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Study of seasonal and spatial variability among Benzene, Toluene, and p-Xylene (BTp-X) in ambient air of Delhi, India
2019
Garg, A. | Gupta, N.C. | Tyagi, S.K.
This study was carried out to analyze the variations of Benzene, Toluene, and para- Xylene (BTp-X) present in the urban air of Delhi. These pollutants can enter into the human body through various pathways like inhalation, oral and dermal exposure posing adverse effects on human health. Keeping in view of the above facts, six different locations of Delhi were selected for the study during summer and winter seasons (2016-2017). The concentrations of BTp-X on online continuous monitoring system were analyzed by chromatographic separation in the gaseous phase followed by their detection using a Photo Ionization Detector (PID). The concentrations of BTp-X were found maximum at a high traffic intersection area as 68.35±48.26 µg/m3 and 86.84±32.55 µg/m3 in summer and winter seasons respectively and minimum at a residential area as 4.34±2.48 µg/m3 and 15.42±9.8 µg/m3 in summer and winter seasons respectively. The average BTp-X concentrations of summer and winter seasons were found as 9.88, 20.68, 28.52, 49.75, 64.04, and 77.59 µg/m3 at residential, institutional, commercial, low traffic intersection, moderate traffic intersection and high traffic intersection areas respectively. Clearly, it has been found that the concentrations of these compounds were more on the traffic areas indicating that the vehicles are the major emission source. Hence, it may be concluded that the number of vehicles along with the high traffic congestion on the city streets and roads results in more accumulation of aromatic compounds and deteriorate the urban air quality.
显示更多 [+] 显示较少 [-]Efficiency of Washing Techniques for Removal of Heavy Metals from Industrial Sludge
2019
J., Sumalatha | B. P., Naveen | R. K., Malik
The effluent treatment plant sludge is one of the major sources of contamination with toxic metals. Since the sludge contains heavy metals, it must be pretreated to reduce the contamination. The heavy metals from the sludge can be reduced/ separated by washing it with a suitable leaching solution. In the present study, the efficiencies of three leaching solutions to remove the contaminants from an industrial sludge were studied and the leaching process was modeled. The leaching solutions used are 0.1 N HCl, 0.1 N EDTA and 0.1 N FeCl3. The efficiencies of leaching solutions were assessed by conducting column leaching experiments on the sludge and the migration rates of heavy metal ions of Cu, Zn, Ni, Cd, Pb, Fe and Cr present in the sludge were estimated. These migration rates are useful to estimate the quantity of leaching solution required at the site to achieve the required levels of concentrations in the sludge.
显示更多 [+] 显示较少 [-]Influence of Copper Oxide Nanoparticle on Hematology and Plasma Biochemistry of Caspian Trout (Salmo trutta caspius), Following Acute and Chronic Exposure
2019
Kaviani, E. F. | Naeemi, A. S. | Salehzadeh, A.
The Caspian trout is an endangered and quite vulnerable fish, considered for a natural protection program in the southern area of the Caspian Sea. Copper oxide nanoparticles (CuO-NPs) are toxic substances, which induce oxidative stress, not to mention other pathophysiological states. The toxicity of nanoparticles on fish needs more characterization for short- and long-term effects. Thus, the present paper examines the acute and chronic effects of CuO-NPs on hematology and plasma biochemistry of juvenile Caspian trout. After determining the lethal concentrations (LC50), juvenile Caspian trout is exposed to 0.1 LC5096 CuO-NPs for 28 days in three replicates. The blood samples are then collected from fish after 24, 48, 72, and 96 hours as well as 1, 2, 3, and 4 weeks of exposure to the CuO-NPsto deal with short- and long-term effects, respectively. Analysis of these samples shows that some hematological factors like hemoglobin (Hb), red blood cells (RBC), and hematocrit (Hct) are significantly increased after acute exposure, compared to the control group (p<0.05). The number of white blood cells (WBC), neutrophilis, and monocytes are also increased after acute and chronic exposure with significant differences (p< 0.05). Furthermore, the levels of lactate dehydrogenase after acute and alkaline phosphatase along with aspartate aminotransferase after acute and chronic exposure are significantly increased (p<0.05). Thus, results indicate that the presence of even a tiny amount of CuO-NPs can affect most haematological and metabolic enzymes of the Caspian trout in the short and long-term exposure. It is therefore essential to prevent these nanomaterials from entering the aquatic environment.
显示更多 [+] 显示较少 [-]Degradation of Hydrocarbons and Lignin-like compounds by Alcaligenes sp. strain 3k isolated from Ilorin
2019
Adetitun, D. O. | Fathepure, B. | Hugh, H. | Kolawole, O. M. | Olayemi, A. B.
The primary goal of this study was to isolate hydrocarbon-degrading organisms and assess their ability to bioremediate petroleum-contaminated soil and water. Nigeria is one of the major oil producing countries and petroleum contamination is widespread in agricultural soil. Alcaligenes sp. strain 3k was isolated from a kerosene-polluted soil in Ilorin, Nigeria. We also assessed its ability to degrade plant lignin, as lignin is a complex aromatic heteropolymer commonly found in soil and aquifer environment. Strain 3k was originally grown on mineral salts medium with kerosene as a sole energy and carbon source. The capacity of the isolate to degrade both aromatic, aliphatic hydrocarbons and lignin-like compounds was tested. Among the tested compounds, the organism utilized kerosene, hexadecane, cyclohexane, phenol and benzoate as the sole sources of carbon. In addition, strain 3k also degraded various lignocellulose compounds as the sole source of carbon. However, hexane, benzene, toluene, ethylbenzene and xylene were not metabolized. Our study demonstrates that soil organisms like Alcaligenes could play important role in the reclamation of petroleum-contaminated soil and water. Utilization capacity of lignin as the sole carbon source suggest that these organisms can survive on plant detritus and also have the ability to degrade hydrocarbons upon accidental or deliberate contamination of agricultural soil and water.
显示更多 [+] 显示较少 [-]Estrous Cycle and Early Pregnancy of White Mice Exposed to Methomyl
2019
Toledo, J. M. | Gamalo, L. E. | Maligalig, M. D. | Suetos, K. J. | Galapon, M.
Methomyl is an oxime carbamate pesticide that is widely used in the Philippines. This insecticide is known to be an endocrine disrupting chemical and a potent genotoxic in mammalian cells. However, limited studies were conducted specifically on its direct effects on estrous cycle and its teratogenic effect. This study aimed to (a) assess the effect of methomyl on the body weight and on the estrous cycle of mice, and; (b) examine the teratogenic effect of methomyl on the progeny of the female albino mice. Five week-old experimental mice in three treatment setups were used in the study for both independent experiments. The treatment schedule for pregnant mice was administered during organogenesis (day 6 to 15 of gestation). Results showed that the average gained weight of the mice of both high dose (HD) and low dose (LD) groups were lower as compared to the average gained weight of the control group but did not show any statistical significant differences (p=0.562). For the experiment 1, methomyl significantly (p=0.013) affect the estrous cycle of the mouse especially in LD group. For experiment 2, results revealed that there was a significant difference among the treatment set-ups (p=0.0001) in terms of fetal morphometric measurement. Furthermore, abnormality and high number of resorption was also observed in both LD and HD treatment groups. Therefore, methomyl significantly affect the body weight, estrous cycle and fetal morphometry. This further confirm that methomyl is an endocrine disrupting and genotoxic chemical that affects the estrous cycle and causes teratogenic effect.
显示更多 [+] 显示较少 [-]Simulating the Influence of Greenhouse Gases on the Climate of West Africa
2019
Adeniyi, M. O. | Nymphas, E. F. | Oladiran, E. O.
The response of climate to perturbations in GHGs is location dependent. Six experiments: control (CTRL); double CH4; double CO2; double N2O; halved CFC11 and halved CFC12 were carried out to reveal the local area response to different GHGs levels in the atmosphere over West Africa. Double CH4, CO2 and N2O generally induce wetness but they also induce localized dryness at the hilly and mountainous areas of SW Ghana, Central Nigeria, Northern Cameroon and South-eastern Central African Republic. Increase in ground temperature is induced by double GHGs with intensified warming at the north by double CO2. However, patches of cooling are induced at the north. Changes in specific humidity induced by double CO2, CH4 and N2O are similar. Intensified tropical easterly jet is induced by double GHGs. A dipole anomaly of wind with positive at the lower latitude and negative at higher latitude is induced at the northern part of West Africa. Significant reduction in cloud water content is induced from 900 to 400 hPa and 0 and 15oN.
显示更多 [+] 显示较少 [-]Assessment of Contamination Potential of Leachate from Municipal Solid Waste Landfill Sites for Metropolitan Cities in India
2019
B. P., Naveen | R. K., Malik
With increased population, rapid industrialization and life style changes, the characteristics and the rates of solid waste generation have gone under drastic change in India. Generally, in India, management of solid waste landfill is of major concern with respect to the existing circumstances. The illegal dumping of municipal solid waste on the outskirts of cities is creating major environmental and public health problems. Improper and unscientific waste management results in potential threats from leachate leakage with subsequent impact on environment (i.e. soil, air and waterbodies) and human being. It is therefore, important to evaluate the contamination potential threat of landfill leachate. This study assesses the potential contamination from the landfill leachate by an index called leachate pollution index (LPI) and suggestions are given the landfill sites of five major cities i.e. Bangalore, Chennai, Delhi, Navi Mumbai & Kolkata in India. The landfill leachate samples from these sites have been assessed using leachate pollution index for the implementation of appropriate leachate treatment techniques for reducing the adverse effects on the environment. The results show that the Pallikkaranai landfill site for Chennai city and Mavallipura landfill site for Bangalore city are highly deteriorating and may lead to increase in human health risk for nearby dwellings.
显示更多 [+] 显示较少 [-]Efficient Removal of Methylene Blue from Aqueous Solution by Adsorption on Cerium Vanadate Nanoparticles
2019
Dehghan Abkenar, Sh. | Hosseini, M. | Sadeghpour Karimi, M. | Ganjali, M. R.
Cerium vanadate nanoparticles (CVNPs) were used as a solid phase adsorbent for removing methylene blue (MB) from aqueous media. The nanoparticles were obtained through a direct precipitation procedure in aqueous solutions, and were characterized by X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). The results proved the product to comprise 25-45 nm particles. Batch adsorption experiments to determine the optimal adsorption conditions and the different factors which influence the adsorption efficiency (i.e. pH, amount of CVNPs, contact time, and the concentration of MB) were also evaluated. The experimental data were analyzed using the Langmuir and freundlich adsorption models.The data were satisfactorily fitted to the Langmuir model and a maximum adsorption capacity of 181.8 mg/g was obtained at pH of 3.0. Further kinetics studies were performed on the parameters. The adsorption of the model dye (MB) was found to reach equilibrium after 10 min, following a pseudo-second-order kinetic model. Desorption of the dye and recycling potential of the adsorbent was also studied.
显示更多 [+] 显示较少 [-]Uptake of Some Elements with Aquatic Plants Exposed to the Effluent of Wastewater Treatment Plant
2019
Tatar, S. | Obek, E. | Arslan Topal, E. I. | Topal, M.
In this study, in the removal of macro (P, S, Na, K, Ca, Mg) and micro (Sb, Ba, Co, Cu, Fe, Pb, Mn, Hg, Mo, Se, Ag, Zn) elements in the effluent of Elazig Wastewater Treatment Plant, the efficiency of Lemna minor L. and Lemna gibba L. has been studied comparatively. For this aim, fronds of these plants have been adapted to the effluent of the treatment plant that feeds pilot scale reactors. The concentrations of elements in fronds harvested during the working period were analyzed by ICP/MS. The analytical results show that Lemna minor L. has a high accumulation potential for P, Sb, Ba, Co, Fe, Pb, Mn, Hg, Ag and Zn while Lemna gibba L. has a high accumulation potential for S, Na, Ca, Mg, Cu, Mo and Se. The results show that Lemna minor L. and Lemna gibba L. can be used as phytoremediators of wastewater.
显示更多 [+] 显示较少 [-]Evaluating the Potential of Plants (leaves) in Removal of Toxic Metals from Urban Soils (Case Study of a District in Tehran City)
2019
Eghbal, N. | Nasrabadi, T. | Karbassi, A. R. | Taghavi, L.
Urban soil pollution has become a major concern in megacities around the world. Due to their non-degradable characteristic, toxic metals are among the most notorious pollutants. In this study determination of total and bioavailable fraction of toxic metals Ni, Cu, Cr, Zn, Co, Cd, Pb and Mn, in surface soils of district 16th in Tehran municipality is considered. Furthermore, metals uptake potential of a variety of endemic plants is also investigated. Forty one surface soil samples and eleven composite leaf samples were collected within the study area in winter 2015. Except for Cd and Pb, other toxic metals showed generally lower concentrations in comparison with shale and mean earth crust values. Intensified traffic load within the district may be considered as the main reason for such augmented concentrations. The order of bioavailable fraction from total metal concentrations detected to be as: Zn(2.78%) > Cd(2.71%) > Co(1.92%) > Mn(1.79%) > Cu(1.59%) > Pb(.89%) > Ni(.7%) > Cr(.4%). Concentration of different metals in leaf samples revealed that berry, eucalyptus, plane and acacia are more capable in comparison with others in translocating toxic metals from soil. Paying more attention to pollution removal capability of urban plants may play a key role in sustainable municipal management of megacities like Tehran.
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