A novel tellurite-resistant photosynthetic bacterium, Rhodopseudomonas palustris strain TX618, was isolated from wastewater and reduction of tellurite by this strain was investigated. The results showed that Rhodopseudomonas palustris strain TX618 could reduce tellurite to elemental tellurium, both anaerobically and aerobically. During anaerobic and illuminated growth, strain TX618 possessed a high-level resistance and removal efficiency to tellurite, that it could resist up to 180 mg/L Na₂TeO₃ in the medium and removed 91.9% of 90 mg/L Na₂TeO₃ over 8 days. The high efficiency in the removal of tellurite could sustain wide variations in pH (5.0–9.0), temperature (20–40 °C), light intensity (1500–3000 lx), and initial tellurium concentration (30–180 mg/L Na₂TeO₃). It could be observed by scanning electron micrograph (SEM), transmission electron micrograph (TEM), and X-ray diffraction (XRD) analysis that the cells suffered serious deformation due to the toxicity of tellurite, and the less toxic black precipaite (Te⁰) generated by bioreduction of tellurite mostly located in the central cytoplasm. This is the first study to observe that Rhodopseudomonas palustris can reduce tellurite to elemental tellurium, which will provide a new microbial species for bioremediation and biotransformation of toxic tellurite.

The current study aimed to evaluate the removal of a pesticide mixture composed of the insecticides chlorpyrifos (CP) and diazinon (DZ) from liquid medium, soil and a biobed biomixture by a Streptomyces mixed culture. Liquid medium contaminated with 100 mg L⁻¹ CP plus DZ was inoculated with the Streptomyces mixed culture. Results indicated that microorganisms increased their biomass and that the inoculum was viable. The inoculum was able to remove the pesticide mixture with a removal rate of 0.036 and 0.015 h⁻¹ and a half-life of 19 and 46 h⁻¹ for CP and DZ, respectively. The sterilized soil and biobed biomixture inoculated with the mixed culture showed that Streptomyces was able to colonize the substrates, exhibiting an increase in population determined by quantitative polymerase chain reaction (q-PCR), enzymatic activity dehydrogenase (DHA) and acid phosphatase (APP). In both the soil and biomixture, limited CP removal was observed (6–14%), while DZ exhibited a removal rate of 0.024 and 0.060 day⁻¹ and a half-life of 29 and 11 days, respectively. Removal of the organophosphorus pesticide (OP) mixture composed of CP and DZ from different environmental matrices by Streptomyces spp. is reported here for the first time. The decontamination strategy using a Streptomyces mixed culture could represent a promising alternative to eliminate CP and DZ residues from liquids as well as to eliminate DZ from soil and biobed biomixtures.

The research goal was to determine if onsite wastewater system (OWS) density had an influence on the concentrations and watershed exports of Escherichia coli and enterococci in urbanizing watersheds. Eight watersheds with OWS densities ranging from < 0.1 to 1.88 systems ha⁻¹ plus a watershed served by sewer (Sewer) and a mostly forested, natural watershed (Natural) in the Piedmont of North Carolina served as the study locations. Stream samples were collected approximately monthly during baseflow conditions between January 2015 and December 2016 (n = 21). Median concentrations of E. coli (2014 most probable number (MPN) 100 mL⁻¹) and enterococci (168 MPN 100 mL⁻¹) were elevated in streams draining watersheds with a high density of OWS (> 0.77 system ha⁻¹) relative to watersheds with a low (< 0.77 system ha⁻¹) density (E. coli: 204 MPN 100 mL⁻¹ and enterococci: 88 MPN 100 mL⁻¹) and control watersheds (Natural: E. coli: 355 MPN 100 mL⁻¹ and enterococci: 62 MPN 100 mL⁻¹; Sewer: 177 MPN 100 mL⁻¹ and 130 MPN 100 mL⁻¹). Samples collected from watersheds with a high density of OWS had E. coli and enterococci concentrations that exceeded recommended thresholds 88 and 57% of times sampled, respectively. Results show that stream E. coli and enterococci concentrations and exports are influenced by the density of OWS in urbanizing watersheds. Cost share programs to help finance OWS repairs and maintenance are suggested to help improve water quality in watersheds with OWS.

Selenium (Se) is an essential nutritional element for human beings. Many studies have been conducted on concentration and distribution patterns of soil Se in low Se, Se-enriched, and selenosis areas; however, soil Se has not been systematically studied in a watershed, especially in Se-enriched longevity region and karst area in South China. This study is carried out to explore the controlling factors of Se-enriched soils in Baishou river tributary watershed, where soils are Se-enriched, and local people have the phenomenon of longevity. The area-weighted average rock Se concentration in the watershed is 0.054 mg/kg, and there are no significant differences in rock Se concentration between different strata and between different lithological rocks. The area-weighted average concentration of Se in soils (0–20 cm) is 0.80 mg/kg, and the soil Se concentration is of high level in the watershed. Soil Se concentration decreases from upstream to downstream in the watershed, and significantly correlated with elevation. Climate is the main factor causing high content of soil Se in the watershed which lacks black rock series. The difference of clastic and carbonate parent materials in soil forming process and the physical and chemical properties (pH, OM, etc.) are the main reasons for the spatial variation of Se distribution in the watershed. The research will be beneficial to the development and utilization of Se-enriched soil in Se-enriched area.

Light emitting diodes (LEDs) emitting at 392 nm were successfully used as an irradiation light source and associated to TiO₂/β-SiC solid alveolar foams for designing a small-size, flow-through structured photocatalytic device for purifying air from airborne T2 bacteriophage viruses. Light emitting diodes are characterized by a high electricity-to-light yield, strength, a long lifetime, to ability to use a direct current power source, an almost-complete recycling rate, and a lack of mercury. Irrespective of the number of LEDs, we showed that the decontamination efficiency associated with removing airborne T2 bacteriophage viruses resulted from both the photocatalytic activity and the passive filtration effect of the TiO₂/β-SiC solid alveolar foams. A high photocatalytic filtration efficiency was observed with 56 LEDs and a logarithmic abatement of 3 was achieved for 60 min of run time, with an apparent time constant of 11.0 min after correcting for the natural decay of the bioaerosol. The pure filtration effect corresponded to a logarithmic abatement of 1, with an apparent time constant of 43.1 min. The interest in using 56 LEDs vs. 40 LEDs was highlighted in terms of the logarithmic abatement as well as energy effectiveness.

Photocatalytic treatment of real community wastewater using Fe-doped TiO₂ nanofilm was prepared by modified sol-gel method together with a simple dip-coating technique. The process was investigated in a home-made batch photoreactor. The as-prepared nanocomposite film was characterized by UV-Vis diffuse, XRD, BET, and Fe-SEM analysis. The poultry processing wastewater was collected from Nakhonsawan Municipality. Subsequently, the photocatalytic treatment of the wastewater was performed using a home-made photoreactor operated in batch mode to demonstrate the effects of Fe-dopant concentration with various layer numbers. The catalysts were irradiated using four lamps of 15 W power that emitted visible light and performed at room temperature. The samples were collected every 15 min and analyzed for biochemical oxygen demand (BOD) and chemical oxygen demand (COD) removal efficiency compared to pure TiO₂ nanofilm and direct photolysis. From the results, the mixture of rutile and anatase was obtained with the maximum specific surface area of 150.12 mg²/g and the average particle size of 39.95 nm for 3 layers of 0.15% wt/v Fe-doped TiO₂. The BOD and COD value at 90 min time treatment was presented to be 8.87 and 32 mg L⁻¹, respectively, in the presence of 0.15% wt/v Fe-doped TiO₂ film photocatalysts. Moreover, atomic absorption spectrometric result ensured that no Ti contamination was detected in all parts of plants after watering by the treated water. Hence, the photocatalytic treatment markedly improved the quality of the community wastewater.

Relatively high concentrations of particulate matter (PM) are characteristic to Israel and the Middle East. This is mostly attributed to natural dust storms and partly to anthropogenic sources, local, or remote. The research deals with relations between concentrations of PM₁₀ and PM₂.₅, and between synoptic conditions and regional climatic stress. Our particular focus is the summer, a season with no dust outbreaks when mostly one synoptic system, the Persian Trough prevails over the region, with associated northwesterly Etesian winds. Therefore, the “climate to environment” approach to distinguishing among PM concentrations by classes of synoptic systems is not very successful in the summer. In contrast, the climatic stress index (CSI), representing the “environment to climate” approach, was found positively correlated with PM concentrations in Haifa, Israel, and more effective in explaining inter-diurnal variations of PM pollution. Synoptic analysis performed through composite anomaly maps for days with higher and lower PM concentration, indicates a weakening of the Etesian winds in days with high CSI. On the one hand, the weaker winds reduce imported PM, but, on the other hand, the lower marine inversion in days with high CSI enhances PM pollution from local sources, by weakening the dispersion mechanisms, both vertical and horizontal. The higher level of PM pollution in days with high CSI indicates dominance of the local PM sources. The positive correlation between climatic stress and PM pollution, and increased climatic stress associated with global and regional warming, necessitate further tightening of control on anthropogenic pollution sources.

Using aluminum nitrate (AlN) and bauxite tailings (BTs) as different dopants, and lime mud (LM) as calcium source, a series of CaO-based sorbents were prepared for CO₂ capture by dry mixing method; then, the carbonation conversions of multiple carbonation/calcination cycles were detected in a thermogravimetric analyzer (TGA). Effects of different dopants, dopant contents, precalcination conditions, and a long series of cycles on CO₂ absorption properties were scrutinized, and the phase composition and morphologies were tested by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Durability studies show that the sample doped with AlN remains a higher absorption conversion (30.88%) after 30 carbonation/calcination cycles. In the meantime, the sorbent doped with BTs showed a lower conversion, which is probably resulted from the impurities from waste BTs. However, the sample BT has a better cyclic absorption stability. In addition, the incorporation of BTs, as a kind of solid waste, not only decreases the preparation cost but also is good for environment. The occurrence of Ca₁₂Al₁₄O₃₃ phase is considered to provide a stable framework inhibiting inactivation of CaO, and improve the CO₂ adsorption stability. Graphical abstract ᅟ

Two hundred forty-nine groundwater samples collected from 55 irrigation water supply wells in Al-Mahala Al-Kubra, Samannoud, and Al-Santa districts of the Gharbiya Governorate (Egypt) during a monitoring survey carried out in January, June, and in November in 3 years (2013–2015). The prime objective was to document, for the first time, the status and sustained trends in the concentrations of pesticides in the shallow Nile Delta aquifer. The non-parametric Mann–Kendall and Thiel–Sen trend statistical tests were applied for detection and estimation of trends and their magnitude. Violation of standards clarified emergence of methyl parathion (98.1%), endrin (97.9%), endosulfan sulfate (96.5%), dieldrin (55.3%), atrazine (42.3%), and simazine (40.4%), in decreasing order of abundances. Malathion obeyed the permissible limits (900 μg L⁻¹) in all samples. Methyl parathion showed an average rate of deterioration (μg L⁻¹ year⁻¹) of 0.82 that was largest in Al-Santa (1.0) followed by Al-Mahala Al-Kubra (0.63). Malathion proved the second largest rate emerging in Al-Mahala Al-Kubra (0.67) followed by Al-Santa (0.65). Endosulfan sulfate came third in deterioration rate (av. 0.37) followed by endrin (av. 0.32), atrazine (av. 0.32), dieldrin (av. 0.25), and simazine (av. 0.23). Groundwater improvements of pesticide contents propagated faster eastward and northward associated with larger surface water recharge rates from dense complex irrigation canals through thicker topmost silty clay layer and thicker peat layers inter-bedded in the sediments. For sustainable agriculture to alleviate negative impacts on groundwater resources and the environment, the use of ecofriendly bio-degradable or quickly deactivated pesticides along with awareness of farmers with the health hazards and the protective measures while handling pesticides are strongly recommended.

This study aimed to assess the chemical composition of the rainwater in three areas of different environmental impact gradients in Southern Brazil using the receptor model EPA Positive Matrix Factorization (EPA PMF 5.0). The samples were collected in a bulk sampler, from October 2012 to August 2014, in three sampling sites along with the Sinos River Basin: Caraá, Taquara, and Campo Bom. The major ions NH₄⁺, Na⁺, K⁺, Ca²⁺, Mg²⁺, F⁻, Cl⁻, NO₃⁻, SO₄²⁻, and pH were analyzed, as well as identify the main emission sources. The most abundant cations and anions were Ca²⁺, Na⁺, Cl⁻, and SO₄²⁻, respectively. The mean pH value in the Sinos River Basin during the study period was 6.07 ± 0.49 (5.13–7.05), which suggests inputs of alkaline species into the atmosphere. The most important neutralizing agents of sulfuric and nitric acids in the Sinos River Basin are Ca²⁺ (NF = 1.36) and NH₄⁺ (NF = 0.57). The source apportionment provided by the EPA PMF 5.0 resulted in four factors, which demonstrate the influence of anthropogenic and natural sources, in the form of (a) industry/combustion of fossil fuels (F⁻ and SO₄²⁻), (b) marine contribution (Na⁺ and Cl⁻), (c) crustal contribution (K⁺, Ca²⁺, and NO₃⁻), and (d) agriculture/livestock (NH₄⁺). Therefore, this study allows a more appropriate understanding of factors that contribute to rainwater chemical composition and also to possible changes in air quality.