in runoff. Ochre amendment of soils (with no further P inputs) was effective at decreasing DRP concentrations to acceptable levels. A rate of 30 g ochre kg−1 soil was needed to decrease DRP concentrations to acceptable levels for P inputs of ≤10 mg L−1, which represents the vast majority of cases in grassland runoff experiments. However, although very quick and sustained metal release above environmental limits occurred, which makes it unfeasible for use as a soil amendment to control P release to a waterbody, the methodology developed within this paper may be used to test the effectiveness and feasibility of other amendments.