A novel, ex-situ remediation process for perchlorate contaminated soil is reported in this study. This approach comprises washing the contaminated soil with water, followed by treatment of the wash water in a bioreactor. The treated water reused for the next batch of soil, and the cycle continued. The pilot-scale treatment unit comprising of a soil washing unit (0.75 m3) and a fixed-film bioreactor (140 L), both connected in series for continuous operation for a period of three months. The bioreactor was inoculated with a novel perchlorate reducing microbial consortium comprising Serratia marcescens (Gen bank no. HM751096), Bacillus pumilus (Gen bank no. JQ820452) and Micrococcus sp. (Gen bank no. KJ410671). The microbial activity was supported by glucose (glucose/perchlorate ratio = 5), and trace mineral solution. In a typical washing cycle, 2.5 g perchlorate (KClO4) spiked in 670 kg soil was completely removed in three washing cycles, that completed in 6.3 h consuming ∼360 L water. The pooled wash water containing perchlorate at 8.5 mg/L was treated completely in the bioreactor operated at 4.5 h HRT and −200 mV ORP. Compared with both in-situ and ex-situ remediation methods reported, the present approach has many advantages for treating perchlorate contaminated soil.

Three functional zones, namely the industrial (IND), the agricultural (AGR), and the grassland (GRA) areas from Inner Mongolia (a remote province in northern China), were selected to evaluate the levels and distributions of PBDEs and the risks posed to local humans. PBDEs concentrations in surface soils and tree bark were detected and the air levels were estimated based on bark measurements. The total concentrations (∑8PBDEs) of BDE-28, -47, −100, −99, −154, −153, −183, and −209 in soils were 1.71–64.9 ng/g dry weight (d.w.), 0.720–4.08 ng/g d.w., and 0.604–3.76 ng/g d.w. in the IND, AGR and GRA areas respectively. The average total concentrations in bark and air were 0.792 ng/g d.w. and 0.125 ng/m³ in the AGR areas respectively, which were lower than those (1.69 ng/g d.w. in the bark and 0.476 ng/m³ in the air) in the IND areas. BDE-209 was the dominant congener, consistent with DeBDE being the dominant commercial products used in China. However, except for BDE-209, BDE-28 and BDE-47 in the AGR and GRA areas averagely contributed about half of the total PBDEs concentrations in soils. BDE-28 concentrations in the bark samples of the AGR areas were significantly higher (p < 0.05) than in the IND areas, and the average total hazard quotients (∑8PBDEs) were higher for humans in the AGR areas (0.12) than in the IND areas (0.08). Degradation of higher-brominated congeners (e.g., BDE-209) and migration of lower-brominated congeners (mainly BDE-28 and BDE-47) may increase the risks to humans in pristine areas.

The present study explores the rapid chlopyrifos (CPs) biodegradation potential of plant growth promoting (PGP) psychrophilic bacteria isolated from brackish water by the enrichment culture technique. Based on biochemical tests and 16S rDNA sequencing the isolate was identified as Shewanella sp. The isolate Shewanella BT05 showed significant growth when cultivated with the various concentrations of (10-50 mg/L) CPs. The isolate produced plant growth promoting factors including IAA (20.8 ± 1.2 and 15.4 ± 1.0 μg/ml), and siderophores (60.67 ± 1.2 and 57.5 ± 0.9 %) in the absence and presence of CPs. Further, the isolate BT05 solublized phosphate (16.5 ± 1.0 and 12.0 ± 1.0 mm in size respectively), and produce hydrogen cyanide (excellent and moderate) in the presence and absence of CPs. The isolate BT05 degraded 94.3, 91.8, 87.9, 82.6, and 80.5% of CPs at 10, 20, 30, 40, and 50 mg/L, respectively, within 24 h. Further, the media conditions were optimized for enhanced CPs removal and observed 93% removal in the presence of 3.5 % glucose in pH 7.0 at 32.5 ˚C. Fourier-transform infrared spectroscopy and high-performance liquid chromatography results indicated a role for Shewanella BT05 in the biomineralization of CPs. The results suggested the isolate BT05 could be used as potent candidate for CPs removal as well as PGP activity of plants cultivated under CPs stress.

In this research, UiO-66 and its composite nanoparticles with thermally oxidized nanodiamond (OND) were synthesized via a simple solvothermal method and utilized as solid adsorbent for the removal of anionic methyl red (MR) dye and cationic malachite green (MG) dye from contaminated water. The synthesized adsorbents were analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), N2 adsorption–desorption, and zeta potential analyzer. The influences of various factors such as initial concentrations of the dyes, adsorption process time, solution pH, solution temperature and ionic strength on adsorption behavior of MR dye onto OND-UiO hybrid nanoparticle were investigated. The adsorption of MR onto OND-UiO hybrid nanoparticle could be well described by Langmuir isotherm model. Meanwhile, pseudo-second order kinetic model was found to be suitbale for illustration of adsorption kinetics of MR onto OND-UiO. Thermodynamic investigation suggeted that the adsorption process was spontaneous and endothermic, and controlled by an entropy change instead of enthalpy effect. The experimental adsorption results indicated that OND-UiO hybrid nanoparticle could simultaneously adsorb 59% of MR and 43% of MG from the mixture of both dyes in only 2 minutes showing synergistic effect compared with single UiO-66 and OND nanoparticles in terms of adsorption rate and removal capacity of anionic dyes. The appropriate removal efficiency, rapid adsorption kinetic, high water stability, and good reusability make OND-UiO hybrid nanoparticle attractive candidate for simultaneously removal of both anionic MR and cationic MG dyes from wastewater.

Toxicity Identification Evaluation (TIE) is a useful method for the classification and identification of toxicants in a composite environment water sample. However, its extension to a larger sample size has been restrained owing to the limited throughput of toxicity bioassays. Here we reported the development of a high-throughput method of TIE Phase I. This newly developed method was assisted by the fluorescence-based cellular oxidation (CO) biosensor fabricated with roGFP2-expressing bacterial cells in 96-well microplate format. The assessment of four river water samples from Langat river basin by this new method demonstrated that the contaminant composition of the four samples can be classified into two distinct groups. The entire toxicity assay consisted of 2338 tests was completed within 12 h with a fluorescence microplate reader. Concurrently, the sample volume for each assay was reduced to 50 μL, which is 600 to 4700-times lesser to compare with conventional bioassays. These imply that the throughput of the CO biosensor-assisted TIE Phase I is now feasible for constructing a large-scale toxicity monitoring system, which would cover a whole watershed scale.

This paper presents an evaluation of UV/PAA process for degradation of four pharmaceuticals venlafaxine (VEN), sulfamethoxazole (SFX), fluoxetine (FLU) and carbamazepine (CBZ) with comparison to UV/H2O2 process. The effectiveness of combining PAA and H2O2 at various proportions while irradiating with UVC were also evaluated. UVC/PAA (λ = 254 nm) was effective in degrading all four pharmaceuticals and followed pseudo first-order kinetics. Increasing PAA dosage or UVC intensity resulted in a linear increase in pseudo-first order rate coefficient. Both PAA in dark conditions and UVA/PAA (λ = 360 nm) were marginally effective to degrade SFX and ineffective to degrade VEN, CBZ and FLU; indicating the need for UVC irradiation for activation of PAA. For similar oxidant dosages of 50 mg/L UVC/H2O2 was found to be faster than UV/PAA for VEN, CBZ and FLU by 55%, 75% and 33%, respectively. Under similar conditions, SFX was degraded 24% faster by UV/PAA. Increase in the proportion of H2O2 to PAA in UVC/PAA/H2O2 improved kinetics of degradation compared to PAA alone. Tests on TOC were conducted to determine the amount of acetic acid that is released to water when treatment by UVC/PAA is conducted. Results demonstrated that 70% of PAA by mass was ultimately converted to acetic acid and remained in the treated solutions. Hydroxyl radical attack is hypothesized to be the main mechanism of degradation by UV/PAA as degradation intermediates identified for all the target pharmaceuticals coincided with by-products identified during UV/H2O2 process.

Atmospheric particulate matters have a crucial impact on climate change, visibility and human health. In this study, a detailed characteristic of summertime PM1 was real-time measured in south suburb of Beijing from 16th August to 16th September 2018. Averaged PM1 concentration of 24.1 ± 18.0 μg m−3 was observed, consisting of OM (50.8%), SO42− (16.0%), BC (13.2%), NO3− (10.2%), NH4+ (9.2%), and Cl− (0.6%). There was an accumulation mode with a peak diameter of ∼500 nm for all the species (except BC), and OM was additionally characterized by a smaller mode of <100 nm. Elemental analysis of OM showed that the diurnal variations of H/C, O/C, N/C, and S/C were correlated to the photochemical and aqueous-phase process. Four organic factors including one hydrocarbon-like (HOA) and three oxygenated (LO-OOA, SV-OOA and MO-OOA) organic aerosol factors were identified by positive matrix factorization (PMF) analysis. The contributions of these factors varied with PM1 concentration and their average values were 31%, 30%, 14%, and 25%, respectively. Contribution of HOA was RH-independent but decreased with the increasing PM1 concentration, while OOA factors were a combined result of RH and Ox (=O3+NO2), revealing the important role of photochemical and aqueous-phase process in OA evolution. The contribution of SV-OOA with the highest S/C increased significantly with RH, indicating a certain number of S-containing organics. Our results also showed that secondary OA was the dominant species, as well as increased with the pollution level, implicating VOCs and NOx should be controlled to relieve the secondary OA pollution.

Composites of polypeptidylated hemoglobin supported on different iron oxide weights (0.5:1 and 1:1) were developed and demonstrated to function as efficient adsorbents for Eriochrome black-T dye removal. The synthesis of these adsorbents were performed through N-carboxyanhydride (NCA) polymerization at low temperature (4 °C) and near-neutral pH for 24 h followed by chemical co-precipitation. The synthesized adsorbents were found to exhibit BET surface area (54–87 m2/g), pore volume (0.30–0.35 cm3/g), average pore diameter (160–218 Å) and average pore width (136–171 Å). The developed adsorbents were tested in a batch dye adsorption system. Adsorption was found to follow pseudo-second order kinetics and the Langmuir adsorption capacities were 123, 204 and 217 mg/g for Fe3O4, 0.5:1 and 1:1 adsorbent samples, respectively. Chemical regeneration was successfully carried out using methanol and the reusability of the adsorbents were demonstrated with a decrease in adsorption capacities from ∼49 to ∼33 mg/g after the fourth reuse.

Copper as developmental toxicants have been reported extensively in freshwater fish, however, the sublethal and chronic toxic effects of Cu to the early life stages of marine fish are not clear. Embryo (3–5 hpf) and newly hatched larvae of marine medaka (Oryzias melastigma) were exposed to 0.01–1.28 mg L−1 waterborne Cu to investigate the developmental toxic effects. The results showed that Cu accumulation in the whole embryos presented a dose- and time-response increase while it decreased dramatically once hatching. Most of Cu accumulated in the chorion suggests that chorion is an effective barrier to Cu absorption. However, Cu that penetrated chorion and entered embryo still caused significant lethal and sublethal effects. Cu concentrations at ≥0.16 mg L−1 led to low hatchability, delayed hatching, high mortality, morphological abnormalities and increased egg size in the embryos. Heart beats and the total body length of the newly hatched larvae were significantly increased when exposed to ≥0.02 mg L−1. Cu exposure accelerated early development and promoted or delayed hatching of embryo. High Cu concentration (≥0.16 mg L−1) exposure induced morphological abnormalities of embryo and larvae, particularly skeletal and vascular system abnormalities and reduction of pigmentation. The 30 d-LC50 for embryo development was 0.138 mg L−1 and 7d LC50 for larvae survival was 10.15 mg L−1, demonstrating that embryos were more sensitive to Cu than larvae. In summary, O. melastigma embryos development is highly sensitive to Cu exposure, and the sublethal effects occurred at low Cu concentration might be as potential biomarkers in marine fish.

Due to their use in various domestic and industrial formulations, benzalkonium compounds have been isolated in many environmental matrices. Sorption to soil components has been shown to play a key role in their environmental fate. Whereas sorption of benzalkonium compounds to soils is attributed to cation exchange and van der Waals forces, the relative contributions of these two mechanisms at environmental levels have not been clearly defined. In this study a previously reported algal toxicity assay-based method was employed to determine the distribution coefficients (Kd) of benzalkonium compounds between water and soil components, at environmental concentrations. Cation exchange capacity corrected Kd values for organic matter and clays were all within one order of magnitude. This implies that ion exchange is the dominant mechanism of sorption benzalkonium compounds. When the sorption data were used to compute sorption energies for four homologues of benzalkonium ions, the magnitude of the free energy change of sorption increased with size of the molecule. The increase in sorption energy could be partly explained by increased energy of hydration with addition of methylene groups to the alkyl chain. A model that predicts sorption coefficients of benzalkonium compounds to soils using organic carbon content and cation exchange capacity was also defined. When tested using an artificial soil, the model estimates were all within one order of magnitude of the experimental values.

Quorum sensing signals regulate various functions within activated sludge processes such as formation of microbial aggregates. Disturbance of this signaling system, known as quorum quenching (QQ), provides opportunities for eliminating some problems related to biological wastewater treatment (e.g., biofouling and excess sludge production). However, it is poorly understood how and to what extent QQ systems can affect the microbial aggregation processes and the following floc formation. In particular, an in-depth structural characterization at the scale of microbial aggregate while considering nutrient conditions in the reactor is still largely disregarded. Here, we evaluated the QQ effects at the short-term time scale (i.e., after 4 h for the exogenous period and 19 h for exogenous/endogenous period), by combining advanced techniques for microbial characterization (flow cytometry, CARD-FISH, and confocal laser scanning microscopy) and conventional physical-chemical assessments. The results indicated that by implementing QQ agents (immobilized Acylase I enzyme in porous alginate beads) the abundance of single cells and suspended microbial aggregates in the supernatant did not show significant changes during the exogenous period. Conversely, at the end of the exogenous/endogenous period a significant increase of single prokaryotic cells, small and large microbial aggregates favored the growth of grazers, including free-living nanoflagellates and ciliates. Flocs became looser and thinner than those in the control reactor, thus affecting the sludge settling behavior. Inability of microbial community in degradation of soluble protein during the endogenous period confirmed that the QQ agents are likely to inhibit the secretion of protease enzyme within microbial communities of activated sludge.

This study proposes the use of an aluminum-based drinking water treatment residue (DWTR) to adsorb ferrocyanide. The batch tests and chemical characterization results showed that ferrocyanide adsorption increased as the pH, ion strength, and the solid and solution ratio decreased, and as the initial ferrocyanide concentration increased. The pseudo-first (R2 = 0.906) and pseudo-second-order (R2 = 0.966) kinetic models well described the adsorption kinetics, and the adsorption isotherm was also well fittted by Langmuir (R2 = 0.989) and Freundlich (R2 = 0.989) models. The calculated initial ferrocyanide adsorption rate by the pseudo-second-order kinetic model was 0.0190 mg-CN g−1 h−1, and the estimated maximum adsorption capacity determined by the Langmuir model was 20.9 mg-CN g−1. The main structure and elemental distributions showed nearly no change in DWTR after adsorption. Adsorption involved electrostatic interactions and ligand exchanges with Al in DWTR, as evidenced by the 1.40 eV increase in the Al binding energy after adsorption. Furthermore, ferrocyanide adsorption had a dual effect on the DWTR porosity (including both increase and decrease effect), resulting in a slight increase in the specific surface area and total pore volume of DWTR after adsorption. This dual effect was likely related to Fe present in ferrocyanide, which introduced new vacant sites on DWTR. Overall, recycled DWTR is a promising potential adsorbent for ferrocyanide.

Humic acid plays an important role in controlling the toxicity of nanoparticles to organisms. However, little is known about the influence of different fractions of dissolved humic acid (DHA) from soil on the toxicity of nanoparticles to organisms. The concentration of γ-Fe2O3 and the exposure time affected the malondialdehyde (MDA) content, reactive oxygen species (ROS) production and lactate dehydrogenase (LDH) activity in P. chrysosporium cells and were inversely proportional to the relative activities of the cells. P. chrysosporium was exposed to γ-Fe2O3 and DHA1 for 3 h, 6 h and 12 h. Catalase (CAT) and peroxidase (POD) activities were generally higher than control. Particularly, under the influence of 50 mg/L DHA1 and different concentrations of γ-Fe2O3 (10 and 50 mg/L), the CAT and POD activities were higher than those of cells exposed to γ-Fe2O3 alone. Conversely, both activities of P. chrysosporium exposed to DHA4 combined with γ-Fe2O3 for 12 h were lower than those of cells exposed to γ-Fe2O3 alone and gradually decreased with increasing DHA4 concentration (0, 10 and 50 mg/L). The μ-XAFS normalized spectrum indicated that Fe3+ entering the cells tended to transform into Fe2+ as the stress time prolonged. TEM analysis confirmed the toxicity of high concentrations of γ-Fe2O3 to P. chrysosporium. The comet assay showed that DHA4 in soil enhanced the toxicity of γ-Fe2O3 to P. chrysosporium more than DHA1 did. Namely, compared to DHA1, DHA4 made it easier for nano-Fe2O3 to enter P. chrysosporium cells, causing more toxicity of γ-Fe2O3 to P. chrysosporium.

Many removal mechanisms in treatment wetlands involve absorption to organic matter. Optical properties and DOC levels of waters entering and exiting 4 treatment wetland systems in Orange County, Southern California, were measured to characterize the dissolved organic matter pool. Average DOC levels decreased between the inlets and outlets, except for Forge Street (FS), which increased. For 3 wetlands, absorption coefficients decreased between inlet and outlet; the exception was FS, which increased. Average spectral slopes for the inlets and outlets were similar. Average intensities of terrestrial humic peaks A and C from 3D EEM fluorescence spectra decreased between the inlets and outlets for most wetlands. No EEM protein peaks were observed. Average flu/abs ratios for inlets and outlets were similar (high point for FS inlet excluded), suggesting chromophoric dissolved organic matter (CDOM) of a similar composition was present. The average FI value for the inlets and outlets was ∼1.5, consistent with terrestrial sources of CDOM. Average BIX values for the inlets and outlets were ∼0.8, suggesting limited contributions from autochthonous production of CDOM. Dominant plant species in the wetlands were cattail and bulrush. Humic peaks A and C, along with protein peaks, were observed in plant leachates. Protein peaks rapidly degraded with solar simulator irradiation. Results indicate that most of the wetlands are a net sink for CDOM, possibly due to absorption to sediments. The FS wetland appears to have a source of non-CDOM optically active organic carbon, possibly from a pollutant.

In the present study, embryos of four food fishes viz. Cyprinus carpio, Ctenopharyngodon idella, Labeo rohita and Cirrhinus mrigala were given acute (96 h) exposure to their respective LC0, LC10 and LC30 (causing 0, 10 and 30% mortality, respectively) concentrations of triclosan [TCS, 5-chloro-2-(2,4-dichlorophenoxy) phenol], a broad spectrum biocide. Bioaccumulation, contents of protein, non-enzymatic antioxidants (GSH and GSSG), MDA (lipid peroxidation product) and organic acids (fumarate, succinate, malate and citrate) along with the activities of AChE (neurological enzyme), GST (detoxification enzyme) and three metabolic enzymes (LDH, AST and ALT) were estimated after 48 and 96 h exposure and 10 days post exposure. Around 1/10 of the TCS in water got accumulated in the hatchlings after 96 h, increase over 48 h values was maximum at LC0 (+195.30, +143.23 and +140.75%) but minimum at LC30 (+89.62, +84.26 and +126.72%) for C. idella, L. rohita and C. mrigala, respectively. In C. carpio, TCS got accumulated only at LC30 after 48 h but at all the concentrations after 96 h exposure. Contents of protein, GSH, GSSG and activity of AChE decreased but activities of GSH, LDH, AST and ALT and contents of MDA and organic acids increased concentration dependently in all the fishes. TCS declined by 85-90% but its toxic effects on biomolecules prolonged till the end of recovery period. Such acute exposures are accidental but there is a need to evaluate biomarkers for prolongation of the stress of small concentrations especially LC0 and LC10 (causing negligible mortality) of lipophilic pollutants like TCS.

Lead (Pb)-poisoning is a serious public health concern and dogs have been useful as a sentinel-animal for Pb exposure of humans. In the present study, the blood Pb concentrations (BLC), isotope ratios (208 Pb/206 Pb and 207 Pb/206 Pb), and biochemistry of 120 domestically owned dogs living around a Pb mining area, in Kabwe, Zambia were analyzed to determine factors associated with Pb exposure. The overall mean value of Pb in dog blood in the present study was 271.6 μg/L. The BLC in the dogs from sites near the mine were significantly higher than those in the dogs from a site 4 km from the mine (352.9 ± 205.1 μg/L versus 28.0 ± 13.9 μg/L). BLC significantly decreased with both increasing age of the dogs and distance from the mine. The Pb isotope ratios in the dog that resided near the mine showed values similar to those reported at the galena mine in Kabwe, which is considered to be the source of Pb exposure. In contrast to the high metal exposure that was determined in these dogs, the mean values of most analyzed parameters in the blood biochemical analysis were surprisingly within or close to the standard reference values. Moreover, none of the dogs showed overt signs of Pb-poisoning or other clinical symptoms. The results of analysis of Pb exposure of the dogs obtained in the present study, which are similar to the previously reported results in human in this location, suggest that dogs could be useful as a sentinel animal for Pb exposure of humans in Kabwe.

Emerging epidemiologic studies suggested that particulate matter (PM) was a risk factor for the incidence of chronic kidney disease (CKD). However, few studies were conducted to examine whether PM was associated with cause-specific deaths in the CKD progression. This study aimed to estimate the association between fine particulate matter (PM2.5) and a spectrum of deaths among CKD patients. We took leverage of the Elderly Health Service cohort (n = 66,820), a large Hong Kong elderly cohort followed up till 2010. A total of 902 CKD incident patients in the cohort were identified during the follow-up period. We estimated yearly PM2.5 at the residential address for each CKD patient based on a satellite-based spatiotemporal model. We used Cox proportional hazards models with attained age as the underlying timescale to assess the association between long-term exposure to PM2.5 and cause-specific mortality among CKD patients. A total of 496 patients died during the follow-up, where 147 died from cardiovascular disease, 61 from respiratory disease and 154 from renal failure. The mortality hazard ratio (HR) per interquartile-range increase in PM2.5 (4.0 μg/m3) was 1.97 (95% confidence interval (CI): 1.34 to 2.91) for ischemic heart disease (IHD) among CKD patients, and was 1.42 (95%CI: 1.05 to 1.93) for CKD among those patients concomitantly with hypertension. Associations were not of statistical significance between PM2.5 and mortality hazard ratios of all-cause, stroke, and pneumonia among CKD patients. Our findings suggest that long-term exposure to PM2.5 may contribute to the CKD progression into ischemic heart diseases.

There emerges an urgent stipulation towards the enhanced toluene catalytic combustion nanocatalysts for whittling down the footprint of toluene, a notorious air pollutant. Unfortunately, Few materials which are currently made accessible both present the high catalytic performance lower than 250 °C and keep durable at elevated temperatures. Herein, we demonstrate an expeditious salt hydrolysis-driven redox-precipitation protocol wherein H+ donated by the hydrolysis of copper salt was used to initiate the regioselective reduction of KMnO4 by H2O2 under controlled redox kinetics in order to assemble the homogeneous mixed solid solution hollow microsphere Cu–Mn-based structure. Manifold characterization technologies unveil that in this unique nanbomicrosphere the abundant microscaled pores are successfully created across Cu–Mn bulks with fine-modulating the chemical properties. In sharp contrast with the compact counterparts without tailed porosity, the tuned crystallinity, accessed edge sites with the unsaturated coordination, fast redox chemistry, and boosted gaseous diffusion during reactions synergize to result in the signally good toluene oxidation, with the complete elimination activity at 252 °C, T90 at 237 °C, and prominent long-term durability under the stringent reaction atmospheres. Our current study ushers in an alternative and tractable arena to excogitate the porous oxide materials for multifarious catalysis implementations.

The objective of the study was to determine the human serum elimination half-life of polybrominated diphenyl ethers (PBDEs) adjusted for ongoing exposure in subjects moving from a higher exposure region (North America) to a lower exposure region (Australia). The study population was comprised of exchange students and long-term visitors from North America moving to Brisbane, Australia (N = 27) and local residents (N = 23) who were followed by repeated serum sampling every other month. The local residents were sampled to adjust for ongoing exposure in Australia. Only one visitor remained in Australia for a period of time similar to the elimination half-life and had a sufficiently high initial concentration of PBDEs to derive a half-life. This visitor arrived in Australia in March of 2011 and remained in the country for 1.5 years. Since the magnitude of PBDE exposure is lower in Australia than in North America we observed an apparent 1st order elimination curve over time from which we have estimated the serum elimination half-lives for BDE28, BDE47, BDE99, BDE100, and BDE153 to be 0.942, 1.19, 1.03, 2.16, and 4.12 years, respectively. Uncertainty in the estimates were estimated using a Monte Carlo simulation. The human serum elimination half-life adjusted for ongoing exposure can allow us to assess the effectiveness and reduction in exposure in the general population following phase out of commercial penta- and octaBDE in 2004 in the United States.

Plasma-catalysis technologies (PCTs) have the potential to control the emissions of volatile organic compounds, although their low-energy efficiency is a bottleneck for their practical applications. A plasma-catalyst reactor filled with a CeO2/γ-Al2O3 catalyst was developed to decompose toluene with a high-energy efficiency enhanced by the elevating reaction temperature. When the reaction temperature was raised from 50 °C to 250 °C, toluene conversion dramatically increased from 45.3% to 95.5% and the energy efficiency increased from 53.5 g/kWh to 113.0 g/kWh. Conversely, the toluene conversion using a thermal catalysis technology (TCT) exhibited a maximum of 16.7%. The activation energy of toluene decomposition using PCTs is 14.0 kJ/mol, which is far lower than those of toluene decomposition using TCTs, which implies that toluene decomposition using PCT differs from that using TCT. The experimental results revealed that the Ce3+/Ce4+ ratio decreased and Oads/Olatt ratio increased after the 40-h evaluation experiment, suggesting that CeO2 promoted the formation of the reactive oxygen species that is beneficial for toluene decomposition.

Cadmium (Cd) is an increasingly important environmental pollutant due to its high toxicity to fish and aquatic animals. In the present study, we cultured common carp (Cyprinus carpio L.) in two groups, a control group and a Cd group, with the Cd group being exposed to Cd for 30 d. The antioxidant enzyme activities of T-AOC and CAT and the GSH content were differentially decreased during Cd exposure. miRNAome profiling indicated that 23 differentially expressed miRNAs were potential biomarkers for Cd exposure; 7 miRNAs were up-regulated, and 16 miRNAs were down-regulated. The expression levels of miR-122, novel-miR6, miR-193a-3p and miR-27a-5p in the Cd group were 0.43-fold, 0.47-fold, 0.49-fold and 2.4-fold greater than in the control group, respectively. qRT-PCR further detected that the expression levels of apoptosis-related genes, including BAX, BAD, BAK, CASPASE9 and PIDD, were differentially increased, while BCL2 was decreased. Western blot analysis showed that the protein expression levels of BAX and BAD were increased and that of BCL2 was differentially decreased during Cd exposure. Alterations in the levels of miR-122, novel-miR6, miR-193a-3p and miR-27a-5p expression may play an important role in diagnosing oxidative stress-induced apoptosis during Cd exposure in the head kidney. These markers may contribute to diagnosing the early stage of Cd exposure in common carp.

Ambient SO2 pollution poses a great threat on air quality, human health, and ecosystem safety. The ground-level SO2 monitoring sites over China have been established during the past years, while the long-term SO2 data was still missing before 2014, which cannot reveal the evolution trend of SO2 pollution and assess its response to the anthropogenic activity. In this work, we developed a high-quality random forest (RF) model to simulate the long-term SO2 concentration across the entire China from 1973 to 2014, based on substantial explanatory variables (e.g., meteorological factors, SO2 emission intensity, land use types). The 10-fold cross-validation R2 value and root mean square error (RMSE) over China reached 0.64 and 17.06 μg/m3, respectively, both of which were significantly higher than those of other models such as back propagation neural network (BPNN) and generalized regression neutral network (GRNN). Among all of the predictors, T displayed the highest relative importance value, followed by WS, Prec, SO2 emission intensity, RH, DOY, elevation, and the lower one for land use types and P. The estimated mean SO2 concentration during 1973–2014 displayed the remarkably spatial variation with the higher value in North China Plain (NCP) and Middle part of Inner Mongolia. This historical SO2 level estimation suggested that air pollution was not a new environmental issue that could be dated back to 1973. Overall, the annually mean SO2 level for each grid increased from 29.46 ± 9.79 to 31.44 ± 8.77 μg/m3 from 1973 to 2014. The annually mean SO2 concentration in NCP showed rapid increase from 34.32 ± 3.05 to 36.97 ± 3.18 μg/m3 during 1973–2002, whereas they decreased significantly after 2003 (from 37.46 ± 3.20 to 36.13 ± 3.48 μg/m3 during 2003–2014). The gradual decrease since 2003 was benefitted from the adjustment of the energy consumption structure and the adoption of emission control technologies. However, the SO2 levels in some western regions showed the violent increases since 2003 due to the proposal of “development of the western region”. The estimated daily SO2 concentration across the entire China could provide the essential data for epidemiological research and air pollution prevention.

A number of studies have reported that fine particulate matter (PM2.5) exposure is associated with adverse pregnancy outcomes. Moreover, PM2.5 exposure contributes to changes of gut microbiota. However, influences of PM2.5 exposure during gestation on maternal gut microbiota and pregnancy outcomes were not well understood. Here we performed a study using mice models. Dams were exposed to PM2.5 suspension by intratracheal instillation on gestational day (GD) 3, 6, 9, 12 and 15. Pregnancy outcomes, maternal gut microbiota and short chain fatty acids on GD 18 were all measured. The fetal body weight of PM2.5 group was significantly lower than that of control group (p < 0.05). Meanwhile, the fetal body length of PM2.5 group was significantly shorter than that of control group (p < 0.05). The Shannon or Simpson index of PM2.5 group were higher than that of control group (p < 0.05). At the phyla level, compared to dams in control group, mice in the PM2.5 group had higher ratio of phyla Proteobacteria, Candidatus Saccharibacteria and Fusobacteria and lower ratio of phyla Acidobacteria, Gemmatimonadetes and Deferribacteres in the gut. Compared with control group, the concentration of isobutyric acid was higher in PM2.5 group, but butyric acid concentration was lower in PM2.5 group (p < 0.05). These findings suggested that prenatal exposure to PM2.5 had an effect on birth weight of fetus. Meanwhile, PM2.5 tracheal exposure during gestation caused changes in the distribution and structure of gut microbiota of dams.

Reactivity of the singlet oxygen (SO), which is assumed to be one of the important oxidizers in natural waters, towards to a set of persistent herbicides, was measured for the first time using time resolved luminescence technique. It was observed that rate constants of SO reactions with the majority of studied herbicides are less than 106 M−1s−1 allowing to conclude about negligible participation of SO in oxidation of the compounds in natural waters.

Over 90% of microplastics that enter wastewater treatment plants end in the wasted activated sludge. The effect of microplastic abundance on the activated sludge anaerobic digestion has been rarely reported. This study investigated the methane production performance during anaerobic digestion with different abundance of microplastic doses (0, 1,000, 3,000, 6,000, 10,000, 30,000, 60,000, 100,000 and 200,000 polyester particle/kg activated sludge). The methane production was reduced to 88.53±0.5%, 90.09±1.2%, 89.95±4.7%, 95.08±0.5%, 90.29 ±0.5%, 93.16±0.8%, 92.92±1.3%, and 92.72±0.6% as compared with control after digestion for 59 days. The methane production of all conditions was fitted with the logarithm model (R2>0.95) and one-substrate model (R2>0.99). The predicted and actual methane production values of digestion for 59 days had high correlation in all conditions with R2>0.95. The analysis based on the biochemical methane potential test model indicated that the methane production potential (B0) and hydrolysis coefficient (k) decreased at nearly all tested conditions. The reactor digestate with microplastics retained higher organic matter and nutrient concentration and had slightly lower dewaterability than the control. The inhibition of methane production potential could be attributed to the incomplete digestion with the existence of microplastics. The microbial community showed no significant difference with and without microplastics.

Heterogeneous electro-Fenton (HEF) is as an alternative to the conventional electro-Fenton (EF) process. HEF uses a solid phase catalyst, whereas EF employs a solubilized one. This implies that in HEF, material can be recovered through a simple separation process such as filtration or magnetic separation in HEF. HEF also has the advantage of not requires a previous pH adjustment, which facilitates working in a higher pH range. In this work, Fe, Cu and Fe/Cu bimetallic nanoparticles (Fe/Cu NPs) were synthesized, characterized and used for the degradation of Nafcillin (NAF). The effect of the adsorption and the anodic oxidation (AO-H2O2) process was tested to assess their influence on HEF. NAF adsorption did not exceed 24% of antibiotic removal and the AO-H2O2 process eliminated the total NAF after 240 min of electrolysis. Through the HEF process, the antibiotic was completely removed using Fe/Cu NPs after 7.0 min of electrolysis, while these NPs, mineralization reached 41% after 240 min. In this case, NAF degradation occurs mainly due to the generation of hydroxyl radicals in the BDD electrode, and the Fenton reaction with Fe and Cu NPs. The main organic intermediates produced during the degradation of NAF by HEF were identified allowing the proposal of degradation pathway. Finally, the antibiotic was also completely eliminated from a wastewater from slaughterhouse after 15 min of treatment by HEF and using Fe/Cu bimetallic NPs.