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Taguchi Optimization of Adsorptive Treatment of Effluent from Lead-acid Battery Recycling unit Using Pressmud-a Sugar Industry Waste Полный текст
2020
Meshram, S. | Thakur, C. | Soni, A. B.
Lead-acid battery recycling is one of the organized process which helps in overcoming the demand of lead for the production of the storage batteries. During recycling, a large amount of effluent is generated which contains lead beyond the permissible limit and harmful for the environment. This effluent was treated by adsorption as an alternative technique by using another waste (pressmud) as an adsorbent obtained from the sugar industry. Properties of the pressmud were determined through Fourier transform infrared spectroscopy, scanning electron microscope and X-ray diffraction analysis. Taguchi method L16 orthogonal array (4^3) was used for batch adsorption study for the parameters, initial pH, adsorbent dose and contact time. The optimum value for the adsorption of Pb(II) onto pressmud was found at effluent pH 4.5, adsorbent dose 1.0 g/50mL and time 240 min from the Signal-to-Noise ratio analysis. Kinetic and isotherm studies were also carried out to understand the mechanism of adsorption. Langmuir isotherm fitted best to the experimental data with R2=0.994 and kinetics of adsorption followed the pseudo-second-order model with R2=0.993.
Показать больше [+] Меньше [-]Application of Pollution Indices and Health Risk Assessment of Heavy Metals in the waters of a South-eastern Nigeria River Полный текст
2020
Anyanwu, E. D. | Adetunji, O. G. | Nwachukwu, E. D.
This study on the heavy metal content of a local drinking water source in South-east Nigeria was carried out in 3 sampling stations between May 2019 and October 2019. Pollution indices and health risk assessment for non-carcinogenic were used to check the water’s suitability for human consumption. The indices were heavy metal pollution index (HPI) and Contamination Index (Cd). Eight metals were evaluated with standard methods and compared with Nigerian and WHO drinking water standards. Some metals like iron, lead and cadmium exceeded the recommended limits. The stations Heavy Metal Pollution Index ranged between 511.4 and 512.4 while the monthly values ranged between 279.8 and 547.6; all exceeding the threshold value of 100. Contamination Index ranged between 3.12 and 3.32 (stations) and -0.80 to 4.80 (month) indicating high contamination potential and low to high contamination potentials respectively. All the hazard indices also exceeded one (1). Stations 1 and 2 were higher in all the indices. All the indices were linked the high values of iron, lead and cadmium, influenced by sand mining activities. The pollution indices and Health Risk Assessment converged to show that the waters of Iyiakwu River are not fit for human consumption. The children are more vulnerable since it the main source of drinking water in the area.
Показать больше [+] Меньше [-]Application of the Triangular Model in quantifying landfill gas emission from municipal solid wastes Полный текст
2019
Yusuf, R. O. | Adeniran, J. A. | Sonibare, J. A. | Noor, Z. Z.
Municipal solid waste landfills are significant parts of anthropogenic greenhouse gas emissions. The emission of significant amount of landfill gas has generated considerable interest in quantifying such emissions. The chemical composition of the organic constituents and potential amount of landfill gas that can be derived from the waste were determined. The chemical formulae for the rapidly biodegradable waste (RBW) and slowly biodegradable waste (SBW) were determined as C39H62O27N and C36H56O20N, respectively. The triangular method was used to calculate landfill gas obtainable from rapidly biodegradable waste over a 5-year period and for slowly biodegradable waste over a 15-year period. A plot was obtained for a landfill life span of 20 years. The volume of methane and carbon dioxide from RBW were 12.60 m3 and 11.76 m3 respectively while those from SBW were 6.60 m3 and 5.48 m3 respectively at STP. For the initial deposit of 2002 the highest landfill gas emission rate occurred in 2007 at 0.2829 Gg/yr with an average cumulative emission of 0.3142 Gg while for a landfill closed after five years the highest landfill gas emission rate was in 2010 at 1.2804 Gg/yr with an average cumulative emission of 1.5679 Gg while this cumulative emission will start declining by the year 2029.
Показать больше [+] Меньше [-]Study of seasonal and spatial variability among Benzene, Toluene, and p-Xylene (BTp-X) in ambient air of Delhi, India Полный текст
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.
Показать больше [+] Меньше [-]Efficiency of Washing Techniques for Removal of Heavy Metals from Industrial Sludge Полный текст
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.
Показать больше [+] Меньше [-]Influence of Copper Oxide Nanoparticle on Hematology and Plasma Biochemistry of Caspian Trout (Salmo trutta caspius), Following Acute and Chronic Exposure Полный текст
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.
Показать больше [+] Меньше [-]Degradation of Hydrocarbons and Lignin-like compounds by Alcaligenes sp. strain 3k isolated from Ilorin Полный текст
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.
Показать больше [+] Меньше [-]Estrous Cycle and Early Pregnancy of White Mice Exposed to Methomyl Полный текст
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.
Показать больше [+] Меньше [-]Simulating the Influence of Greenhouse Gases on the Climate of West Africa Полный текст
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.
Показать больше [+] Меньше [-]Assessment of Contamination Potential of Leachate from Municipal Solid Waste Landfill Sites for Metropolitan Cities in India Полный текст
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.
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