The use of plants and microorganisms to mitigate sediment contaminated by copper was studied in microcosms that mimic the functioning of a stormwater basin (SWB) connected to vineyard watershed. The impact of phytoremediation and bioaugmentation with siderophore-producing bacteria on the fate of Cu was studied in two contrasted (batch vs. semi-continuous) hydraulic regimes. The fate of copper was characterised following its discharge at the outlet of the microcosms, its pore water concentration in the sediment, the assessment of its bioaccessible fraction in the rhizosphere and the measurement of its content in plant tissues. Physico-chemical (pH, redox potential) and biological parameters (total heterotrophic bacteria) were also monitored. As expected, the results showed a clear impact of the hydraulic regime on the redox potential and thus on the pore water concentration of Cu. Copper in pore water was also dependent on the frequency of Cu-polluted water discharges. Repeated bioaugmentation increased the total heterotrophic microflora as well as the Cu bioaccessibility in the rhizosphere and increased the amount of Cu extracted by Phragmites australis by a factor of ~2. Sugar beet pulp, used as a filter to avoid copper flushing, retained 20 % of outcoming Cu and led to an overall retention of Cu higher than 94 % when arranged at the outlet of microcosms. Bioaugmentation clearly improved the phytoextraction rate of Cu in a small-scaled SWB designed to mimic the functioning of a full-size SWB connected to vineyard watershed. HIGHLIGHTS: - Cu phytoextraction in constructed wetlands much depends on the hydraulic regime and on the frequency of Cu-polluted water discharges - Cu phytoextraction increases with time and plant density - Cu bioaccessibility can be increased by bioaugmentation with siderophore-producing bacteria

Systematization of knowledge on nanomaterials has become a necessity with the fast growth of applications of these species. Building up predictive models that describe properties (both beneficial and hazardous) of nanomaterials is vital for computational sciences. Classic quantitative structure– property/activity relationships (QSPR/QSAR) are not suitable for investigating nanomaterials because of the complexity of their molecular architecture. However, some characteristics such as size, concentration, and exposure time can influence endpoints (beneficial or hazardous) related to nanoparticles and they can therefore be involved in building a model. Application of the optimal descriptors calculated with the so-called correlation weights of various concentrations and different exposure times are suggested in order to build up a predictive model for cell membrane damage caused by a series of nano metal-oxides. The numerical data on correlation weights are calculated by the Monte Carlo method. The obtained results are in good agreement with the experimental data.

The goal of this research was to develop a new approach for tertiary water treatment, particularly disinfection and removal of refractory organic compounds, without adding any chemical. Hydrogen peroxide can indeed be produced from dissolved oxygen owing to electrochemical processes. Using various current intensities (1.0 to 4.0 A), it was possible to in situ produce relatively high concentration of H₂O₂with a specific production rate of 0.05 × 10⁻⁵ M/min/A. Likewise, by using ultraviolet-visible absorption spectroscopy method, it was shown that other reactive oxygen species (ROS) including HO*radical and O₃could be simultaneously formed during electrolysis. The ROS concentration passed from 0.45 × 10⁻⁵ M after 20 min of electrolysis to a concentration of 2.87 × 10⁻⁵ M after 100 min of electrolysis. The disinfection and the organic matter removal were relatively high during the tertiary treatment of municipal and domestic wastewaters. More than 90 % of organic compounds (chemical oxygen demand) can be removed, whereas 99 % of faecal coliform abatement can be reached. Likewise, the process was also effective in removing turbidity (more than 90 % of turbidity was removed) so that the effluent became more and more transparent.

It has previously been shown that certain halophytes can grow and produce biomass despite of the contamination of their saline biotopes with toxic metals. This suggests that these plants are able to cope with both salinity and heavy metal constraints. NaCl is well tolerated by halophytes and apparently can modulate their responses to Cd. However, the underlying mechanisms remain unclear. This study explores the impact of NaCl on growth, Cd accumulation, and Cd speciation in tissues of the halophyte Sesuvium portulacastrum. Seedlings of S. portulacastrum were exposed during 1 month to 0, 25, and 50 μM Cd combined with low salinity (LS, 0.09 mM NaCl) or high salinity (HS, 200 mM NaCl) levels. Growth parameters and total tissue Cd concentrations were determined, in leaves, stems, and root. Moreover, Cd speciation in these organs was assessed by specific extraction procedures. Results showed that, at LS, Cd induced chlorosis and necrosis and drastically reduced plant growth. However, addition of 200 mM NaCl to Cd containing medium alleviated significantly Cd toxicity symptoms and restored plant growth. NaCl reduced the concentration of Cd in the shoots; nevertheless, due to maintenance of higher biomass under HS, the quantity of accumulated Cd was not modified. NaCl modified the chemical form of Cd in the tissues by increasing the proportion of Cd bound to pectates, proteins, and chloride suggesting that this change in speciation is involved in the positive impact of NaCl on Cd tolerance. We concluded that the tolerance of S. portulacastrum to Cd was enhanced by NaCl. This effect is rather governed by the modification of the speciation of the accumulated Cd than by the reduction of Cd absorption and translocation.

Hydrocarbons found in the environment are typically characterized by gas chromatography (GC). The shape of the GC chromatogram has been used to identify the source of petroleum contamination. However, the conventional practice of simply comparing the peak patterns of source products to those of environmental samples is dependent on the subjective decisions of individual analysts. We have developed and verified a quantitative analytical method for interpreting GC chromatograms to distinguish refined petroleum products in contaminated soils. We found that chromatograms for gasoline, kerosene, and diesel could be divided into three ranges with boundaries at C₆, C₈, C₁₆, and C₂₆. In addition, the relative peak area (RPAGC) of each range, a dimensionless ratio of the peak area within each range to that of the total range (C₆–C₂₆), had a unique value for each petroleum product. An identification index for GC chromatograms (IDGC), defined as the ratio of RPAGC of C₈–C₁₆ to that of C₁₆–C₂₆, was able to identify diesel and kerosene sources in samples extracted from artificially contaminated soils even after weathering. Thus, the IDGC can be used to effectively distinguish between refined petroleum products in contaminated soils.

Tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) were analyzed in 12 tissues of prey (mud carp) and predator (northern snakehead) fish from an e-waste area, South China. The TBBPA concentrations in different tissues ranged from 0.03 to 2.85 ng/g wet weight (ww) in mud carp and 0.04 to 1.30 ng/g ww in northern snakehead. The concentrations of HBCDs ranged from 0.07 to 96.9 ng/g ww in mud carp and 0.18 to 240 ng/g ww in northern snakehead. HBCD levels in tissues were correlated with lipid content for both fish species, while this correlation was only found in mud carp for TBBPA. Meanwhile, northern snakehead exhibited higher HBCD levels but lower TBBPA levels than mud carps. These observations are attributed to the more polar and reactive properties of TBBPA than HBCDs. α-HBCD was the predominant diastereoisomer of HBCDs in all tissues of mud carp and northern snakehead, except for chyme of mud carp. All the analyzed tissues in mud carp showed an enrichment of (+)-α-HBCD enantiomer with EF (enantiomeric fraction) values of 0.53–0.62, but that in northern snakehead showed an enrichment of (−)-α-HBCD enantiomer with EF values of 0.35–0.5. Considering the fact that the mud carp is one of the diet items of northern snakehead, the different enantiomer accumulation characteristics of α-HBCD between the two fish species in the present study indicated that prey and predator fish could prefer to biotransform different enantiomers of α-HBCD.

The environmental stress is a major area of scientific concern because it constraints plant as well as crop productivity. This situation has been further worsened by anthropogenic activities. Therefore, there is a much scientific saddle on researchers to enhance crop productivity under environmental stress in order to cope with the increasing food demands. The abiotic stresses such as salinity, drought, cold, and heat negatively influence the survival, biomass production and yield of staple food crops. According to an estimate of FAO, over 6 % of the world’s land is affected by salinity. Thus, salinity stress appears to be a major constraint to plant and crop productivity. Here, we review our understanding of salinity impact on various aspects of plant metabolism and its tolerance strategies in plants.

A system is needed to predict the behavior, fate, and occurrence of environmental pollutants for effective environmental monitoring. Available monitoring data and computational modeling were used to develop a one-box multimedia model based on the mass balance of the emitted chemicals. Eight physiochemical phenomena in the atmosphere, soil, water, and sediment were considered in this model. This study was carried out in the Lake Biwa-Yodo River basin which provides multiple land uses and also the natural water resource for nearly 13 million of population in the region. Annual emissions for 214 nonmetallic compounds were calculated using the chemical emission data on Japanese pollutant release and transfer registry and used for executing the model simulations for 1997, 2002, and 2008 as input data. The calculated chemical concentrations by the model for all the environmental media were analyzed to determine trends in concentration over this study span. The majority of the chemicals decreased in concentration over time. Among the 214 nonmetallic chemical pollutants, 36 chemicals did not decrease in concentration and were in the top 10 % for concentration on average. Of these 36 pollutants, 7 occur in all 4 environmental media and pose a potential health risk at humans in the Lake Biwa-Yodo River basin.

Due to their mobility and toxicity, crude oil volatile organic compounds (VOCs) are representative components for oil pipeline contaminated sites detection. Therefore, contaminated location risk assessment, with airborne light detection and ranging (LIDAR) survey, in particular, requires ground-based determinative methods for oil VOCs, the interaction between oil VOCs and soil, and information on how they diffuse from underground into atmosphere. First, we developed a method for determination of crude oil VOC binary mixtures (take n-pentane and n-hexane as examples), taking synergistic effects of VOC mixtures on polydimethylsiloxane (PDMS) solid-phase microextraction (SPME) fibers into consideration. Using this method, we further aim to extract VOCs from small volumes, for example, from soil pores, using a custom-made sampling device for nondestructive SPME fiber intrusion, and to study VOC transport through heterogeneous porous media. Second, specific surface Brunauer–Emmett–Teller (BET) analysis was conducted and used for estimation of VOC isotherm parameters in soil. Finally, two models were fitted for VOC emission prediction, and the results were compared to the experimental emission results. It was found that free diffusion mode worked well, and an empirical correction factor seems to be needed for the other model to adapt to our condition for single and binary systems.

Nanomaterial (NM) release into wastewater treatment plants (WWTPs) is inevitable due to increased production and application throughout past decades and in the future. Concern arose about environmental risks and impact on activated sludge. Environmental risk assessment (ERA) for NMs according to established guidelines is considered not suitable, because NMs exhibit unique characteristics. For hazard identification on activated sludge, standard test organisms for aquatic toxicity testing are not meaningful. In this study, we developed an acute toxicity test for ciliates (Paramecium tetraurelia) as representatives of the important functional group of microbial predators and filter feeders. We chose silver nanoparticles (nAg) exemplarily for ion releasing nanoparticles and regarded toxicity by ions as well. Our results indicate that ions are more toxic (EC₅₀0.73 mg/L) than nanoparticles themselves (EC₅₀2.15 mg/L). However, nAg must be considered as a source of ions and requires size, surface coating, and compartment-specific ERA. We strived to develop such ERA based on our results, modeled environmental concentration data from literature, and surface area concentrations. Results indicated a probable risk toward activated sludge. This likely has effects on effluent water quality. We conclude that carefully modeled environmental concentrations are vital for more exact ERA for nAg and other NMs.