The aims of the present study were to identify the halophilic Archaea that can degrade aromatic hydrocarbons (namely, p-hydroxybenzoic acid, naphthalene, phenanthrene, and pyrene) and to determine their catabolic pathways in the process of degrading the hydrocarbons. It was determined nine archaeal isolates used p-hydroxybenzoic acid, naphthalene, phenanthrene, and pyrene as sole carbon and energy sources. The isolates were identified as Halobacterium piscisalsi, Halorubrum ezzemoulense, Halobacterium salinarium, Haloarcula hispanica, Haloferax sp., Halorubrum sp., and Haloarcula sp. by 16S rRNA gene sequences. Activity of catechol 1,2 dioxygenase and protocatechuate 3,4 dioxygenase enzyme of the ortho cleavage pathway were detected. Determination of the genes of these dioxygenases was also shown. This study clearly demonstrated for the first time that Halorubrum sp. and H. ezzemoulense among the isolates were able to grow at 20 % (w/v) NaCl, utilizing p-hydroxy-benzoic acid, naphthalene, phenanthrene, and pyrene as the sole carbon sources.

A new analytical methodology based on ultra high performance liquid chromatography (UHPLC) after microwave assisted extraction, followed by a clean-up and preconcentration step with solid phase extraction (MAE-SPE) has been developed for the simultaneous determination of 11 endocrine-disrupting compounds (EDCs), including alkylphenolic compounds, bisphenol A, and various synthetic and natural steroidal hormones, in sewage sludge samples. The effects of different variables on MAE-SPE were studied and optimised. The recoveries obtained were higher than 77 %, whereas the relative standard deviations were less than 9 %. The detection limits ranged between 0.1 and 0.7 ng g -1. The developed methodology was successfully applied to the assessment of the presence of EDCs to sewage sludge samples that were collected bimonthly during 1 year and a half from two wastewater treatment plants (WWTPs) located in Las Palmas de Gran Canaria (Canary Islands, Spain). All compounds were consistently found in all the samples under study. © 2013 Springer Science+Business Media Dordrecht.

High applications of P fertilizers and manure are general practice in intensive agriculture and may cause eutrophication in adjacent streams. Bioavailability of P can be estimated by sequential extractions commonly used for soil or sediment. A single combined method may facilitate more effective comparisons of topsoils and adjoining stream sediments, and enhance management decisions. In this study, the suitability of an established soil P sequential extraction was tested on stream bed sediments. The study was conducted in the Sumas River watershed in the agricultural Lower Fraser Valley, Canada. Sediment samples with differing land use (forest, low and high intensity agriculture) from 1993, 1994, 2008, and 2009 from 14 sites along the Sumas River and tributaries were used. Total sequential extraction concentrations were in agreement with aqua regia digestion (Rs = 0.96) and showed consistency over the study time sequence. P fractions released by 0.5 M NaHCO3 (median 14 %), 0.1 M NaOH (33 %), and 1.0 M HCl (38 %) were significantly (α = 0.05) higher than P released by other extractants. These three extraction steps provide a practical and time-effective assessment of P lability in stream sediments and may be used as a combined scheme for sediment and soil. Analytical results further revealed that land use has a major and characteristic impact on P lability. With a land use change from forest to intensive agriculture, results showed an increase in total P concentrations (30 to 4,000 ppm) and in P lability, in particular for the moderately labile NaOH-P fraction (20 to 50 %). © 2013 Springer Science+Business Media Dordrecht.

The environmental impact assessment of mining sites represents nowadays a large interest topic in Romania. Historical pollution in the Rosia Montana mining area of Romania caused extensive damage to environmental media. This paper has two goals: to investigate the environmental pollution induced by mining activities in the Rosia Montana area and to quantify the environmental impacts and associated risks by means of an integrated approach. Thus, a new method was developed and applied for quantifying the impact of mining activities, taking account of the quality of environmental media in the mining area, and used as case study in the present paper. The associated risks are a function of the environmental impacts and the probability of their occurrence. The results show that the environmental impacts and quantified risks, based on quality indicators to characterize the environmental quality, are of a higher order, and thus measures for pollution remediation and control need to be considered in the investigated area. The conclusion drawn is that an integrated approach for the assessment of environmental impact and associated risks is a valuable and more objective method, and is an important tool that can be applied in the decision-making process for national authorities in the prioritization of emergency action.

Apart from the generation of fly ash, brine (hyper-saline wastewater) is also a waste material generated in South African power stations as a result of water re-use. These waste materials contain major species such as Al, Si, Na, K, Ca, Mg, Cl and SO₄. The co-disposal of fly ash and brine has been practiced by some power stations in South Africa with the aim of utilizing the fly ash to capture the salts in brine. The effect of the chemical interaction of the species contained in both fly ash and brine, when co-disposed, on the mobility of species in the fly ash–brine systems is the focus of this study. The up-flow percolation test was employed to determine the mobility of some major species in the fly ash–brine systems. The results of the analysed eluates from the up-flow percolation tests revealed that some species such as Al, Ca and Na were leached from the fly ash into the brine solution while some species such as Mg, Cl and SO₄ were removed to some extent from the brine solution during the interaction with fly ash. The pH of the up-flow percolation systems was observed to play a significant role on the mobility of major species from the fly ash–brine systems. The study showed that some major species such as Mg, Cl and SO₄ could be removed from brine solution using fly ash when certain amount of brine percolates through the ash.

Sorption characteristics of phenanthrene were studied in batch equilibrium experiments with 32 Australian soils that varied widely in physicochemical properties. Sorption of phenanthrene varied widely among the soils and was generally nonlinear, with the nonlinearity index (n) of the Freundlich isotherm varying from 0.62 to 1.01. Simple regression analyses revealed that total organic carbon (TOC) accounts for about 68 % of the variation in the partition coefficient (K′ f ) for sorption among the soils at an equilibrium concentration (C e ) of 0.05 mg/L. The organic carbon normalized distribution coefficient (K OC ), varied considerably between soils with >70 % of the variance of logK OC being accounted for by logTOC, clay and log dissolved organic carbon (DOC). These results show that the phenanthrene C e is influenced by both TOC as well as the DOC in soil suspensions. The effects of ionic strength (IS) and index cation were investigated using four contrasting soils. Results show that with an increase in IS from 0.03 to 0.15 M sorption of phenanthrene generally increased in CaCl2 background solutions, whereas the effect was less significant and variable in NaCl background solutions. Sorption of phenanthrene was slightly higher at low IS (0.03 M) with Na+ as index cation compared with that of Ca2+, whereas an opposite trend was observed at higher IS (0.15 M). For two soils high in TOC, the flocculation of endogenous DOC in the presence of Ca2+ reduced the influence of background electrolyte and resulted in a more linear sorption isotherm as well as higher sorption capacity. This trend was more significant with Ca2+ relative to Na+. © 2013 Springer Science+Business Media Dordrecht.

The sorption of chromium (Cr) species to soil has become the focus of research as it dictates the bioavailability and also the magnitude of toxicity of Cr. The sorption of two environmentally important Cr species [Cr(III) and Cr(VI)] was examined using batch sorption, and the data were fitted to Langmuir and Freundlich adsorption isotherms. The effects of soil properties such as pH, CEC, organic matter (OM), clay, water-extractable SO₄ ²– and PO₄ ³–, surface charge, and different iron (Fe) fractions of 12 different Australian representative soils on the sorption, and mobility of Cr(III) and Cr(VI) were examined. The amount of sorption as shown by K f was higher for Cr(III) than Cr(VI) in all tested soils. Further, the amount of Cr(III) sorbed increased with an increase in pH, CEC, clay, and OM of soils. Conversely, the chemical properties of soil such as positive charge and Fe (crystalline) had a noticeable influence on the sorption of Cr(VI). Desorption of Cr(VI) occurred rapidly and was greater than desorption of Cr(III) in soils. The mobility of Cr species as estimated by the retardation factor was higher for Cr(VI) than for Cr(III) in all tested soils. These results concurred with the results from leaching experiments which showed higher leaching of Cr(VI) than Cr(III) in both acidic and alkaline soils indicating the higher mobility of Cr(VI) in a wide range of soils. This study demonstrated that Cr(VI) is more mobile and will be bioavailable in soils regardless of soil properties and if not remediated may eventually pose a severe threat to biota.

Biochars derived from the straws of rice, soybean, and peanut were prepared and modified with aluminum [Al(III)]. These modifications shifted zeta potential-pH curves of the biochars in a positive-value direction and changed surface charge of biochars from negative to positive under acidic conditions. The isoelectric points for 0.6 M Al(III)-modified rice, soybean, and peanut straw biochars were 8.0, 7.8, and 7.5, respectively. Electrostatic attraction of the positively charged surfaces on Al(III)-modified biochars to arsenate [As(V)] enhanced its sorption. The sorption of As(V) by these Al(III)-modified biochars was investigated in batch experiments. Al(III)-modified biochars had greater sorption capacity under acidic conditions compared with corresponding unmodified biochars. While unmodified biochars sorbed negligible amounts of As(V), their Al(III)-modified forms sorbed 445-667 mmol kg-1 at pH 5.0, which were predicted by the Langmuir equation. Modifications with 0.3 M Al3+ improved sorption capacity of As(V) on soybean straw biochar to 445 mmol kg-1, which was further increased by 50 % after modification with 0.6 M Al3+. These As(V) sorption capacities of biochars modified with 0.6 M Al3+ were larger than those of Fe/Al oxides determined at the same pH, which were < 500 mmol kg-1. Thus, biochars modified with 0.6 M Al3+ could substitute Fe/Al oxides used for water purification. However, the sorption of As(V) by the Al(III)-modified biochars increased with decreasing suspension pH. Thus, As(V) removal by Al(III)-modified biochars is suggested to be conducted under acidic conditions, but at pH > 4.0. © 2013 Springer Science+Business Media Dordrecht.

To clarify the relationship between the transport distance of spheroidal carbonaceous particles (SCPs) and particle size, we investigated the spatial distribution of SCP sizes in swimming pool deposits in the central Osaka Plain, central Japan. Median particle size of SCPs generally decreases with distance (0 to ∼20 km) downwind from the local coastal industrial area where SCP sources are distributed widely. This suggests that most SCPs found in the study area are derived from the industrial area. Samples with >40 % of particles >20 μm were predominantly collected within 2 km of the industrial area, while samples with >40 % of particles <10 μm were mostly collected over 10 km from the industrial area. Based on the results of our study and previous studies, we conclude that a higher proportion of particles of size >20 μm indicates that the origin of SCPs is within a few kilometres upwind of the sample site, whereas the presence of higher proportion of particles <10 μm indicates that their source is generally further than 10 km upwind. However, other factors may affect the size distribution of SCPs at a given location (e.g. fuel type, quality of the particle precipitator and topography of the terrain). Pool deposits provide more suitable samples than lake sediments for investigating atmospheric precipitation.

In this study, the effectiveness of subcritical water extraction (SCWE) was assessed by extracting four pesticides, namely diazinon, parathion, phenthoat, and EPN, from contaminated soil. The extraction efficiencies of different temperatures (25, 75, 100, 125, and 150 C); times (10, 20, 30, and 40 min); pressures (1, 2, and 3 MPa); and water flow rates (0.5, 0.7, 1.0, and 1.5 mL/min) were investigated. The optimum temperature, time, pressure, and flow rate were found to be 150 C, 20 min, 2 MPa, and 0.5 mL/min, respectively, in lab-scale. At this operating condition, the residual concentration of pesticide was less than 0.5 mg/kg, corresponding to an extraction efficiency of 99.9 %. The aim of this study was to also evaluate the removal efficiency on 30- and 167-fold scale-up extraction at optimum extraction condition obtained from lab-scale studies. The scale-up method considering constant ratio of the volume of water to soil mass was a feasible procedure. The results of our study suggest that SCWE is a promising option for effective disposal of pesticide- contaminated soil. © 2013 Springer Science+Business Media Dordrecht.