Chelate-induced phytoextraction of metal polluted soils with Brachiaria decumbens

Chelate-induced phytoextraction with high biomass plant species has been proposed for the clean-up of heavy metal polluted soils. In the current work, the effect of the application of two different chelating agents, i.e. EDTA and EDDS, on the metal phytoextraction capacity of Brachiaria decumbens was studied. Although EDTA was, in general, more effective in soil metal solubilization, EDDS, a chelate less harmful to the environment, was more efficient inducing metal accumulation in B. decumbens shoots than EDTA. Indeed, in a moderately heavy metal polluted soil, EDDS caused a 2.54, 2.74 and 4.30-fold increase in Cd, Zn, and Pb shoot metal concentration, respectively, as compared to control plants. In this same soil, EDTA caused a 1.77, 1.11 and 1.87-fold increase in Cd, Zn, and Pb shoot metal concentration, respectively, as compared to control plants. EDDS was also more effective than EDTA in stimulating the translocation of metals from roots to shoots. B. decumbens plants were able to grow in the metal polluted soils showing no visible symptoms of phytotoxicity, which suggests their metal tolerance. Finally, B. decumbens, a fast-growing, high biomass, aluminum tolerant plant species, that has a well-established agronomic system, fulfills most of the requirements for chemically-induced phytoextraction.     

Anaerobic digestion of microalgal biomass after ultrasound pretreatment

High rate algal ponds are an economic and sustainable alternative for wastewater treatment, where microalgae and bacteria grow in symbiosis removing organic matter and nutrients. Microalgal biomass produced in these systems can be valorised through anaerobic digestion. However, microalgae anaerobic biodegradability is limited by the complex cell wall structure and therefore a pretreatment step may be required to improve the methane yield. In this study, ultrasound pretreatment at a range of applied specific energy (16–67 MJ/kg TS) was investigated prior to microalgae anaerobic digestion. Experiments showed how organic matter solubilisation (16–100%), hydrolysis rate (25–56%) and methane yield (6–33%) were improved as the pretreatment intensity increased. Mathematical modelling revealed that ultrasonication had a higher effect on the methane yield than on the hydrolysis rate. A preliminary energy assessment indicated that the methane yield increase was not high enough as to compensate the electricity requirement of ultrasonication without biomass dewatering (8% VS).     

Efficiency of physicochemical and biological treatments of vinasse and their influence on indigenous microbiota for disposal into the environment

Molasses-based distilleries are one of the most polluting industries generating large volumes of high strength wastewater called vinasse. Different processes covering anaerobic, aerobic as well as physicochemical methods have been employed to treat this effluent. This study evaluated the microbial communities present in the vinasse during different stages of its treatment by traditional and molecular methods. The analysis of the efficiency of each treatment was performed by physicochemical parameters and toxicity analysis. The treatment of vinasse was performed in the following steps: high flow fermentation; filtration; chemical flakes; low-flow fermentation; filtration; and neutralization. The physicochemical analysis in different stages of the vinasse treatment demonstrated that phases of treatment influenced the performance of the evaluated parameters. Among the 37 parameters, 9 were within the limits established by the Commission for Environmental Policy of Minas Gerais, Brazil (COPAM), especially BOD (96.7% of pollution reduction), suspended solids (99.9%), pH, copper (88%), iron (92.9%), and manganese (88%). Some parameters, even after treatment, did not fit the maximum allowed by legislation. The microbial population decreased reaching 3 log CFU/ml present in the steps of the flakes chemical and disinfection treatment of vinasse. Lactobacillus brevis and Pichia kudriavzevii were present in all stages of the treatments, showing that these microorganisms were resistant and demonstrated that they might be important in the treatment of vinasse. The vinasse showed a significant reduction of pollution load after the disinfection treatment however still should not be discarded into water bodies because the high values of tannins and sediment solids, but suggest the use of the effluent in the cooling coil during the distillation process of the beverage.     

An assessment of coastal land-use and land-cover change from 1974–2008 in the vicinity of Mobile Bay,Alabama

The purpose of this research is to quantify and assess geospatial land-use and land-cover (LULC) changes in the coastal counties of Mobile and Baldwin, Alabama using nine Landsat images from 1974–2008. A study-specific classification scheme was devised comprising upland herbaceous, upland forest, non-woody and woody wetlands, open water, and urban categories. Upland forest was the most dominant terrestrial cover type. Wetlands averaged 17% and urban averaged 7%. A majority of the urban expansion occurred between 1974 and 1979 (26%). Thirty-four percent of the 2008 urban areas were upland forest in 1974. Watershed-scale analysis of Three Mile Creek and D’Olive Bay highlights the temporal and spatial differences of urbanization for watersheds found within the same region. This study is a Gulf of Mexico Alliance (GOMA) Application Pilot project that uses NASA data products to benefit coastal environmental managers and community members. Results have led to increased effectiveness of coastal conservation decision-making, increased understanding of post-hurricane LULC change, continued research on habitat change impacts, and contributed to timely conservation planning efforts. This study has benefited the development of watershed management plans by the Mobile Bay National Estuary Program, which is especially important given projected climate change.     

Isolation of single circulating trophoblasts from maternal circulation for noninvasive fetal copy number variant profiling

Objective

To develop a multi-step workflow for the isolation of circulating extravillous trophoblasts (cEVTs) by describing the key steps enabling a semi-automated process, including a proprietary algorithm for fetal cell origin genetic confirmation and copy number variant (CNV) detection.

Methods

Determination of the limit of detection (LoD) for submicroscopic CNV was performed by serial experiments with genomic DNA and single cells from Coriell cell line biobank with known imbalances of different sizes. A pregnancy population of 372 women was prospectively enrolled and blindly analyzed to evaluate the current workflow.

Results

An LoD of 800 Kb was demonstrated with Coriell cell lines. This level of resolution was confirmed in the clinical cohort with the identification of a pathogenic CNV of 800 Kb, also detected by chromosomal microarray. The mean number of recovered cEVTs was 3.5 cells per sample with a significant reverse linear trend between gestational age and cEVT recovery rate and number of recovered cEVTs. In twin pregnanices, evaluation of zygosity, fetal sex and copy number profiling was performed in each individual cell.

Conclusion

Our semi-automated methodology for the isolation and single-cell analysis of cEVTS supports the feasibility of a cell-based noninvasive prenatal test for fetal genomic profiling.     

Investigating the potential of functionalized MCM-41 on adsorption of Remazol Red dye

The modification of MCM-41 was performed with 3-aminopropropyltrimethoxysilane. The structural order and textural properties of the synthesized materials were studied by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry/differential thermogravimetry, nitrogen adsorption, and desorption analysis. The adsorption capacity of NH₂-MCM-41 was studied with Remazol Red dye. The following parameters were studied in the adsorption process: pH, temperature, adsorbent dosage, and initial concentration. The desorption process was studied in different concentrations of NaOH solutions. The Freundlich isotherm model was found to be fit with the equilibrium isotherm data. Kinetics of adsorption follows the modified Avrami rate equation. The maximum adsorption capacity was estimated to be 45.9 mg?g^?1, with removal of the dye of 99.1 %. The NH₂-MCM-41 material exhibited high desorption capacity with 98.1 %.     

An alternative way to determine the size distribution of airborne particulate matter

We developed and tested a methodology to extract both the size-segregated source apportionment of atmospheric aerosol and the size distribution of each detected element. The experiment is based on the parallel use of a standard low-volume sampler to collect Particulate Matter (PM) and an Optical Particle Counter (OPC). The approach is complementary to size-segregated PM sampling, and it was tested versus a 12-stage cascade impactor. Samples were collected inside the urban area of Genoa (Italy) and their elemental composition was measured by Energy Dispersive-X Ray Fluorescence (ED-XRF). Positive Matrix Factorization (PMF) was applied to time series of elemental concentrations to identify major PM sources, and both PM mass concentration and size-segregated particle number concentration were apportioned. Source profiles and temporal trends extracted by PMF were analyzed together with the OPC data to obtain the size distribution for several elements. The new methodology proved to be reliable for the PM apportionment as well as in providing the elemental concentrations in PM10, PM2.5, and PM1 (PM with aerodynamic diameter, D_ae < 10, 2.5, and 1 μm, respectively). The elemental size distributions are in good agreement with those obtained by the cascade impactor for several elements but some discrepancies, in particular for traffic emissions, are stressed and discussed in the text. The new methodology has two main advantages: it only requires standard semi-automatic sampling equipment and compositional analysis and it provides size-segregated information averaged over quite long periods (typically several months). This is particularly important since campaigns with cascade impactors are generally laborious and thus limited to short periods.     

Air pollution sources of PM10 in Buenos Aires City

To elucidate the sources of PM(10) air pollution from the experimental information collected in a local air quality monitoring campaign we have applied two methods, effective variance and genetic algorithms, in the solution of the chemical mass balance. The comparison of these two mathematical approaches show that the identification of the possible sources and the evaluation of its contributions are quite independent of them. The role of possible different sources for major and trace elements and the significance of standardizing available data is also addressed. We also present a simple method for identifying the number of candidate sources, a key element defining the dimension of the search space.     

Sediment Quality Assessment in the Gulf of Gdańsk (Baltic Sea) Using Complementary Lines of Evidence

Sediments from Polish coastal environments were classified by a quality assessment approach that took into account trace metal and organic micropollutant concentrations, grain-size distribution, and organic carbon content. Generally, no benthic organisms were found at sites where sediments were classified as heavily polluted. However, areas characterized by a moderate contamination showed a variable composition of the benthic community and changing bioaccumulation patterns; therefore, no single species found in the Gulf of Gdańsk could be considered representative of the whole benthic environment. Although sediment monitoring must be considered a suitable tool to detect hot-spot pollution areas in coastal and inland waters, it should be complemented by bioaccumulation measurements to evaluate the actual risk posed by contaminants to benthic organisms. This “biological information” allows a better appreciation of the real benthic infaunal community exposure to chemicals and can usefully complement the existing sediment quality guidelines.     

The response of epiphytic lichens to air pollution and subsets of ecological predictors: a case study from the Italian Prealps

We investigated the response of epiphytic lichens to air pollution, against the background of other ecological predictors in a prealpine heterogeneous area, using Non-Parametric Multiplicative Regression (NPMR). The best NPMR model for total lichen diversity according to N environmental predictors at tree level has a cross R(2)=0.709. It includes 10 variables, belonging to three different subsets of factors: two pollution-related factors (distance in meters from the road and from the cement factory); four stand-related (habitat, heat index, LAI and elevation) and four substrate-related factors (inclination, circumference and texture and tree species). Considering separately the effects of each subset on lichen diversity, substrate- and stand-related factors produce good models with similar cross R(2) (0.490 and 0.500, respectively), whereas pollution-related factors produce a model with a lower cross R(2) (0.340). Hence, we provide information to investigate the applicability of lichen biomonitoring to complex heterogeneous areas where standardized protocols are not reliable.