J Environ Sci Health A Tox Hazard Subst Environ Eng [journal]
- Kinetics of methane production and biodegradation of linear alkylbenzene sulfonate from laundry wastewater. [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Aug 17.:1-15.
This study evaluates the kinetics of methane production and degradation of standard linear alkylbenzene sulfonate (LAS) (50 ± 3.5 mg/L) and LAS from laundry wastewater (85 ± 2.1 mg/L) in anaerobic batch reactors at 30°C with different sources of inoculum. The inocula were obtained by auto-fermentation (AFM) and UASB reactors from wastewater treatment of poultry slaughterhouse (SGH), swine production (SWT) and wastewater treatment thermophilic of sugarcane industry (THR). The study was divided into three phases: synthetic substrate (Phase I), standard LAS (Phase II) and LAS from laundry wastewater (Phase III). For SGH, the highest values for cumulative methane productions (1,844.8 ± 149 µmol-Phase II), methane production rate (70.8 ± 88 µmol/h-Phase II and 4.01 ± 07 µmol/h-Phase III) were observed. The use of thermophilic biomass (THR) incubated at 30°C was not favorable for methane production and LAS biodegradation, but the highest kinetic coefficient degradation (k1(app)) was obtained for LAS (0.33 ± 0.3 h) compared with mesophilic biomass (SGH and SWT) (0.13 ± 0.02 h). Therefore, both LAS sources influenced the kinetics of methane production and organic matter degradation. For SGH, inoculum obtained the highest LAS degradation. In the SGH inoculum sequenced by MiSeq-Illumina was identified genera (VadinCA02, Candidatus Cloacamonas, VadinHB04, PD-UASB-13) related to degrade toxic compounds. Therefore, it recommended the reactor mesophilic inoculum UASB (SGH) for the LAS degradation.
- Distributions of SO2 and NO2 in the lower atmosphere of an industrial area in Bhutan. [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Aug 17.:1-10.
Two important air pollutants, sulfur dioxide (SO2) and nitrogen dioxide (NO2), were sampled and monitored in the spring season in the biggest industrial area of Bhutan. Field measurements of SO2 and NO2 were performed using standard colorimetric methods, and air samples were collected using an active sampling technique. Sampling sites were selected to cover all the potential catchment areas like settlements, staff quarters, shops and schools. The main objective of this sampling work was to see the distribution of these two pollutants from the source of emission (small scale industries) and to obtain and establish a baseline data. The active sampler was first tested and validated in a laboratory using liquid and gas standards of SO2 and NO2. Good linearity from 0.050 to 1.0 µg mL(-1) for SO2 and from 0.010 to 1.0 µg mL(-1) for NO2 were obtained (R(2) > 0.99) with limits of detection of 30 and 50 ng mL(-1) for SO2 and NO2, respectively. Daylong sampling was done at selected sites with a range of distances away from the sources of emission. The ambient concentration of SO2 and NO2 were in the range of 0.45-4.46 and 0.56-5.68 µg m(-3), respectively.
- Hydrocarbons biodegradation by activated sludge bacteria in the presence of natural and synthetic surfactants. [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Aug 17.:1-7.
Fuels, such as diesel oil, can have a substantial impact on the microbial equilibrium of activated sludge and have a negative influence on work of wastewater treatment plant. The primary objective of the research was to examine the possibility of using the surfactants to improve pollutants biodegradation by bacteria from activated sludge. The results showed that the addition of rhamnolipids allows to increase the hydrocarbon biodegradation from 47% up to 75% in the cultures inoculated with the consortium. The saponins increased the degradation of diesel oil by the two isolated strains: from 27% to 43% for Alcaligenes sp. and from 44% to 64% for Pseudomonas sp. The addition of surfactants to the cultures growth with diesel oil caused a significant decrease of the surface charge for Alcaligenes strain in the presence of saponins, but not in other cases. The obtained results revealed the potential of natural surfactants to support hydrocarbon biodegradation in wastewater treatment plants.
- Relationship between air pollution and metal levels in cancerous and non-cancerous lung tissues. [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Aug 17.:1-6.
We aimed to check the relationships between levels of metals (Ca, Cd, Cu, Fe, Hg and Zn) in cancerous and non-cancerous lung tissues and their link to air pollution, expressed as particulate matter (PM) concentrations. The study also examines the influence on metal concentration in the lung tissue of patients' sex and the distance of their homes from the nearest emitter. We found that the general pattern of ascending concentrations in tumor tissue was as follows: Hg < Cd < Cu < Ca < Zn < Fe. In non-affected lung tissue the order of concentrations of Ca and Fe was reversed. With the exception of Cd and Cu, levels of metals were found in higher accumulations in non-cancerous tissue (e.g., Fe 326.423 and Ca 302.730 μg/g d.w) than in tumorous tissue (Fe 150.735 and Ca 15.025 μg/g d.w). Neither the PM10 (PM of a diameter of 10 μm) concentration nor sex revealed any connection with metal concentrations. The shorter the distance from the emitter, the higher the metal concentrations that tended to be observed for almost all metals, but a statistically significant (but weak) relationship was noted only for Cu in tumor tissue (rs: -0.4869).
- Performance evaluation of micro-aerobic hydrolysis of mixed sludge: Optimum aeration and effect on its biochemical methane potential. [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Aug 17.:1-9.
This study evaluated the performance of a micro-aerobic hydrolysis of mixed sludge and its influence as a pretreatment of this waste for its subsequent anaerobic digestion. Three experimental series were carried out to evaluate the optimum micro-aeration levels in the range from 0.1 to 0.5 air volume/min.reactor volume (vvm) and operation times within the range of 24-60 h. The maximum methane yield [35 mL CH4/g volatile suspended solids (VSS) added] was obtained for an aeration level of 0.35 vvm. This methane yield value increased 114% with respect to that obtained with the non-aerated sludge. In the micro-aeration process carried out at an aeration level of 0.35 vvm, increases in soluble proteins and total sugars concentrations of 185% and 192% with respect to their initial values were found, respectively, after 48 h of aeration. At the above micro-aerobic conditions, soluble chemical oxygen demand (CODS) augmented 150%, whereas VSS content decreased until 40% of their initial respective values. Higher COD increases and VSS decreases were found at 60 h of micro-aeration, but the above parameters did not vary significantly with respect to the values found at 48 h.
- Metagenomic insight of nitrogen metabolism in a tannery wastewater treatment plant bioaugmented with the microbial consortium BM-S-1. [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Jul 28.:1-9.
Nitrogen (N) removal in a tannery wastewater treatment plant was significantly enhanced by the bioaugmentation of the novel consortium BM-S-1. In order to identify dominant taxa responsible for N metabolisms in the different stages of the treatment process, Illumina MiSeq Sequencer was used to conduct metagenome sequencing of the microbial communities in the different stages of treatment system, including influent (I), buffering (B), primary aeration (PA), secondary aeration (SA) and sludge digestion (SD). Based on MG-RAST analysis, the dominant phyla were Proteobacteria, Bacteroidetes and Firmicutes in B, PA, SA and SD, whereas Firmicutes was the most dominant in I before augmentation. The augmentation increased the abundance of the denitrification genes found in the genera such as Ralstonia (nirS, norB and nosZ), Pseudomonas (narG, nirS and norB) and Escherichia (narG) in B and PA. In addition, Bacteroides, Geobacter, Porphyromonasand Wolinella carrying nrfA gene encoding dissimilatory nitrate reduction to ammonium were abundantly present in B and PA. This was corroborated with the higher total N removal in these two stages. Thus, metagenomic analysis was able to identify the dominant taxa responsible for dissimilatory N metabolisms in the tannery wastewater treatment system undergoing bioaugmentation. This metagenomic insight into the nitrogen metabolism will contribute to a successful monitoring and operation of the eco-friendly tannery wastewater treatment system.
- The antimicrobial agents triclocarban and triclosan as potent modulators of reproduction in Potamopyrgus antipodarum (Mollusca: Hydrobiidae). [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Jul 26.:1-7.
In this study, we assessed the chronic effects of the two antimicrobial substances triclocarban (TCC) and triclosan (TCS) on reproduction of a mollusk species by using the reproduction test with the New Zealand mudsnail Potamopyrgus antipodarum. Snails coming from a laboratory culture were exposed for 28 days to nominal concentrations ranging from 0.1 up to 10 µg/L for both chemicals (measured 0.082-8.85 µg TCC/L; 0.068-6.26 µg TCS/L). At the end of the experiment, snails were dissected and embryos in the brood pouch were counted to assess the individualized reproductive success of adult snails. Exposure to TCC resulted in an inverted u-shaped concentration-response relationship, with a stimulation of reproduction at low concentrations followed by an inhibition at higher concentrations. The no observed effect concentration (NOEC) and the lowest observed effect concentration (LOEC) were 0.082 and 0.287 µg/L, respectively. TCS caused significantly increased embryo numbers at all tested concentrations, except in the group of 0.170 µg/L. Therefore, the NOEC for TCS was 0.170 µg/L and the LOEC was 0.660 µg/L. These results indicate that TCC and TCS may cause reproductive effects at environmentally relevant concentrations indicating a potential risk for aquatic organisms in the environment.
- Geochemical hunting of lithogenic and anthropogenic impacts on polymetallic distribution (Bregalnica river basin, Republic of Macedonia). [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Jul 26.:1-15.
The main subject of this investigation was the assessment of the lithogenic and anthropogenic distribution of 69 elements in the sediments and fluvisol in the Bregalnica river basin. Alluvial soil and fluvisol samples were collected from the total of eighteen locations along the course of the Bregalnica river and additional thirteen samples were collected from its tributaries. The matrix elements accumulation patterns followed the order: Fe > Na > Al > Ca > Mg > K > Ti > P. The potentially toxic elements, such as As, Cd, Pb, and Zn, have enriched content in the sediments in the medium course of the river, where the main anthropogenic introduction activities occurred. By multivariate analysis the dominant geochemical associations were extracted, as follows: F1: Y-Eu-Lu-Cr-V-La-Gd-Nb-Co-Hf-Zr-Ga-Mg-Fe-Sr-Ta-Sn-Li-Na-Rb-Ni-Ge-Be-Cs; F2: As-W-Ba-Ag-Cu-Tl-Zn-Sb-Mo-In-Cd-Te-Bi-Pb and F3: I-Sc-Br-K. Lead and zinc contents were strongly correlated with the hydrothermal exploitations, especially in the area of Neogene clastite and vulcanite. These elements occur as dominant geochemical markers of the anthropogenic impacts of polymetallic enrichments due to the hydrothermal ore exploitation (Factor 2). The impact of Oligocene volcanism (Kratovo-Zletovo region) was observed in the lithological enrichments of Pb, Zn, Cu, As, Sb, Mo and Bi. Despite the natural distribution along the course of the Bregalnica river, an exceptional anomaly in the iron distribution of the old polymetallic unused mineralization was detected in Zone 1 (Berovo region).
- Analysis and pollution sources speculations of toxic gases in a secondary fiber paper mill. [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Jul 26.:1-8.
This paper quantitatively investigates the compositions of the gaseous pollutants in the ambient air of a secondary fiber paper mill. Total volatile organic compounds (TVOC), formaldehyde (HCHO), sulfur compounds (H2S), and hydrocarbon compounds (CxHy) were analyzed on six sampling sites with photo-ionisation detector, acetylacetone spectrophotometric method, and gas detector. The results revealed that, the high levels of TVOC and CxHy were detected at the wet end of paper machine and the office area, respectively; all the H2S contents on the six sites exceeded the limit (0.06 mg m(-3)) seriously; the HCHO concentrations at other five sites were out of the limit (0.10 mg m(-3)) except for the wastewater treatment plant. Furthermore, the necessary discussions about the possible pollution sources were considered on the process flow, the chemical agents used, and the ambient conditions in the paper mill. For the sake of air pollution control in paper mills, these remarkable results and analysis lay some technical basis in the following researches that should attract more attentions.
- Evaluation of the cytotoxic activity of Hypericum spp. on human glioblastoma A1235 and breast cancer MDA MB-231 cells. [JOURNAL ARTICLE]
- J Environ Sci Health A Tox Hazard Subst Environ Eng 2016 Jul 26.:1-7.
Cytotoxic activity of 16 Hypericum ethanolic extracts was evaluated by MTT assay on two human cancer cell lines: glioblastoma A1235 and breast cancer MDA MB-231. Morphology and the type of induced cell death were determined using light and fluorescence microscopy. The majority of Hypericum extracts had no significant cytotoxic effect on MDA MB-231 cells. Eight extracts exhibited mild cytotoxic effect on A1235 cells after 24 h incubation, ranging from 8.0% (H. patulum) to 21.7% (H. oblongifolium). After 72 h of treatment, the strongest inhibition of A1235 viability was observed for extracts of H. androsaemum (26.4-43.9%), H. balearicum (25.8-36.3%), H. delphicum (14.8-27.4%) and H. densiflorum (11.2-24.1%). Micro-scopic examination of cells showed apoptosis as the dominant type of cell death. Due to observed high viability of treated cells, we propose that cytotoxic effects of Hypericum extracts could be related to alternations/interruptions in the cell cycle.