Removal of PAHs, TSS, oils and fats from ammonium-rich coke wastewater by granular filtration.

Coke wastewater is a complex industrial wastewater due to its high content of toxic compounds such as cyanides, thiocyanates, phenols, tar, oils, and fats. After a series of treatments, wastewater with a high ammonium content is obtained (around 4,150 mg·L-1). A stripping process is used to reduce it. Certain pollutants in the influent, such as tar, polycyclic aromatic hydrocarbons (PAHs), oils, fats and total suspended solids (TSS), interfere with stripping and therefore must be previously removed. In this study, the performance of a pilot-scale airlift sand filter was evaluated under real conditions for the reduction of the concentration of tar, PAHs, oils, fats and TSS, before stripping. Prior to the sand filter, a cationic flocculant was added to the influent (2 ppm). High (10 mm.min-1), medium (7.5 mm.min-1) and low sand speeds (1.9-2.6 mm.min-1) were assessed. The latter conditions gave the best results: a decrease of 98.2% in TSS, 99.7% in oils, fats and grease and 97.6% in PAHs. The final effluent (≤ 1.6 mg PAHs·L-1, ≤ 5 mg TSS·L-1 and ≤ 0.05 mg·L-1 of fats, oils and grease) was suitable for the stripping process.

Asynchronous characteristics of Feammox and iron reduction from paddy soils in Southern China.

Recently, the newly discovered anaerobic ammonium oxidation coupled with iron reduction (i.e., Feammox) has been proven to be a widespread nitrogen (N) loss pathway in ecosystems and has an essential contribution to gaseous N loss in paddy soil. However, the mechanism of iron-nitrogen coupling transformation and the role of iron-reducing bacteria (IRB) in Feammox were poorly understood. This study investigated the Feammox and iron reduction changes and microbial community evolution in a long-term anaerobic incubation by 15N isotope labeling combined with molecular biological techniques. The average rates of Feammox and iron reduction during the whole incubation were 0.25 ± 0.04 µg N g-1 d-1 and 40.58 ± 3.28 µg Fe g-1 d-1, respectively. High iron oxide content increased the Feammox rate, but decreased the proportion of Feammox-N2 in three Feammox pathways. RBG-13-54-9, Brevundimonas, and Pelomonas played a vital role in the evolution of microbial communities. The characteristics of asynchronous changes between Feammox and iron reduction were found through long-term incubation. IRB might not be the key species directly driving Feammox, and it is necessary to reevaluate the role of IRB in Feammox process.

Association of Particulate Matter Exposure With Lung Function and Mortality Among Patients With Fibrotic Interstitial Lung Disease.

Importance: Particulate matter 2.5 µm or less in diameter (PM2.5) is associated with adverse outcomes for patients with idiopathic pulmonary fibrosis, but its association with other fibrotic interstitial lung diseases (fILDs) and the association of PM2.5 composition with adverse outcomes remain unclear. Objective: To investigate the association of PM2.5 exposure with mortality and lung function among patients with fILD. Design, Setting, and Participants: In this multicenter, international, prospective cohort study, patients were enrolled in the Simmons Center for Interstitial Lung Disease Registry at the University of Pittsburgh in Pittsburgh, Pennsylvania; 42 sites of the Pulmonary Fibrosis Foundation Registry; and 8 sites of the Canadian Registry for Pulmonary Fibrosis. A total of 6683 patients with fILD were included (Simmons, 1424; Pulmonary Fibrosis Foundation, 1870; and Canadian Registry for Pulmonary Fibrosis, 3389). Data were analyzed from June 1, 2021, to August 2, 2022. Exposures: Exposure to PM2.5 and its constituents was estimated with hybrid models, combining satellite-derived aerosol optical depth with chemical transport models and ground-based PM2.5 measurements. Main Outcomes and Measures: Multivariable linear regression was used to test associations of exposures 5 years before enrollment with baseline forced vital capacity and diffusion capacity for carbon monoxide. Multivariable Cox models were used to test associations of exposure in the 5 years before censoring with mortality, and linear mixed models were used to test associations of exposure with a decrease in lung function. Multiconstituent analyses were performed with quantile-based g-computation. Cohort effect estimates were meta-analyzed. Models were adjusted for age, sex, smoking history, race, a socioeconomic variable, and site (only for Pulmonary Fibrosis Foundation and Canadian Registry for Pulmonary Fibrosis cohorts). Results: Median follow-up across the 3 cohorts was 2.9 years (IQR, 1.5-4.5 years), with death for 28% of patients and lung transplant for 10% of patients. Of the 6683 patients in the cohort, 3653 were men (55%), 205 were Black (3.1%), and 5609 were White (84.0%). Median (IQR) age at enrollment across all cohorts was 66 (58-73) years. A PM2.5 exposure of 8 µg/m3 or more was associated with a hazard ratio for mortality of 4.40 (95% CI, 3.51-5.51) in the Simmons cohort, 1.71 (95% CI, 1.32-2.21) in the Pulmonary Fibrosis Foundation cohort, and 1.45 (95% CI, 1.18-1.79) in the Canadian Registry for Pulmonary Fibrosis cohort. Increasing exposure to sulfate, nitrate, and ammonium PM2.5 constituents was associated with increased mortality across all cohorts, and multiconstituent models demonstrated that these constituents tended to be associated with the most adverse outcomes with regard to mortality and baseline lung function. Meta-analyses revealed consistent associations of exposure to sulfate and ammonium with mortality and with the rate of decrease in forced vital capacity and diffusion capacity of carbon monoxide and an association of increasing levels of PM2.5 multiconstituent mixture with all outcomes. Conclusions and Relevance: This cohort study found that exposure to PM2.5 was associated with baseline severity, disease progression, and mortality among patients with fILD and that sulfate, ammonium, and nitrate constituents were associated with the most harm, highlighting the need for reductions in human-derived sources of pollution.

Long-term exposure to PM2.5 constituents in relation to glucose levels and diabetes in middle-aged and older Chinese.

BACKGROUND: Previous studies have indicated the associations between fine particulate matter (PM2.5) exposure and diabetes or glucose levels. However, evidence linking PM2.5 constituents and diabetes or glucose levels was extensively scarce, particularly in developing countries. This study aimed to investigate the associations of exposure to PM2.5 and its five constituents (black carbon [BC], organic matter [OM], nitrate [NO3-], sulfate [SO42-], and ammonium [NH4+]) with diabetes and glucose levels among the middle-aged and elderly Chinese populations. METHODS: A national cross-sectional sample of participants aged 45+ years was enrolled from 28 provinces across China's mainland. Health examination and questionnaire survey for each respondent were performed during 2011-2012. Diabetes was determined by alternative definitions, and the main definition (MD) was self-report diabetes or antidiabetic medicine use or HbA1c ≥6.5 or fasting glucose ≥7 mmol/L or random glucose ≥11.1 mmol/L. Monthly exposure to PM2.5 mass and its five constituents (BC, OM, NO3-, SO42-, and NH4+) for each participant at residence were estimated using satellite-based spatiotemporal prediction models. Generalized linear models and linear mixed-effects models were used to assess the effects of exposure to PM2.5 and its constituents on diabetes or glucose levels, respectively. Stratification analyses were done by sex and age. RESULTS: We included a total of 17,326 adults over 45 years in this study. The 3-year mean (interquartile range [IQR]) concentrations of PM2.5, BC, OM, NO3-, SO42-, and NH4+ were 47.9 (27.4) µg/m3, 2.9 (2.2) µg/m3, 9.2 (6.6) µg/m3, 10.2 (9.4) µg/m3, 11.0 (5.2) µg/m3, and 7.1 (4.4) µg/m3, respectively. Per IQR rise in exposure to PM2.5 was significantly associated with an increase of 0.133 mmol/L (95% confidence interval, 0.048-0.219) in glucose concentrations. Similar positive associations were observed for BC (0.097 mmol/L [0.012-0.181]), OM (0.160 mmol/L [0.065-0.256]), NO3- (0.145 mmol/L [0.039-0.251]), SO42- (0.111 mmol/L [0.026-0.196]), and NH4+ (0.135 mmol/L [0.041-0.230]). Under different diabetes definitions, PM2.5 mass and selected constituents with the exception of SO42- were all associated with a higher risk of prevalent diabetes. In MD-based analysis, similar positive associations were observed for four constituents, with corresponding odds ratios of 1.180 (1.097-1.270) for PM2.5, 1.154 (1.079-1.235) for BC, 1.170 (1.079-1.270) for OM, 1.200 (1.098-1.312) for NO3-, and 1.123 (1.037-1.215) for NH4+. Stratified analyses showed a significantly higher risk of diabetes in males (1.225 [1.064-1.411]) than females (1.024 [0.923-1.136]) when exposed to PM2.5. Participants under 65 years were generally more vulnerable to diabetes hazards related to PM2.5 constituents exposure. CONCLUSIONS: Exposures to PM2.5 and its constituents (i.e., BC, OM, NO3-, and NH4+) were positively associated with increased risks of prevalent diabetes and elevated glucose levels in middle-aged and older adults.

Chemometric and risk assessment of nitrogen composition of atmospheric rainwater from diverse surfaces in Rivers State, Nigeria.

Organic and inorganic nitrogen ions in the environment play important role across environmental matrices. Rainwater samples collected from ambient and different roofing surfaces (zinc, aluminium, asbestos and stone-coated roofing sheets) from selected locations at Ogale, Rumuodomaya/Rumuodome, Diobu and Chokocho within Rivers State, Niger Delta, Nigeria, from April to June, July to August and September to October depicting three regiments of early, mid and late rains. The samples were analysed for Kjeldahl nitrogen, ammonium, nitrate and nitrite using APHA methodology. Quantitative assessment showed that Kjeldahl nitrogen were in range of 0.11 to 28.05 mg/L; ammonium 0.50 to 20.22 mg/L, nitrate from 0.12 to 22.69 mg/L and nitrite from 0.15 to 3.90 mg/L. Parameters decreased from early to late rain, which can be attributed to rain dilution factor potential, wind pattern and emission from anthropogenic sources that influenced the rainwater quality across surfaces. Nitrogen results showed that dry and wet deposition has great impact; atmospheric aerosols and biogeochemical interactions can affect water quality. Monthly variation showed that Ogale had high regression compared to other locations due to close proximity to oil and gas emission and marine contribution. Neutralization factor showed that nitrate-nitrite compounds have strong correlation with ammonium ion. Non-carcinogenic risk assessment using US EPA model showed hazard index less than one (1), thus no associated health effect of nitrate and nitrite in rainwater. In conclusion, it is evident that nitrate/nitrite levels and other nitrogen derivatives in rainwater in crude oil-producing Niger Delta and its continuous consumption can cause negative health outcome.

Chemical constituents of ambient fine particulate matter and obesity among school-aged children: A representative national study in China.

BACKGROUND: Studies show that fine particulate matter (PM2.5) contributes to childhood obesity. However, evidence on the effects of its constituents on obesity has not been explored. METHODS: Using multistage stratified cluster sampling, we enrolled 41,439 school-age children (aged 6-17 years) from a representative nationwide survey of 30 provinces in China (mean age ± standard deviation: 12.0 ± 3.3 years). Weight and height were measured using a physician beam scale with a height rod, and covariates were determined using a standard questionnaire. The concentration of PM2.5 chemical constituents was estimated by a chemical transport (GEOS-Chem) model using input satellite data and ground-based observations. The constituents included black carbon, ammonium, nitrate, organic matter, sulfate, and soil dust. Generalized linear models were used to estimate the association between the chemical constituents of PM2.5 and obesity. RESULTS: A positive association between the constituents of PM2.5 and obesity were observed. Children were more susceptible to black carbon than other species. A 1-µg/m3 increase in black carbon led to a 0.079 (95 % confidence interval [CI]:0.028, 0.130)-kg/m2 increase in body mass index (BMI). This also increased the odds of being obese and overweight to 1.174 (95 % CI: 1.111, 1.240) and 1.165 (95 % CI: 1.116, 1.216), respectively. Stratified analyses showed that the effects were stronger in girls and older children, as well as in urban and Northeast regions. The effect of the PM2.5 constituents on obese and overweight children from urban areas significantly interacted with that of rural areas. CONCLUSIONS: The PM2.5 constituents were associated with an increased BMI and childhood obesity. Further studies are warranted to validate these results and clarify their potential mechanisms. We suggest focusing on black carbon and Northeast regions.

Microbial electrochemical driven anaerobic ammonium oxidation coupling to denitrification in a single-chamber stainless steel reactor for simultaneous nitrogen and carbon removal.

Anodic ammonium oxidation mainly focuses on autotrophic process, and the removal combined with organic matter oxidation is still unclear in microbial electrolysis cell (MEC). Here, a stainless-steel tank is constructed as an MEC for anaerobic ammonium oxidation and organic matter removal. Results show that MEC increases ammonium oxidation from 3.83 ± 2.51% to 32.90 ± 3.39%, and the organic matter removal rises from 75.69 ± 0.59% to 92.12 ± 0.57%, and the energy consumption is only 0.80 ± 0.09 kWh kg-1N, indicating an energy-efficient approach for simultaneous ammonium and carbon removal. Cyclic voltammetry reveals two pairs of oxidative peaks (-0.4 V and + 0.6 V) which demonstrate the electrochemical activity of biofilms for organic matter and ammonium oxidation, respectively. 16S rRNA gene analysis clarifies the anodic biofilm mainly enriched by the genus of Azoarcus, Hydrogenophaga and Paracoccus. Further analysis indicates that anodic potential controls the community succession of heterotrophic and hydrogenotrophic denitrifying bacteria, and then regulates the nitrogen and carbon removal processes, which extend the insights of anodic anaerobic ammonium oxidation coupling to denitrification under organic conditions.

Real-Time Diagnosis of Helicobacter pylori During Endoscopy by Gastric Juice Analysis.

EndoFaster is a high precision device for gastric juice analysis in real time during gastroscopy that enables detection of Helicobacter pylori infection and hypochlorhydric/achlorhydric conditions through the measurement of ammonium concentration and gastric pH. The high accuracy and feasibility of this technology enables a more accurate diagnosis and a reduced number of histologies, focusing the attention of the endoscopist on patients with high risk for cancer progression and limiting or avoiding biopsies on the low-risk ones while also saving costs and time.

Amino acids, betaines and related ammonium compounds in Neapolitan limmo, a Mediterranean sweet lime, also known as lemoncetta Locrese.

BACKGROUND: The so-called 'Neapolitan limmo' or 'lemoncetta Locrese' is an old and now rare Mediterranean sweet lime, similar to lemon but smaller. It is a fruit distinguished from orange, lemon, mandarin, and lime for its sweeter, watery, and non-acidic taste, with a pH between 5.6 and 5.9. No compositional studies are currently available for this citrus fruit. Here we report, for the first time, the distribution in the limmo juice of free amino acids and their main derivatives such as betaines and related ammonium compounds. RESULTS: Seven proteinogenic amino acids (proline, asparagine, serine, aspartic acid, glutamine, alanine, and threonine) and a non-protein amino acid (γ-aminobutyric acid) characterize Neapolitan limmo juice. Proline betaine is the predominant betaine. The data were compared with those of other important citrus juices. CONCLUSION: The specific 'taste quality' of Neapolitan limmo juice can be attributed to its peculiar composition in amino acids. The species-specific presence of the ammonium compound derivatives of the amino acid proline, with proline betaine as the predominant betaine, characterize the non-acidic varieties of Mediterranean sweet lime. Our study constitutes an important step towards the repopulation of this ancient plant and its exploitation in food industry. © 2020 Society of Chemical Industry.

Loofah-derived activated carbon supported on nickel foam (AC/Ni) electrodes for the electro-sorption of ammonium ion from aqueous solutions.

Activated carbon (AC), prepared from dried loofah sponge, was supported on nickel foam to fabricate AC/Ni electrodes. The characteristics of ammonium electrosorption on AC/Ni electrodes was studied. Results showed that AC prepared in one-step activation (without pre-pyrolysis), i.e., OAC, had relatively low crystallinity, high mesoporosity, and high specific capacitance compared to those made in two-step carbonation followed by activation. Adsorption and desorption density of NH4+ were measured at constant potential of -1.0 V (vs. Hg/HgO) and +0.1 V (vs. Hg/HgO), respectively. Non-faradaic charging contributed to the electrochemical storage and adsorption of ammonium ions on the AC surface with a maximal charge efficiency of 80%, at an applied potential of -1.0 V (vs. Hg/HgO). Multiple-layer adsorption isotherm better described the electrosorption of ammonium ion on OAC/Ni electrodes yielding a maximum adsorption capacity of 6 mg-N g-1, which was comparable with other similar systems. Overall, results clearly demonstrated the effect of synthesis strategy on the capacitive charging behaviors of AC/Ni electrodes and its relationship to NH4+ electrosorption.

Ammonium nutrition mitigates cadmium toxicity in rice (Oryza sativa L.) through improving antioxidase system and the glutathione-ascorbate cycle efficiency.

Nitrogen (N) forms not only affect cadmium (Cd) accumulation in plants, but also affect plant resistance to Cd toxicity. However, few researches have been reported underlying the mechanism of the relationship between nitrogen forms and plant resistance under Cd exposure. Here, we explored the mechanism on how different NO3-/NH4+ ratios affect antioxidase system and the glutathione-ascorbate cycle under five different ratios of NO3-/NH4+ (1:0, 2:1, 1:1, 1:2, 0:1) and three dosages of Cd exposure (0, 1, 5 µmol L-1 Cd) in rice (Oryza sativa L.). The results showed that high NO3- and high Cd exposure both significantly inhibited tissue growth of rice plants, and this inhibiting trend was mitigated with increasing NH4+ ratios as proved by the increased biomass and the decreased concentrations of malonaldehyde (MDA) and hydrogen peroxide (H2O2), as well as the levels of Cd contents in rice tissues. Additionally, high NH4+ ratios elevated the SOD activities in rice tissues, especially at high Cd treatment. However, other two antioxidases (CAT and APX) were insensitive to changes of NO3-/NH4+ ratios (except the full NO3-). Furthermore, high NH4+ ratios induced increasing of the efficiency of glutathione-ascorbate cycle (GSH-AsA) under two levels of Cd exposure, as evidenced by increasing concentrations of GSH and AsA and the activities of GR and DHAR in rice tissues. Overall, these results revealed that ammonium nutrition caused an enhancement resistance to Cd stress in rice plants was responsible for increasing of partial antioxidase system and the efficiencies of GSH-AsA cycle.

Correlación entre los microorganismos oxidantes del amonio y los factores ambientales durante el compostaje de estiércol de ganado / Correlation between ammonia-oxidizing microorganisms and environmental factors during cattle manure composting

Abstract Cattle manure composting was performed in an aerated vessel. Community structure and diversity of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) were investigated using polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) techniques targeting the ammonia monooxygenase alpha subunit (amoA) gene and the correlation between AOB and AOA communities and environmental factors was explored. Thirteen (13) AOB sequences were obtained, which were closely related to Nitrosomonas spp., Nitrosomonas eutropha, and Nitrosospira spp. and uncultured bacteria, among which Nitrosomonas spp. were predominant. Excessively high temperature and high ammonium concentration were not favorable for AOB growth. Five AOA sequences, belonging to Candidatus Nitrososphaera gargensis and to an uncultured archaeon, were obtained. During composting, community diversity of AOB and AOA fluctuated, with AOA showing a higher Shannon-Wiener index. The AOB community changed more dramatically in the mesophilic stage and the early thermophilic stage, whereas the most obvious AOA community succession occurred in the late thermophilic stage, the cooling stage and the maturity stage. Water content, total nitrogen (TN) and ammonium concentration were more relevant to the AOB community structure, while higher correlations were observed between ammonia, nitrate and TN and the AOA community. AOB community diversity was negatively correlated with pH (r = -0.938, p < 0.01) and water content (r = -0.765, p < 0.05), while positively correlated with TN (r = 0.894, p < 0.01). AOA community diversity was negatively correlated with ammonium concentration (r = -0.901, p < 0.01). Ammonium concentration played an important role in the succession of AOB and AOA communities during composting.

Resumen Se llevó a cabo un compostaje de estiércol de ganado en un recipiente aireado. Se investigó la estructura de la comunidad y la diversidad de bacterias oxidantes del amoníaco (AOB) y las arqueas oxidantes del amoníaco (AOA) mediante el uso de las técnicas de reacción en cadena de la polimerasa y la electroforesis en gel con gradiente de desnaturalización (PCR-DGGE) dirigidas al gen de la subunidad alfa de la amonio monooxigenasa (amoA), y se exploró la correlación entre las comunidades AOB, AOA y los factores ambientales. Se obtuvieron 13 secuencias de AOB, las cuales se relacionaron estrechamente con Nitrosomonas spp., Nitrosomonas eutropha y Nitrosospira spp., y bacterias no cultivadas, entre las cuales fueron predominantes las Nitrosomonas spp. La temperatura excesivamente alta y la concentración de amonio elevada no fueron favorables para el crecimiento de las AOB. Se obtuvieron 5 secuencias de AOA, pertenecientes a Candidatus Nitrososphaera gargensis y un Archaeon no cultivado. Durante el compostaje, la diversidad de AOB y AOA fluctuó y las AOA mostraron un índice de Shannon-Wiener más alto. La comunidad de AOB cambió significativamente en la etapa mesofílica y la etapa termofílica temprana, mientras que la sucesión más obvia de la comunidad AOA ocurrió en la etapa termofílica tardía y las etapas de enfriamiento y de maduración. El contenido de agua, el nitrógeno total (TN) y la concentración de amonio fueron más relevantes para la estructura de la comunidad AOB, mientras que se observaron correlaciones mayores entre amoníaco, nitrato y TN, y la comunidad AOA. La diversidad de la comunidad AOB se correlacionó negativamente con el pH (r= -0,938; p < 0,01) y el contenido de agua (r = -0,765; p < 0,05), mientras que se relacionó positivamente con TN (r = 0,894; p < 0,01). La diversidad de la comunidad AOA se correlacionó negativamente con la concentración de amonio (r = -0,901; p < 0,01). La concentración de amonio desempenó un papel importante en la sucesión de las comunidades AOB y AOA durante el compostaje.

Diversity and abundance of denitrifiers during cow manure composting / Diversidad y abundancia de desnitrificadores durante el compostaje del estiércol de vaca

Diversity and abundance of the denitrifying genes nirK, nirS and nosZ were investigated in cow manure compost using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and real-time quantitative PCR (qPCR), respectively. These three genes were detected in all the stages of the composting process. Phylogenetic analysis showed that the nirK gene was closely related to Rhizobiales, Burkholderiales, the nirS gene was closely related to Pseudomonadales and Burkholderiales, and the nosZ gene was closely related to Rhodospirillales, Rhizobiales, Pseudomonadales, and Alteromonadales. qPCR results showed that the abundance of these three genes (nirK, nirS and nosZ) reached the peak value in the late thermophilic stage of composting and abundance of the nirK gene was higher than that of the nosZ gene and the nirS gene. Redundancy analysis (RDA) showed that the diversity of the nirK and nirS genes was significantly correlated with ammonium (p < 0.05), the diversity of the nosZ gene was significantly correlated with pH (p < 0.05) and the abundance of the nirK nirS and nosZ genes was significantly correlated with temperature (p< 0.05).

La diversidad y la abundancia de los genes desnitrificadores nirK, nirS, nosZ en el compost de estiércol de vaca se investigaron por medio de la reacción en cadena de la polimerasa seguida de electroforesis en gel con gradiente de desnaturalización (PCR-DGGE) y por PCR cuantitativa (qPCR) en tiempo real, respectivamente. Estos 3 genes fueron detectados durante todas las fases del compostaje. El análisis filogenético mostró estrecha relación del gen nirK con Rhizobiales y Burkholderiales, del gen nirS con Pseudomonadales y Burkholderiales y del gen nosZ con Rhodospirillales, Rhizobiales, Pseudomonadales y Alteromonadales. Los resultados de la qPCR mostraron que la abundancia de los genes nirK, nirSy nosZ alcanzó el valor máximo en la fase termofílica tardía del compostaje, y que la abundancia del gen nirK era más elevada que los de los genes nosZ y nirS. El análisis de redundancia (RDA) mostró que la diversidad de los genes nirK y nirS estaba significativamente correlacionada con la concentración de amonio (p<0,05), mientras que la del gen nosZ estaba significativamente correlacionada con el pH (p<0,05). También mostró que la abundancia de los genes nirK, nirS y nosZ estaba significativamente correlacionada con la temperatura (p<0,05).

Impact of organic contaminants from dumpsite leachates on natural water sources in the Enugu Metropolis, southeastern Nigeria.

This study evaluates the impact of leachates from a municipal dumpsite on the quality of domestic water sources in the area for potable use. Concentrations of leachate-associated organic contaminants (such as diethyl-phthalate, total organic halogen (TOH); 2,4-dichlorophenol; nonylphenol-ethoxylate; methyl-ethyl-phthalate; borneol; total organic carbon (TOC); total Kjeldahl-nitrogen (TKN); ammonium-nitrogen (NH3-N); nitrate (NO3); nitrate-nitrogen (NO3-N); and total phosphorus (TP)) in rivers and groundwater in the Enugu Metropolis in southeastern Nigeria were assessed in this study. Results of laboratory analyses indicate that the average values of diethyl-phthalate, borneol, TOH, nonylphenol-ethoxylate and TOC are 0.08 mg/l, 0.04 mg/l, 1.05 mg/l, 0.2 mg/l and 1.64 mg/l, respectively for groundwater and 0.1 mg/l, 0.03 mg/l, 0.74 mg/l, 0.19 mg/l and 1.74 mg/l, respectively, for rivers. Three (diethyl-phthalate, borneol and TOH) out of these major five contaminants, in both rivers and groundwater, exceeded the maximum permissible limits, suggesting that the domestic water sources are marginally contaminated by the leachates. ANOVA test result suggests that the data sources were significantly variable, while principal component and correlation analyses identified TOH, 2,4-dichlorophenol, TKN, NO3, NO3-N, TP and borneol, which originated most probably from degradation of plastic materials and organic wastes in the dumpsite, as the priority contaminants. Consumption of domestic water sources within the dumpsite area, in untreated state, could lead to health risks as these priority organic contaminants are mostly carcinogenic, toxic and injurious to human systems.

Gastrointestinal digestion of food-use silver nanoparticles in the dynamic SIMulator of the GastroIntestinal tract (simgi®). Impact on human gut microbiota.

The increasing use of silver nanoparticles (AgNPs) in consumer products has led to concern about their impact on human health. This paper aims to provide new scientific evidence about the modifications and potential effects of AgNPs with food applications during their passage through the digestive tract. For that, two types of AgNPs [solid polyethylene glycol-stabilised silver nanoparticles (PEG-AgNPs 20) and liquid glutathione-stabilised silver nanoparticles (GSH-AgNPs)] were initially subjected to gut-microbial digestion simulation in an in vitro static model. Based on these experiments, digestion of GSH-AgNPs was carried out in a dynamic model (simgi®) that simulated the different regions of the digestive tract (stomach, small intestine and the ascending, transverse and descending colon) in physiological conditions. Dynamic transport of GSH-AgNPs in the simgi® was similar to that observed for the inert compound Cr-EDTA, which discarded any alterations in the intestinal fluid delivery due to the AgNPs. Also, feeding the simgi® with GSH-AgNPs seemed not to induce significant changes in the composition and metabolic activity (i.e., proteolytic activity) of the gut microbiota. Concerning monitoring of AgNps, it was observed that the GSH-AgNPs underwent several transformations in the gastrointestinal fluids and appeared to expose the intestine in ways that were structurally different from the original forms. In compliance with European guidelines, the simgi® model can be considered a useful in vitro tool to evaluate the effects of nanoparticles at the digestive level, prior to human studies, and, therefore, minimising animal testing.

Study on the denitrification performance of FexLayOz/activated coke for NH3-SCR and the effect of CO escaped from activated coke at mid-high temperature on catalytic activity.

Currently, activated coke is widely used in the removal of multiple pollutants from industrial flue gas. In this paper, a series of novel FexLayOz/AC catalysts was prepared by the incipient wetness impregnation for NH3-SCR denitrification reaction. The introduction of Fe-La bimetal oxides significantly improved the denitrification performance of activated coke at mid-high temperature, and 4% Fe0.3La0.7O1.5/AC exhibited a superior NOx conversion efficiency of 90.1% at 400 °C. The catalysts were further characterized by BET, SEM, XRD, Raman, EPR, XPS, FTIR, NH3-TPD, H2-TPR, et al., whose results showed that the perovskite-type oxide of LaFeO3 and oxygen vacancies were produced on the catalysts' surfaces during roasting. Fe-La doping enhanced the amount of acid sites (mainly Lewis and other stronger acid sites) and the content of multifarious oxygen species, which were beneficial for NOx removal at mid-high temperature. Moreover, it was investigated that the effect of released CO from activated coke at mid-high temperature on the NOx removal through the lifetime test, in which it was found that a large amount of CO produced by pyrolysis of activated coke could promote the NOx removal, and long-term escaping of CO on the activated coke carrier did not have a significant negative impact on catalytic performance. The results of the TG-IR test showed that volatile matter is released from the activated coke while TG results showed that the weight loss rate of 4% Fe0.3La0.7O1.5/AC only was 0.0015~0.007%/min at 300-400 °C. Hence, 4% Fe0.3La0.7O1.5/AC had excellent thermal stability and denitrification performance to be continuously used at mid-high temperature. Finally, the mechanisms were proposed on the basis of experiments and characterization results.

Electro-sorption of ammonium ion onto nickel foam supported highly microporous activated carbon prepared from agricultural residues (dried Luffa cylindrica).

An electrode made of loofah sponge derived activated carbon supported on nickel foam (AC/Ni) was successfully fabricated and used to remove ammonium ion (NH4+) from aqueous solution. A multilayer adsorption isotherm was used to describe ammonium electro-sorption on AC/Ni electrodes at different temperature, initial NH4+ concentration, and electrical field. The cyclic voltammetry (CV) results suggested that the electrical capacitance of AC/Ni electrodes, with the AC being prepared without preheating (OAC) or with low temperature heating (i.e., 300 AC), were higher than those prepared at high preheating temperature (i.e., 400 AC and 500 AC). Increasing the electro-sorption temperature from 10 to 50 °C decreased the monolayer NH4+ adsorption capacity from 5 to ca. 2-3 mg-N g-1, respectively. Background electrolyte, namely, sodium sulfate, exhibited significant competitive effect on the adsorption of ammonium ion at sodium ion concentration > 10-2 M. The activation energy and heat of adsorption were 9-23.2 kJ mol-1 and -3.7--10.7 kJ mol-1, respectively, indicating a physisorption and exothermic adsorption characteristics. Based on the kinetics and thermodynamics analysis, there was slight increase in the activation energy with elevating preheating temperature, which increased the quantity of micro-pores and surface heterogeneity of the AC materials. Overall, results clearly demonstrated that carbon pyrolysis played a role on the capacitive charging behaviors of electrodes and the efficiency of NH4+ electro-sorption on the AC/Ni electrodes.

Soil nutrient heterogeneity affects the accumulation and transfer of cadmium in Bermuda grass (Cynodon dactylon (L.) pers.).

There have been no studies demonstrating the correlation between soil nutrient heterogeneity and cadmium (Cd) absorption of Bermudagrass. In this study, a pot experiment was carried out to study the correlation between them. The purpose is to find soil nutrient factors which are conducive to improving the Cd absorption and translocation. The eighth group had the largest total number of surviving plants, the highest Fv/Fo value (3.24) and the best growth characteristics. The fifth group had the lowest total number of surviving plants, Fv/Fo (2.47) and the worst growth. The Cd content of the fifth group (36.11 mg kg-1) was close to the eighth group (35.72 mg kg-1), but the two groups had significant differences in plant height, stem node length and stem node number (P < 0.05). The eighth group showed the highest contents of nitrate nitrogen (NO3--N), available potassium and urease activity. The fifth group showed the lowest NO3--N content, but the highest ammonium nitrogen (NH4+-N) and available phosphorus content. There was significant difference of the Cd bioconcentration factors (BCF) and translocation factor (TCF) between the fifth and the eighth group although they had the similar total soil Cd content (P < 0.05). The fifth group had the highest BCF and TCF. RDA analysis indicated the BCF and TCF were positively correlated with soil NH4+-N and available phosphorus and negatively correlated with soil NO3--N. The results demonstrated that soil NH4+-N and available phosphorus were important soil ecological factors to enhance Cd absorption and translocation of bermudagrass.

Chemical modeling of groundwater quality in the aquifer of Seini town - Someș Plain, Northwestern Romania.

This paper presented a groundwater quality monitoring in Seini town, North-West of Romania, by assessing 18 physicochemical parameters (pH, EC, COD, turbidity, ht, NH4+, NO2-, NO3-, Cl-, Al, Fe, Mn, Pb, Zn, Cd, Cr, Ni and As) from 12 private dug wells and 5 private drilled wells, each with unique characteristics and used as a drinking water source. The pollution, quality status and risk assessment of drinking water sources were assessed, by pollution, quality and risk indices. Statistical methodology and cluster analysis were applied in order to elaborate and improve upon a mathematical model. 2 D and 3 D mathematical models were elaborated to show the functions that better describe the dependence between a set of physicochemical parameters. Heavy metal pollution index (HPI) and heavy metal evaluation index (HEI) results indicated that the studied drinking water sources presented no heavy metal contamination. Human health risk assessment indices showed that the consumption of studied waters presented no non-carcinogenic risk at heavy metals, but potential non-carcinogenic risk at NO3-. The water quality index (WQI) classifies the majority of samples as waters with excellent quality and the minority of samples in waters with poor and very poor quality. By geostatistical techniques, the spatial patterns of the main physicochemical indicators were established for both the surface of the aquifer and its depth. The aim of the water quality study was to establish the toxicity degree of water, its influence on human health and to inform the population regarding the use of individual water sources.

Effects of plant diversity on greenhouse gas emissions in microcosms simulating vertical constructed wetlands with high ammonium loading.

Wastewater with relatively high nitrogen concentrations is a major source of nitrous oxide (N2O) and methane (CH4) emissions and exerts multiple stresses on the environment. Studies have shown that plant diversity plays an important role in ecosystem functioning. However, the effects of plant species diversity on CH4 and N2O emissions under high ammonium (NH4+-N) loading rates remain unclear. In this study, a microcosm experiment simulating vertical constructed wetlands supplied with high NH4+-N water levels was established. The treatments included four species richness levels (1, 2, 3, 4) and 15 species compositions. There was no significant relationship between species richness and N2O emissions. However, N2O emissions were significantly reduced by specific plant species composition. Notably, the communities with the presence of Rumex japonicus L. reduced N2O emissions by 62% compared to communities without this species. This reduction in N2O emissions may have been a result of decreased N concentrations and increased plant biomass. CH4 emissions did not respond to plant species richness or species identity. Overall, plant species identity surpassed species richness in lowering N2O emissions from constructed wetlands with high NH4+-N water. The results also suggest that communities with R. japonicus could achieve higher N removal and lower greenhouse gas emissions than other wetland species.