The main objective of the present study is to measure the levels of heavy metals in important fruit species such as apple, apricot, and nectarine and their nine, five, and six cultivars, respectively. This work investigates the accumulation of Fe, Cu, Zn, Ni, Cd, Pb, and Cr in flowers of above species, to measure the levels of heavy metal contamination. The obtained results revealed that amounts of heavy metals significantly varied among cultivars at the same species and were within the permissible amounts in general. The Cd was not detected in apricot, nectarine, and the most of apple cultivars. Results for floral Fe, and also for Cu and Zn, which are the most important micronutrients for fruit production, suggest that levels of these elements might be used for assessing the storage of these elements during the previous season. We assume that the production of apple, apricot, and nectarine is safe, and there is no risk of contamination with heavy metals.

Fluoride is among the most phytotoxic atmospheric pollutants, commonly linked to the appearance of lesions in susceptible plants around emitting sources. In order to assess the effects of fluoride on leaves of Spondias dulcis Parkinson (Anacardiaceae), plants were examined 78 km (non-polluted area) and 0.78 km (polluted area) from an aluminium smelter. The level of fluoride increased with the exposure time of the plants in the polluted area. On the third day of exposure in the polluted area, necroses with typical colouration were observed. Micromorphological damage began at the abaxial epidermis, mainly associated with the stomata. Starch grain accumulation was more pronounced in the midrib. The cell membranes and chloroplasts were greatly affected by the pollutant. We observed accumulation of phenolic compounds and electron-dense material at the boundaries of the ending veinlets. The microscopic events described precede the appearance of symptoms and are therefore of prognostic value in predicting injury by fluoride and will be useful as biomarkers. The high sensitivity of S. dulcis to fluoride and the specificity of the symptoms confirm, for the first time, in an experiment of active biomonitoring, the potential of this species as a bioindicator.

The increased industrial and economic developments that have occurred in recent decades, particularly in mining, agricultural and metal recycling activities have decisively contributed to the increased concentration of heavy metals in soil. This study was carried out to evaluate the performance of Sorghum bicolor and Chrysopogon zizanioides in the citric acid-assisted phytoextraction of Pb in a field experiment setup in an area contaminated by automotive battery waste. Two soils amendments were used and they were dolomitic limestone and silicate slag at doses of 4.74 and 12.80 t ha⁻¹, respectively. Commercial citric acid was applied in each experimental parcel on the 63rd day of the cultivation in order to enhance Pb solubilisation and plant availability. Citric acid, which was applied at a dose of 40 mmol kg⁻¹of soil, was efficient in the solubilisation of Pb in soil and in the induction assisting of the removal of Pb from soil by the both species tested. Commercial citric acid is indicated for use in the area, due to its low cost and high biodegradability. Due to the low natural solubility of Pb and the large amount of time required, i.e. more than 900 years, phytoextraction without the application of chelating agents is not viable for remediation of the study area. Sorghum grown in soil amended with silicate slag combined with the application of the chelating agent commercial citric acid is the recommended phytoextraction programme for the remediation of an area with moderate Pb contamination.

The medium most directly affected by anthropic contamination is soil and, hence, groundwater (saturated and unsaturated zones). In the phytoremediation process, the direct absorption of soil contaminants through the roots is a surprising pollutant removal mechanism. Plants can act as a natural filter of shallow groundwater contamination, controlling and reducing the vertical percolation of contaminants into the soil, and after reaching the level of the water table, the roots can absorb contaminants dissolved in the water, thus reducing the size of the plume and protecting receptor sites (water supply wells, rivers, lakes) from possible contamination. In the first phase of the research, assays were performed to evaluate the tolerance of plant species to the direct injection of a benzene solution into the roots. Subsequent experiments involved direct absorption and spraying. The aim of this study was to evaluate the potential for tolerance and reaction to high levels of benzene. Three plant species were used, an herbaceous ornamental plant (Impatiens walleriana), a fern (Pteris vittata), and forage grass (Brachiaria brizantha). At the end of the study, the surface changes caused by VOCs (aerial structures) of benzene were evaluated, using an environmental scanning electron microscope (ESEM) to identify possible mechanisms of resistance of the plant to air pollution, i.e., hydrocarbon pollution. The plant material used here was young plant species selected for study. For the analysis by gas chromatography (GC), the plant material was separated into aerial (stem, leaves, and flowers) and underground parts (roots). A comparison of the benzene content in different parts of the plant indicated a higher concentration in the stem + leaves, followed by the roots, which is justified by its translocation inside the plant. P. vittata showed low uptake (5.88 %) mainly in the root and (<2 %) in the leaves, which was also observed in the tolerance experiment, in which visual symptoms of toxicity were not observed. I. walleriana showed benzene removal rates of approximately 18.7 % (injection into the soil) as a result of direct absorption through the roots. After the treatment was suspended, I. walleriana gradually reacted to the detoxification process by recovering its stem stiffness and normal color. B. brizantha showed intermediate behavior and did not react to the detoxification process.

Considerable amount of gasoline from natural and anthropogenic sources, such as urban runoff during hurricanes and oil discharges from pleasure crafts, has been released into Lake Pontchartrain, Louisiana, which poses a threat to the lake marsh ecosystems. In this research, we evaluated the impact of gasoline on indigenous bacterial communities in three types of marsh sediments collected from the Lake Pontchartrain. Our data show that several bacterial species are significantly enriched in gasoline-treated sediments. DNA sequencing data indicate that the enriched bacteria in response to the gasoline treatment are Acidocella and Burkholderia spp. in freshwater marsh; Mariprofundus, Nitrosospira, and Ferrimicrobium spp. in brackish marsh; and three Pseudomonas spp. in salt marsh. Our research will help to understand a gasoline bioremediation by indigenous bacteria and to develop site-specific bioremediation strategies for the Lake Pontchartrain.

A 3-year study was conducted to determine the effects of anaerobic digestion (AD), large particle solids, and manure additive (More Than Manure, MTM™) on ammonia (NH₃) and greenhouse gas (GHG; carbon dioxide, nitrous oxide, and methane) emissions when raw and treated manure were surface-applied. The presence of large particle solids resulted in greater NH₃ emissions, probably, due to reduced infiltration of liquid manure into soil (P < 0.05). Anaerobic digestion did not have a consistent effect on NH₃ emission. Manure with greater ammoniacal nitrogen (AN) concentrations had significantly greater NH₃ loss after manure application (P < 0.05). Anaerobic digestion of manure also did not have a significant effect on GHG flux (P > 0.05). Raw manure with large particle solids had significantly greater CO₂ flux than the other raw manure treatments on the day of manure application (P < 0.05). There was no significant manure treatment effects (P > 0.2) on methane flux over the 3-day period after manure application. The manure additive MTM™ did not have significant effects (P > 0.05) on NH₃ and GHG fluxes. The results of this study suggest that solids and AN concentrations in manure are the most important factors affecting NH₃ emissions after surface application.

Natural and anthropogenic aerosols over coal mines regions in India play a significant role in influencing the regional radiation budget, causing climate implications to the overall hydrological cycle of India. In the reference of regional climate change and air quality, we discuss aerosol optical depth (AOD) variability and long-term trends (from Mar 2000–Dec 2012) over eastern, southeast, and south coalfield regions in India. The present work analyses the variations and trends in aerosol loading using Terra-MODIS (Moderate-Resolution Imaging Spectroradiometer) AOD₅₅₀data in the period 2000–2012. Overall, an increasing trend in AOD₅₅₀has been observed over all regions namely Raniganj (7.31 %) in eastern and Korba (5.0 %) in southeast, and Godavari Valley (32 %) in the south coalfield region in India. This increasing trend predominantly owes to a constant increase in the seasonal/monthly averaged AOD during the winter (Dec–Feb) and post-monsoon (Oct–Nov) seasons dominated by anthropogenic emissions. In contrast, a decreasing trend is observed during pre-monsoon (Mar–May) season over eastern coalfield region (−13 %), while at south coalfield region (44 %) and southeastern coalfield region (0.8 %), increasing trends are observed. Similarly, increasing trends is observed over all regions in monsoon (Jun–Sep) months. Furthermore, the values of Hurst exponent, fractal dimension, and predictability index for AODs are 0.5, 1.5, and 0, respectively suggesting that the AODs in all sites follow the Brownian time series motion (true random walk). High AOD values (0.59 ± 0.21) are observed over eastern region Raniganj.

A method for simultaneous analysis of bisphenol A (BPA) and 17α-ethinylestradiol (EE2) in water supply was developed using solid-phase extraction and high-performance liquid chromatography with fluorescence detection. The linearity was evaluated between 2.5 and 200 μg L⁻¹(r> for the analytes. The limits of quantification were 1.5 and 2.1 ng L⁻¹for BPA and EE2, respectively. The extraction was made with C18 cartridges, and recoveries obtained varied between 70 and 102 % for the strengthening of 5 μg L⁻¹. After the validation, the method was applied in the determination of pollutants in surface water and water supply of Sao Luis, Brazil, where BPA was found in two of the eight samples analyzed, with concentrations of 1.11 and 3.61 μg L⁻¹.

The degradation of methyl orange (MO) in aqueous solution by microwave irradiation in the presence of granular-active carbon (GAC) was investigated. It was found that a synergistic rather than an additive effect of microwave irradiation and GAC contributes to the high-degradation efficiency. The ultraviolet and visible spectrum (UV–vis), infrared spectroscopy (IR), and scanning electron microscopy (SEM) measurements were conducted to trace the MO degradation process. It was demonstrated that the decrease in performance of GAC after repetitive use is largely attributed to the adsorption of some intermediate products on the surface of GAC. The regeneration of the spent GAC under microwave radiation was also investigated. The results show that the activity of spent GAC can be effectively recovered by microwave radiation and 74.1 % of its initial activity remains after six reaction cycles.

The effects of municipal-treated wastewater on growth and gas exchange characteristics were studied in eucalyptus plants cultivated in a greenhouse under continuous sub irrigation with 70 % Long Ashton solution as a control, 100 % treated wastewater, and treated wastewater diluted 50 % with tap water. Irrigation with wastewater resulted in a reduction of total dry matter per plant and the shoot-to-root ratio and increased specific leaf mass, irrespective of the dilution. The gas exchange characteristics were adversely affected by the irrigation with wastewater, with photosynthetic rates been negatively affected. Total chlorophyll and carotenoids content were reduced in plants grown under treated wastewater. The results demonstrated that when the eucalyptus plants were grown under treated wastewater as the only source of mineral nutrients they were able to produce nearly 50 % of the dry matter produced by the plants grown under appropriate mineral nutrient supply, irrespective of the dilution. Therefore, the contribution of mineral nutrients and organic matter from the treated wastewater used as agricultural irrigation will be significant in lower the fertilizer rates without reducing dry matter production per plant.