Abstract  The study is aimed at the analysis of the spatial-structural organization of Pb(II) in Chernozem soils and the relationship between the metal ion and the soil components using X-ray absorption spectroscopy and chemical extractive fractionation. In a model experiment, soil samples were artificially contaminated with elevated rates of Pb(NO3)(2) and PbO (2000 and 10,000 mg kg(-1)). The samples of mineral phases (bentonite, gibbsite, kaolinite, calcite, and hydromuscovite) were saturated with Pb2+ ions. The sequential fractionation of Pb in the soil was conducted by the Tessier method. X-ray absorption near-edge fine structure (XANES) spectra at the Pb L-III-edge (13.040 keV) were obtained on a Rigaku R-XAS Looper spectrometer. Extended X-ray absorption fine structure (EXAFS) L-III-edge Pb was measured at the Structural Materials Science beamline of the Kurchatov Center for Synchrotron Radiation. The results of successive extraction showed that Pb is associated with strongly bound organic substances, Fe and Mn (hydr)oxides, and carbonates. An increase in the portion of exchangeable fraction is observed under extreme loads. At the addition of Pb in the form of oxide and nitrate to the soil, the fractional compositions were similar, which indicates the good transformation of PbO in Chernozem. The features of XANES spectra indicate different orbital transitions in the electron shells of Pb2+ ions for monoxide (PbO) and soluble salt (Pb(NO3)(2)), which affect the ion properties and determine the individual structure of the coordination sphere. The analysis of XANES revealed that sorption of Pb in the soil samples and in the samples of mineral phases does not change its bond valence. The increased degree of soil contamination with Pb is accompanied by decreasing the stable connection between metal and soil components. Lead ions in bentonite, kaolinite, hydromuscovite, gibbsite, and calcite are incorporated in the positions of the inner-sphere complex replacing some aluminum ions in the octahedral sites. This results in changes the Pb-O distances in Pb-bearing octahedrons. We may suggest that Pb2+ is also sorbed by dimer (Pb-Pb) silicate and/or aluminum groups. The structure of adsorbent surface plays the key role in the sorption of Pb2+ by mineral phases.

Abstract  Metal nanoparticles have been reported to influence plant growth and productivity. However, the molecular mechanisms underlying the effects have not been completely understood yet. Current work describes the physio-biochemical basis of iron sulfide nanoparticle induced growth and yield enhancement in Brassica juncea. Iron sulfide nanoparticles (0, 2, 4, 6, 8 and 10 ppm) were used for foliar treatment of B. juncea at 30, 45 and 60 days after sowing, under field conditions. Foliar treatment of 4 ppm iron sulfide nanoparticle solution at 30 days after sowing brought maximal enhancement in agronomic attributes of the treated plants. Results of assays i.e. total chlorophyll, electrolyte leakage, Malondialdehyde (MDA), proline, H2O2 and antioxidant enzyme activities indicated the benign effect of iron sulfide nanoparticles on plants. Consequently, improved redox status of the treated plants, enabled them to assimilate higher photosynthate. The augmentation in growth and seed yield in iron sulfide nanoparticle treated plants was amply supported by activation of RUBISCO small subunit (rubisco S), RUBISCO large subunit (rubisco L), glutamine synthetase (gs) and glutamate synthase (gogat) genes. Thus, iron sulfide nanoparticle induced growth and yield enhancement is proposed to be mediated through activation of carbon and nitrogen assimilatory pathways at specific growth stage. The iron content in the leaves and root tissues of the treated plants was also significantly improved.

Abstract  Reactions of manganese benzoate dihydrate and lanthanide nitrate hexahydrate with 2-(hydroxymethyl)pyridine (hmpH) as ligand in the mixture solutions of acetonitrile and ethanol according to different molar ratios of NEt3 generated two kinds of Mn-Ln compounds[(Mn4La2III)-La-III(O)(2)(hmp)(7)(PhCO2)(2)(NO3)(5)] center dot 5H(2)O(1) and [(Mn2Gd2III)-Gd-III(hmp)(6)(PhCO2)(4)(NO3)(2)] center dot 3CH(3)CN center dot 3C(2)H(5)OH center dot 2H(2)O (2). By comparison of the two compounds, there exist considerable effects of reaction alkalinity on the structures and magnetic properties of products. Compound 1 possesses a core of [(Mn4La2III)-La-III(mu(4)-O)(mu(3)-O)(mu(3)-OR)(mu(2)-O)(7)](2-), which comprises three face-sharing defected cubane units. The core topology represents a new core type of Mn-Ln clusters. Compound 2 has a planar-butterfly structure. The solid-state dc magnetic susceptibility analyses indicate the antiferromagnetic interactions within compound 1 and ferromagnetic interactions within compound 2. Compound 1 has an S = 0 ground state, while compound 2 possesses an S = 11 ground state, fitting of the dc data for the tetranuclear Mn2Gd2 with the Magpack program gives parameters of J(Mn-Mn) = 3.11 cm(-1), J(Mn-Gd) = 0.02 cm(-1) and g = 1.96.

Abstract  Preparates containing active microorganisms (bacteria, fungus) were tested in the field experiment with maize (Zea mays L.) on cambisol at Lipa site in combination with phosphorus (rock phosphate or triple superphosphate) and nitrogen fertilizers (calcium nitrate or ammonium sulfate with a nitrification inhibitor). Application of active microorganisms had statistically significant effect only on the sulfur content, which was probably due to the application of ammonium sulphate. Due to relatively balanced content of other selected elements in plants as well as above ground dry mass yield among treatments, it is not possible to clearly prove positive effect of bioeffectors.

Abstract  Nitrosamines such as N-nitrosodiethylamine (NDEA) are commonly detected by spectrophotometry after photolysis and Griess reaction (PG) in food industries for lower cost. Results of this research indicate that NDEA decays rapidly under UV irradiation, and concentrations of the generated NO2- and NO3- ions vary with photolysis conditions. Thus, the measurement of the PG method may be inconsistent because it is based on the amount of photoproduced NO2-. In addition, more errors may be present in the PG method since NO3- cannot be measured colorimetrically using Griess reagent. In this work, the sum of the concentrations of photoproduced NO2- and NO3- was found to be equivalent to the initial NDEA before photolysis, and a photolysis ion chromatography method was validated, which may serve as a feasible and accurate method to determine nitrosamines. Copyright (C) 2015, Food and Drug Administration, Taiwan. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license.

Abstract  The terrestrial biosphere's ability to capture carbon is dependent upon soil nitrogen (N) availability, which might reduce as CO2 increases, but global warming has the potential to offset CO2 effects. Here we examine the interactive impact of elevated CO2 (eCO(2)) and warming on soil N availability and transformations in a low-fertility native grassland in Tasmania, Australia.

Using ion exchange membranes, we examined soil nitrogen availability during the growing season from 2004 to 2010 in the TasFACE experiment. We also estimated soil N transformation rates using laboratory incubations.

Soil N availability varied strongly over time but was more than doubled by experimental warming of 2A degrees C, an impact that was consistent from the fifth year of the experiment to its conclusion. Elevated CO2 reduced soil N availability by 28%, although this varied strongly over time. Treatment effects on potential N mineralisation also varied strongly from year to year but tended to be reduced by eCO(2) and increased by warming.

These results suggest that warming should increase soil N availability more strongly than it is suppressed by eCO(2) in low fertility grasslands such as this, stimulating terrestrial carbon sinks by preventing eCO(2)-induced nitrogen limitation of primary productivity.

Abstract  The Desert Southwest Coarse Particulate Matter Study was undertaken to further our understanding of the spatial and temporal variability and sources of fine and coarse particulate matter (PM) in rural, arid, desert environments. Sampling was conducted between February 2009 and February 2010 in Pinal County, AZ near the town of Casa Grande where PM concentrations routinely exceed the U.S. National Ambient Air Quality Standards (NAAQS) for both PM10 and PM2.5. In this desert region, exceedances of the PM10 NAAQS are dominated by high coarse particle concentrations, a common occurrence in this region of the United States. This work expands on previously published measurements of PM mass and chemistry by examining the sources of fine and coarse particles and the relative contribution of each to ambient PM mass concentrations using the Positive Matrix Factorization receptor model (Clements et al., 2014).

Coarse particles within the region were apportioned to nine sources including primary biological aerosol particles (PBAPs - 25%), crustal material (20%), re-entrained road dust (11%), feedlot (11% at the site closest to a cattle feedlot), secondary particles (10%), boron-rich crustal material (9%), and transported soil (6%), with minor contributions from ammonium nitrate, and salt (considered to be NaCl). Fine particles within the region were apportioned to six sources including motor vehicles (37%), road dust (29%), lead-rich (10%), with minor contributions from brake wear, crustal material, and salt. These results can help guide local air pollution improvement strategies designed to reduce levels of PM to below the NAAQS. (C) 2017 Turkish National Committee for Air Pollution Research and Control. Production and hosting by Elsevier B.V. All rights reserved.

Abstract  Volatilization losses reduce the efficiency of surface-applied urea for crop N uptake, and can be controlled using urease inhibitors to retard hydrolysis or by the presence of other amendments that enhance retention of NH4+ formed by urea hydrolysis. A greenhouse study was conducted to evaluate the effectiveness of oxidized charcoal (OCh; 150 g kg(-1) fertilizer) applied with or without Cu and/or Zn (similar to 0.5-2 g kg(-1) fertilizer), and of Cu and/or Zn applied without OCh, for increasing uptake of urea N-15 by a common tropical pasture grass, capim-Mombasa (Panicum maximum Jacq. Cv. Mombasa), grown on a coarse-textured Oxisol. Cuttings were collected 5, 14, 28, 42, and 56 days after surface placement of amended or unamended urea pellets to estimate dry matter production, total N uptake, and N-15 recovery. Soil sampling was carried out in conjunction with the first and fourth cuts to evaluate exchangeable NH4+ and NO3- concentrations. At the concentrations studied, OCh was more effective than Cu and/or Zn for prolonging NH4+-N availability in urea-treated soil; however, OCh alone or in combination with Zn and Cu had no effect on biomass production or N recovery and can safely be eliminated as a useful option for pasture improvement. The most promising amendment was Zn, which significantly increased total N uptake and the efficiency of urea N fertilization. The use of Zn in conjunction with urea has practical potential to improve forage production on tropical soils. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  Little is known about the natural phenomena that govern the chemical composition of spring waters in Alvand mountain ecosystem. A total of 50 spring water samples of the Avand mountains, Hamadan, western Iran were collected and analyzed for the main components in an effort to both identify ion chemistry and establish background concentrations of major ions and some trace elements (Cd, Fe, Mn, Ni, Zn). The order of relative abundance of major cations in the spring waters was Ca, Mg, Na, K, while that of anions was HCO3, Cl, SO4, NO3. Most spring water samples were undersaturated with respect to calcite. The major water types in spring waters were Ca-HCO3 (group 1), CaHCO3-Cl, CaMg-HCO3Cl, and CaMg-Cl-HCO3 (group 2), which were mainly due to the dissolution of carbonate minerals and silicate weathering and partly due to the ion exchange. Activity diagrams showed that spring waters fall into the kaolinite field due to the short interaction with silicate minerals. In general, mineralization, pH, mean concentrations of Ca, Mg, HCO3, TDS, saturation indices of calcite, dolomite and PCO2 were greater in water samples from the group 1 than in water samples from group 2. Spring waters were mainly soft water (84%) in group 2 and hard water (16%) in group 1. The factor analysis performed on spring water samples identified four factors controlling their variability in spring water samples. Four extracted factors explained 84.7% of data set variance. Factor 1 had the highest factor loadings of EC, HCO3, SO4, Cl, Ca, Mg, Na, Mn, Cd, Ni, and Fe, while factor 2 had the highest factor loadings of Zn. Factors 3 and 4 had the highest factor loading for NO3, P and K, respectively. Factors 1, 2 and 4 together may be related to the dissolution of carbonate minerals (group 1) and silicate weathering, while factor 3 may be due to the anthropogenic input. Different statistical methods were used in the evaluation of background values of the spring waters. Trace element concentration in spring waters was low and associated with local mineralogy. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  Benzotriazole (BT) and 5-methyl-1H-benzotriazole (5-MeBT) are broadly used in industrial applications, such as anti-icing fluids and dishwashing detergent, and act as the primary building blocks for UV absorbers and photostabilizers. This study examined the occurrence of these two compounds in the environment and their unique photochemical behavior affecting photosensitizers and other micro-organic pollutants in aqueous environments. BT and 5-MeBT were detected in all river water samples from the major rivers in Taipei City in the concentration ranges of 147 to 1560 ng/L and 22 to 235 ng/L, respectively, and both compounds persisted through a conventional wastewater treatment plant. The direct photolysis half-lives of BT and 5-MeBT were 56.9 and 14.0 h, respectively. The half-life of photolysis in river water for BT was 44.2 h, whereas the half-life of 5-MeBT was 24.7 h. The long half-lives in real-water matrices resulted in their prevalence in water bodies, and these compounds were also found to minimize the photosensitizing ability of nitrate and dissolved organic matter (DOM) and increase the persistence of other micro-organic pollutant. With BT present, the production of ·OH in nitrate photolysis was reduced, the degradation of DOM under sunlight was hindered, and the photodegradation of pharmaceutical residues in surface water, such as methotrexate, was completely impeded. This study suggests that in cases in which BT and 5-MeBT are highly concentrated, the effectiveness of natural attenuation process, i.e., photodegradation, in the aqueous environment is diminished, which increases the persistence of the pollutants as well as the risk of exposure.

Abstract  In the present work we have tested the effects of graphene doping by nitrate ions and chlorine anions on graphene/n-silicon Schottky barrier solar cells, by the exposure to nitric acid and thionyl chloride vapors. In both cases the graphene doping process had beneficial effects on the power conversion efficiency (PCE) and thionyl chloride doping showed a better improvement than the one obtained with nitric acid. A solar cell with an initial PCE of 1.99% could be increased to 4.02% by nitric acid doping treatment while a solar cell with an initial PCE of 1.49% could be increased to 4.32% by thionyl chloride doping treatment.

Abstract  Al Asfar Lake is a shallow wetland and habitat for wildlife and birds in a desert environment. The water of this lake is originated from the drainage water collected by earthen drainage network and discharged into the lake. The purpose of this study was to assess physico-chemical characteristics and some of heavy metals in Al Asfar lake water. The studied parameters are iron, manganese, copper, zinc, cadmium, chromium, lead, pH, electrical conductivity, and nitrate. Forty-five surface water samples were collected in March 2013. The results revealed that the pH ranged from 7.33 to 8.67, electrical conductivity ranged from 8.28 to 11.34 dS/m, and NO3 ranged from 0.84 to 2.29 mg/L. In addition, heavy metals concentrations in water were found in the following order: Fe > Mn > Cu > Zn > Cd > Cr = Pb. The mean concentrations of heavy metals in surface water of Al Asfar lake ranged from 0.027 to 0.159 ppm, 0.007 to 0.142 ppm, 0.005 to 0.017 ppm, 0.005 to 0.066 ppm, 0.001 to 0.033 ppm, 0 ppm, and 0 ppm for iron, manganese, copper, zinc, cadmium, chromium, and lead, respectively. Moreover, pH, NO3-, Fe, Mn, and Zn concentrations in the surface water of Al Asfar Lake were found to be within the international permissible limits. On the other hand, Cu and Cd concentrations exceeded the international permissible limits. The high level of some parameters of the measured heavy metals could be attributed to the contamination of Al Asfar Lake with discharge water enriched with chemical fertilizers in addition to domestic and industrial effluents.

Abstract  Organic carbon export and burial in coastal upwelling regions is an important mechanism for oceanic uptake of atmospheric CO2. In order to understand how these complex systems will respond to future climate forcing, further studies of nutrient input, biological production and export are needed. Using a Be-7-based approach, we produced an 18-month record of upwelling velocity estimates at the San Pedro Ocean Time-series (SPOT), Southern California Bight. These upwelling rates and vertical nutrient distributions have been combined to make estimates of potential new production (PNP), which are compared to estimates of net community oxygen production (NOP) made using a one-dimensional, two-box non-steady state model of euphotic zone biological oxygen supersaturation. NOP agrees within uncertainty with PNP, suggesting that upwelling is the dominant mechanism for supplying the ecosystem with new nutrients in the spring season, but negligible in the fall and winter. Combining this data set with estimates of sinking particulate organic carbon (POC) flux from water column Th-234:U-238 disequilibrium and sediment trap deployments, and an estimate of the ratio of dissolved organic carbon (DOC):POC consumption rates, we construct a simple box model of organic carbon in the upper 200 m of our study site. This box model (with uncertainties of +/- 50%) suggests that in spring, 28% of net production leaves the euphotic zone as DOC, of this, similar to 12% as horizontal export and 16% via downward mixing. The remaining similar to 72% of net organic carbon export exits as sinking POC, with only 10% of euphotic zone export reaching 200 m. We find the metabolic requirement for the local heterotrophic community below the euphotic zone, but above 200 m, is similar to 105 +/- 50 mmol C m(-2) d(-1), or similar to 80% of net euphotic zone production in spring. (C) 2016 Elsevier Ltd. All rights reserved.

Abstract  Eutrophication is a complex process and often associated with not only a change in overall algal biomass but also with a change in biodiversity. Common metrics of eutrophication (e.g., chlorophyll a), total nitrogen (TN) and phosphorus (TP) are not adequate for understanding biodiversity changes, especially those associated with harmful algal bloom (HAB) proliferations. Harmful algae can increase disproportionately with eutrophication, depending on which nutrients change and in what proportion. This paper challenges several classic paradigms in our understanding of eutrophication and associated biodiversity changes. The underlying message is that nutrient proportions and forms can alter biodiversity, even when nutrients are at concentrations in excess of those considered limiting. The global HAB problem is on a trajectory for more blooms, more toxins, more often, in more places. Our approach to management of HABs and eutrophication must consider the broader complexity of nutrient effects at scales ranging from physiological to ecological.

Abstract  The effect of lanthanum content on catalytic properties of cobalt catalysts for ammonia synthesis has been studied. The amount of La in the studied catalysts ranged from 0 to 55.7 wt.%, whereas the barium content was constant (approx. 1.5 mmol g(co)(-1)). The characterization studies included a determination of properties of the catalysts precursors (N-2 physisorption, XRPD), as well as the catalysts in the active form (TPR-MS, XRPD, SEM-EDX and H-2 chemisorption). The activity of the obtained Co/La/Ba catalysts in NH3 synthesis was tested in a flow differential reactor operating under conditions close to the industrial ones (p = 6.3 MPa, T= 400 degrees C, H-2/N-2 = 3:1). It has been found that lanthanum plays the role of an effective structural promoter. However, there is a strong correlation between the La content in the catalysts and their properties: increasing amount of lanthanum is accompanied by the improvement in textural properties of both the precursors and catalysts in the reduced form. Lanthanum does not work as an activator for the cobalt surface. The increase in the activity of Co/La/Ba catalysts was observed as a result of a development of the active phase surface by increasing the La content. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  In the current investigation, we have reported on the preparation of mordenite zeolite nanostrUctures using a low-cost hydrothermal treatment of silica gel, aluminum nitrate, and sodium hydroxide. The influence of organic templates such as ethylene glycol, glycerol, and polyethylene glycol 200 (PEG 200) on the zeolite products was studied. The crystallite sizes of the as-fabricated samples increased in the following order: (PEG 200) < (ethylene glycol) < (glycerol) < (without template). The PEG 200 organic template generated a mordenite product with 57.51 nm crystallite size and 28.26 m(2)/g BET surface area. The as-prepared products were identified using FE-SEM, FT-IR, XRD, HR-TEM, and BET analysis. The as-prepared mordenite product could be successfully applied to purify the crude soybean oil from the yellow and red colors. The mordenite product also showed good adsorption properties toward the removal of methylene blue (MB) dye from wastewater. Kinetic data exhibited that the dye adsorption process obeyed pseudo-first-order, intra-particle diffusion, liquid film diffusion, and pore diffusion models whereas the rate determining step of the adsorption is only controlled by the pore diffusion model. Adsorption data fitted well both Langmuir and Dubinin-Radushkevich (D-R) isotherm models. Moreover, the adsorption is a physisorption and exothermic process. (C) 2017 Elsevier B.V. All rights reserved.

Abstract  This paper presents the results of research on the impact of the composition of wastewater discharged from a hybrid constructed wetland wastewater treatment plant on the quality of water in the Urzedowka River, a right tributary of the WyZnica River. During the years 2011-2013, samples of treated wastewater and water from the river were collected (upstream and downstream of the wastewater discharge point) and subjected to physicochemical analysis and, in 2013, also to microbiological analysis. The study showed that the treated wastewater outflowing from the treatment plant did not have any negative influence on the quality of the water in the receiver. Water from the Urzedowka River met clarity standards for class I waters; only the concentrations of total phosphorus and nitrate nitrogen exceeded the limit values for water clarity class II. The studies have shown that waters from the Urzedowka River upstream of the treatment plant contained a huge concentration of E. coli bacteria, fecal coliform bacteria and fecal enterococci, which indicates the impact of other sources of microbiological pollution.

Abstract  Survey and monitoring rangelands projects is one the important plans in rangelands management. For this purpose, the survey and monitoring methods could be time-consuming and costly. Sampling strategies of plant patches are effective in sampling procedures that cause minimizing sampling variance and time. In this study, for decreasing sampling time and cost, increasing speed, plant patches parameters (including length, width, height, area, and distance between the patches) were compared. Three transects with 50 m length at three aspect slopes were located randomly systematic at the selected site with different grazing intensities. Soil samples for nitrate (NO3-), total nitrogen (TN), ammonium (NH4+), phosphorus (P), sodium absorption ration (SAR), soil acidity or soil reaction (pH), sodium (Na), electrical conductivity (EC), organic carbon (OC), and potassium (K) content were taken in these transects. The data were subjected to analysis of variance (ANOVA), and the average of the measured parameters in the transects was compared by Duncan Multiple Range test using SPSS16 software. The soil characteristics compared between the regions were analyzed with Discriminant Function Analysis using STATISTICA(10) software. Results showed that the transect slope aspect and soil characteristics had an effect on measured parameters. It was suggested to withdraw the located transect at one of the North or South and West or East Slope aspects for increasing sampling efficiency. It was also suggested that to avoid time consumtion, sampling can be recorded on plant patches' width instead of area. It is also suggested that it would be better to record the length of the plant patches instead of their area in the non-grazed zones and record the length and the width of the plant patches in the moderate-and the high-grazed zones.

Abstract  It has been demonstrated that sonophotodeposition can be one choice as a green method to synthesize bimetallic supported photocatalysts with enhanced performance for selective oxidations. A series of Pd-Cu supported on Titania-P90 photocatalysts were successfully prepared using this innovative method of effective synergistic combination of sonication and light. In addition, our method does not require the use of strong chemical reduction agent and it is executed in a short time, room temperature and atmospheric pressure. The prepared materials were characterized by a number of techniques such as High-Resolution Transmission Electron Microscopy (HRTEM), DR UV-vis spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and powder X-ray diffraction (XRD). Additionally, better bimetallic systems were obtained (methanol conversion >50% and selectivity to methyl formate >80%) by SonoPhotoDeposition (SPD) than in the case of the conventional photodeposition methodology. It has been discussed the possible reasons of the observed slight deactivation (8% after 2 h reaction test) of the best performing material in gas phase methanol selective photo-oxidation. (C) 2015 Elsevier B.V. All rights reserved.

Abstract  In this paper, the influence of structural and textural characteristics of sulfide minerals on their leaching from a polymetallic concentrate by sulfuric acid and sodium nitrate solution is presented. The starting material was Pb-Zn-Cu sulphide polymetallic concentrate enriched during the flotation of a polymetallic ore in the "Rudnik" flotation plant (Rudnik - Serbia). Leaching experiments were carried out in a closed glass reactor, which provides stable hermetic conditions and allows heating at constant temperature. Chemical, XRD, qualitative and quantitative microscopic and SEM/EDX analyses were used to characterizes samples of the polymetallic concentrate and leach residue. It was determined that chalcopyrite, sphalerite, galena, pyrrhotite and quartz were present in the polymetallic concentrate. The content of sulphide minerals was 69.5%, of which 60.9% occurred as liberated grains: 88.3% of chalcopyrite, 59.3% of sphalerite, 25.1% of galena and 51.6% of pirrhotite. The rest of chalcopyrite, sphalerite, galena and pirrhotite grains were in the forms of inclusions, impregnations, and simple and complex intergrowths. During the leaching process by sodium nitrate and sulphuric acid solution, it was shown previously that the leaching rate of sulphide minerals decreased with time while a part of the sulphide minerals remained in the leach residue. After leaching at 80 degrees C for 120 min, the yields were 69.8, 82.7 and 67.1% for Cu, Zn and Fe, respectively. Lead, in the form of insoluble anglesite, remained in the leach residue. In addition to the anglesite, unleached sulfide minerals and quartz, elemental sulfur was found in the solid residue. The content of sulphide minerals was 35% of which 33.7% minerals occur independently. In specific, 54.7% of chalcopyrite, 31.9% of sphalerite, 8.2% of galena and 37.6% of pyrrhotite appear as separate grains with highly corroded surfaces. Therefore, the structural assembly of sulphide grains in the polymetallic concentrate is favourable and it is not the reason for the observed decrease in the leaching rate in the final process stages. The obtained findings may be explained by the presence of elemental sulphur that is formed during the reaction and precipitated at the grain surfaces, thus creating a diffusion barrier for the leach solution.

Abstract  The water samples from Rasina District (Serbia) were evaluated for principal physical and chemical parameters, as well as for microbiological contaminants. Results were compared to National and World Health Organization (WHO) water quality standards. Several samples contained total organic matter, ammonia, residual chlorine, nitrite, nitrate, iron and manganese above proposed legislation limits. For samples contaminated with faecal bacteria, Streptococcus faecalis, aerobic mesophilic bacteria, coliform bacteria and sulfite-reducing clostridia special attention should be payed to drinking water disinfecting methods. The potential health risks of waterborne diseases due to consumption of water from contaminated sources could be implied.

Abstract  V2O5/S-doped TiO2 was prepared by the sol-gel and impregnation methods. The adsorption of NO, NH3, and O-2 over the catalyst was studied by in situ DRIFTS spectroscopy to elucidate the reaction mechanism of the low-temperature selective catalytic reduction of NO with NH3. Exposing the catalyst to O-2 and NO, three types of nitrates species appeared on the surface. The introduction of S to TiO2 could generate large amounts of acid sites for ammonia adsorption on the catalyst, which was believed to be an important role in the SCR reaction and hereby improved the catalytic activity. The results indicated two possible SCR reaction pathways for catalyst. One was that NO was absorbed to form nitrite species, which could react with NH3 on Lewis acid sites, producing N-2 and H2O. Another way was that NH3 was adsorbed, then reacted with gas phase NO (E-R) and nitrite intermediates on the surface (L-H).

Abstract  This paper investigates the problem of the sustainable ammonium nitrate transport. The significance of this problem is increasing, considered the occurrence of the worldwide agricultural production boost. The existing international regulations for the transport of the dangerous chemical substances are not sufficient to obtain a satisfactory solution for the sustainable transport. The main reason for that is the fact that the safety criteria can easily become dominated by the economic factors.

In this paper, the authors use the COMET method to identify a decision making model for the selection of the best scenario of sustainable transport. The COMET method is a new multicriteria decision-making technique that is free of the rank reversal phenomenon. The identified model provides information about the global and local significance level of each of the criteria. The proposed approach can be easily expanded by using a greater number of criteria, depending on the particular problem analyzed. The proposed methodology is an efficient and highly accurate solution to make decisions based on experts' knowledge.

Abstract  The demand for seedlings of Brazilian native tree species has increased due to the growing number of recovery projects for degraded areas. In order to obtain success in the revegetation, high quality seedlings should be used. Among the factors that affect the quality of seedlings there is nitrogen fertilization, since nitrogen (N) is one of the nutrients required in the largest amount by plants. Thus, this study aimed to evaluate the response of Cassia grandis and Peltophorum dubium seedlings to N sources and doses. The treatments were represented by a factorial of three sources (ammonium nitrate, calcium nitrate and ammonium sulfate) by five N doses (0, 50, 100, 150 and 200 mg dm(-3)), arranged in randomized complete block design, with four replicates. After 145 days of sowing, were obtained: height (H), collar diameter (CD), shoot dry matter (SDM), root dry matter (RDM), total dry matter (TDM), and calculated the dry matter mass ratio of shoot and root (SDM/RDM) and the Dickson Quality Index (DQI). Nitrogen fertilization resulted in growth gains and improved the seedlings quality of both species. However, the sources and the source x doses interaction were not significant for all variables. For the studied substrate (Red-Yellow Latosol) the recommended dose is 185 mg dm-3 of N for the production of Peltophorum dubium seedlings. For the production of Cassia grandis seedlings was not able to find the optimum dose of N.

Abstract  The study of metal-tolerant bacteria is important for bioremediation of contaminated environments and development of green technologies for material synthesis due to their potential to transform toxic metal ions into less toxic compounds by mechanisms such as reduction, oxidation and/or sequestration. In this study, we report the isolation of seven lead-tolerant bacteria from a metal-contaminated site at Zacatecas, México. The bacteria were identified as members of the Staphylococcus and Bacillus genera by microscopic, biochemical and 16S rDNA analyses. Minimal inhibitory concentration of these isolates was established between 4.5 and 7.0 mM of Pb(NO3)2 in solid and 1.0-4.0 mM of Pb(NO3)2 in liquid media. A quantitative analysis of the lead associated to bacterial biomass in growing cultures, revealed that the percentage of lead associated to biomass was between 1 and 37% in the PbT isolates. A mechanism of complexation/biosorption of lead ions as inorganic phosphates (lead hydroxyapatite and pyromorphite) in bacterial biomass, was determined by Fourier transform infrared spectroscopy and X-ray diffraction analyses. Thus, the ability of the lead-tolerant isolates to transform lead ions into stable and highly insoluble lead minerals make them potentially useful for immobilization of lead in mining waste.