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Impact of multi-metals (Cd, Pb and Zn) exposure on the physiology of the yeast Pichia kudriavzevii Full text
2015
Mesquita, Vanessa A. | Machado, Manuela D. | Silva, Cristina F. | Soares, Eduardo V.
Metal contamination of the environment is frequently associated to the presence of two or more metals. This work aimed to study the impact of a mixture of metals (Cd, Pb and Zn) on the physiology of the non-conventional yeast Pichia kudriavzevii. The incubation of yeast cells with 5 mg/l Cd, 10 mg/l Pb and 5 mg/l Zn, for 6 h, induced a loss of metabolic activity (assessed by FUN-1 staining) and proliferation capacity (evaluated by a clonogenic assay), with a small loss of membrane integrity (measured by trypan blue exclusion assay). The staining of yeast cells with calcofluor white revealed that no modification of chitin deposition pattern occurred during the exposure to metal mixture. Extending for 24 h, the exposure of yeast cells to metal mixture provoked a loss of membrane integrity, which was accompanied by the leakage of intracellular components. A marked loss of the metabolic activity and the loss of proliferation capacity were also observed. The analysis of the impact of a single metal has shown that, under the conditions studied, Pb was the metal responsible for the toxic effect observed in the metal mixture. Intracellular accumulation of Pb seems to be correlated with the metals’ toxic effects observed.
Show more [+] Less [-]Enhanced hydroxyl radical generation in the combined ozonation and electrolysis process using carbon nanotubes containing gas diffusion cathode Full text
2015
Wu, Donghai | Lü, Guanghua | Zhang, Ran | Lin, Qiuhong | Yan, Zhenhua | Liu, Jianchao | Li, Yi
Combination of ozone together with electrolysis (ozone-electrolysis) is a promising wastewater treatment technology. This work investigated the potential use of carbon nanotube (CNT)-based gas diffusion cathode (GDC) for ozone-electrolysis process employing hydroxyl radicals (·OH) production as an indicator. Compared with conventional active carbon (AC)-polytetrafluoroethylene (PTFE) and carbon black (CB)-PTFE cathodes, the production of ·OH in the coupled process was improved using CNTs-PTFE GDC. Appropriate addition of acetylene black (AB) and pore-forming agent Na₂SO₄ could enhance the efficiency of CNTs-PTFE GDC. The optimum GDC composition was obtained by response surface methodology (RSM) analysis and was determined as CNTs 31.2 wt%, PTFE 60.6 wt%, AB 3.5 wt%, and Na₂SO₄ 4.7 wt%. Moreover, the optimized CNT-based GDC exhibited much more effective than traditional Ti and graphite cathodes in Acid Orange 7 (AO7) mineralization and possessed the desirable stability without performance decay after ten times reaction. The comparison tests revealed that peroxone reaction was the main pathway of ·OH production in the present system, and cathodic reduction of ozone could significantly promote ·OH generation. These results suggested that application of CNT-based GDC offers considerable advantages in ozone-electrolysis of organic wastewater.
Show more [+] Less [-]Removal of carbamazepine from spiked municipal wastewater using electro-Fenton process Full text
2015
Komtchou, Simon | Dirany, Ahmad | Drogui, Patrick | Bermond, Alain
Removal of carbamazepine from spiked municipal wastewater using electro-Fenton process Full text
2015
Komtchou, Simon | Dirany, Ahmad | Drogui, Patrick | Bermond, Alain
The electrochemical degradation of carbamazepine (CBZ) in both synthetic solutions (CBZo = 12 mg/L) and enriched municipal effluents (CBZo = 60–70 μg/L) was investigated using an electro-Fenton (EF) process. Different operating parameters were investigated, including current intensity, pH, reaction time, ferrous ion concentration, and the type of anode material. The current intensity, the type of anode material, and the concentration of ferrous ions played an important role in the CBZ degradation efficiency. The degradation was mainly attributed to direct anodic oxidation. The best operating conditions for the synthetic sample were obtained at a current density of 0.2 A, a pH of 3.0, and 120 min of treatment using a boron-doped diamond (BDD) anode in the presence of 0.25 mM of Fe²⁺. Under these conditions, 52 % of total organic carbon (TOC) and 73 % of CBZ were removed. The process was also tested as tertiary treatment for a municipal wastewater treatment plant effluent, and CBZ was completely removed.
Show more [+] Less [-]Removal of carbamazepine from spiked municipal wastewater using electro-Fenton process Full text
2015
Komtchou, Simon | Dirany, Ahmad | Drogui, Patrick | Bermond, Alain
The electrochemical degradation of carbamazepine (CBZ) in both synthetic solutions (CBZo = 12 mg/L) and enriched municipal effluents (CBZo = 60–70 μg/L) was investigated using an electro-Fenton (EF) process. Different operating parameters were investigated, including current intensity, pH, reaction time, ferrous ion concentration, and the type of anode material. The current intensity, the type of anode material, and the concentration of ferrous ions played an important role in the CBZ degradation efficiency. The degradation was mainly attributed to direct anodic oxidation. The best operating conditions for the synthetic sample were obtained at a current density of 0.2 A, a pH of 3.0, and 120 min of treatment using a boron-doped diamond (BDD) anode in the presence of 0.25 mM of Fe2+. Under these conditions, 52 % of total organic carbon (TOC) and 73 % of CBZ were removed. The process was also tested as tertiary treatment for a municipal wastewater treatment plant effluent, and CBZ was completely removed.
Show more [+] Less [-]Ecophysiological and ultrastructural effects of dust pollution in lichens exposed around a cement plant (SW Slovakia) Full text
2015
Paoli, Luca | Guttová, Anna | Grassi, Alice | Lackovičová, Anna | Senko, Dušan | Sorbo, Sergio | Basile, Adriana | Loppi, Stefano
The study investigated the ecophysiological and ultrastructural effects of dust pollution from a cement industry in the lichen species Evernia prunastri and Xanthoria parietina, which were exposed for 30, 90 and 180 days around a cement mill, two quarries, and inhabited and agricultural sites in SW Slovakia. The results showed that dust deposition from quarrying activities and cement works at the cement mill (mainly enriched in Ca, Fe and Ti) significantly affected the photosynthetic apparatus of E. prunastri (sensitive to dust and habitat eutrophication), while X. parietina (tolerant to dust and habitat eutrophication) adapted to the new environment. The length of the exposure strongly affected the vitality of the mycobiont (measured as dehydrogenase activity) in transplanted lichens. Dust deposition led to ultrastructural alterations, including lipid droplets increase, swelling of cellular components, thylakoid degeneration and sometimes plasmolysis, which, on the whole, gave the cells an aged appearance. Photosynthetic parameters deserve further attention as potential indicators for monitoring early biological symptoms of the air pollution caused during cement production.
Show more [+] Less [-]Arsenic in coal of the Thar coalfield, Pakistan, and its behavior during combustion Full text
2015
The aim of the current study is to evaluate the occurrence of arsenic in coal collected from Thar coalfield, Pakistan, and its behavior during the combustion. Fractionation of arsenic (As) in coal samples was carried out by Community Bureau of Reference sequential extraction scheme (BCR-SES) and single-step-based BCR method (BCR-SS). These methods are validated using the certified reference material of sediment BCR 701 and standard addition method. The stepwise fractions of As in laboratory-made ash (LMA) have been also investigated. The extractable As content associated with different phases in coal and LMA samples were analyzed by electrothermal atomic absorption spectrophotometer. The extraction efficiency of As by BCR-SS was slightly higher than BCR-SES, while the difference was not significant (p < 0.05). The BCR-SS method is a time-saving method because it can reduce the extraction time from 51 to 22 h. The As contents in LMA revealed that during combustion of the coal, >85 % of As may be released into atmosphere. The relative mobility of As in the coal samples was found in increasing order as follows: oxidizable fraction < reducible fraction < acid soluble fraction. The total and extractable As obtained by BCR-SES and BCR-SS were higher in coal samples of block III as compared to block V (p > 0.05).
Show more [+] Less [-]Application of modified export coefficient method on the load estimation of non-point source nitrogen and phosphorus pollution of soil and water loss in semiarid regions Full text
2015
Wu, Lei | Gao, Jian-en | Ma, Xiao-yi | Li, Dan
Chinese Loess Plateau is considered as one of the most serious soil loss regions in the world, its annual sediment output accounts for 90 % of the total sediment loads of the Yellow River, and most of the Loess Plateau has a very typical characteristic of “soil and water flow together”, and water flow in this area performs with a high sand content. Serious soil loss results in nitrogen and phosphorus loss of soil. Special processes of water and soil in the Loess Plateau lead to the loss mechanisms of water, sediment, nitrogen, and phosphorus are different from each other, which are greatly different from other areas of China. In this study, the modified export coefficient method considering the rainfall erosivity factor was proposed to simulate and evaluate non-point source (NPS) nitrogen and phosphorus loss load caused by soil and water loss in the Yanhe River basin of the hilly and gully area, Loess Plateau. The results indicate that (1) compared with the traditional export coefficient method, annual differences of NPS total nitrogen (TN) and total phosphorus (TP) load after considering the rainfall erosivity factor are obvious; it is more in line with the general law of NPS pollution formation in a watershed, and it can reflect the annual variability of NPS pollution more accurately. (2) Under the traditional and modified conditions, annual changes of NPS TN and TP load in four counties (districts) took on the similar trends from 1999 to 2008; the load emission intensity not only is closely related to rainfall intensity but also to the regional distribution of land use and other pollution sources. (3) The output structure, source composition, and contribution rate of NPS pollution load under the modified method are basically the same with the traditional method. The average output structure of TN from land use and rural life is about 66.5 and 17.1 %, the TP is about 53.8 and 32.7 %; the maximum source composition of TN (59 %) is farmland; the maximum source composition of TP (38.1 %) is rural life; the maximum contribution rates of TN and TP in Baota district are 36.26 and 39.26 %, respectively. Results may provide data support for NPS pollution prevention and control in the loess hilly and gully region and also provide scientific reference for the protection of ecological environment of the Loess Plateau in northern Shaanxi.
Show more [+] Less [-]Less indoor cleaning is associated with poor health and unhappiness in adults: Japanese General Social Survey, 2010 Full text
2015
Shiue, Ivy
Indoor environment is important to human health and well-being. The aim of the present study was to investigate the relationships among indoor cleaning, rubbish disposal and human health and well-being in a national and population-based setting. Data was retrieved from the Japanese General Social Survey, 2010. Information on demographics, lifestyle factors, frequency of indoor cleaning and rubbish disposal and self-reported health and well-being in Japanese adults was obtained by household interview. Analysis included chi-square test, logistic and multi-nominal regression modelling. Of 5003 Japanese adults (aged 20–89) included in the study cohort, 11.4 % (n = 566) never cleaned their living place, 39.1 % had occasional cleaning and 49.6 % had frequent cleaning. Moreover, 17.5 % (n = 869) never disposed rubbish, 24.9 % had occasional rubbish disposal and 57.6 % had frequent rubbish disposal. 15.0 % of Japanese adults claimed poor self-rated health, and 5.9 % reported unhappiness. Compared to people who frequently cleaned the living place, others tended to report poor self-rated health condition (relative risk ratios (RRR) 1.52, 95 % confidence intervals (CI) 1.24–1.85, P < 0.001) and unhappiness (RRR 1.47, 95 % CI 1.10–1.95, P < 0.001). The combined effects of never cleaning and never rubbish disposal significantly impacted on poor self-rated health (RRR 2.61, 95 % CI 1.40–4.88, P = 0.003) and unhappiness (RRR 2.72, 95 % CI 1.72–4.30, P < 0.001). Only half of the Japanese population frequently cleaned their living place and disposed rubbish. Less or never cleaning and rubbish disposal were associated with poor self-rated health, subjective happiness and potentially other health conditions. Public education on maintaining clean indoor environments to optimise psychological well-being in addition to the known physical health would be suggested.
Show more [+] Less [-]Household pesticide exposure and the risk of childhood acute leukemia in Shanghai, China Full text
2015
Childhood acute leukemia (AL) is the most common malignant tumor in children, but its etiology remains largely unknown. We investigated the relationship between household exposure to pesticides and childhood AL. Between 2009 and 2010 in Shanghai, a total of 248 newly diagnosed cases of AL and 111 gender-, age-, and hospital-matched controls were included. Five nonspecific dialkyl phosphate (DAP) metabolites of organophosphate pesticides (OPPs) [including dimethyl phosphate (DMP), diethyl phosphate (DEP), dimethyl thiophosphate (DMTP), diethyl thiophosphate (DETP), and diethyl dithiophosphate (DEDTP)] in the urine were analyzed by gas chromatography. The results showed that the median DMP, DEP, DMTP, DETP, and DEDEP levels adjusted for creatinine (Cr) in cases (13.2, 10.0, 31.3, 8.5, and 6.1 μg g⁻¹, respectively) were all significantly elevated compared with those in controls (3.6, 3.6, 13.3, 2.7, and 1.7 μg g⁻¹, respectively) (P < 0.05). The household use of mosquito repellent was significantly associated with an increased risk of childhood AL (odds ratio (OR) = 1.9; 95 % confidence interval (CI) 1.2–3.1). Moreover, higher exposures were significantly associated with an elevated risk of childhood AL for DMs, DEs, and DAPs. Our findings support the notion that the household use of pesticides may play a role in the etiology of childhood AL and provide some evidence to warrant further investigation of the link between household pesticide exposures and childhood AL in Shanghai.
Show more [+] Less [-]Chitosan-induced antiviral activity and innate immunity in plants Full text
2015
Iriti, Marcello | Varoni, Elena Maria
Immunity represents a trait common to all living organisms, and animals and plants share some similarities. Therefore, in susceptible host plants, complex defence machinery may be stimulated by elicitors. Among these, chitosan deserves particular attention because of its proved efficacy. This survey deals with the antiviral activity of chitosan, focusing on its perception by the plant cell and mechanism of action. Emphasis has been paid to benefits and limitations of this strategy in crop protection, as well as to the potential of chitosan as a promising agent in virus disease control.
Show more [+] Less [-]Organic matter and pollutants monitoring in reed bed systems for sludge stabilization: a case study Full text
2015
Peruzzi, Eleonora | Macci, Cristina | Doni, Serena | Volpi, Maurizio | Masciandaro, Grazia
In this study, results about sludge stabilization and pollutant monitoring in a reed bed system (RBSs) situated in Central Italy (Colle di Compito, 4,000 p.e.) were presented. In order to evaluate the process of sludge stabilization, parameters that highlighted the biochemical, chemical and chemico-structural properties of organic sludge matter have been followed during the entire period of operation (7 years). Moreover, the trend of heavy metals (bioavailable fractions and total content) and toxic organic compounds (LAS, NPE and DEHP) was monitored during all the period. The trend of all parameters related clearly demonstrated that sludge stabilization successfully proceeded in RBS. Moreover, through statistical analysis modelling, it is possible to determine how the stabilization process proceeded in terms of organic matter mineralization and humification, and how these processes influenced the content of pollutant compounds present in the stabilized sludges.
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