A multivariate analysis was performed in the city of Florence (Italy) to investigate the influence of road traffic and meteorology on air pollution levels at urban traffic stations. Focussing on main traffic-related pollutants (CO, NO, NO₂, NO ₓ and PM₁₀), two typical urban road configurations were analysed: a street canyon and an open road. In addition to traffic flows, basic meteorological parameters were considered: wind speed, air temperature and relative humidity. The influence of all drivers by period of the year and day of the week was analysed with correlation analysis, while a statistical model was developed to predict concentrations at traffic stations by using predictors as urban background concentrations, traffic flows and a site-specific constant. Trained on a 1-year period (2008), the model was validated over an independent 1-year period (2007). The highest correlation of urban traffic concentrations was found vs. background concentrations, markedly for PM₁₀ (r = 0.85–0.87). The influence of road traffic was the highest for NO₂ (r = 0.51–0.58) and the lowest for PM₁₀ (r = 0.36–0.40). Urban-scale poor advection conditions proved to affect PM₁₀ peak levels more significantly than local traffic increase. For all pollutants, good forecasting capability was achieved by the developed statistical model, generally performing better at the street canyon (r = 0.79–0.86) than at the open road (r = 0.72–0.82).

The presence of pharmaceuticals and personal care products (PPCPs) as trace pollutants in natural surface water bodies, ground water and drinking water has recently led to some concern. Advanced oxidation processes (AOPs), which utilize free radical reactions to degrade chemical contaminates, are an alternative to traditional water treatment. Anti-inflammatory drug balsalazide (as model compounds) besides actual wastewater samples were UV photodegraded using suspended titanium silicon oxide (TiSiO₄) or UV/H₂O₂/O₂ systems. The photodegradation was favourable in the pH 8–12.8 range. The effect of various parameters such as photocatalyst amount, balsalazide (BSZ) concentration, pH of aqueous solution, irradiation time, addition of H₂O₂ and temperature on photocatalytic oxidation was investigated. The kinetics of the photocatalytic oxidation of BSZ in aqueous TiSiO₄ suspensions was investigated as a function of catalyst loading (2–12 mg/L) and the concentration of BSZ (0.01–0.05 mg/mL) at pH 11.5. The optimum conditions for the degradation of the BSZ have been found as 0.045 mg/mL drug concentration, pH 11.5 and 0.1 g/L catalyst dose. The results indicated that the photocatalytic degradation of BSZ was well described by pseudo-first-order kinetics according to the Langmuir–Hinshelwood model. The effect of temperature on the efficiency of photodegradation of BSZ was also studied in the range 278–298 K. The activation energy was calculated according to Arrhenius plot and was found equal to 24 ± 1 kJ mol⁻¹ for TiSiO₄. Decolourization and mineralization of BSZ in the absence of light and/or catalyst were performed to demonstrate that the presence of light and catalyst is essential for the decolourization of this BSZ. This work adds to the global discussion on the role of the advanced oxidation processes in water treatment.

Groundwater samples collected from an unconfined shallow aquifer were analysed for major and trace element (TE) concentrations with the aim to investigate small-scale variations possibly linked to fertilizer residual products applied until 2004. The field site, located near Ferrara (Northern Italy), covers an area of 200 m²and was a former agricultural field then converted into a park and equipped with a grid of 13 monitoring wells. Three monitoring campaigns were carried out in June 2007, March and June 2009 in order to detect spatial and temporal variations in water quality. Groundwater nitrate, chloride, bromide and sulphate concentrations decreased with time indicating that the fertilizer plume was slowly replaced by unpolluted groundwater. However, the groundwater composition showed values of TEs (Fe, Mn, Al, As and Hg) above the recommended international and national guideline values. Dissolved TE concentrations varied randomly in the three campaigns, while TEs in the solid matrix did not show particular enrichment factors induced by fertilizer use. The data indicated that the dominant factor involved in determining small-scale spatial variability of TE concentrations in this shallow aquifer was the sediment-water interaction, while the temporal variation of TEs was driven by the organic matter leaching from the topsoil and by water table oscillations, which in turn drove the groundwater redox status. This study emphasizes the need of small-scale TE spatial resolution to discriminate between anthropogenic non-point sources of pollution (like fertilizers) and background concentrations.

The impact of Fe₂O₃and TiO₂nanoparticles (NPs) on the removal of trichloroethylene (TCE) in a granular activated carbon (GAC)-fixed bed adsorber was investigated in the presence of humic acid (HA). The surface charges of GAC and NPs were obtained in the presence and absence of HA with the NPs behaving similarly. Isotherm and column studies were conducted in the presence and absence of the NPs and HA. NPs had no effect on TCE adsorption during isotherm studies. However, in the column studies conducted with organic-free water, the presence of NPs resulted in a reduction in TCE capacity most likely due to pore blockage by aggregating NPs. This effect was completely mitigated in the presence of HAs that prevented an association between the GAC and the NPs, and between NPs. The presence of HA provided a high negative charge on the GAC and on the nanoparticles resulting in repulsive forces between the GAC and the NPs, and between NPs, thereby preventing pore blockage. Both Fe₂O₃and TiO₂NPs demonstrated that charge characteristics are more important than chemical characteristics. Pore-size distribution of the fresh and the spent GAC confirmed the adsorption data but points to some HA and NP interaction with the carbon.

We highlighted some of the key problems associated with the use of beneficial microorganisms for improving adaptation of plants to soils, polluted with heavy metals (HMs), especially Cd. Inoculation of pea line SGE and its Cd-tolerant mutant SGECdᵗ with nodule bacteria Rhizobium leguminosarum bv. viciae demonstrated that nodulation process may be disturbed at Cd concentrations below threshold toxicity levels for each partner and the plant genotype plays a major role in nodulation under Cd stress. A comparative mathematical analysis of available information about Cd tolerance, accumulation of HMs (Cd, Cr, Cu, Ni, Pb, Sr and Zn), response to mycorrhizal fungus Glomus sp. and 15 phenotypic traits of 99 pea varieties revealed that (1) the Cd-sensitive varieties were more efficient in exploring the protective potential of symbiosis to compensate their deficit in Cd tolerance and (2) correlations between the studied traits exist and can be helpful for selection of plant-microbe systems adapted to polluted soils. In pot experiment with 11 varieties of Indian mustard, the plant growth-promoting effect of rhizobacterium Variovorax paradoxus 5C-2 negatively correlated with Cd tolerance and shoot Cd concentration of the plants grown in Cd-supplemented soil. In an outdoor pot experiment, inoculation of willow with the ectomycorrhizal fungus Pisolithus tinctorius and a cocktail of rhizobacteria stimulated root exudation, decreased soil pH and increased Cd mobilization in soil and Cd uptake by plants, but decreased plant growth at a moderate contamination level (25 mg Cd kg⁻¹). Opposite effects were observed in highly contaminated soil (77 mg Cd kg⁻¹). We propose a preliminary systematic framework of interactions between these factors that determine the success of microbial inoculation aimed at improving crop performance on HM-polluted soils or enhancing phytoremediation.

Nitrogen significantly regulated (p < 0.05) the effects of spiramycin on the growth and antioxidant responses of Microcystis aeruginosa as well as the biodegradation of spiramycin by M. aeruginosa during a 7-day exposure test. At a nitrogen level of 0.5 mg L⁻¹, the activities of superoxide dismutase and catalase were stimulated by 100–400 ng L⁻¹of spiramycin to protect algal cells from oxidative damage, resulting in alleviated toxicity of spiramycin and low malondialdehyde content in M. aeruginosa. The catalase activity was inhibited by 400 ng L⁻¹of spiramycin at higher nitrogen levels of 5–50 mg L⁻¹, leading to significant growth inhibition (p < 0.05) and higher malondialdehyde content through accumulation of hydrogen peroxide. Stimulated glutathione content and glutathione S-transferase activity were coupled to the biodegradation of spiramycin in M. aeruginosa. The 7-day biodegradation percentage of spiramycin varied from 8.9 to 29.6 %, which was enhanced by increased nitrogen concentration and decreased spiramycin concentration. Due to the regulation of algal growth, the toxicity of M. aeruginosa were significantly enhanced (p < 0.05) by 100 ng L⁻¹of spiramycin at a nitrogen concentration of 0.5 mg L⁻¹while significantly reduced (p < 0.05) by 400 ng L⁻¹of spiramycin at nitrogen levels of 5–50 mg L⁻¹, according to the luminescent bacteria test. Low concentration of coexisting spiramycin contaminant should be considered during the control of M. aeruginosa bloom, especially under nitrogen deficient condition.

Biochar has great advantages and potentials on soil amendment and polluted soil remediation. In order to explore these applications, a pot experiment was carried out to research the effect of biochar on the heavy metal speciation in paddy soil and the heavy metal accumulation of paddy rice from Chengdu plain, Sichuan Province. The experimental results show that wine lees-derived biochar can efficiently increase soil pH, decrease the contents of soil exchangeable heavy metals, and promote heavy metal transformation to residual fraction. Moreover, application of biochar can reduce the accumulation of heavy metals in paddy plant, decrease the migration ability of heavy metals to the aboveground part of the plant, and consequently cut down contents of heavy metals in rice. When biochar dosage was 0.5 % in weight, the contents of soil exchangeable Cr, Ni, Cu, Pb, Zn, and Cd decreased 18.8, 29.6, 26.3, 23.0, 23.01, and 48.14 %, respectively, which all significantly differed from CK (P < 0.05), and the contents of heavy metals in plant roots, stems, leaves, rice husk, and rice all decreased accordingly, among which Zn, Cd, and Pb decreased 10.96, 8.89, and 8.33 % respectively. When biochar dosage increased to 1 %, heavy metal contents in roots, stems, leaves, rice husk, and rice decreased further. Therefore, wine lees-derived biochar shows a great potential in remediation of heavy-metal-polluted soil, and this work provides theoretical basis for restoring heavy-metal-polluted soil using biochar.

A simple, cost-effective, and efficient pretreatment method, namely, vortex- and shaker-assisted liquid–liquid microextraction (VSA-LLME) coupled with gas chromatography and mass spectrometry (GC-MS), is developed for determining 16 trace-level polycyclic aromatic hydrocarbons (PAHs) in offshore produced water. The parameters affecting the VSA-LLME performance including solvent volume, ion strength, shaking time, and centrifuge speed were optimized. Under the optimized condition, the enrichment factors range between 68 and 78. The method linearities (R ²) for all 16 PAHs were above 0.99 at concentration range between 10 and 200 ng/L. The recoveries of the method were 74–85 %, and the limits of detection were as low as 2 to 5 ng/L. The relative standard deviations (RSD%) were 6~11 %. The developed method was also validated in industrial wastewater sample and showed good capability in determination of 16 PAHs in offshore produced water. The developed method offers advantages including simplicity of operation, low cast, and high sensitivity.

Peatlands serve as important stores of organic matter and regulators of nutrient and metal export to surface waters, yet relatively little is known regarding the impact of more than a century of metal, sulfur, and acid deposition on microbial activity in acidic, nutrient-poor peatlands that are common features around Sudbury, Ontario. In this study, eight peatlands were selected at varying distances from the Copper Cliff Smelter that was once the largest point source of sulfur dioxide and sampled for analysis of nutrient and metal content. Basal microbial respiration, relative response to substrate addition (four synthetic and four natural substrates) assessed as CO₂production rates and microbial biomass were assessed in surface (0–10 cm) peat samples. Bacterial and fungal communities within the peat samples were profiled using terminal restriction fragment length polymorphism analysis. Basal respiration (i.e., carbon mineralization in absence of substrate addition) was lowest and Cu and Ni concentrations and the degree of humification (assessed by the von Post scale) in surface peat samples were highest close to the smelter. Each peatland had a unique bacterial community when assessed using non-metric multidimensional scaling, whereas the fungal community was variable with no consistent patterns across the sites. Despite differences in microbial communities, substrate-induced respiration rates did not differ among peatlands as sites generally responded similarly to carbon substrate additions. Basal respiration rates were related to the humification status of the peat, which was potentially related to environmental degradation in the peatlands or surrounding terrestrial systems closer to the Sudbury smelters.

The aboveground tissue of plants is important for providing roots with constant photosynthetic resources. However, the aboveground biomass is usually harvested before winter to maintain the permanent removal of nutrients. In this work, the effects of harvest on plants’ involvement in oxygen input as well as in microbial abundance and activity were investigated in detail. Three series of constructed wetlands with integrated plants (“unharvested”), harvested plants (“harvested”), and fully cleared plants (“cleared”) were set up. Better performance was found in the unharvested units, with the radial oxygen loss (ROL) rates ranging from 0.05 to 0.59 μmol O₂/h/plant, followed by the harvested units that had relatively lower ROL rates (0.01 to 0.52 μmol O₂/h/plant). The cleared units had the lowest removal efficiency, which had no rhizome resources from the plants. The microbial population and activity were highest in the unharvested units, followed by the harvested and cleared units. Results showed that bacterial abundances and enhanced microbial activity were ten times higher on root surfaces compared with sands. These results indicate that late autumn harvesting of the aboveground biomass exhibited negative effects on plant ROL as well as on the microbial population and activity during the following winter.