This article exploits a new approach for synthesis of polysaccharide-based grafted sodium styrene sulfonate (SSS) super absorbent hydrogels (SAHs) in aqueous solution by γ-radiation under ambient conditions. Important optimal conditions for preparation of hydrogels with the best swelling ratio, such as gamma irradiation dose and the ratio of feed composition have been discussed. Characterization techniques such as the SEM/EDS, FTIR and DSC were used in describing the newly prepared hydrogels. The FTIR gave characteristic peaks for -SO₃Na group at 1042 and 988 cm⁻¹, showing successful grafting of SSS onto the polysaccharide base material. The dependence of swelling behaviors in various pH solutions and salts solutions were investigated in detail. The prepared hybrid hydrogel showed most optimum swelling capacity at neutral pH whereas equilibrium swelling of SAHs was achieved within 5 h. The swelling of SAHs influenced obviously to metal ion removal percentage in solution.

In this study, the molecular mechanisms involved in Ralstonia eutropha Q2-8-induced increased biomass and reduced cadmium (Cd) and arsenic (As) uptake in wheat plants (Triticum aestivum cv. Yangmai 16) were investigated in growth chambers. Strain Q2-8 significantly increased plant biomass (22–75%) without and with Cd (5 μM) + As (10 μM) stress and reduced plant above-ground tissue Cd (37%) and As (34%) contents compared to those in the controls. Strain Q2-8 significantly increased the proportions of Cd and As in wheat root cell walls. Under Cd and As stress, 109 root proteins were differentially expressed among which those involved in metabolisms, stress and defence, and energy were dominant in the presence of strain Q2-8. Furthermore, energy-, defence-, and cell wall biosynthesis-related proteins were found to be up-regulated. Notably, differentially expressed cell wall biosynthesis-related proteins in roots were only found in bacteria-inoculated plants under Cd and As stress. The results suggest that strain Q2-8 can alleviate Cd and As toxicity to wheat plant seedlings and reduce above-ground tissue Cd and As uptake by increasing the efficiency of root energy metabolism, defence, and cell wall biosynthesis under Cd and As stress.

Mg-Al-Ox supported monometallic (Ni) and bimetallic (Ni-Co) catalysts with different compositions of Mg and Al were investigated for CO₂ reforming of CH₄, using both coal and pure gas feeds, to limit the emission of these environmental pollutant gases into the atmosphere. Results showed that all the catalysts were active for dry reforming reaction using both feeds. Reactants conversion, stoichiometric product selectivity, and resistance to carbon deposition of catalysts remarkably improved when the Mg/Al ratio was greater than 1. Characterization results revealed changes in the bulk structure, textural and surface properties as the Mg/Al ratio and composition of catalysts changed. Improved active metal reduction, metal-support and metal-metal interaction (in the bimetallic) were also noted in the catalysts with Mg/Al ratio greater than 1. With respect to feed composition, less carbon deposition was recorded in the corresponding catalysts using coal gas compared to the pure gas. Ni-Co interaction and their interaction with MgO facilitated better basicity, increased metal dispersion and smaller particle size in Ni-Co-Mg₁.₇-Al₁-Ox, which showed best catalytic performance with no carbon deposition in both feeds. These interactions and properties stabilized the Ni site, which made the Ni-Co-Mg₁.₇-Al₁-Ox, catalyst resistant to sintering and carbon deposition.

Triclosan is one of the most frequently detected emerging contaminants in aquatic environment. In this study, we investigated the biouptake, toxicity and biotransformation of triclosan in freshwater algae Cymbella sp. The influence of humic acid, as a representative of dissolved organic matter, was also explored. Results from this study showed that triclosan was toxic to Cymbella sp. with 72 h EC₅₀ of 324.9 μg L⁻¹. Humic acid significantly reduced the toxicity and accumulation of triclosan in Cymbella sp. SEM analysis showed that Cymbella sp. were enormously damaged under 1 mg L⁻¹ triclosan exposure and repaired after the addition of 20 mg L⁻¹ humic acid. Triclosan can be significantly taken up by Cymbella sp. The toxicity of triclosan is related to bioaccumulated triclosan as the algal cell numbers decreased when intracellular triclosan increased. A total of 11 metabolites were identified in diatom cells and degradation pathways are proposed. Hydroxylation, methylation, dechlorination, amino acids conjunction and glucuronidation contributed to the transformative reactions of triclosan in Cymbella sp., producing biologically active products (e.g., methyl triclosan) and conjugation products (e.g., glucuronide or oxaloacetic acid conjugated triclosan), which may be included in the detoxification mechanism of triclosan.

The partitioning behavior of polycyclic aromatic hydrocarbons (PAHs) between gaseous and particulate phases from coal-fired power plants (CFPPs) is critically important to predict PAH removal by dust control devices. In this study, 16 US-EPA priority PAHs in gaseous and size-segregated particulate phases at the inlet and outlet of the fabric filter unit (FFs) of a circulating fluidized bed (CFB) boiler were analyzed. The partitioning mechanisms of PAHs between gaseous and particulate phases and in particles of different size classes were investigated. We found that the removal efficiencies of PAHs are 45.59% and 70.67–89.06% for gaseous and particulate phases, respectively. The gaseous phase mainly contains low molecular weight (LMW) PAHs (2- and 3-ring PAHs), which is quite different from the particulate phase that mainly contains medium and high molecular weight (MMW and HMW) PAHs (4- to 6-ring PAHs). The fractions of LMW PAHs show a declining trend with the decrease of particle size. The gas-particle partitioning of PAHs is primarily controlled by organic carbon absorption, in addition, it has a clear dependence on the particle sizes. Plot of log (TPAH/PM) against logDp shows that all slope values were below −1, suggesting that PAHs were mainly adsorbed to particulates. The adsorption effect of PAHs in size-segregated PMs for HMW PAHs is more evident than LMW PAHs. The particle size distributions (PSDs) of individual PAHs show that most of PAHs exhibit bi-model structures, with one mode peaking in the accumulation size range (2.1–1.1 μm) and another mode peaking in coarse size range (5.8–4.7 μm). The intensities of these two peaks vary in function of ring number of PAHs, which is likely attributed to Kelvin effect that the less volatile HMW PAH species preferentially condense onto the finer particulates. The emission factor of PAHs was calculated as 3.53 mg/kg of coal burned, with overall mean EFPAH of 0.55 and 2.98 mg/kg for gaseous and particulate phase, respectively. Moreover, the average emission amount of PAHs for the investigated CFPP was 1016.6 g/day and 371073.6 g/y, respectively.

Hypermethylation of СpG islands in the promoter regions of several genes with basic protective function in blood leukocytes of individuals exposed to ionizing radiation long time ago (2–46 years), and differential effects of age and radiation exposure on hypermethylation was reported in our previous work. To validate these results, epigenetic modifications were assessed in an independent series of 49 nuclear industry workers from the “Mayak” facility (67–84 years old at sampling) with documented individual accumulated doses from the prolonged external γ-radiation exposure (95.9–409.5 cGy, end of work with radiation:0.3–39 years ago), and in 50 non-exposed persons matched by age. In addition to the genes analyzed before (RASSF1A, p16/INK4A, p14/ARF, GSTP1), four additional loci were analyzed: TP53, ATM, SOD3, ESR1. The frequency of individuals displaying promoter methylation of at least one of the 8 genes (71.4%) was significantly higher in exposed group as compared to the control group (40%), p = .002, OR = 3.75. A significantly elevated frequency of individuals with hypermethylated СpG islands in GSTP1, TP53, SOD3 promoters was revealed among exposed subjects as compared to the control group (p = .012, OR = 8.41; p = .041, OR = 4.02 and p = .009, OR = 3.42, respectively). A similar trend (p = .12, OR = 3.06) was observed for the p16/INK4A gene. As a whole, p16/INK4A and GSTP1 promoter hypermethylation in irradiated subjects from both previously and currently analyzed groups was pronounced. Thus, the direction of the effects was fully confirmed, suggesting the result reproducibility. No statistically significant correlation between promoter methylation and individual radiation dose was found. Further studies are required to create an array of blood epigenetic markers of radiation exposure associating with premature aging and age-related diseases and to accurately evaluate radiation-added effect across the range of doses.The results of studies of epigenetic changes in two independent samples of irradiated subjects indicated the significance of radiation factor in the induction of hypermethylation of CpG islands in gene promoters that is revealed in blood cells years and decades after exposure.

This study investigates trace element concentrations (arsenic (As), manganese (Mn), lead (Pb) and zinc (Zn)) and Pb isotopic compositions in an Australian native bee species, Tetragonula carbonaria, and its products of honey and wax. Co-located soil and dust samples were simultaneously analysed with the objective of determining if the bees or their products had potential application as a proxy for monitoring environmental contamination. The most significant relationships were found between Pb concentrations in honey (r = 0.814, p = 0.014) and wax (r = 0.883, p = 0.004) and those in co-located dust samples. In addition, Zn concentrations in honey and soil were significantly associated (r = 0.709, p = 0.049). Lead isotopic compositions of native bee products collected from background sites adjacent to Sydney national parks (²⁰⁶Pb/²⁰⁷Pb = 1.144, ²⁰⁸Pb/²⁰⁷Pb = 2.437) corresponded to local geogenic rock and soil values (²⁰⁶Pb/²⁰⁷Pb = 1.123–1.176, ²⁰⁸Pb/²⁰⁷Pb = 2.413–2.500). By contrast, inner Sydney metropolitan samples, including native bees and wax (²⁰⁶Pb/²⁰⁷Pb = 1.072–1.121, ²⁰⁸Pb/²⁰⁷Pb = 2.348–2.409), co-located soil and dust (²⁰⁶Pb/²⁰⁷Pb = 1.090–1.122, ²⁰⁸Pb/²⁰⁷Pb = 2.368–2.403), corresponded most closely to aerosols collected during the period of leaded petrol use (²⁰⁶Pb/²⁰⁷Pb = 1.067–1.148, ²⁰⁸Pb/²⁰⁷Pb = 2.341–2.410). A large range of Pb isotopic compositions in beehive samples suggests that other legacy sources, such as Pb-based paints and industrials, may have also contributed to Pb contamination in beehive samples. Native bee data were compared to corresponding samples from the more common European honey bee (Apis mellifera). Although Pb isotopic compositions were similar in both species, significant differences in trace element concentrations were evident across the trace element suite, the bees and their products. The statistical association between T. carbonaria and co-located environmental contaminant concentrations were stronger than those in European honey bees, which may be attributable to its smaller foraging distance (0.3–0.7 km versus 5–9 km, respectively). This implies that T. carbonaria may be more suitable for assessing small spatial scale variations of trace element concentrations than European honey bees.

Antibiotics resistance genes (ARGs) are considered as an emerging pollutant among various environments. As a sink of ARGs, a comprehensive study on the spatial and temporal distribution of ARGs in the estuarine sediments is needed. In the present study, six ARGs were determined in sediments taken along the Yangtze Estuary temporally and spatially. The sulfonamides, tetracyclines and fluoroquinolones resistance genes including sul1, sul2, tetA, tetW, aac(6’)-Ib, and qnrS, were ubiquitous, and the average abundances of most ARGs showed significant seasonal differences, with relative low abundances in winter and high abundances in summer. Moreover, the relative high abundances of ARGs were found at Shidongkou (SDK) and Wusongkou (WSK), which indicated that the effluents from the wastewater treatment plant upstream and inland river discharge could influence the abundance of ARGs in sediments. The positive correlation between intI1 and sul1 implied intI1 may be related to the occurrence and propagation of sulfonamides resistance genes. Correlation analysis and redundancy discriminant analysis showed that antibiotic concentrations had no significant correlation to their corresponding ARGs, while the total extractable metal, especially the bioavailable metals, as well as other environmental factors including temperature, clay, total organic carbon and total nitrogen, could regulate the occurrence and distribution of ARGs temporally and spatially. Our findings suggested the comprehensive effects of multiple pressures on the distribution of ARGs in the sediments, providing new insight into the distribution and dissemination of ARGs in estuarine sediments, spatially and temporally.

PM₂.₅ and its major chemical compositions were sampled and analyzed in January, April, July and October of 2014 at Beijing (BJ), Tianjin (TJ), Langfang (LF) and Baoding (BD) in order to probe the temporal and spatial characteristics as well as source apportionment of PM₂.₅ in the Beijing-Tianjin-Hebei (BTH) region. The results showed that PM₂.₅ pollution was severe in the BTH region. The average annual concentrations of PM₂.₅ at four sampling sites were in the range of 126–180 μg/m³, with more than 95% of sampling days exceeding 35 μg/m³, the limit ceiling of average annual concentration of PM₂.₅ regulated in the Chinese National Ambient Air Quality Standards (GB3095-2012). Additionally, concentrations of PM₂.₅ and its major chemical species were seasonally dependent and demonstrated spatially similar variation characteristics in the BTH region. Concentration of toxic heavy metals, such as As, Cd, Cr, Cu, Mn, Ni, Pb, Sb, Se, and Zn, were higher in winter and autumn. Secondary inorganic ions (SO₄²⁻, NO₃⁻, and NH₄⁺) were the three-major water-soluble inorganic ions (WSIIs) of PM₂.₅ and their mass ratios to PM₂.₅ were higher in summer and autumn. The organic carbon (OC) and elemental carbon (EC) concentrations were lower in spring and summer than in autumn and winter. Five factors were selected in Positive Matrix Factorization (PMF) model analysis, and the results showed that PM₂.₅ pollution was dominated by vehicle emissions in Beijing, combustion emissions including coal burning and biomass combustion in Langfang and Baoding, and soil and construction dust emissions in Tianjin, respectively. The air mass that were derived from the south and southeast local areas around BTH regions reflected the features of short-distant and small-scale air transport. Shandong, Henan, and Hebei were identified the major potential sources-areas of secondary aerosol emissions to PM₂.₅.