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Growth-phase dependent biodesulfurization of Dibenzothiophene by Enterobacter sp. strain NISOC-03
2017
Papizadeh, Moslem | Roayaei Ardakani, Mohammad | Motamedi, Hossein
Petroleum-polluted soil samples from Ahvaz oilfield were enriched, using three methods to detect microorganisms with different dibenzothiophene degradation capabilities. Strain NISOC-03, a nitrate-reducing, oxidase negative, catalase, citrate, and urease positive, gram negative rod, showed interesting dibenzothiophene desulfurization behavior, designated as Entreobacter sp. strain NISOC-03 based on phenotype and genotype analyses. Gas chromatography, biomass measurement, and Gibb’s assay showed that in the presence of benzoate as the carbon source, strain NISOC-03 utilized 64% of 0.8 mM dibenzothiophene, producing 0.27 mM phenyl phenol during the exponential growth phase, though the produced phenyl phenol was degraded in the stationary growth phase. In the presence of glucose as the carbon source, however, strain NISOC-03 metabolized only 19.6% of 0.8 mM dibenzothiophene. Furthermore, replacing glucose with ethanol or glycerol led to the same reduction of the dibenzothiophene utilization. It is thus concluded that the chemistry of the potential carbon source(s) in the culture medium has a significant influence on the quality and the rate of dibenzothiophene metablization, and the enrichment designation has a very vital effect on the biodegradation efficiency of the isolated microorganisms.
Mostrar más [+] Menos [-]Tropospheric Ozone Pollution in Some Major Cities of West Africa and its Relationship with Atmospheric Circulations
2017
Oluleye, Ayodeji | Ochei, M.
This study utilizes a decade long (2005-2014) monthly data of Total Column Tropospheric Ozone (TCTO) in Dubson units to evaluate the spatial and temporal trend of LAO over some major cities of West Africa, namely Lagos, Accra, Niamey, Abuja, Bamako, Dakar, Agadez, Conakry, Kano, and Ouagadougou which are either capital cites or major commercial hubs, where the population ranges from 0.09 million (Agadez, Niger) to over 9 million (Kano and Lagos, Nigeria). The mean (long term average) of TCTO in Lagos (Nigeria) was 34.4±0.6 DU (α=5%) for the entire period, being the highest in all major cities of this study. The lowest TCTO, 30.4±0.5 DU (α=5%), occurred in Bamako (Mali). It was also observed that the concentrations of TCTO vary seasonally. The seasonal changes in TCTO was investigated by categorizing months of the year to very dry months of December, January, and February (DJF), onset of rainy season months of March, April, and May (MAM), wet season months of June, July, and August (JJA), and end of rainy season months of September, October, and November (SON). Seasonal mean of TCTO is higher in all cities, close to the coast during DJF, and cities, north of latitude 12o N, during MAM, compared to rest of the seasons. Elevated TCTO concentrations can be attributed to transport mixing, due to the flow direction of well-known wind regime over the study area. This was established from the analysis of correlation coefficient between the mean of zonal, meridional winds, vertical wind speeds and divergence, and TCTO over region.
Mostrar más [+] Menos [-]Community’s perception of utilization and disposal of plastic bags in Eastern Ethiopia
2017
Negussie, Binyam | Mustefa, Jilalu
Plastics, one of the most abundant materials in the world today, are one of the main sources of pollution. People’s perception of using and disposing plastic bags is primordial as they tend to be a major part of household solid waste. This study aims to determine community’s perception of usage and disposal of plastic bags in Eastern Ethiopia. A quantitative cross-sectional study has been conducted in Harar city of Eastern Ethiopia, using a multi-stage statistical sampling technique. The data concerning all variables have been collected via pretested questionnaire and observational checklist with a response rate of 91% which has then been into SPSS and analyzed by STATA 11.0. About 51% open dump their plastic bag wastes. It has been shown that the majority (88.7%) of the responders perceived plastic bags as having environmental impacts, with 82.8% feeling a growth in their plastic bags utilization and about 54% thinking that plastic bags should be banned. It has also been illustrated that perception of plastic bags' environmental impacts and the willingness to pay for solid waste collection service has an association with plastic bag utilization. This study has found that utilization and open dumping of plastic bags rests at a significantly higher level. Community’s perceptions regarding environmental impacts of plastic bags have been at a higher level, which still requires consideration. A considerably high number of residents believe that utilization of plastic bag should be continued; therefore, a great emphasis should be given to bringing the desired attitudinal change.
Mostrar más [+] Menos [-]Assessment of indoor environmental impacts on human health (Case study: Glass city, Firozabad (India)(
2017
Bano, Nikhat
The present study aims to analyze the existing indoor environmental conditions of Firozabad City along with its impact on people’s health by going through the correlative index of indoor environment’s determinant and different diseases, faced by the people. In order to measure spatial disparities, the statistical technique, i.e. the standard score additive model (Z- score), has been applied to develop a composite score for each set of indicators in order to arrive at the general environmental and health condition of the study area as a whole. The analysis reveals that high intensity of indoor pollution and disease are reported in peripheral and old parts of the city. Preventive measures, likely to have deleterious health effects and improve such harmful environmental conditions, should be adopted. Enhanced use of clean fuel and national uniform housing codes or guidelines that address factors, affecting indoor air quality, makes up the current need.
Mostrar más [+] Menos [-]Biochemical changes of Conocarpus erectus (combretaceae) in response to gas refinery air pollution as an air pollution indicator
2017
Seyyednejad, Seyyed Mansour | Motamedi, Hossein | Lordifard, Parinaz
Environmental pollution consists of different types of pollutants in air, soil, and water. Due to the fact that plants can respond to environmental pollution, they can be used as bio-indicators for environmental monitoring. Air pollution in areas with oil and gas refineries nearby is an important problem. This study aims to survey the effects of gas refinery air pollutants on Conocarpus erectus so that it can be used for air-pollution monitoring. For this purpose, physiological indicators such as proline, protein, and malondealdehyde content as well as Air Pollution Tolerance Index (APTI value) have been used to evaluate these effects. Based on the obtained results, Conocarpus erectus in polluted area showed increased pH, protein, proline, malondealdehyde, and ascorbic acid contents while carotenoid quantity, total leaf chlorophyll content, and relative water content were decreased in comparison to the control plants. Therefore, it proves that air pollution affects the plant.
Mostrar más [+] Menos [-]Natural radioactivity and heavy metal distribution in reservoirs in Ghana
2017
Darko, Godfred | Ansah, Eugene | Faanu, Augustine | Azanu, David
The present paper has determined the radioactivity concentrations, which are due to natural occurrence of radionuclides along with heavy metal concentration in water, sediment, and fish from 2 reservoirs in Ghana. Heavy metal concentrations in all samples were generally within the WHO safe limits with the average activity concentrations of 238U, 232Th, and 40K in water being respectively 0.42±0.20, 0.33±0.31, and 1.59±1.07 Bq/L in case of Lake Bosomtwe and 0.26±0.14, 0.67±0.34 and 1.47±0.62 Bq/L for Bui Dam in Ghana. The average annual effective dose due to ingestion of radionuclides in water ranged from 20.5 to 156 for Lake Bosomtwe and 26.5 to 162 μSv/year for Bui dam and the absorbed dose rate and annual effective dose, measured for Lake Bosomtwe, was 15.45±2.00 nGy/year and 18.95±2.95 mS/year respectively while in case of Bui dam it accounted to 10.44±4.11 nGy/year and 12.88±5.01 mS/year respectively, found to be within the UNSCEAR recommended limits of 59 nGy/year and 100 mS/year respectively. The observed metal concentrations, within safety limits, imply that metal-associated diseases cannot be expected among patrons of these reservoirs. Therefore, radionuclides and heavy metals levels in the reservoirs are not expected to cause any significant health problem for humans.
Mostrar más [+] Menos [-]Assessment of surface water pollution in urban and industrial areas of Savar Upazila, Bangladesh
2017
Anny, Fahima | Kabir, Mohammad | Bodrud-Doza, Md.
The present study has been conducted to determine the surface water quality of urban area in Savar, Dhaka, Bangladesh by determining some water quality parameters (Transparency, Temperature, pH, EC, Eh, DO, TSS, TDS, TS, BOD5, COD, TOC, Cl-, Br-, SO4-2, NO3-, NO2-, PO4-3, TP, HCO3- and Total alkalinity) as well as the status of phytoplankton’s community in the water from two lakes (Tiger Lake and AERE Lake) and one canal (Karnapara Canal). It has been shown that, with exception of BOD and COD, all water quality parameters of AERE Lake in the present study are within the acceptable limits, recommended by local and international standards. Among water quality parameters of Tiger Lake and Karnapara Canal, the concentration of transparency, temperature, EC, DO, TSS, TDS, BOD, COD, TOC, NO2-, and TP exceed the acceptable limits. Organic Pollution Index (OPI) demonstrate that the water bodies are severely polluted by organic matters. R mode Cluster Analysis (CA) suggests that common sources of water quality parameters are industrial, agricultural, and natural. The Principle Component Analysis/Factor Analysis (PCA/FA) identifies two dominant factors, responsible for data structure, explaining 100% of total variance in the data set. The PCA agrees with CA, suggesting that multiple anthropogenic and natural sources are responsible for the water quality parameters. The present study reflects the actual scenario of surface water quality of Savar urban area, thus helping the policy planers and makers of the People’s Republic of Bangladesh to take proper management and abatement strategies for the management of sustainable water resource in Bangladesh.
Mostrar más [+] Menos [-]Urban vegetable farming: Anthropic level, bioavailability, and health implication associated with bioaccumulated trace metals in selected vegetables in Ilorin, Nigeria
2017
Ogunkunle, Clement | Aniefiok, Ite | Adeniyi, Sunday | Akintola, Elizabeth | Okere, Uche
Urban horticulture is of growing importance in developing and developed countries around the world; however, contamination of urban horticultural products can exceed the precautionary values, posing significant human health risks due to dietary exposure to high levels of the pollutants. In this study, samples of rhizosphere soil and corresponding vegetables have been collected from an urban garden in Ilorin, Nigeria, to assess the contamination level of trace metals as well as the health risk, associated with dietary intake of contaminated vegetables, in adult sub-population. The range of Cu, Pb, and Cd in garden topsoil was 14.0-52.50, 33.00-121.40, and 1.00-4.50 mg/kg, respectively. The metals sources were both anthropogenic and lithogenous, though the long-term accumulation of trace metals in the soil led to significant soil-plant transfer as evident in the levels of metals in some of the vegetables. The estimated daily intakes (EDI) of Cu and Pb through vegetable consumption were far below the recommended tolerable daily intakes (TDI) and the hazard quotient (HQ) values were within the safe zone for the adult population. In contrast, the EDI of Cd for the vegetables was several folds greater than the TDI, thus greatly contributing to a high hazard index (HI>1.0), observed in all vegetables. Therefore, risk assessment of trace metal ingestion through consumption of the vegetables in the adult sub-population depicts serious health hazards with Cd, mainly contributing to vegetable contamination in the studied area.
Mostrar más [+] Menos [-]Evaluation of the status of heavy metal pollution in surface water and sediments of the Nil River (North Eastern Algeria)
2017
Krika, Abderrezak | Krika, Fouad
Water and sediment samples were collected from six different stations, located along the Nil River between February and June 2015. Concentrations of cadmium, lead, zinc, and copper were determined. The extent of the sediment pollution was assessed, using the multiple pollution indices, namely contamination factor (CF), pollution load index (PLI), and the geoaccumulation index (Igeo). The results showed that the level of metals in water samples exceeded background concentrations for Cd and Pb, and the average values for those elements were higher than those of Zn and Cu, ranked as the following: Pb (0.58)> Zn (0.38)> Cd (0.32)> Cu (0.061). For sedimentary samples, the results showed that Zn and Pb concentrations were greater than the concentrations of Cu and Cd, exceeding the background values (except for Cu). The concentration of the tested heavy metals decreased to the following order: Zn (96.2)> Pb (61.5)> Cu (38.83)> Cd (2.34). The Igeo values revealed that Cd (2.87) and Pb (1.61) had accumulated significantly in the Nil River. Contamination factor (CF) confirmed that the sedimentary samples were moderate to very high in terms of Cd, Pb, and Zn contamination. The Pollution Load Index (PLI) values were above one (>1), indicating an advanced decline of the sediment quality. Also, the results showed that the stations, located at the middle portion of the river (S3, S4, and S5) have higher levels of metals than the other stations (S1, S2, and S6). The assessment of heavy metals' levels in water and sedimentary samples indicated that river water and the sediments in the study area were strongly impacted by agricultural activities and domestic waste water.
Mostrar más [+] Menos [-]Identification of the sources of dust storms in the City of Ahvaz by HYSPLIT
2017
Broomandi, Parya | Dabir, Bahram | Bonakdarpour, Babak | Rashidi, Yousef
Dust particles have dangerous impacts on human health, the environment, and the economy. Recently dust storms, originating from Arabian countries, have increased remarkably, affecting western and central parts of Iran.HYSPLIT model and the mean monthly maps of AAI (Absorbing Aerosol Index), surface skin temperature, and top soil layer moisture from OMI (Ozone Measurement Instrument) have been used to study the origins and trajectories of suspended particles of dust storms from wind erosion during the warm period in 2010.According to HYSPLIT Model, during their move from their source areas to the downwind ones, dust particles could arrive at city of Ahvaz in different directions: (a) NW-SE (the dust particles are transported from north western region of Iraq and eastern Syria), (b) W-E (the dust particles are transported from central parts of Iraq to the south western and western parts of Iran). Also, inspecting dust emission potential with the aerosol index data from Ozone Measurement Instrument (OMI) shows a persistent intense dust activity in north western parts of Iraq and eastern Syria, hitting South-West of Iran, especially the city of Ahvaz. As a result, the main origins of dust particles in the city of Ahvaz include north west Iraq as well as east Syria.
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