Macdonaldballing0668

Worldwide graphene use is rapidly increasing in a variety of industrial applications to such an extent that efflux into the environment seems inevitable where the likely final reservoirs of graphene wastes is likely to be wastewater treatment plants are. Despite this an understanding of how graphene products impact the bioleaching of metals from sludge is still limited. In this study, the effect of reduced graphene oxide synthesized from eucalyptus leaf extracts (EL-rGO) on Zn2+ and Cu2+ bioleaching from sludge was investigated. The major new findings were that EL-rGO had a negative effect on Acidithiobacillus ferrooxidans (A. ferrooxidans) growth; since optical density decreased by 0.059 as EL-rGO dose increased from 1 to 50 mg/L, and the bioleaching of Cu2+ and Zn2+ decreased by 27.7 and 20.2%, respectively. While at a EL-rGO dose of 1 mg/L A. ferrooxidans grew better, scanning electron microscopy (SEM) confirmed that exposure to EL-rGO caused cell membrane disruption at 50 mg/L. Cytotoxicity tests showed that this was related to an increase in lactate dehydrogenase (LDH) release rate and a decrease in superoxide dismutase (SOD) activity. These new findings provide evidence that green synthesized rGO is toxic to microorganisms and that toxicity increased with rGO dose.On-road remote sensing (RS) is a rapid, non-intrusive and economical tool to monitor and control the emissions of in-use vehicles, and currently is gaining popularity globally. However, a majority of studies used a single RS technique, which may bias the measurements since RS only captures a snapshot of vehicle emissions. This study aimed to use a unique dual RS technique to assess the characteristics of on-road vehicle emissions. The results show that instantaneous vehicle emissions are highly dynamic under real-world driving conditions. The two emission factors measured by the dual RS technique show little correlation, even under the same driving condition. This indicates that using the single RS technique may be insufficient to accurately represent the emission level of a vehicle based on one measurement. To increase the accuracy of identifying high-emitting vehicles, using the dual RS technique is essential. Despite little correlation, the dual RS technique measures the same average emission factors as the single RS technique does when a large number of measurements are available. Statistical analysis shows that both RS systems demonstrate the same Gamma distribution with ≥200 measurements, leading to converged mean emission factors for a given vehicle group. These findings point to the need for a minimum sample size of 200 RS measurements in order to generate reliable emission factors for on-road vehicles. In summary, this study suggests that using the single or dual RS technique will depend on the purpose of applications. Both techniques have the same accuracy in calculating average emission factors when sufficient measurements are available, while the dual RS technique is more accurate in identifying high-emitters based on one measurement only.The biodegradable S,S-ethylenediaminedisuccinic acid (EDDS) is a promising chelant for chelant-assisted phytoextraction of trace metals in polluted soil. The interactions between EDDS and trace metals/major elements in the soil affect the metal bioavailability and their subsequent phytoextraction efficiency. This study aimed to investigate the macroscopic and molecular-level interactions of EDDS with Cu in the rhizosphere and non-rhizosphere of a Cu-polluted agricultural soil. A multi-interlayer rhizobox planted with ryegrass was used to simulate the transport of EDDS and Cu from the non-rhizosphere to rhizosphere soils. The results showed that EDDS (5 mM kg-1) significantly dissociated Cu (285-690 fold), Fe (by 3.47-60.2 fold), and Al (2.43-5.31 fold) from the soil in comparison with a control group. this website A combination of micro-X-ray fluorescence, X-ray absorption near-edge structure spectroscopy, and sequential extraction analysis revealed that EDDS primarily chelated the adsorbed fraction of Cu by facilitating the dissolution of goethite. Moreover, as facilitated by ryegrass transpiration, CuEDDS was moved from the non-rhizosphere to rhizosphere and accumulated in ryegrass. In situ processes of Cu extraction and transport by EDDS in the rhizosphere were further elucidated with chemical speciation analysis and geochemical modeling methods.Fossil fuels still prevail over other energy sources in the world's consumption energy matrix. Thus, oil transportation and operations over maritime routes have been in high demand for a long time. Although oil spill accidents caused by these activities have reduced significantly over the last few decades, they still cause great concern. From this perspective, this paper presents simulation analyses of oil spill case studies using TELEMAC-3D hydrodynamic model coupled with an oil model. Hence a location susceptible to such accidents was selected and three real oil spills were simulated, for each of which there were official technical monitoring reports available. The obtained results contribute to the knowledge of oil pollution susceptibility in environmentally sensitive areas, as well as provide information concerning oil slick behaviour. Additionally, similarities between the modelled results and the technical reports were confirmed. These findings are useful for contingency planning and responding to these probable accidents.The presence of organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) was analysed in air particulate matter ≤ 2.5 μm (PM2.5) and ≤10 μm (PM10) collected in the Metropolitan Zone of Mexico Valley (MZMV), during 2013 and 2014, respectively. Spatial and seasonal distributions of PM and their organic content named solvent extracted organic matter (SEOM) were determined. PM mass concentration and SEOM/PM ratios were compared with previous studies in 2006 in Mexico City. PM2.5 concentration was like found in 2006, however, PM10 decreased ∼43%. The SEOM/PM10 ratio was kept constant, suggesting a decrease in SEOM as well as PM10 emitted from natural sources, probably as a result of changes in the land use due to urban growth. A decrease ∼50% SEOM/PM2.5 ratio was observed in the same period, linked to adequate strategies and public policies applied by the local and federal governments to control the organic matter emitted from anthropogenic sources. Seven out of sixteen OCPs and five out of six PBDEs were found.