In the present study, a novel synthesized adsorbent material based on 3-mercaptopropyltrimethoxysilane-functionalized multi-walled carbon nanotubes was used to increase the Pb²⁺ adsorption from aqueous solutions in a flow injection solid-phase extraction system coupled to flame atomic absorption spectrometry. Spectroscopic and microscopic techniques (Fourier transform infrared spectroscopy, energy dispersive spectroscopy, and scanning electron microscopy) were employed to confirm the chemical modification of the adsorbent surface. Preconcentration conditions (sample pH, flow rate, buffer solution, and eluent concentrations) were optimized using factorial and Doehlert matrix designs that made it possible to construct a linear graph in the 5.0- to 130.0-μg L⁻¹ range (r = 0.9999) and estimate detection and quantification limits (1.7 and 5.7 μg L⁻¹, respectively). The method precision was found to be 4.20 and 1.97 % for 5.0 and 100.0 μg L⁻¹ Pb²⁺ solutions, respectively. When using the 3-mercaptopropyltrimethoxysilane-functionalized multi-walled carbon nanotubes, the sensitivity for the Pb²⁺ trace determination was improved to 95 % compared with the oxidized multi-walled carbon nanotubes, thus evidencing the significant enhancement of the adsorption capacity. The developed method was successfully applied to the analysis of Pb²⁺ species in different water samples and the PACS-2 marine sediment-certified reference material.

Volcanic rock is a potential adsorbent for metallic ions from wastewater. This study determined the capacity of Gisenyi volcanic rock found in Northern Rwanda to adsorb Cd, Cu, Pb and Zn using laboratory scale batch experiments under a variety of experimental conditions (initial metal concentration varied from 1 to 50 mg/L, adsorbent dosage 4 g/L, solid/liquid ratio of 1:250, contact time 120 h, particle size 250–900 μm). The adsorbent had a surface area of 3 m2/g. The adsorption process was optimal at near-neutral pH 6. The maximal adsorption capacity was 6.23, 10.87, 9.52 and 4.46 mg/g for Cd, Cu, Pb and Zn, respectively. The adsorption process proceeded via a fast initial metal uptake during the first 6 h, followed by slow uptake and equilibrium after 24 h. Data fitted well the pseudo second-order kinetic model. Equilibrium experiments showed that the adsorbent has a high affinity for Cu and Pb followed by Cd and Zn. Furthermore, the rock is a stable sorbent that can be reused in multiple sorption–desorption–regeneration cycles. Therefore, the Gisenyi volcanic rock was found to be a promising adsorbent for heavy metal removal from industrial wastewater contaminated with heavy metals.

Spheroidal carbonaceous particles (SCPs) are produced by the high-temperature combustion of fossil fuels and are emitted to the atmosphere. We examined the surface morphology and the chemical composition of SCPs in samples of surface sediment from five industrial cities each of Japan and China, using scanning electron microscopy with energy dispersive spectroscopy (EDS). There exists a relationship between surface morphology and the chemical composition of SCPs in China, but not for SCPs in Japan. The chemical compositions of SCPs differ between Japan and China: those in Japan are S-rich, whereas those in China are Ti-rich. The results suggest that EDS can be used to identify China-derived SCPs in East Asian countries such as Japan, South Korea, and Taiwan.

In situ denitrification walls and biofilters made of wood chips are being implemented as innovative technologies for the removal of nitrates in tile drainage water from farms to reduce pollution of surface waters and the hypoxia problem in the Gulf of Mexico. Although fairly effective in removing nitrates, not much is known about the effectiveness of the biofilters in removal of herbicides, pesticides, and antibiotics in the drainage water. Using weathered wood chips obtained from an in situ denitrification wall, four common pollutants tested sorbed strongly to wood chips in the following order: enrofloxacin > monensin A > atrazine > sulfamethazine. Of the four chemicals tested, enrofloxacin was found to desorb the least by water extraction. The apparent hysteresis index for atrazine was found to be lower than that for enrofloxacin and sulfamethazine indicating greater sorption–desorption hysteresis for atrazine than enrofloxacin and sulfamethazine. Consecutive steps of water desorption and organic solvent extraction indicated that more than 65% of the sorbed atrazine, 70% of sulfamethazine, 90% of enrofloxacin, and 80% of monensin A were retained in wood chips. Results of this study showed that wood chip denitrification walls or biofilters have an added benefit in retaining herbicides and antibiotics and therefore can act as a barrier to reduce pollution of surface water and groundwater.

Marine waters are most vulnerable to crude oil pollution due to increased sea-based oil-related activities. Successful remediation of such polluted environments is normally carried out in a laboratory with suitable physical and environmental alterations. However, it is challenging to alter the physical and environmental conditions in crude oil-contaminated natural environments. In a previous study, six hydrocarbonoclastic bacteria were isolated from an oil-contaminated site. Here we report on their ability to mineralise weathered crude oil as a carbon source in seawater mesocosms, in order to construct a hydrocarbonoclastic consortia for the effective mineralisation of hydrocarbons present in the weathered crude oil at seawater-based environment. This was completed without altering the physical and environmental parameters (salinity, pH and temperature) and followed by the detection of microbial community changes. The total amount of oil mineralised by these six isolates individually over 28-day incubation ranged from 4.7 to 10 %. The bacterial consortia composed of these six strains showed a greater mineralisation rate (18.5 %). Temperature gradient gel electrophoresis revealed that the functionally dominant species were present after the first week (week 2 to week 4) following the addition of the consortia, which were represented in dendrogram by cluster 2 and also these weeks representing a distinct point on the Pareto–Lorenz curve; no community could be identified in controls in which no consortia were added. This shows that the addition of consortia potentially dealt with changing environmental conditions and preserved its functionality followed by effective mineralisation of weathered crude oil.

Metals, as well as other air toxic pollutants, can be responsible for a range of human health effects via inhalation or ingestion. European normatives regulate lead, arsenic, cadmium, mercury and nickel ambient air levels in order to prevent potential damage to human health and ecosystems; annual target levels of 500, 6, 5 and 20 ng/m³ for Pb, As, Cd and Ni are set for these pollutants in directives 2008/50/CE and 2004/107/CE. Air quality models constitute a powerful tool to understand tropospheric dynamic and to assign concentration values to areas where no measurement is available. However, not many models include heavy metals in their code, and mainly results for Pb, Cd and Hg have been published. In this paper, we present preliminary results on modelling Pb, Cd, As, Ni, Cu, Zn, Cr and Se air background concentration in Europe using the CHIMERE model, at a 0.2° resolution and the evaluation of the model performance in order to see its capability to reproduce observed levels. This evaluation was performed by comparing simulated values with observations at the EMEP monitoring sites, as only values at background sites can be captured at the 0.2° model resolution. Important uncertainties mainly related to emissions should be solved in order to obtain an improvement of model performance; more recent annual totals, information on snap activities for each metal, higher spatial resolution and a better knowledge of the temporal emission behaviour is necessary to adequately model these air pollutants. Also a better treatment of these particles considering more realistic metal size distribution, more refined deposition processes or some chemical processes regarding Se could result in better model results. A larger number of stations and a better temporal coverage of observations are also important to carry out a better statistical analysis of model performance.

The magnetic-poly(divinylbenzene-1-vinylimidazole) [m-poly(DVB-VIM)] microbeads (average diameter 53–212 μm) were synthesized and characterized; their use as adsorbent in removal of Cr(VI) ions from aqueous solutions was investigated. The m-poly(DVB-VIM) microbeads were prepared by copolymerizing of divinylbenzene (DVB) with 1-vinylimidazole (VIM). The m-poly(DVB-VIM) microbeads were characterized by N2 adsorption/desorption isotherms, ESR, elemental analysis, scanning electron microscope (SEM) and swelling studies. At fixed solid/solution ratio the various factors affecting adsorption of Cr(VI) ions from aqueous solutions such as pH, initial concentration, contact time and temperature were analyzed. Langmuir, Freundlich and Dubinin–Radushkvich isotherms were used as the model adsorption equilibrium data. Langmuir isotherm model was the most adequate. The pseudo-first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models were used to describe the adsorption kinetics. The apparent activation energy was found to be 5.024 kJ mol−1, which is characteristic of a chemically controlled reaction. The experimental data fitted to pseudo-second-order kinetic. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes. The thermodynamic parameters obtained indicated the endothermic nature of adsorption of Cr(VI) ions. Morever, after the use in adsorption, the m-poly(DVB-VIM) microbeads with paramagnetic property were separeted via the applied magnetic force. The magnetic beads could be desorbed up to about 97% by treating with 1.0 M NaOH. These features make the m-poly(DVB-VIM) microbeads a potential candidate for support of Cr(VI) ions removal under magnetic field.

During the intensive flood in May–June 2010, the floodplains in Little Poland Vistula Gap, used mostly for agriculture, were waterlogged for a period of over 1 month. The aim of the study was to assess the effect of the flood on the level of contamination of the soils in this region. The analysis included basic physicochemical soil properties, contents of ten metals, and concentrations of 16 polycyclic aromatic hydrocarbons (PAHs). The studies cover two territories on opposite sites of the river Vistula (Wilkow and Janowiec) differing in their areas (70 and 4.6 km2) and time of water logging (30 and 10 days). Forty soil samples were collected from both areas immediately after the flood event from the upper (0–30 cm) soil layer together with four samples from the 30–60-cm depth layer. This was supplemented by eight samples from the flood-deposited sediment layer (thickness, 2 cm). The concentrations of identified metals (As, Ba, Cr, Sn, Zn, Cd, Co, Cu, Ni, Pb) at all the sampling points were below the Polish legal limits for the upper layer of soils for agriculture use. The same regarded the median contents of nine PAHs compounds specified in the Polish regulations. In both areas, the median contents of Σ16 PAHs (0.21–0.35 mg kg−1), Zn (10.3–10.6 mg kg−1), Pb (9.2–10.7 mg kg−1), and Cd (0.03 mg kg−1) were much below the mean concentrations of those contaminants in arable soils on the national and European levels. The results show that this severe flooding episode in “clean” agricultural area had no immediate negative impact on the soils as regards the basic physicochemical properties (organic matter content, acidity, nitrogen content) and did not result in excessive soil contamination.

The embryos of a marine abalone, Haliotis diversicolor supertexta, were exposed to a typical environmental estrogen, 17α-ethynylestradiol (EE2), for 96 h, to examine the acute toxicity of EE2 to the embryogenesis of the abalone. A marine diatom, Navicula incerta, was used in the test media as settlement substrate and food for the abalone larvae. During the embryo culture, more than 30 % of EE2 could be removed from the test media by the diatom, mainly via biodegradation, leading to a decrease of water-borne exposure dose. Further, the exposure concentrations of EE2 around the living microenvironment of the abalone larvae could be magnified 350–468 times after the larvae settled on the diatom, as indicated by the bioconcentration factors of EE2 in the diatom. Increased bioaccumulation of EE2 in the diatom caused greater inhibition on the metamorphosis of the abalone larvae by enhancing the uptake of EE2 in the larvae via dietary exposure, while declined water-borne exposure dose did not affect the embryonic toxicity of EE2 and its uptake in the abalone larvae. The 96-h median effective concentration of EE2 to the metamorphosis of the abalone larvae was 10.01 μg L⁻¹, when the exposure doses in both the test media and the diatom were controlled stable. The 96-h hazard concentration for 5 % of the species was 1.20 μg L⁻¹, which was still higher than but close to the reported upper contamination level of EE2 and could be employed as the safety threshold for the metamorphosis of the abalone embryos.

Development of treatment technologies to alleviate water pollution has been a challenging and demanding task for researchers. Furthermore, synthetic dyes fabricated of complex aromatic structures turned out to be a great hazard as they impart color to water reservoirs making them abhorrent for human use. Reactive dyes being water soluble prove difficult to be eliminated by conventional treatment technologies. In recent times, biosorption has gained prominence as a finishing technology to remove pollutants being cost-effective and environment friendly. This paper describes the hazards posed by dyeing effluents, exclusively reactive dyes, on the environment and use of various biosorbents to remove reactive dyes from aqueous solution under optimum physicochemical parameters. Enhancement of biosorption capacity by chemical treatment and immobilization; equilibrium, kinetic and thermodynamic modeling of biosorption process; characterization by FTIR and SEM and regeneration of biosorbents is also plainly and comprehensively discussed.