The content of As and heavy metals (Pb, Cd, Ni, and Cu) in total suspended particulate (TSP) and PM₁₀ at 3 locations (Park, Institute, and Jugopetrol) near the copper smelter in Bor (Serbia) has been analyzed within the period 2004 to 2015 with the aim of investigating the seasonal and spatial changes of those pollutants in the suspended particles. The content of As in TSP and PM₁₀ was over the annual EU limit value at all measuring points during the entire period of observation, while contents of Cd and Pb were periodically above the annual EU limits. There were no statistically significant seasonal changes between mean levels of the observed elements in the cold (October–March) and warm (April–September) periods during the year. A strong and moderate positive correlation was detected between the concentrations of each particular element (except Ni) at all measuring points. Additionally, Cd was the most enriched element followed by Pb, As, and Cu, while Ni was low-enriched. The constant air pollution with As particles, sometimes in concentrations even 20 times higher than the permitted annual value, requires urgent undertaking of concrete actions in order to reduce anthropogenic emission of suspended particles in Bor.

The Highveld and Waterberg regions in South Africa contain extensive coal fields and therefore have a high concentration of coal-fired power stations. Previous studies assessed the impact of atmospheric deposition of S- and N-containing species from anthropogenic sources in the region but did not include the effect of biogenic emissions. This study models biogenic NOX soil emissions for the regions and includes them in an atmospheric dispersion model to study the effects of biogenic emission on nitrogen deposition rates. Simulated sulfur deposition rates for the Highveld area are also reported on. Anthropogenic and biogenic sulfur and nitrogen emission sources were inventoried for the Highveld and Waterberg regions. Using previous work by Yienger and Levy, biogenic soil NOX emissions were quantified by constructing models for both areas using land use data, rainfall data, and atmospheric ground level temperatures from CALMET data. A CALPUFF dispersion model was used to predict deposition rates for S- and N-containing species with and without biogenic NOₓ emissions to determine the impact of biogenic emissions for the Highveld. As rainfall is highly variable in the region, meteorological data representative of high, average, and low rainfall years was used to determine the effect of rainfall on deposition rates for the various species. The biogenic NOₓ made up 3.96, 4.14, and 3.34% of total released NOₓ for 2001 (average rainfall), 2003 (low rainfall), and 2010 (high rainfall), respectively. Dry nitrogen deposition rates were affected most by the biogenic component, adding from 1.7 to 6.2% at various receptor locations. Wet deposition rates were affected very little (0.13 to 0.75%). Effect on total nitrogen deposition rates ranged from 0.32 to 1.77%. Biogenic emissions for the Waterberg area, being more arid, were calculated to be only 2.3% of total NOₓ emissions for the area and accordingly have little effect on deposition rates.

In this work, ciprofloxacin (CIP) degradation is investigated using different photo-chemical advanced oxidation processes (AOPs): Fe²⁺/H₂O₂/UV, TiO₂/UV, and H₂O₂/UV. At natural pH, direct oxidation at the photo-generated holes showed to be the main pathway during TiO₂/UV process, while H₂O₂/UV and Fe²⁺/H₂O₂/UV degradation mainly occurred by hydroxyl radical attack. The identification of degradation by-products confirmed the differences in the degradation pathways. Water matrix effects were also investigated by evaluating the influence of the initial pH and testing CIP degradation in mineral natural water and distilled water. Significant differences were observed associated to the pH, the H₂O₂/UV system being the less affected process. Natural water showed to be an inhibitor medium for the tested photo-chemical processes. Interestingly, H₂O₂/UV system showed again to be not considerably affected by the natural water matrix. Additionally, degradation extent of treated solutions was determined by the mineralization level (TOC removal) and the antimicrobial activity (AA) elimination using Staphylococcus aureus and Escherichia coli as probe microorganisms. Despite mineralization was no reached in any case, AA elimination was promoted by all processes suggesting the formation of by-products with non-antibiotic character. However, due to the particular degradation pathway, interesting differences were observed according to the type of bacteria when TiO₂ photo-catalysis was used.

The removal of copper, nickel, and cobalt ions from synthetic mining wastewater was investigated in this study using micellar-enhanced ultrafiltration (MEUF). The effect of surfactant-to-metal (S/M) ratio and pH on metal rejection and permeate flux were examined. A Monte Carlo-based artificial neural network (ANN) modeling approach was proposed to predict the MEUF performance and to reveal the importance of process parameters. The results showed that model-predicted values were in agreement with experimental data (R > 0.99). S/M ratio and pH had relatively greater contributions (30–50%) to the metal rejection rate and permeate flux, whereas sampling time contributed less (10%), which indicated high MEUF efficiency. An S/M ratio of 8.5 with a pH of 8–10 was found to be the optimal condition for MEUF, under which the rejection rates of all three metals exceeded 99% and were in compliance with Canadian environmental standards. Flux decrease and concentration polarization effect were observed during the experimental procedure. Statistical analysis showed that the type of metal examined in this study did not affect MEUF performance.

Chicken feather, which is consisted of keratin, has always been abandoned as solid waste. The utilization technologies of waste keratin have been developed in electric zones and materials fields so far. Recently, numerous new types of adsorbents have been used for antibiotic removal. The chicken feather carbon is supposed to be a potential one. In this study, an activated feather carbon (AFC) was developed as the absorbent of amoxicillin (AMOX) in simulated wastewater. The micropore structures of AFC were detected by the scanning electron microscope (SEM). X-ray photoelectron spectrum (XPS) was recorded and analyzed. A BET surface area, as high as 1838.86 m²/g, was measured in this study. At the meantime, a rapid adsorption (5∼7 min) and high removal efficiency (99.63%) could be observed. The kinetics, isotherms, and thermodynamic studies indicated that the adsorption of AMOX by AFC was an exothermic physic-adsorption. The interaction between AMOX and AFC surface was supposed to be a multiple-layer adsorption process for it is well fitted with the Freundlich model. The adsorption behavior could be described by pseudo-second-order model almost perfectly in kinetic studies. In addition, effect of pH, ionic strength, and reusability properties were also discussed in this paper. The AFC was proved to be the most rapid, efficient, and economically absorbent for AMOX removal, which was effective enough under various temperatures and saline circumstances. It was also proved useful, convenient, and renewable in dealing with the tough antibiotic pollutant problems and rebuilding of antibiotic sewage treatment facilities.

The purpose of this study was to determine the different kinds and concentrations of intermediates, and investigate on the effects of contact time and ozone (O₃) doses on the removal of humic acid (HA), which is served as the main disinfection by-product (DBP) precursor. Based on that, the knowledge gap of DBPs generated was made up. The results showed that HA was the major precursor material for aldehydes and carboxylic acids. The concentrations of aldehydes increased as contact time and O₃ doses, and reached up maximum at 2~10 min but approached a plateau at the higher O₃ doses. The concentrations of formic and acetic acids increased as contact time and O₃ doses. However, aromatic acids, including protocatechuic, 3-hydroxybenzoic, and benzoic acids, declined rapidly at longer reaction time and higher O₃ doses. It was worth mentioning that aromatic acids had been rarely reported. Besides, a possible formation pathway was proposed: (a) HA was degraded into fulvic acid (FA)-like compounds; (b) FA-like compounds were further converted into aromatic acids; (c) aromatic acids were transformed into low-molecular-weight organic matters; (d) chlorine reacted with aldehydes and/or carboxylic acids by addition, hydrolysis, and decarbonylation reactions, leading to DBP formation. Furthermore, not only HA were the main DBPs precursors, but also the oxidation intermediates of HA could be the DBPs precursors, and they gave a certain amount of DBPs. Consequently, aldehydes and carboxylic acids should be under control in drinking water treatment plants.

Artificial adamite [Zn₂(AsO₄)(OH)] is a convenient structural model because it is isostructural with other rock-forming minerals in secondary ore deposits formed in cementation zones. Microbial activity in these zones accelerates mineral biogeochemical deterioration and metal release, and our results confirmed that Pseudomonas, Rhodococcus and Cupriavidus strains accelerate adamite leaching by 10 to 465 times compared to controls. Here, the Pseudomonas chlororaphis ZK-1 bacterial strain in a static 42-day cultivation proved more effective than Rhodococcus and Cupriavidus by leaching over 90% arsenic and 10% zinc from adamite in one-step in vitro. We evaluated adamite with the VESTA visualization system for electronic and structural analysis, and our results enhance understanding of zinc and arsenic biogeochemical cycles and mobilization, and highlight bacteria’s beneficial natural and biotechnological application in environmental geochemistry and biohydrometallurgy.

Mercury (Hg) poses environmental and health risks due to its global distribution and high toxicity exhibited in some of its chemical forms. Although Hg is naturally present in the environment, human activities have increased its cycling among the land, atmosphere and ocean by a factor of three to five comparing the pre-industrial period to the present day. The Torviscosa chlor-alkali plant (CAP), which operated since the beginning of twentieth century, was one of the most important Cl₂ production capacity in the Northern Italy and was responsible for an uncontrolled discharge of Hg in the surrounding area. Previous studies reported the high degree of Hg pollution in soils, river sediments and surface waters of the area, but the Hg level in the atmospheric media was never taken into consideration. In this work, an integrated approach was applied with the aim to assess the level, distribution and dispersion of gaseous elemental mercury (GEM) close to the CAP area. GEM levels were monitored by means of four surveys conducted from September 2014 to July 2015, at fixed locations and covering an area of about 10 km² (including CAP area, Torviscosa village and reclaimed land), accomplished to Hg bioaccumulation measurements in selected lichens. The results indicate that the CAP area currently represents the main source of GEM in the Friuli Venezia Giulia region. The highest levels were found close to the old factory’s buildings (more than 5000 ng m⁻³), whereas other sites are less impacted. The emission of GEM is not clearly related to the intensity of solar radiation (temperature) at the soil level; however, this latter influences the release from the old buildings employed in the past for the production activities. The most important factor driving the GEM dispersion is the wind, as confirmed by the map of lichens bioaccumulation. In this context, the GEM plume partially affects the nearby village of Torviscosa (about 1 km), but the values found were always well below the international thresholds for residential areas, thus excluding the risk of inhalation for local inhabitants.

The use of low-polarity organic solvents is widespread in cleanup/extraction processes in order to carry compounds of interest, remove interferences and separate phases, among other uses. A large number of studies have used delipidation to remove excess of lipids to analyse carbon stable isotopes in biological tissues for trophic and behavioural ecology investigations. In this context, the primary aim of this study is to assess the influence of one delipidation process on the results of total mercury (Hg) analyses and the possible use of delipidated samples from previous analyses, such as for stable isotopes, in Hg level determination. Samples of vegetation (angiosperm, lichens and mosses), invertebrates (krill and limpets), fish (marbled and black rockcod), bird liver and eggs (Antarctic, Gentoo and Adélie penguins, kelp gull, Antarctic tern, cape petrel and giant southern petrel) and pinniped tissues (Weddell seal, crabeater seal, southern elephant seal and Antarctic fur seal) were analysed for Hg before and after delipidation by cyclohexane. The difference between the two measurements ranged individually from −63 to 136% (in the moss Sanionia uncinata) and the averages ranged from −60 to 66% (in pinniped tissues). The proportion of organic Hg, which presents considerable lipophilicity, but also high affinity for sulfhydryl groups in proteins, might be responsible for such variability. Given the limitations of our study, we think it is safe to say that delipidated samples could not be used to infer total Hg values in non-delipidated ones.

The Pantanal is an extensive flooded plain, rich in biodiversity and considered a Biosphere Reserve and World Heritage Site. It has great complexity and can be divided into regions due to its each distinct characteristic. Nhecolândia is a very peculiar region because it is made up of thousands of freshwater and brackish ponds. The study objective was to evaluate the physical-chemical parameters of the Nhecolândia ponds and to analyze the vegetation indexes generated from UAV aerial photographs in order to identify what best distinguishes freshwater and brackish ponds and to differentiate study area features. The in-field and image data collection were performed on June 20, 2015. The aerial photographs were processed to obtain mosaic which served as a vegetation index basis. The indexes and wavelengths in the visible region analyses were performed for each of the area’s ponds. It was observed that bays and salines have a differentiated spectral behavior. The excess green and normalized excess green vegetation indexes presented results enough to separate freshwater from brackish ponds, plus to differentiate many study area features.