Application of an agricultural residue (rice husk, RH) as a raw material for catalyst support for advanced oxidative processes (AOPs) was evaluated. The supported catalyst was produced by the calcination of TiCl₄ impregnated in RH, thereby providing a composite TiO₂/Si-C, which was characterized by elemental analysis (CHN), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX), X-ray photoelectron spectroscopy (XPS), UV/VIS diffuse reflectance spectroscopic (DRS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), atomic force microscopy (AFM), SEM, and nitrogen adsorption–desorption isotherms (BET and BJH). Catalytic photodecomposition of methylene blue (MB), naphthalene, phenol, and abamectin and acid drainage of a mine by a titania-based catalyst composite were investigated. For comparative purposes, a commercial photocatalyst (TiO₂) was also employed. Photocatalytic degradation of MB, phenol, naphthalene, abamectin, and from coal mining effluent ranged from 8 to 93 % of the initial concentration. Performances of both catalysts were comparable. Additionally, in these evaluated systems, the toxicity of the effluent decreased after photocatalysis, either for Daphnia magna or for Scenedesmus subspicatus (employed as bioindicators).

The current study estimates premature mortality caused by long-term exposure to elevated concentrations of PM₂.₅ (particulate matter with aerodynamic diameter equal to or less than 2.5 μm) in Japan from 2006 to 2009. The premature mortality is calculated based on a relative risk of 1.04 (95 % CI, 1.01–1.08) per 10 μg m⁻³ increase above the annual mean limit of 10 μg m⁻³ taken from the World Health Organization Air Quality Guidelines. The spatiotemporal variations of PM₂.₅ are estimated based on the measurements of suspended particulate matter (SPM) (with aerodynamic diameter approximately less than 7.0 μm) at 1,843 monitors. The improvements of air quality in Japan by reducing the emissions of SPM from 2006 to 2009 could save 3,602 lives based on a reduction target of 10 μg m⁻³ annual mean concentration. This finding could be a tangible benefit gained by reducing the emissions of particulate matter in Japan.

Although concentrations of endocrine-disrupting chemicals (EDCs) in seawaters of Japan are relatively low, vitellogenin and ovotestis inductions are still being observed in some males of mullet and flounder collected in coastal areas. These fish species are benthic and could be affected by EDCs in marine sediments. Therefore, the concentrations of EDCs in marine sediments of Osaka Bay were determined by LC-MS/MS. In addition, the estrogen receptor binding potencies as estrogenic potencies of these sediments were assessed by the medaka estrogen receptor-α binding assay. Results show that estrogenic potencies were higher in sediments of the inner part of the bay especially at station 13 (off Sakai City) where quite strong estrogenic potency was detected. Through calculation of total E2 equivalent concentration (EEQ) in sediments, it was established that approximately 50 % of estrogenic potency was due to nonylphenol (NP), estrone and 17β-estradiol, suggesting that these compounds play important roles as endocrine disruptors in coastal environments of Osaka Bay.

A first-to-date comprehensive climatological aspect of the regime of aerosol loading over the entire broader Greek region (19 E-30 E and 34 N-43 N) is obtained using pixel-level (50 km × 50 km) monthly aerosol optical depth (AOD) products derived from raw Level-2 (10 km × 10 km) MODIS-Terra AOD data at 550 nm. The AOD climatology (for the 8-year period from March 2000 to February 2008) indicates that the study region is significantly loaded by aerosols (mean regional AOD equal to 0.196 ± 0.030 on an annual basis, with values ranging from 0.126 up to 0.382 at pixel level). It is also found that our high-resolution AOD data can reveal spatial patterns that are not evident in studies based on lower resolution data. There is a distinct longitudinal gradient of AODs, with higher values in the eastern than western part of the Greek peninsula. There is also a strong latitudinal gradient with decreasing values from south to north attributed to the presence of the Sahara Desert in northern Africa. The annual AOD cycle presents double maximum values, in spring and summer, and minimum ones in winter. There is also a remarkable year-by-year variability of AOD levels, especially as to their maxima, influenced by varying transport of desert dust, from the south, or biomass burning aerosols, from the north, to the region under prevailing favorable synoptic conditions. In this work, the processing, consisting in averaging over space and time, is done applying/testing five different criteria varying in their flexibility/severity in both spatial and temporal data availability. The criteria selection affects the magnitude of computed regional mean AOD value modifying it by up to 19 %, although the patterns of geographical distribution of AOD and its intra-annual variability do not change drastically. © 2013 Springer Science+Business Media Dordrecht.

One of the major obstacles to zerovalent iron nanoparticles (nZVI) application in soil and groundwater remediation is the limited transport, especially in low-permeability soils. In this study, direct current (constant potential of 5.0 V) was used to enhance polymer-coated nZVI mobility in different porous media, including a bed of glass beads and kaolin clay. The tests were conducted using a modified electrophoretic cell and with nZVI concentrations typical of field applications (4 g L-1). Experimental results indicate that the use of direct current can enhance the transport of the polymer-modified nanoparticles when compared with natural diffusion in low permeability or surface neutral porous medium. The applied electric field appeared to enhance the oxidation-reduction potential, creating a synergistic effect of nZVI usage with electrokinetics. Aggregation of the nanoparticles, observed near the injection point, remained unresolved. © 2013 Springer Science+Business Media Dordrecht.

Rhizoremediation is a complex type of green clean-up technology that involves both plants and the rhizosphere-associated microorganisms to decompose hazardous compounds. The success of the strategy strongly depends on plant tolerance towards the pollutant, as well as plant's interactions with the rhizospheric microbes. The microorganisms may be stimulated by the secreted root exudates, which results in an increased breakdown of contaminants in the rhizosphere. The main goal of this study was to establish a potential rhizoremediation combination for a diesel-polluted site. Inoculation of plant roots or seeds with indigenous rhizospheric populations is a common approach in the rhizoremediation. However, we introduced hydrocarbon-degrading consortia (M10, R3, and K52) that were previously isolated from crude oil-contaminated soil instead of indigenous microbes. Bioaugmentation with these petroleum degraders was applied to screen four high biomass crop species (Indian mustard, alfalfa, high erucic acid rapeseed, HEAR, and low erucic acid rapeseed, LEAR) for their tolerance towards diesel oil. At no pollution, a promoting effect of M10 bacteria could be observed on germination and root elongation of all plant species. Moreover, M10 consortiums increased the germination index at 6,000 mg diesel oil per kilogram dry soil in the case of Indian mustard, alfalfa, and HEAR. The latter species was found to increment its dry weight upon bioaugmentation with M10 bacteria and all diesel oil treatments (6,000 and 24,000 mg diesel oil per kilogram dry soil). The initial results indicate HEAR and the M10 bacterial consortium as a promising plant-microbe tandem for a long-term rhizoremediation process. © 2013 The Author(s).

In this study, we have reported the synthesis of new amino-substituted p-tert-butylcalix[4]arene (3) and its application for the removal of two carcinogenic azo dyes, i.e., Chicago Sky Blue (CSB) and Tropaeolin 000 (TP) from aqueous environment. The newly synthesized calix–ligand 3 is characterized by FT-IR and ¹H NMR spectroscopy as well as elemental analysis. The extraction efficiency of newly calix–ligand 3 for CSB and TP dyes from aqueous media was evaluated through liquid–liquid extraction experiments. The newly synthesized calix–ligand 3 showed outstanding extraction percentage and maximum percent extraction, i.e., 97 and 96 % of CSB and TP dyes was achieved at pH 9, respectively. During the extraction process, effect of various parameters was monitored and found that extraction is highly dependent on pH and salinity. Moreover, cyclic structure, cavity size, functional groups of the calixarene derivative, hydrophobicity, and the ionic property of guest molecules also affect the extraction efficiency. The comparative data prop up calix–ligand 3 as an effective extractant for both CSB and TP dyes.

Chlorpyrifos (O, O-diethyl-O-(3,5,6-trichloro-2-pyridyl) phosphorothioate) is a broad-spectrum organophosphate insecticide and acaricide, widely used in our country. Nowadays, it is the principal insecticide in the market employed for agricultural purposes. A number of studies tending to study the affinity of different pesticides with soil have been performed, but only a few refer to chlorpyrifos. Because of its intensive use, a wide range of terrestrial ecosystems may be contaminated with chlorpyrifos, and there is a need to evaluate its environmental behavior and effects. The aim of our work is to study the interaction and persistence of a commercial formulation of chlorpyrifos on an agricultural soil from Provincia de Buenos Aires, Argentina. In this case, recovery percentages increased with the increase of initial concentration of the pesticide until a concentration of about 25 ppm is reached, and then a decrease was observed. The half-time life was not affected by an increase in chlorpyrifos concentration.

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.

Land use in east China tends to change from paddy rice to vegetables or other high-value cash crops, resulting in high input rates of organic manures and increased risk of contamination with both heavy metals (HMs) and antibiotics. This investigation was conducted to determine the accumulation, distribution and risks of HMs and tetracyclines (TCs) in surface soils and profiles receiving different amounts of farmyard manure. Soil samples collected from suburbs of Hangzhou city, Zhejiang province were introduced to represent three types of land use change from paddy rice to asparagus production, vineyards and field mustard cultivation, and divided into two portions, one of which was air-dried and sieved through 2-, 0.3- and 0.149-mm nylon mesh for determination of pH and heavy metals. The other portion was frozen at -20 °C, freeze-dried and sieved through a 0.3-mm nylon mesh for tetracyline determination. HM and TC concentrations in surface soils of 14-year-old mustard fields were the highest with total Cu, Zn, Cd and ∑TCs of 50.5, 196, 1.03 mg kg(-1) and 22.9 μg kg(-1), respectively, on average. The total Cu sequence was field mustard > vineyards > asparagus when duration of land use change was considered; oxytetracycline (OTC) and doxycycline were dominant in soils used for asparagus production; OTC was dominant in vineyards and chlortetracycline (CTC) was dominant in mustard soils. There were positive pollution relationships among Cu, Zn and ∑TCs, especially between Cu and Zn or Cu and ∑TCs. Repeated and excessive application of manures from intensive farming systems may produce combined contamination with HMs and TCs which were found in the top 20 cm of the arable soil profiles and also extended to 20-40 cm depth. Increasing manure application rate and cultivation time led to continuing increases in residue concentrations and movement down the soil profile.