Petroleum Hydrocarbons Rhizodegradation by Sebastiania commersoniana (Baill.) L. B. SM. & Downs

Petroliferous activities in Brazil have an accelerated development in the last years. As a consequence, the incidence of environmental accidents such as oil spills and contamination of soils has increased significantly. Therefore, it is extremely necessary to develop remediation techniques with lower costs, decontamination efficiency and impact minimisation. The aim of this work was to evaluate Sebastiania commersoniana phytoremediation potential in soil contaminated by petroleum. This species, which is a native tree, was selected due to its proven capacity for surviving in areas contaminated by petroleum. Experiments were carried out with soils that were vegetated but non-contaminated, soils that were freshly contaminated (25, 50 and 75 g kg^?1) but non-vegetated, and soils that were vegetated and contaminated, samples were collected 60 and 424 days after contamination with the purpose of evaluating the percentage of petroleum degradation in relation to the time. The results obtained in the present study allow us to state that S. commersoniana proves to be tolerant to petroleum contamination with respect to plant’s growth. The degradation of petroleum hydrocarbons was evaluated by gas chromatography with a flame ionisation detector (GC-FID) equipped with a capillary column HP-5 (5% phenyl-methylpolysiloxane, 30 m; 0.25 mm; 0.25 μm). According to chromatographic analysis, samples in contact with S. commersoniana showed a significant area reduction of the hydrocarbon peaks. Analysis of the 60-day samples showed a reduction of petroleum hydrocarbons area higher than 60% and the 424-day samples showed a reduction higher than 94%, which demonstrates that a petroleum degradation process is occurring.     

Satellite Rainfall Estimates Over South America – Possible Applicability to the Water Management of Large Watersheds1

Pereira Filho, Augusto J., Richard E. Carbone, John E. Janowiak, Phillip Arkin, Robert Joyce, Ricardo Hallak, and Camila G.M. Ramos, 2010. Satellite Rainfall Estimates Over South America – Possible Applicability to the Water Management of Large Watersheds. Journal of the American Water Resources Association (JAWRA) 46(2):344-360. DOI: 10.1111/j.1752-1688.2009.00406.x Abstract: This work analyzes high-resolution precipitation data from satellite-derived rainfall estimates over South America, especially over the Amazon Basin. The goal is to examine whether satellite-derived precipitation estimates can be used in hydrology and in the management of larger watersheds of South America. High spatial-temporal resolution precipitation estimates obtained with the CMORPH method serve this purpose while providing an additional hydrometeorological perspective on the convective regime over South America and its predictability. CMORPH rainfall estimates at 8-km spatial resolution for 2003 and 2004 were compared with available rain gauge measurements at daily, monthly, and yearly accumulation time scales. The results show the correlation between satellite-derived and gauge-measured precipitation increases with accumulation period from daily to monthly, especially during the rainy season. Time-longitude diagrams of CMORPH hourly rainfall show the genesis, strength, longevity, and phase speed of convective systems. Hourly rainfall analyses indicate that convection over the Amazon region is often more organized than previously thought, thus inferring that basin scale predictions of rainfall for hydrological and water management purposes have the potential to become more skillful. Flow estimates based on CMORPH and the rain gauge network are compared to long-term observed average flow. The results suggest this satellite-based rainfall estimation technique has considerable utility. Other statistics for monthly accumulations also suggest CMORPH can be an important source of rainfall information at smaller spatial scales where in situ observations are lacking.     

Evaluation of Cyto- and Genotoxicity of Poly(lactide-co-glycolide) Nanoparticles

This work reports on an analysis of the cyto- and genotoxicity of poly(lactide-co-glycolide) polymer nanoparticles, in an attempt to evaluate their mutagenic effects. Fibroblast (3T3) and human lymphocyte cell cultures were exposed to solutions containing three different concentrations of nanoparticles (5.4, 54 and 540 μg/mL, polymer mass/volume of solution). The nanoparticles were characterized in terms of their hydrodynamic diameters, zeta potentials and polydispersity indices. The morphology of the particles was determined by atomic force microscopy. The PLGA nanospheres presented a size of 95 nm, a zeta potential of −20 mV and a spherical morphology. Cellular viability assays using fibroblast cells showed no significant alterations compared with the negative control. A cytogenetic analysis of human lymphocyte cells showed no significant changes in the mitotic index in relation to the control, indicating that in the concentration range tested, the particles used in the experimental models did not present cyto- or genotoxicity. For the tests conducted in this work we can conclude that biodegradable and biocompatible PLGA nanospheres are not toxic in the cell cultures tested (fibroblast and lymphocyte cells) and in the range of concentrations employed. The results provide new information concerning the toxic effects of particles produced using PLGA.     

Methane production potential from anaerobic digestion of plant biomass residues and food waste as substrates

Journal of Material Cycles and Waste Management - This research aimed to evaluate the production of biogas from anaerobic digestion (AD) using swine manure inoculum associated with different...     

The Impact of the Macaíba Components Addition on the Biodegradation Acceleration of Poly (Ɛ-Caprolactone) (PCL)

Journal of Polymers and the Environment - Nowadays, there is a need to obtain eco-friendly materials, especially plastics that are responsible for most of the environmental pollution. In this...     

Effects of activated sludge and UV disinfection processes on the bacterial community and antibiotic resistance profile in a municipal wastewater treatment plant

Environmental Science and Pollution Research - Wastewater tertiary treatment has been pointed out as an effective alternative for reducing the concentration of antibiotic resistant bacteria and...     

Seasonal variations in sugar contents and microbial community in a ryegrass soil

The relationship among sugar concentrations, microbial community and physical variables (precipitation and soil temperature) was investigated in a ryegrass soil from January 2004 to January 2005. Mono- and disaccharide sugars were extracted using a mixture of dichloromethane and methanol and analyzed as their TMS derivatives by GC-MS. Changes in microbial community were assessed using phospholipid and neutral lipid fatty acids (PLFA and NLFA, respectively) analysis. The results of a one-year study showed that the seasonal variability of sugar contents found in the soil samples is mainly related to biomass or nutritional status of the fungal community. The increase in sucrose and fructose exudation by plant roots in the beginning of the growing season (early spring) may be responsible for the highest fungal biomass amount (PLFAs) observed in this study. Fungal storage lipid abundances (NLFAs) peaked in summer, during the same period that the highest concentrations of mannitol and trehalose were detected. This is consistent with these two sugars being stress-induced fungal metabolites, produced due to the low soil moisture observed during this season. In contrast, bacterial community growth seems to be more dependent on plant substrate than on physical variables, since the strongest decrease in bacterial biomass amounts (PLFAs) was found after cutting of the ryegrass field in early July.     

Hydrocarbons in particulate samples from wildfire events in central Portugal in summer 2010

In summer 2010, twenty eight(14 PM_(2.5)samples plus 14 samples PM_(2.5–10)) smoke samples were collected during wildfires that occurred in central Portugal. A portable high-volume sampler was used to perform the sampling, on quartz fibre filters of coarse(PM_(2.5–10)) and fine(PM_(2.5)) smoke samples. The carbonaceous content(elemental and organic carbon) of particulate matter was analysed by a thermal–optical technique. Subsequently, the particulate samples were solvent extracted and fractionated by vacuum flash chromatography into three different classes of organic compounds(aliphatics, polycyclic aromatic hydrocarbons(PAHs) and carbonyl compounds). The organic speciation was performed by gas chromatography–mass spectrometry(GC–MS). Emissions were dominated by the fine particles, which represented around 92% of the PM_(10). A clear predominance of carbonaceous constituents was observed, with organic to elemental carbon(OC/EC)ratios ranging between 1.69 and 245 in both size fractions. The isoprenoid ketone6,10,14-trimethyl-2-pentadecanone, a tracer for secondary organic aerosol formation, was one of the dominant constituents in both fine and coarse particles. Retene was the most abundant compound in all samples. Good correlations were obtained between OC and both aliphatic and PAH compounds. Pyrogenic processes, thermal release of biogenic compounds and secondary processing accounted for 97% of the apportioned PM_(2.5)levels.