The aim of the present study was to isolate several bacterial consortia from a soil sample and to establish if they could colonize zirconium-tin alloy, such as Zircaloy-4. Two bacterial consortia containing aerobic heterotrophic bacteria and anaerobic sulfate-reducing bacteria were isolated from a soil sample. The aerobic heterotrophic bacteria exhibited a higher capability to utilize different sole carbon sources, as compared with anaerobic sulfate-reducing bacteria. Based on a morphological, biochemical, and molecular analysis, bacterial isolates were identified as Pseudomonas putida IBBHA₁, Pseudomonas aeruginosa IBBHA₂, Achromobacter spanius IBBHA₃, Citrobacter freundii IBBSR₁, Citrobacter youngae IBBSR₂, and Citrobacter braakii IBBSR₃. Isolated bacterial consortia which possess distinct DNA fingerprints were able to form biofilms and colonize the surface of zirconium-tin alloy coupons, although the colonization of coupons by the aerobic heterotrophic bacteria or anaerobic sulfate-reducing bacteria alone was lower compared with that observed when the coupon was immersed in a mixture of both bacterial consortia. Coupons immersed in these bacterial consortia revealed changes in the surface characteristics, which can facilitate or accelerate zirconium-tin alloy corrosion. The accumulation of corrosion products on coupons surface was less significant when the coupons were immersed solely in aerobic heterotrophic bacteria or anaerobic sulfate-reducing bacteria, compared with that observed when the coupon was immersed in a mixture of both bacterial consortia.

Our study evaluated 163 individuals, being 74 soybean farmers, occupationally exposed to pesticides, and 89 individuals from Goias municipalities, Central Brazil, with similar conditions to the exposed group, comprising the control group. Of the 74 soybean farmers, 43 exposed directly to pesticides and 31 exposed indirectly. The exposed group consisted of individuals aged 19 to 63 years, 21 women and 53 men, and the control group had ages ranging from 18 to 64 years, being 36 women and 53 men. 18.9% of the exposed group were poisoned by pesticides, and the most common symptoms were headache and gastrointestinal problems. The genotype frequencies of the rs2031920 (T>C) polymorphism in the CYP2E1 gene present significant differences between the exposed and control groups (p = 0.02), showing that 24.3% of the exposed group were heterozygotes against 6.7% in the control group. For the OGG1 gene, two SNPs, rs1052133 (G>C) and rs293795 (T>C), were evaluated and the genotype frequencies were not statistically different between the exposed and control groups. The DNA damage was distinct (p < 0.05) in the three analyzed comet parameters (tail length, Olive tail moment, %DNA) between groups. However, there was no influence of age and alcohol consumption between the groups associated with the polymorphisms in the CYP2E1 and OGG1 genes and DNA damage. We also did not find altered hematological and biochemical parameters in the exposed group. Thus, this pioneering study at Goias State carried out an overview of the health of soybean farmers. We evaluated classic laboratory exams, associated with exposure markers (comet assay) and susceptibility markers (genetic polymorphisms), emphasizing the need to expand the Brazilian health assessment protocol. We found, in soybean farmers, increased DNA damage and a higher number of heterozygotes in CYP2E1 gene, compared with the control group, despite the lack of association with age, educational level, smoking, drinking habits, and genetic polymorphisms.

The biomixture composition and the presence of a grass layer in a biobed bioremediation system can improve the performance of these systems to minimize pesticide point-source contamination. In this study, a novel biomixture composed with organic wastes from vineyards and wine industries (vermicompost of winery wastes and vine shoots) and top soil (W) was elaborated. The impact of three pesticides, commonly used in vineyards, on its microbial activity and on the development of turfgrass was determined in a short-term experiment. Moreover, the dissipation of the assayed pesticides was evaluated to stablish their distribution patterns between the turfgrass and the biomixture. For comparison, the original biomixture composed with top soil, peat, and straw (P) was also studied. After 15 days of pesticide application, the development of the turfgrass in both biomixtures was similar. However, the oxidoreductases (dehydrogenase and ortho-diphenol oxidase) and the hydrolytic (FDA and β-glucosidase) enzyme activities were greater in W-biomixture than in P-biomixture. The dissipation of metalaxyl and imidacloprid recorded in the W-biomixtures was significantly greater than in the P-biomixtures. The pesticide dissipation in W-biomixtures followed the same order of their octanol water partition coefficients. Except for tebuconazole, the lower biological activity in the P-biomixture would explain the limited pesticide dissipation. In the grassed biomixtures, most (> 83%) of the non-dissipated imidacloprid and tebuconazole remained in the biomixtures, while metalaxyl was rapidly translocated to the aerial part of the turfgrass. Our results show the potential capability of the novel biomixture as an alternative to the original one in a biobed.

The objective was to evaluate removal efficacy of agrichemicals from water using a small-scale granular activated carbon (GAC) system. The GAC system consisted of a series of three 1.9- to 4.1-L filter canisters filled with 8 × 30 US mesh (595 to 2380 μm) bituminous coal GAC. In experiment 1, 11 agrichemicals (acephate, bifenthrin, chlorpyrifos, flurprimidol, glyphosate, hydrogen peroxide + peracetic acid, imidacloprid, paclobutrazol, didecyldimethylammonium chloride (DDAC), triclopyr, and uniconazole) used in greenhouse and nursery production were exposed to 0, 12, or 64 s of GAC contact time. Chemical concentrations were prepared at a 1:10 dilution of a recommended label rate for ornamental crops to represent a possible residual concentration found in recaptured irrigation or surface water. In experiment 2, three other chemicals [iron ethylene diamine-N,N′-bis(hydroxy phenyl acetic acid) (iron-EDDHA, a chelated iron fertilizer), soracid blue dye (a fertilizer dye), and sodium hypochlorite (a sanitizing agent)] were also tested with 0, 12, 38, or 64 s of GAC contact time. Agrichemical concentration was reduced with 12 s of GAC contact time compared with the 0 s for all chemicals tested, and in most cases was further increased at 64-s contact time. Chemicals reduced below their minimum detection limits with 64 s GAC included acephate, flurprimidol, paclobutrazol, uniconazole, peracetic acid, DDAC, and chlorine (free and total). Percent reduction for other chemicals with 64 s GAC was 72.2% for bifenthrin, 89% chlorphyrifos, 85.3% imidacloprid, 99% glyphosate, 99.4% triclopyr, 99.3% hydrogen peroxide, 47.6% iron-EDDHA, and 94.6% soracid blue dye. Iron-EDDHA and soracid blue dye could be used as indicator chemicals for onsite monitoring of GAC filter efficacy. Results indicate that GAC filtration can remove a wide range of agrichemical contaminants commonly used in greenhouse and nursery production, although the required contact time in commercial production is expected to be greater than in this research study.

Water treatment residuals (WTRs) are by-products of the coagulation and flocculation phase of the drinking water treatment process that is employed in the vast majority of water treatment plants globally. Production of WTRs are liable to increase as clean drinking water becomes a standard resource. One of the largest disposal routes of these WTRs was via landfill, and the related disposal costs are a key driver behind the operational cost of the water treatment process. WTRs have many physical and chemical properties that lend them to potential positive reuse routes. Therefore, a large quantity of literature has been published on alternative reuse strategies. Existing or suggested alternative disposal routes for WTRs can be considered to fall within several categories: use as a pollutant and excess nutrient absorbent in soils and waters, bulk land application to agricultural soils, use in construction materials, and reuse through elemental recovery or as a wastewater coagulant. The main concerns and limitations restricting current and future beneficial uses of WTRs are discussed within. This includes those limitations linked to issues that have received much research attention such as perceived risks of undesirable phosphorous immobilisation and aluminium toxicity in soils, as well as areas that have received little coverage such as implications for terrestrial ecosystems following land application of WTRs.

Co-contamination with heavy metals and pesticides is a severe environmental problem, but little information is available regarding the simultaneous removal of these pollutants. In this study, we showed that Aspergillus sydowii strain PA F-2 isolated from soil contaminated with heavy metal and pesticides can simultaneously degrade trichlorfon (TCF) and adsorb Cd(II) from mineral salt medium. The maximum removal rates for TCF and Cd(II) were 55.52% and 57.90%, respectively, in the treatment containing 100 mg L⁻¹ TCF and 2 mg L⁻¹ Cd(II). As the initial Cd(II) concentration increased (2, 5, and 10 mg L⁻¹), the PA F-2 biomass, TCF degradation rate, and Cd(II) adsorption efficiency decreased, whereas the Cd(II) adsorption capacity by PA F-2 increased. The addition of exogenous glucose and sucrose significantly increased the PA F-2 biomass as well as the removal of TCF and Cd(II). Moreover, the TCF degradation pathway and Cd(II) adsorption mechanism were investigated by gas chromatography–mass spectrometry, scanning electron microscopy, and Fourier transform infrared spectroscopy. These results suggest that PA F-2 has potential applications in the bioremediation of TCF and Cd(II) co-contamination.

In this work, coal bottom ash, a residue generated in thermoelectric power plant, was employed as an alternative catalyst in photo-Fenton reaction for the degradation of sunset yellow dye from liquid solution under visible irradiation. The residue was characterized by techniques such as XRD, XRF, N₂ adsorption/desorption isotherms, SEM/EDS, and FT-IR. The influence of reaction parameters such as solution pH, catalyst dosage, and H₂O₂ concentration on dye removal was analyzed by a central composite rotatable design 2³. According to the characterization results, the presence of iron in the material was confirmed by analysis of chemical composition by XRF, presenting 5.5 wt% in terms of iron oxide. Through the response surface methodology, it was possible to adjust the polynomial model and determine the optimum region of dye removal. The regression model was predictive and significant, with a coefficient of determination (R²) equivalent to 91%, showing a good fit between the experimental and theoretical values. The optimum region reaching a color removal of 91% has a pH level of 2.7, catalyst dosage of 0.9 g L⁻¹, and H₂O₂ concentration of 10 mmol L⁻¹. Therefore, coal bottom ash, an abundant residue with low cost, showed to be a potential catalyst in a photo-Fenton process for the removal of organic contaminant from liquid solution.

Human health and well-being are strongly linked to the state of the environment. The high industrial pressure present in the Province of Brescia, located in Northern Italy, produced strong environmental and health concerns. This narrative review of the literature aims at identifying the studies focused on the association between exposure to environmental pollutants and health effects in the population living in this area. Thirteen papers fitted the inclusion criteria: five were focused on the connection among pollutants present in air matrix and health effects, seven on both air and soil, and one on soil. No study investigated the relationship with water pollution. The great variability in the analyzed end-points made it difficult to draw precise conclusions, but the fact that, in almost all the studies, the investigated health effects have a positive association with the exposure to different kinds of pollutants, allows us to hypothesize that the considered population is living in an area where the “environmental pressure” could produce significant health effects in the future.

N-nitrosodimethylamine (NDMA), a toxic disinfection byproduct commonly associated with chloramination, has recently been found to form from an anti-yellowing agent (4,4′-hexamethylenebis (1,1-dimethylsemicarbazide) (HDMS)) during ozonation but the mechanisms are unclear. In this paper, the potential roles of molecular ozone (O₃) and hydroxyl radical (∙OH) on NDMA formation from HDMS were investigated under various oxidation conditions (ozone dosages, pH) and different components in water (bromide ion (Br⁻), bicarbonate ion (HCO₃⁻), sulfate ion (SO₄²⁻), and humic acid (HA), as well as natural organic matter (NOM) from a lake). Moreover, HDMS transformation pathways by ozonation were determined. The results indicated that the formation of NDMA was enhanced through the combined effect of O₃ and ∙OH compared to that by O₃ alone (addition of tert-butyl alcohol (tBA) as ∙OH scavenger). ∙OH itself cannot generate NDMA directly; however, it can transform HDMS to intermediates with higher NDMA yield than parent compound. The NDMA generation was affected (small dosages promoted but high dosages inhibited) by HA or Br⁻ no matter with or without tBA. The presence of SO₄²⁻ and HCO₃⁻ ions lowered NDMA formation through ∙OH scavenging effect. Increasing pH not only increased degradation rate constant by enhancing ∙OH generation but also affected HDMS dissociation ratio, reaching the maximum NDMA formation at pH 7–8. Natural constituents in selected water matrix inhibited NDMA formation. Impacts of these influencing factors on NDMA formation by only O₃ however were significantly less pronounced over that by the joint roles of O₃ and ∙OH. Based on the result of Q-TOF, LC/MS/MS, and GC/MS, the possible transformation pathways of HDMS by ozonation were proposed. The NDMA enhancement mechanism by the combined effect of O₃ and ∙OH can be attributed to greater amounts of intermediates with higher NDMA yield (such as unsymmetrical dimethylhydrazine (UDMH)) produced. These findings provide new understanding of NDMA formation upon ozonation of typical amine-based compounds.

Selenium (Se) is a vital element which leads to strong antioxidation in animals and humans. However, the mechanism underlying natural cereal Se–induced biological changes is not well understood. This study intended to explore the gene differential expression in naturally aged mice exposed to selenium by RNA-Seq technique. A total spectrum of 53 differentially expressed genes was quantified in mice heart tissues treated with Se-rich and general rice. The GO functional annotation of differentially expressed genes disclosed the enrichment of cellular process, ionic binding, biological regulation, and catalytic activity. One hundred twenty-three differential pathways (cardiovascular diseases, immune system, transport and catabolism, longevity regulating, and PI3K-AKT signaling) were identified according to KEGG metabolic terms. Afterwards, the effect of Se-rich rice on the antioxidant activity was assessed. The selenium-rich diet increased the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in mice serum and livers while significantly reduces methane dicarboxylic aldehyde (MDA) contents. FOXO1 and FOXO3 genes, which acted as the regulators of apoptosis and the antioxidant enzyme, were significantly enhanced in mice when fed with Se-rich rice. In short, the present findings disclosed the alluring insights of organic and inorganic selenium sources on certain biological processes and antioxidant activity of living bodies. However, long-term trials are still required to draw a definitive conclusion, including risks and benefit analysis for various management strategies.