Abstract  A novel photocatalysis-membrane reactor (PMR) is designed by coupling Ag/BiOBr visible-light photo catalysis with thermal driven membrane distillation. Ag/BiOBr films coated on glass substrates in a thin rectangular wastewater tank could avoid light-shielding effect from color solution containing dye pollutant. Meanwhile, Ag-modification promotes the photocatalysis process owing to both the plasma effect and electric conductivity, which could enhance absorbance capability for visible lights and facilitate the separation of photo-induced electrons from holes to inhibit their recombination. When the PMR is used for treating wastewater containing picrolonic acid (PC), Ag/BiOBr photocatalyst could thoroughly decompose PC into CO2 and inorganic nitrogen species (such as NO2-, NO3- and NH4+) under visible lights irradiation on the feed side. At the same time, membrane distillation could produce high-quality water on the permeate side as the distillate product. Polytetrafluoroethylene (PTFE) membrane could stop the pass of PC and as-produced nitrogen species into water side due to its hydrophobic property and the non-volatile nature of both PC and nitrogen species. Moreover, as membrane distillation only allow water transporting through the membrane, such a membrane distillation process also promotes photocatalysis since it could retard the decrease of PC concentration during its degradation by transporting water to the other side. (C) 2017 Elsevier B.V. All rights reserved.

Abstract  Nitrate (NO3-) leaching and nitrous oxide ((NO)-O-2) emission from urine patches in grazed pastures are key sources of water and air pollution, respectively. Broadcast spraying of the nitrification inhibitor dicyandiamide (DCD) has been shown to reduce these losses, but it is expensive. As an alternative, it had been demonstrated that feeding DCD to cattle (after manual mixing with supplementary feeds) was a practical, effective and cheaper method to deliver high DCD rates within urine patches. This two-year study carried out on simulated urine patches in three application seasons (spring, summer, autumn) explored the efficacy of DCD feeding to cattle to reduce Nlosses from grazed pasture soil in a heavy-textured soil under temperate climatic conditions. In each application season, DCD fed to cows, then excreted with urine and applied at a rate of 30 kg DCD ha(-1) (treatment U + DCD30-f) was as effective as powdered DCD mixed with normal urine and applied at the same rate (treatment U + DCD30) at reducing cumulative N2O-N emissions and the N2O-N emission factor (EF3, expressed as % of N applied). Increasing DCD loading within urine patches from 10 to 30 kg DCD ha(-1) improved efficacy by significantly reducing the EF3 from 34% to 64%, which highlights that under local conditions, 10 kg DCD ha(-1) (the recommended rate for commercial use in New Zealand) was not the optimum DCD rate to curb N2O emissions. The modelling of EF3 in this study also suggests that Nmitigation should be given more attention when soil moisture is going to be high, which can be predicted with short-term weather forecasting. DCD feeding, for instance in autumn when cows are not lactating and the risk of N losses is high, could then be reduced by focusing mainly on those forecasted wet periods. (C) 2017 Elsevier B.V. All rights reserved.

Abstract  Anthropogenic nitrogen pollution is a critical problem in freshwaters. Although riverbeds are known to attenuate nitrate, it is not known if large woody debris (LWD) can increase this ecosystem service through enhanced hyporheic exchange and streambed residence time. Over a year, we monitored the surface water and pore water chemistry at 200 points along a similar to 50 m reach of a lowland sandy stream with three natural LWD structures. We directly injected N-15-nitrate at 108 locations within the top 1.5 m of the streambed to quantify in situ denitrification, anammox and dissimilatory nitrate reduction to ammonia, which, on average, contributed 85, 10 and 5% of total nitrate reduction, respectively. Total nitrate reducing activity ranged from 0 to 16 A mu M h(-1) and was highest in the top 30 cm of the stream bed. Depth, ambient nitrate and water residence time explained 44% of the observed variation in nitrate reduction; fastest rates were associated with slow flow and shallow depths. In autumn, when the river was in spate, nitrate reduction (in situ and laboratory measures) was enhanced around the LWD compared with non-woody areas, but this was not seen in the spring and summer. Overall, there was no significant effect of LWD on nitrate reduction rates in surrounding streambed sediments, but higher pore water nitrate concentrations and shorter residence times, close to LWD, indicated enhanced delivery of surface water into the streambed under high flow. When hyporheic exchange is too strong, overall nitrate reduction is inhibited due to short flow-paths and associated high oxygen concentrations.

Abstract  In this study, we used a comparative cross-system analysis and a standardized methodological approach to understand which abiotic parameters, in addition to salinity, can play an important role in determining larval fish assemblages in tropical estuaries. Surveys were performed by using surface trawls in the same water mass (salinity ranging from 15 to 25) in four Brazilian estuaries (Maca, Sao Joao, Bracui and Pereque-Acu) from May 2013 to March 2015. Water temperature, oxygen saturation, pH, chlorophylla, nitrate, nitrite, ammonia, phosphate and total particulate matter were obtained at each sampling area. Comparative analysis of structural attributes of larval fish assemblages, showed inter-estuarine differences in terms of total abundance and diversity. Pereque-Acu Estuary registered the highest abundance levels and was highly dominated by a typical anadromous species Anchoviella lepidentostole. Maca Estuary presented the most diverse larval fish assemblage, which was comprised by several marine species. Temperature and precipitation, in addition to salinity, were the main environmental variables regulating the larval fish assemblages. Temperature has played an important role in determining anadromous species abundance, since the greatest abundances were associated with high water temperatures recorded mainly in Pereque-Acu Estuary. Precipitation was responsible for episodic events of runoff in Bracui, Sao Joao and Pereque-Acu estuaries, where the high precipitation collaborated to carry anadromous larvae from the spawning habitat to the estuarine zone. Conversely, the low precipitation in Maca Estuary favored the immigration of marine species due to the decrease of the river flow. Oxygen saturation and nutrient load could have operated in an indirect way, through their effect on food supply, but further studies are necessary to investigate this question. Our study highlighted that fish larvae are highly sensitive to environmental variations and emphasized that conservation of estuarine habitats is essential to ensure success in the fish recruitment. (C) 2017 Elsevier B. V. All rights reserved.

Abstract  Plant branching shoot number is strongly influenced by nitrogen (N) supply status. However, detailed descriptions of this phenomenon and the regulatory mechanism are lacking. In this study, we show that, in rice, in comparison to sufficient supply of ammonium sulfate or ammonium nitrate (2.5 or 5 mM N), low N (0.2 mM) or nitrate as the only N source limited shoot branching, i.e., tillering number. We observed that N deficiency did not affect the initiation, but suppressed the elongation of the tiller buds. We carried out in-situ hybridization of the tiller buds and showed that the expression of histone H4, a marker of S-phase in the cell cycle, could not be detected in the tiller buds that had stopped growing, indicating that cell division was suppressed in the tissues. Consistent with this finding, we further detected that the expression of other cell cycle marker genes was decreased in the N-deficient tiller buds in comparison to N-sufficient tiller buds. In addition, expression of the genes involved in the strigolactone pathway was induced in the tiller buds by N deficiency, in accordance with other reports. These results shed light on the importance of proper N application to control tiller bud outgrowth in grain production.

Abstract  In this examination we have experimented the effect of ammonia concentration on shortcut nitrification and denitrification in a moving bed biofilm reactor (MBBR). The results show that, when the influent ammonia concentration slowly increased to 200 mg/L, the ammonia removal rate and the nitrite accumulation rate were respectively 92.7% and 84.2%, which were better than that of other influent ammonia concentration. And when the influent ammonia concentration was 200 mg/L, the average TN removal rate was also better than other influent ammonia concentration, which was 56.0%. The TN removal rate increased first and then decreased with the influent ammonia concentration increase.

Abstract  In this paper, the preparation methods of flocculants are analyzed and summarized. Organic and inorganic polymeric flocculants. Their flocculation properties were studied, and the synthesis of green organic flocculant and its flocculation performance were carried out. Finally, this kind of research is combined with inorganic flocculant to carry out the experimental exploration of oily wastewater. The experimental material uses natural organic polymer material, corn starch, because it is rich in origin and low in price. By using ceric ammonium nitrate as initiator, graft monomer with acrylamide, through graft copolymerization, grafting with starch macromolecule acrylamide, made of green natural organic polymer flocculant. The application of this method to oily wastewater treatment was also studied.

Abstract  This paper introduces a movable detection device for explosives hidden in wall. The device is composed of the 14MeV neutron generator, the silicon detector and Phi 76mm x 76mm LYSO detector. The gamma spectra produced by the inelastic scattering interaction provide the relative counts of C, N, O, which are converted into chemical fractions to distinguish the explosives from the organic compounds. The device using associate particle method reduces the background 200-300 times. The 300g ammonium nitrate and TNT explosive simulated samples placed behind the 15cm-thick and 10cm-thick wall is detected by the device, respectively, when the neutron intensity is 1 x10(7)n/s. Compared with other methods, the experimental results show that the device with associate particle method has higher detection space resolution ability and explosives recognition ability. The device can provide the support for the detection of explosives.

Abstract  Nitrated polycyclic aromatic hydrocarbons (NPAHs) and heterocyclic PAHs (HPAHs) are recognized environmental pollutants. However, the health risks of NPAHs and HPAHs to humans and environmental systems are not well-studied. The developmental zebrafish (Danio rerio) model was used to evaluate the toxicity of a structurally diverse set of 27 NPAHs and 10 HPAHs. The individual activity of each compound towards the aryl hydrocarbon receptor (AHR), including the role of the AHR in observed toxicity, and genetic markers of oxidative stress and cardiac toxicity were evaluated. Zebrafish embryos were exposed from 6 to 120 hours post fertilization (hpf), to a broad concentration range of individual compounds, and evaluated for 22 developmental endpoints. The potential role of AHR was determined using the transgenic Tg(cyp1a:nls-egfp) reporter zebrafish line. All compounds were screened computationally through molecular docking using a previously developed AHR models of zebrafish isoforms 1A, 1B, and 2. Some compounds did not induce observable developmental toxic responses, whereas others produced statistically significant concentration-dependent toxicity. The tested compounds also exhibited a range of predicted AHR binding and cyp1a/GFP induction patterns, including cyp1a expression in the liver, vasculature, skin, and yolk, which we determined to be due to distinct isoforms of the AHR, using morpholino oligonucleotide knockdown. Furthermore, we investigated mRNA expression of oxidative and cardiac stress genes at 48 and 120 hpf, which indicated several potential mechanisms-of-action for NPAHs. Overall, we observed a range of developmental toxicities, cyp1a/GFP expression patterns, and gene expression profiles, suggestive of several potential mechanisms of action.

Abstract  In this work, Au neuronal-like nanostructures (Au NNs) were synthesized by a facile N-methylimidazole-assisted aqueous method, using ascorbic acid as the reducing agent. The as-prepared Au nanocrystals exhibited improved electrocatalytic performances for the reduction of azathioprine, which was further explored to construct an azathioprine sensor with low detection limit of 0.033 mu M (S/N =3), wide linear range from 0.5 to 2300 mu M, good reproducibility, and long-term stability. The as-synthesized Au architectures provide more potential applications in the fabrication of (bio) sensors. (C) 2016 Elsevier B.V. All rights reserved.

Abstract  Using heme entrapped in recombinant silk films, we have produced 3rd generation biosensors, which allow direct electron transfer from the heme center to an electrode avoiding the need for electron mediators. Here, we demonstrate the use of these heme-silk films for the detection of nitric oxide (NO) at nanomolar levels in the presence and absence of oxygen. The sensor was prepared by drop-casting a silk solution on a glassy carbon electrode modified with multiwalled carbon nanotubes (MWCNT) followed by infusion with heme. The sensor was characterized by cyclic voltammetry and showed well defined and reversible Fe+/ Fe3+ redox couple activity, with NO detection by oxidation at potentials above +0.45V or reduction at potentials below - 0.7V. Evaluation of the effect of pH on the sensor response to NO reduction indicated a maximum response at pH 3. The sensor showed good linearity in the concentration range from 19 to 190nM (R2 = 0.99) with a detection limit of 2nM. The sensor had excellent selectivity towards NO with no or negligible interference from oxygen, nitrite, nitrate, dopamine and ascorbic acid and retained 86% of response after 2 months of operation and storage at room temperature.

Abstract  We report on the template electrodeposition of different copper/copper oxide nanoparticles on pencil graphite lead substrate using ionic and neutral surfactant templates. Physical structure and electrochemical properties of the modified electrodes were shown to be influenced by the nature of surfactant template. These copper modified pencil graphite electrodes exhibited very good catalytic activity towards hydrogen peroxide reduction reaction, which could be used for the sensitive and selective detection of H2O2. A maximum sensitivity of ca. 158 mu A/mM/cm(2), lower limit of detection (LOD) of 0.35 +/- 0.04 mu M, response time of <2 seconds and a linearity in wide range of concentration from 1 mu M to 13 mM were observed. These electrodes were highly selective towards hydrogen peroxide with little interference from glucose, fructose, ascorbic acid, dopamine, uric acid, urea, chlorides, nitrates and sulphates even at 100 fold higher concentrations of the interfering species compared to H2O2 concentration. Practical feasibility of the sensor was demonstrated by detecting H2O2 in human blood serum and milk samples with good recovery. Our methodology enables one to prepare the electrode within two minutes and to complete the analysis within another 60 seconds, enabling the quantitative detection of hydrogen peroxide in less than five minutes using a freshly prepared, cost-effective electrode without any complicated procedure. (C) 2017 Elsevier Ltd. All rights reserved.

Abstract  This study investigated the qualitative characteristics of several edible wild herbaceous species, including those most consumed in Foggia Province (southern Italy). Analysis of qualitative characteristics was performed for the edible parts of 11 wild species (Beta vulgaris L., Foeniculum vulgare Miller, Centaurea solstitialis L., Cichorium intybus L., Scolymus hispanicus L., Sonchus oleraceus L., Borago officinalis L., Diplotaxis erucoides L., Diplotaxis tenuifolia (L.) DC, Sinapis arvensis L., Portulaca oleracea L.) and three cultivated species (C. intybus, B. officinalis, D. tenuifolia). The plants were collected from areas in the Foggia countryside, and the edible part of each species was analysed for dry matter, protein, cation and anion contents as well as total phenols and antioxidant activities. Among the cations, calcium was the most differentiated among species, ranging 784 mg kg(-1) fresh weight (Fw) for B. vulgaris to 5886 mg kg(-1) Fw for S. hispanicus. The nitrate contents were also highly variable, from 75 mg kg(-1) Fw for C. intybus to 3874 mg kg(-1) Fw for D. tenuifolia. Total polyphenols ranged from 1054 mg gallic acid equivalents (GAE) mg kg(-1) Fw for C. solstitialis to 3664 mg GAE mg kg(-1) Fw for S. arvensis. Antioxidant activities ranged from 839 mg Trolox equivalents (TE) kg(-1) Fw for B. vulgaris to 5658 mg TE kg(-1) Fw for C. intybus. Significant differences were also noted between wild and cultivated plants in the qualitative parameters. Total polyphenols and antioxidant activity were higher in wild C. intybus and B. officinalis than in their cultivated counterparts. Multivariate analysis (cluster analysis and linear discriminant analysis) allowed integration of the ANOVA data to determine the qualitative characteristics of the wild species that contribute most to group differences. The results of the present study aims to improve current knowledge about edible wild species as vegetable sources in the Mediterranean diet.

Abstract  This study discusses an analysis of combined airborne and ground observations of particulate nitrate (NO3- ((p))) concentrations made during the wintertime DISCOVER-AQ (Deriving Information on Surface Conditions from COlumn and VERtically resolved observations relevant to Air Quality) study at one of the most polluted cities in the United States - Fresno, CA - in the San Joaquin Valley (SJV) and focuses on developing an understanding of the various processes that impact surface nitrate concentrations during pollution events. The results provide an explicit case-study illustration of how nighttime chemistry can influence daytime surface-level NO3- ((p)) concentrations, complementing previous studies in the SJV. The observations exemplify the critical role that nocturnal chemical production of NO3- ((p)) aloft in the residual layer (RL) can play in determining daytime surface-level NO3- ((p)) concentrations. Further, they indicate that nocturnal production of NO3- ((p)) in the RL, along with daytime photochemical production, can contribute substantially to the buildup and sustaining of severe pollution episodes. The exceptionally shallow nocturnal boundary layer (NBL) heights characteristic of wintertime pollution events in the SJV intensify the importance of nocturnal production aloft in the residual layer to daytime surface concentrations. The observations also demonstrate that dynamics within the RL can influence the earlymorning vertical distribution of NO3- ((p)), despite low wintertime wind speeds. This overnight reshaping of the vertical distribution above the city plays an important role in determining the net impact of nocturnal chemical production on local and regional surface-level NO3- ((p)) concentrations. Entrainment of clean free-tropospheric (FT) air into the boundary layer in the afternoon is identified as an important process that reduces surface-level NO3- ((p)) and limits buildup during pollution episodes. The influence of dry deposition of HNO3 gas to the surface on daytime particulate nitrate concentrations is important but limited by an excess of ammonia in the region, which leads to only a small fraction of nitrate existing in the gas phase even during the warmer daytime. However, in the late afternoon, when diminishing solar heating leads to a rapid fall in the mixed boundary layer height (BLH), the impact of surface deposition is temporarily enhanced and can lead to a substantial decline in surface-level particulate nitrate concentrations; this enhanced deposition is quickly arrested by a decrease in surface temperature, which drops the gas-phase fraction to near zero. The overall importance of enhanced late-afternoon gas-phase loss to the multiday buildup of pollution events is limited by the very shallow nocturnal boundary layer. The case study here demonstrates that mixing down of NO3- ((p)) from the RL can contribute a majority of the surface-level NO3- ((p)) in the morning (here, similar to 80 %), and a strong influence can persist into the afternoon even when photochemical production is maximum. The particular day-to-day contribution of aloft nocturnal NO3- ((p)) production to surface concentrations will depend on prevailing chemical and meteorological conditions.

Although specific to the SJV, the observations and conceptual framework further developed here provide general insights into the evolution of pollution episodes in wintertime environments.

Abstract  The use of ethanol in alternative fuels has led to contamination of groundwater with high concentrations of this easily biodegradable organic compound. Previous laboratory and field studies have shown vigorous biodegradation of ethanol plumes, with prevalence of reducing conditions and methanogenesis. The objective of this study was to further our understanding of the dynamic biogeochemistry processes, especially dissolved gas production, that may occur in developing and aging plume cores at sites with ethanol or other organic contamination of groundwater. The experiment performed involved highly-detailed spatial and temporal monitoring of ethanol biodegradation in a 2-dimensional (175cm high×525cm long) sand aquifer tank for 330days, with a vertical shift in plume position and increased nutrient inputs occurring at ~Day 100. Rapid onset of fermentation, denitrification, sulphate-reduction and iron(III)-reduction occurred following dissolved ethanol addition, with the eventual widespread development of methanogenesis. The detailed observations also demonstrate a redox zonation that supports the plume fringe concept, secondary reactions resulting from a changing/moving plume, and time lags for the various biodegradation processes. Additional highlights include: i) the highest dissolved H2 concentrations yet reported for groundwater, possibly linked to vigorous fermentation in the absence of common terminal electron-acceptors (i.e., dissolved oxygen, nitrate, and sulphate, and iron(III)-minerals) and methanogenesis; ii) evidence of phosphorus nutrient limitation, which stalled ethanol biodegradation and perhaps delayed the onset of methanogenesis; and iii) the occurrence of dissimilatory nitrate reduction to ammonium, which has not been reported for ethanol biodegradation to date.

Abstract  In certain alpine systems, glacially-fed lakes and streams have nitrate concentrations one to two orders of magnitude higher than lakes and streams fed by snowmelt alone. To better understand how nitrogen subsidies from glacial meltwater propagate down a chain of lakes and streams we assessed the effects of these subsidies in a set of aquatic chains in the central U.S. Rocky Mountains. Algal biomass, algal community assemblage, and nutrient limitation were measured in a chain of lakes and streams fed by glacial meltwater (GSF) and a chain fed by snowmelt alone (SF). Nitrate (NO3-) concentrations in the GSF chain ranged from 228 to 70 g L-1 declining from the top of the chain to the bottom, while NO3- concentrations in the SF chain were consistently low,<9 g L-1. In the glacial chain, both lakes were phosphorus-limited; the strength of this limitation signal weakened down the chain, with the lake at the bottom showing secondary nitrogen and phosphorus colimitation. In the snowmelt chain, lakes were colimited with no change in strength down the chain. Algal biomass averaged 2.6 g L-1 and 7.3 g m(-2) in SF lakes and streams and 5.4 g L-1 and 9.2 g m(-2) in GSF lakes and streams. Phytoplankton and periphyton communities in the GSF chain were more homogeneous compared to the SF chain. Our results indicate nutrient subsidies in glacial meltwaters can propagate down aquatic chains and alter nutrient limitation patterns and algal communities compared to SF systems, creating heterogeneous patterns across the landscape.

Abstract  Understanding the effects of sediment disturbances on nutrient loadings is important for the management of estuarine settings. This study investigated the initial influence of sediment disturbance on water column nutrient concentrations in a shallow estuarine setting within the Gold Coast Broadwater, using a laboratory-based approach. Undisturbed sediment cores (200 mm Ø × 330 mm length, plexiglass) were incubated before and after being subjected to a disturbance event, to investigate the effect on the immediate and subsequent short-term water column nutrient concentrations. Sediment NH4+bio and PO43−bio concentrations ranged from 150 to 478 and 1.50 to 8.56 nmol g−1 dry wt, respectively. Water column NH4+ concentrations underwent the greatest increase (>1000% or approx. 14 times greater) immediately following disturbance, with mean effluxes increasing by >300%. Thereafter, water column NH4+ concentrations and efflux rates declined to near initial pre-disturbance concentrations. Water column NH4+ concentrations accounted for 0.58%-5.50% of the depth-integrated sediment NH4+bio concentration, indicating mobilization of the sediment bound exchangeable NH4+. The observed changes in PO43− concentrations and fluxes were much lower in comparison to those observed for N-species. Following disturbance, increases in the water column PO43− concentration accounted for 7.16%-8.22% depth-integrated sediment bioavailable PO43− at +1 and +2 hours, and 5.65% at +7 hours, respectively. These results provide important insight into the potential implications of disturbance events, such as vessel activities and dredging operations, within the case study region, providing information for potential management options and relevant water quality concerns.

Abstract  Methacrolein (MACR) is an abundant multifunctional carbonyl compound with high reactivity in the atmosphere. In this study, we investigated the hydroxyl radical initiated oxidation of MACR at various NO/MACR ratios (0 to 4.04) and relative humidities (<3% to 80%) using a flow tube. Meanwhile, a box model based on the Master Chemical Mechanism was performed to test our current understanding of the mechanism. In contrast to the reasonable predictions for hydroxyacetone production, the modeled yields of formaldehyde (HCHO) were twice higher than the experimental results. The discrepancy was ascribed to the existence of unconsidered non-HCHO forming channels in the chemistry of CH3C(CH2)OO, which account for approx. 50%. In addition, the production of hydroxyacetone and HCHO were affected by water vapor as well as the initial NO/MACR ratio. The yields of HCHO were higher under humid conditions than that under dry condition. The yields of hydroxyacetone were higher under humid conditions at low-NOx level, while lower at high-NOx level. The reasonable explanation for the lower hydroxyacetone yield under humid conditions at high-NOx level is that water vapor promotes the production of methacrolein nitrate in the reaction of HOCH2C(CH3)(OO)CHO with NO due to the peroxy radical-water complex formation, which was evidenced by calculational results. And the minimum equilibrium constant of this water complex formation was estimated to be 1.89×10-18cm3/molecule. These results provide new insights into the MACR oxidation mechanism and the effects of water vapor.

Abstract  A modified single sequencing batch reactor (SBR) was developed to remove the nitrogen of the real landfill leachate in this study. To take the full advantage of the SBR, stir phase was added before and after aeration, respectively. The new mechanism in this experiment could improve the removal of nitrogen efficiently by the utilization of carbon source in the raw leachate. This experiment adopts the SBR process to dispose of the real leachate, in which the COD and ammonia nitrogen concentrations were about 3800 mg/L and 1000 mg/L, respectively. Results showed that the removal rates of COD and total nitrogen were above 85% and 95%, respectively, and the effluent COD and total nitrogen were less than 500 mg/L and 40 mg/L under the condition of not adding any carbon source. Also, the specific nitrogen removal rate was 1.48 mgN/(h·gvss). In this process, polyhydroxyalkanoate (PHA) as a critical factor for the highly efficient nitrogen removal (>95%) was approved to be the primary carbon source in the sludge. Because most of the organic matter in raw water was used for denitrification, in the duration of this 160-day experiment, zero discharge of sludge was realized when the effluent suspended solids were 30-50 mg/L.

Abstract  Assessment of groundwater quality is an important aspect of water security, which is the key to ensure sustainable development. The objective of the study is to bring out an integrated approach for assessment of groundwater quality for drinking and irrigation purposes. Gogi region, Karnataka, India was chosen as the study area due to the effect of the presence of medium-grade uranium deposits. An integrated approach including the concentration of major ions, trace elements and uranium was employed to investigate the quality of groundwater. Totally, 367 groundwater samples were collected periodically from 52 wells distributes over the Gogi region and the parameters such as pH, electrical conductivity, total dissolved solids (TDS), Ca2+, Mg2+, Na+, K+, Cl-, SO42-, NO3(-), Zn, Pb, Cu, and uranium of groundwater were analysed. Spatial distribution maps of various chemical constituents were prepared using geographic information system and its temporal variation was plotted in box and whisker plot. The analytical data were compared with Bureau of Indian Standards and World Health Organisation standards to determine drinking water quality and parameters such as salinity hazard, alkalinity hazard and percent sodium were estimated to assess the irrigation quality. Multivariate statistical analysis by cluster analysis was also performed which results in two groups consisting of wells with unsuitable water for drinking purposes. Groundwater in about 15% of the sampling wells were found to be unsuitable for domestic purpose based on TDS and about 17% were unsuitable based on uranium concentration. Finally, integration of spatial variation in TDS and uranium reveals that about 25% of the wells were unsuitable for domestic purposes. It is suggested that such an integrated approach needs to be formulated considering major ions, trace elements and radioactive elements for proper assessment of water quality. Implementation of managed aquifer recharge structures in the study area is suggested since it would potentially reduce the concentration of ions.

Abstract  Microbacterium oleivorans A9 is a uranium-tolerant actinobacteria isolated from the trench T22 located near the Chernobyl nuclear power plant. This site is contaminated with different radionuclides including uranium. To observe the molecular changes at the proteome level occurring in this strain upon uranyl exposure and understand molecular mechanisms explaining its uranium tolerance, we established its draft genome and used this raw information to perform an in-depth proteogenomics study. High-throughput proteomics were performed on cells exposed or not to 10μM uranyl nitrate sampled at three previously identified phases of uranyl tolerance. We experimentally detected and annotated 1532 proteins and highlighted a total of 591 proteins for which abundances were significantly differing between conditions. Notably, proteins involved in phosphate and iron metabolisms show high dynamics. A large ratio of proteins more abundant upon uranyl stress, are distant from functionally-annotated known proteins, highlighting the lack of fundamental knowledge regarding numerous key molecular players from soil bacteria.

BIOLOGICAL SIGNIFICANCE: Microbacterium oleivorans A9 is an interesting environmental model to understand biological processes engaged in tolerance to radionuclides. Using an innovative proteogenomics approach, we explored its molecular mechanisms involved in uranium tolerance. We sequenced its genome, interpreted high-throughput proteomic data against a six-reading frame ORF database deduced from the draft genome, annotated the identified proteins and compared protein abundances from cells exposed or not to uranyl stress after a cascade search. These data show that a complex cellular response to uranium occurs in Microbacterium oleivorans A9, where one third of the experimental proteome is modified. In particular, the uranyl stress perturbed the phosphate and iron metabolic pathways. Furthermore, several transporters have been identified to be specifically associated to uranyl stress, paving the way to the development of biotechnological tools for uranium decontamination.

Abstract  Due to the ever-growing demand of energy nuclear reactor materials and the nuclear energy are now considered to be the most critical materials and source of energy for future era. Deposition of nuclear wastes in different industry, nuclear power sector are very much toxic in open environment which are hazardous to living being. There are different methods for extraction and reprocessing of these materials which are cost effective and tedious process. Ultrasonic assisted solvent extraction process is a most efficient and economical way for extraction of such type materials. The presence of third phase in mixing of extractantsdiluent pair with aqueous phase imposes the problems in extraction of nuclear reactor materials. The appropriate solvent mixture in proper concentration is an important step in the solvent extraction process. Study of thermo-physical properties helps in selecting an optimum blend for extraction process. In the present work, the extraction of uranium with the binary mixture of Methyl Ethyl Ketone (MEK) and Kerosene was investigated and discussed with the variation of ultrasonic frequency for different temperatures. The result shows that the low frequency and low temperature is suitable environment for extraction. The extraction of uranium by this method is found to be a better result for extraction study in laboratory scale as well as industrial sector.