Soil, olive leaves, and fruits, were sampled from an olive grove 200 ha, irrigated with treated municipal wastewater (TMWW), located at Al-Tafilah wastewater processing plant (WWPP), Jordan. Similar samples were also taken from plants not irrigated with TMWW (Control). The heavy metal and essential nutrients were determined in all samples, and the data were statistically processed. The following were found: Much smaller quantities of heavy metals than essential elements were accumulated in the leaves and fruits, the accumulation being independent of the TMWW heavy metal concentration, suggesting a selective uptake of the metals by the olive plants. Also the elemental interactions, which occurred in the olive fruits, contributed mainly essential nutrients and secondarily heavy metals. The trend of heavy metal transfer from soil to olive fruits, and leaves, was almost the same, showing a consistency of transfer.

In recent years, elevated arsenic concentrations in groundwater used for drinking water supplies have been recognised in the Madrid Tertiary detrital aquifer. Although only natural causes have been suggested as the source of arsenic, this study aims to highlight that the anthropogenic contribution cannot be disregarded. During the sub-catchment's areas sampling, we found many geographical sites where natural arsenopyrite [FeAsS] originally encapsulated in pegmatite bodies and quartz veins, was artificially outcropped and dumped out, since mining wastes were scattered and exposed to weathering. Several mineral and ground specimens were collected to analyse its mineralogical and chemical composition by X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) spectrometry and by Environmental Scanning Electron Microscope (ESEM). Both, the abundant existence of secondary phases, such as scorodite [FeAsO₄⋅2H₂O] and jarosite [KFe₃(SO₄)₂(OH)₆], much more soluble than arsenopyrite, and the lixiviation experiments of arsenopyrite in acidic media to simulate acid mine drainage (AMD) conditions, usually found in old mining districts, point to a potential risk of arsenic contamination of surface water bodies, which operate as recharged waters of the aquifer in the studied area. The elemental determination of heavy metals present in ground samples by XRF analyses, reaching up to 1,173 mg kg⁻¹ of copper, 347 mg kg⁻¹ of lead and 113,702 mg kg⁻¹ of arsenic; and the physicochemical and arsenic fractionation studies of soil samples, led us to classify the soil as Spolic Technosol (Toxic). The contamination of the area due to old mining activities could release arsenic to Madrid water supplies; accordingly, additional decontamination studies should be performed.

We present here the effects of ambient ozone (O₃)-induced decline in carbon availability, accelerated foliar senescence, and a decrease in aboveground biomass accumulation in the Aleppo pine (Pinus halepensis Mill.). Aleppo pine seedlings were continuously exposed in open-top chambers for 39 months to three different types of O₃ treatments, which are as follows: charcoal-filtered air, nonfiltered air (NFA), and nonfiltered air supplemented with 40 ppb O₃ (NFA+). Stable carbon isotope discrimination (Δ) and derived time-integrated c i/c a ratios were reduced after an accumulated ozone exposure over a threshold of 40 ppb (AOT40) value from April to September of around 20,000 ppb·h. An AOT40 of above 67,000 ppb·h induced reductions in ribulose-1,5-biphosphate carboxylase/oxygenase activity, aboveground C and needle N and K concentrations, the C/N ratio, Ca concentrations in twigs under 3 mm, and the aerial biomass, as well as increases in needle P concentrations and phosphoenolpyruvate carboxylase (PEPC) activity and the N and K concentrations in twigs under 3 mm. Macronutrients losses, the limitations placed on carbon uptake, and increases in catabolic processes may be the causes of carbon gain diminution in leaves which was reflected as a reduction in aboveground biomass at tree level. Stimulation of PEPC activity, the consequent decreased Δ, and compensation processes in nutrient distribution may increase O₃ tolerance and might be interpreted as part of Aleppo pine acclimation response to O₃.

Differences in the culturable fractions of total and metal-tolerant bacteria inhabiting bulk soil of a metal-mine spoil heap and the rhizosphere of silver birch (Betula pendula) or bushgrass (Calamagrostis epigejos), completed with changes in total microbial community structure in the soil, were assessed by MIDI-FAME (fatty acid methyl ester) profiling of whole-cell fatty acids. In addition, the abundance of metal-tolerant populations among the culturable bacterial communities and their identity and the metal-tolerance patterns were determined. The high proportions of Cu- and Zn-tolerant bacteria that ranged from 60.6% to 94.8% were ascertained in the heap sites. Within 31 bacterial isolates obtained, 24 strains were Gram-positive and Arthrobacter, Bacillus, Rathayibacter, Brochothrix, and Staphylococcus represented those identified. Minimum inhibitory concentration (MIC) data indicated that several strains developed multi-metal tolerance, and the highest tolerance to Cu (10 mM) and Zn (12 mM) was found for Pseudomonas putida TP3 and three isolated strains (BS3, TP12, and SL16), respectively. The analysis of FAME profiles obtained from the culturable bacterial communities showed that Gram-positive bacteria predominated in bulk soil of all heap sites. In contrast, the rhizosphere communities showed a lower proportion of the Gram-positive group, especially for silver birch. For the total microbial community, mostly Gram-negative bacteria (e.g., Pseudomonas) inhabited the heap sites. The results suggest that the quantitative and qualitative development of heterotrophic microbiota in the soil of the metal-mine spoil heap seems to be site-dependent (i.e., rhizosphere vs. bulk soil), according to differences in the site characteristics (e.g., enrichment of nutrients and total metal concentrations) and impact of plant species.

Mining operations are potential sources of airborne metal and metalloid contaminants through both direct smelter emissions and wind erosion of mine tailings. The warmer, drier conditions predicted for the Southwestern USA by climate models may make contaminated atmospheric dust and aerosols increasingly important, with potential deleterious effects on human health and ecology. Fine particulates such as those resulting from smelting operations may disperse more readily into the environment than coarser tailings dust. Fine particles also penetrate more deeply into the human respiratory system and may become more bioavailable due to their high specific surface area. In this work, we report the size-fractionated chemical characterization of atmospheric aerosols sampled over a period of a year near an active mining and smelting site in Arizona. Aerosols were characterized with a ten-stage (0.054 to 18 μm aerodynamic diameter) multiple orifice uniform deposit impactor (MOUDI), a scanning mobility particle sizer (SMPS), and a total suspended particulate collector. The MOUDI results show that arsenic and lead concentrations follow a bimodal distribution, with maxima centered at approximately 0.3 and 7.0 μm diameter. We hypothesize that the sub-micron arsenic and lead are the product of condensation and coagulation of smelting vapors. In the coarse size, contaminants are thought to originate as Aeolian dust from mine tailings and other sources. Observation of ultrafine particle number concentration (SMPS) show the highest readings when the wind comes from the general direction of the smelting operations site.

The feasibility of employing a porous polyurethane–keratin hybrid membrane for the removal of hexavalent chromium was investigated. Keratin was extracted from chicken feathers and incorporated onto a synthetic polyurethane polymer to synthesize a hybrid membrane. Keratin supply active sites to bioadsorb Cr(VI) and polyurethane play an important role as the support to protein. Also, polyurethane–keratin biofiber membranes were synthesized. Biofibers obtained from chicken feathers were modified to activate their surface. The effective pore in membranes is less than 50 nm, which places these materials in the mesopore range. Scanning electron microscopy (SEM) was used to study the morphology of membranes, and mechanical dynamical analysis (DMA) was used to evaluate the viscoelastic properties. NH, C=O, S–S and C–S were determined via Fourier-transform infrared (FTIR) analysis as functional groups of keratin, which participate in the linking sorption of hexavalent chromium. Adsorption of Cr(VI) was carried out in a filtering system at low contact time in continuous flux; the maximum removal reached was 38% at neutral pH of chromium solution. Results indicate that the isoelectric point of keratin is relevant in the adsorption process. pH of keratin solution above the isoelectric point brings about higher adsorption of heavy metals, whereas lower pH causes minor adsorptions, due to the functional groups’ ion charges. Based on the results, keratin extracted from feathers is a natural biosorbent that can be incorporated onto synthetic polymers to develop novel membranes and improve its applications in the heavy metal separation process.

The presence of sexual hormones (female estrogens) was assessed in sediments of a mangrove located in the urban region of southern Brazil. The estrogens are involved in human sexual reproduction. They act as the chemical messengers, and they are classified as natural and synthetic. The estrogens inputs in the environment are from treated and untreated sewage. The presence of estrogens in sewage is excretion from the female due to natural production and use of contraceptives (synthetic estrogens). With the indiscriminate release of sewage into the environment, estrogens can be found in rivers, lakes, and even in oceans. In this work, the presence of estrone (E1), 17-β-estradiol (E2), and 17-α-ethynilestradiol (EE2) in eight sedimentary stations in Itacorubi mangrove located on Santa Catarina Island, south Brazil, was investigated. Historically, the Itacorubi mangrove has been impacted by anthropogenic activities because the mangrove is inserted in the urban area of the Florianopolis. The estrogen EE2, used as contraceptive, had the highest concentration in mangrove sediment, 129.75 ± 3.89 ng/g. E2 was also found, with its concentration ranging from 0.90 ± 0.03 to 39.77 ± 1.19 ng/g. Following the mechanism, under aerobic or anaerobic conditions, E2 will first be oxidized to E1, which is further oxidized to unknown metabolites and finally to CO2 and water (mineralized). EE2 is oxidized to unknown metabolites and also finally mineralized. Theoretically, under anaerobic conditions, EE2 can be reduced to E1 even in environments such as mangrove which is essentially anaerobic.

Mixed microbial culture was isolated from heavy metal-contaminated ground soils located inside iron, vinyl and cement factory area. Isolated mixed microbial culture was used for the heavy metal ions (Fe²⁺, Cu²⁺, Ni²⁺ and Zn²⁺) removal process in horizontal rotating tubular bioreactor (HRTB). In this research, the effect of bioreactor process parameters on the bioprocess dynamics in the HRTB was studied. Results of this research have shown that profiles of heavy metals concentration were gradually reduced along HRTB at all combinations of bioreactor process parameters [inflow rates (0.5-2.0 L h⁻¹) and rotation speed (5-30 min⁻¹)]. Hydrodynamic conditions and biomass sorption capacity have main impact on the metal ions removal efficiency that was varied in the range of 38.1% to 95.5%. Notable pH gradient (cca 0.7 pH unit) along the HRTB was only observed at the inflow rate of 2.0 L h⁻¹. On the basis of obtained results, it is clear that medium inflow rate (F) has higher impact on the heavy metal removal process than bioreactor rotation speed (n) due to the fact that increase of inflow rate was related to the reduction of equilibrium time for all examined metal ions. Furthermore, equilibrium times for all metal ions are significantly shorter than medium residence times at all examined combinations of bioreactor process parameters. The main impact on the biofilm sorption capacity has covalent index of metal ions and biofilm volumetric density. The sorption capacity of suspended microbial biomass is closely related to its concentration. Results of this research have also shown that the removal of heavy metals ion can be successfully conducted in an HRTB as a one-step process.

Resistivity of plastic litter to chemical weathering, mechanical erosion, and biological degradation poses a critical environmental threat. Plastic debris has increased in abundance over the past several decades along shorelines and at sea, where organisms mistake small particles including plastic pellets as a potential food supply. These pellets have been shown to adsorb persistent organic pollutants such as PCBs, which may endanger the organism and become ingested higher in the food chain. Although several studies have been conducted to determine the amount and effects of plastics pollution in marine environments, relatively little is known concerning fresh water plastics pollution. This study represents the first detailed examination of the distribution, types, and physical and chemical degradation processes of plastic particles in a fresh water setting. In conducting field surveys along the shoreline of Lake Huron, Canada, we were able to ascertain that the total number of pellets over multiple sampling localities comprise 94% of plastic debris. The majority of the pellets were found proximal to an industrial sector along the southeastern margin of the lake and their abundance steadily decreased northward, following the dominant lake current patterns. Laboratory analyses using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy indicate predominant mechanical abrasion textures, including grooves, gauges, pits, and flakes, and less common chemical weathering features such as linear and crescentic fractures that developed from shrinkage during subaerial exposure. The predominant type of plastic, polyethylene, appears to be much more resistant to chemical weathering than polypropylene, as indicated by oxidation peaks on FTIR spectra suggesting that polypropylene degrades more readily under natural conditions on freshwater beaches.

Hexavalent chromium is a heavy metal used in a variety of industrial applications which is highly toxic to humans, animals, plants and microorganisms. Moreover, it is a well-established human carcinogen by the inhalation route of exposure and a possible human carcinogen by the oral route of exposure. Therefore, it should be removed from contaminated waters. Its reduction to trivalent chromium can be beneficial because a more mobile and more toxic chromium species is converted to a less mobile and less toxic form. During the last two decades, there has been important interest in using zero-valent iron (ZVI) as a Cr(VI)-reducing agent. A considerable volume of research has been carried out in order to investigate the mechanism and kinetics of Cr(VI) reduction with ZVI, as well as the influence of various parameters controlling the reduction efficiency. Therefore, the purpose of this review was to provide updated information regarding the developments and innovative approaches in the use of ZVI for the treatment of Cr(VI)-polluted waters.