The increased industrial and economic developments that have occurred in recent decades, particularly in mining, agricultural and metal recycling activities have decisively contributed to the increased concentration of heavy metals in soil. This study was carried out to evaluate the performance of Sorghum bicolor and Chrysopogon zizanioides in the citric acid-assisted phytoextraction of Pb in a field experiment setup in an area contaminated by automotive battery waste. Two soils amendments were used and they were dolomitic limestone and silicate slag at doses of 4.74 and 12.80 t ha⁻¹, respectively. Commercial citric acid was applied in each experimental parcel on the 63rd day of the cultivation in order to enhance Pb solubilisation and plant availability. Citric acid, which was applied at a dose of 40 mmol kg⁻¹of soil, was efficient in the solubilisation of Pb in soil and in the induction assisting of the removal of Pb from soil by the both species tested. Commercial citric acid is indicated for use in the area, due to its low cost and high biodegradability. Due to the low natural solubility of Pb and the large amount of time required, i.e. more than 900 years, phytoextraction without the application of chelating agents is not viable for remediation of the study area. Sorghum grown in soil amended with silicate slag combined with the application of the chelating agent commercial citric acid is the recommended phytoextraction programme for the remediation of an area with moderate Pb contamination.

Aluminium is used in diverse anthropogenic processes at the origin of pollution events in aquatic ecosystems. In the Champagne region (France), high concentrations of aluminium (Al) are detected due to vine-growing practices. In fish, little is known about the possible immune-related effects at relevant environmental concentrations. The present study analyzes the simultaneous effects of aluminium and bacterial lipopolysaccharide (LPS), alone and in combination, on toxicological biomarkers in the freshwater fish species Rutilus rutilus. For this purpose, roach treated or not with LPS were exposed to environmental concentrations of aluminium (100 μg/L) under laboratory-controlled conditions for 2, 7, 14 and 21 days. After each exposure time, we assessed hepatic lipoperoxidation, catalase activity, glutathione reductase activity and total glutathione content. We also analyzed cellular components related to the LPS-induced inflammatory response in possible target tissues, i.e. head kidney and spleen. Our results revealed a significant prooxidant effect in the liver cells and head kidney leukocytes of roach exposed to 100 μg of Al/L for 2 days. In liver, we observed more lipoperoxidation products and lower endogenous antioxidant activity levels such as glutathione reductase activity and total glutathione content. These prooxidant effects were associated with a higher oxidative burst in head kidney leukocytes, and they were all the more important in fish stimulated by LPS injection. These findings demonstrate that environmental concentrations of Al induce oxidative and immunotoxic effects in fish and are associated to an immunomodulatory process related to the inflammatory response.

This study deals with the hydrogeochemical changes and metal(loid) attenuation processes along the extremely acidic Rio Tinto (SW Spain). The geochemistry of Tinto headwaters is determined by the variability of mining discharges due to different geological, geochemical and hydrological controls. Downstream of the mining area, a decrease in most dissolved element concentrations is recorded. However, not all elements decreased its concentration to the same extent, and even some did not decrease (e.g., Ba and Pb). A group of elements formed by Al, Cd, Co, Cr, Cu, Li, Mg, Mn, Ni and Zn behaved quasi-conservatively; mainly affected by dilution, except at the lower part of the catchment where seem to be affected by sorption/coprecipitation (e.g., Cd, Cu, and Zn) or mineral dissolution processes (e.g., Al, Mg). Iron and As exhibited a non-conservative behaviour due to ochre precipitation and sorption processes, respectively. A group of elements formed by Ca, Na, Sr and Li did not behave conservatively; waters were enriched in these elements by dissolutive reactions of carbonates and aluminosilicates from bedrocks. The behaviour of Pb in the Rio Tinto is complex; values fluctuate along the river course and its solubility may be related to the nature of Fe precipitates.

This study demonstrates the potential of a new BiOCl₀.₈₇₅Br₀.₁₂₅ photocatalyst to degrade pharmaceuticals in water (i.e., carbamazepine (CBZ), ibuprofen (IBF), bezafibrate (BZF), and propranolol (PPL)), under simulated solar irradiation. Different parameters were examined through their influence on CBZ degradation. Increasing the catalyst concentration up to 500 mg/L increased CBZ degradation rate; however, above 500 mg/L, CBZ degradation rate was slightly reduced, most likely due to the catalyst’s light-screening effect at high concentrations. Increasing the pH of the tested solution from 4 to 9 decreased the degree of CBZ adsorption to the catalyst and consequently its degradation rate. Quantum yield for CBZ degradation was found to be 0.75 ± 0.05 % using an integrating sphere for absorbance measurements to correctly account for scattering of light by the suspended catalyst. Degradation rates of all examined compounds (at pH 7) followed the order PPL > BZF > IBF > CBZ (highest rate for PPL). Interestingly, PPL was least adsorbed to the catalyst, implying that adsorption is not always mandatory for efficient degradation with BiOCl₀.₈₇₅Br₀.₁₂₅. Different adsorption mechanisms were hypothesized for the different pharmaceuticals, including hydrophobic attraction for the neutrally charged CBZ and ion exchange for the negatively charged IBF and BZF.

Analytical method for the determination of six flame retardants (FRs) from two groups was proposed. These groups included the brominated flame retardants (BFRs) 3,3′,5,5′-tetrabromobisphenol A (TBBPA), 1,2,5,6,9,10-hexabromocyclododecane (HBCD) and tetrabromophthalic anhydride (TBPA) and triester organophosphate flame retardants (OPFRs) tris(2,3-dibromopropyl) phosphate (TBPP), ethylhexyl diphenyl phosphate (EHDP) and triphenyl phosphate (TPhP). Reversed phase ultrahigh-performance liquid chromatography (UHPLC) with a UV detector, different chromatographic columns, different mobile phases and gradient elution programmes were used to obtain the best separations within the shortest possible time. Solid-phase extraction (SPE) was examined as a pre-concentration step from distilled water. The column with the highest recoveries (the Bond Elut ENV column gave recoveries over 70 % for all compounds) was then tested on 1-L blank surface water samples. The proposed analytical procedure was applied for the determination of FRs in surface water samples. The concentrations of FRs found in water samples ranged from 0.03 (TPhP) to 3.10 μg L⁻¹(HBCD). Method detection limits (MDLs) ranged from 0.008 to 0.518 μg L⁻¹, and method quantification limits (MQLs) ranged from 0.023 to 1.555 μg L⁻¹for all compounds.

A nitrate-dominant synthetic wastewater simulating slightly polluted water with low C/N and poor biochemical availability was treated in lab-scale vertical-flow (VF)-constructed wetlands, which had Phragmites australis planted with different types of external carbon sources: Platanus acerifolia leaf litters, P. australis litters, glucose and a blank test with no external carbon sources. A comparison of the TN removal and N₂O flux performances among the four wetland reactors indicated higher TN removal efficiencies and N₂O release fluxes in the VF wetland columns with external carbon sources, as measured by the percentage removal of TN (P. acerifolia leaf litters 82.49 %, P. australis litters 70.55 %, glucose 62.50 % and blank 46.45 %) and N₂O flux (P. acerifolia leaf litters 2275.22 μg · m⁻² · h⁻¹, P. australis litters 1920.53 μg · m⁻² · h⁻¹, glucose 1598.57 μg · m⁻² · h⁻¹and blank 1192.08 μg · m⁻² · h⁻¹). This was primarily because of an improved supply of organic carbon from the external carbon sources for heterotrophic denitrification. And, the nitrogen released from the decomposition of plant materials resulted in the N₂O release fluxes to some extent. However, employing P. acerifolia leaf litters and P. australis litters as external carbon sources caused net increases in organics of the final effluent water. Overall, the results not only demonstrated the potential of using external plant carbon sources in VF wetlands to enhance the TN removal efficiency but also showed a risk of excessive organic release and greater N₂O flux feedback to global warming. Hence, future studies are needed to optimise the quantity and method for adding external carbon sources to VF-constructed wetlands so that sufficient nitrate removal efficiency is achieved and the N₂O flux and organic pollution are minimised.

Recent scientific findings and legislations have clearly highlighted the need for comprehensive approaches and methods to evaluate natural dust contributions to an urban atmosphere. The evaluation of chemical compositions of airborne aerosols is of these methods that may employ several advanced analytical techniques and processes. In this paper, an episodic appearance of Saharan dust incursion over a megacity (Istanbul, Turkey) was investigated using size segregated particulate matter (PM) samples in fine and coarse fractions collected between February 27 and March 8, 2009. The Saharan impact was investigated using satellite observations, backward air trajectory statistics, and chemical analyses of the collected samples. In the chemical analyses, Fourier transform infrared coupled with attenuated total reflectance (ATR-FTIR) spectroscopic method was used to determine the functional groups, namely, alcohols, ammonium, aliphatic carbons, carbonyls, organonitrates, nitrate, silicate, silica, kaolinite, and calcium carbonate. Among all the measured functional groups, it was clearly seen that the intensities of IR peaks related to silicate, silica, kaolinite, and calcium carbonate were associated with the increased mass concentrations during the impact period. The observed IR peaks at 1,030 and 800 cm⁻¹for silicate ions in the samples can be used as an indicator of the large dust incursion into the atmosphere (e.g., Saharan dust episodes observed in Istanbul). This study showed that the ATR-FTIR spectroscopic method is a fast and convenient method to identify these peaks and the IR method in general is useful for identifying a large dust incursion into the atmosphere.

In an effort to customize biochars for soil amendments, multiple feedstocks have been combined in various ratios prior to pyrolysis. The resulting variation in the chemistry and structure can affect a biochar’s adsorption capacity, which influences the bioavailability of many chemical compounds in the soil system including phenolic acids. This study characterizes the sorption of 14C-labeled ferulic acid, syringic acid, and chlorocatechol to four biochars prepared from individual feedstocks and four from mixed feedstocks using batch equilibration. Pure feedstock biochar sorption followed switchgrass< swine solids< poultry litter< pine chip for both ferulic (Kd= 1.4-75) and syringic acid (Kd= 0.07-6.03), and appeared to be influenced by the properties of the biochars as well as the chemicals themselves. All biochar Kd values, except pine chip, were lower than that of the reference soil (Waukegan silt loam). The sorptive properties of the combined feedstock biochars could not be predicted from their pure feedstock components and sorption coefficients were both unexpectedly higher and lower than the individual parent materials’ biochars. Further research is necessary to understand the characteristics of these combination biochars, particularly their sorption, which this study has shown is not merely an intermediary of its components.