خيارات البحث
النتائج 671 - 680 من 62,157
Assessment Sugar Factories Wastes’ Performance on Wind Erosion Control
2018
Sabzi, masume | Asgari, H.R. | Afzali, S.F.
Wind erosion is considered a major global environmental problem. Dust storms from the migration of sand dunes can seriously damage civil, industrial, and agricultural areas and a method to stabilize these sand dunes is mulching. The present study investigates the feasibility of using organic wastes of Press mud and Dunder with clay for the production of environmentally-friendly mulches. Sandy soil from the Dejgah Region, Fars Province, has been used as bed treatment. The treatments have been prepared, using different ratios of the above mentioned materials and 250 ml of water has been added to the each mulch combination to be sprinkled on a plot of sand, 50 × 30 × 1 cm in size. The research has measured Mechanical parameters such as Compressive Resistance (CR), Abrasion Resistance (AR), and Impact Resistance (IR), created by mulches, along with Wind Erodibility (WE) of the treatments and has analyzed the resultant measured data by means of SPSS software. An increase in the fraction of organic wastes has significantly increased CR, IR, and AR values, thus reducing WE. Higher amounts of organic matter and clay increase the CR and the application of 100g Dunder plus 100g Clay has been considered the best composition of organic mulch for stabilization of sand dunes.
اظهر المزيد [+] اقل [-]Physiological Evaluation of Apricot (Prunus armeniaca L.) Leaves to Air Pollution for Biomonitoring of Atmospheric Quality
2018
zouari, M. | Elloumi, N. | Mezghani, I. | labrousse, P. | Ben Rouina, B. | Ben Abdallah, F. | Ben Ahmed, C.
Industrialization releases significant amounts of various air pollutants such as F, Cd, Pb, particulate matter, etc., which can in turn have a deleterious effect on a variety of biochemical and physiological processes as well as the structural organization within the cells. Responses from plants species to air pollutants is varied with certain species being very sensitive to such pollutants, ending up with well visible and measurable symptoms. Morphological damage is generally visible through lesions on the aerial parts, while biochemical and physiological changes which are invisible can be measured and quantified. This study has been designed to investigate the biochemical and physiological biomarkers of apricot (Prunus armeniaca L.) exposed to air pollution. It has been observed that, in comparison to unpolluted sites, lipid peroxidation level has increased in the leaves of apricot trees, grown in polluted areas, whereas photosynthetic capacity (Net photosynthesis, stomatal conductance, transpiration rate, total chlorophyll, and carotenoids) along with osmotic regulator (proline and soluble sugars) levels have declined. In P. armeniaca leaves, these symptoms can be used as indicators of air pollution stress for its early diagnosis, making them a reliable marker for a particular physiological disorder.
اظهر المزيد [+] اقل [-]Influence of In-Situ Scaling on Variability of Polluted Soil Erodibility Parameters
2018
Al-Madhhachi, A. T. | Hasan, M. B.
Middle and southern Iraq suffers from polluted soils due to crude oil, spilled on land, leakage from transmitting pipe networks, or petroleum products from refineries. Many researchers have studied pollution impacts on the soil in details, but there is a clear lack of investigation on the influence of crude oil on soil erodibility. Recent researches have investigated the influence of pollution on erodibility parameters, which include critical shear stress (τc) and detachment factor (dc). The variability of dc and τc due to different in-situ scaling has not been thoroughly established for polluted and unpolluted soils. Thus this research aims at investigating the influence of different in-situ scaling ratios (1:1, 1:30, and 1:50) on variability of dc and τc for polluted and unpolluted soils under controlled laboratory conditions, using Jet Erosion Test (JET), and tries to compare the three solution techniques (namely, Blaisdell’s approach, depth scour approach, and iterative approach) to solve dc and τc from JETs for polluted and unpolluted soils. The polluted soil samples have been prepared by submerging the soil surface with crude oil for 24 hours prior to testing. Results show that there have been statistical differences in dc and τc between polluted and unpolluted soil samples on the dry side of water contents with no statistically significant difference of measured dc and τc being observed across different in-situ scale ratios for polluted and unpolluted soils. All told, the study shows less variability of measured dc and τc across different solution techniques, compared to previous study findings.
اظهر المزيد [+] اقل [-]Adsorption of Copper (II) Ions from Aqueous Solution onto Activated Carbon Prepared from Cane Papyrus
2018
Alatabe, M. J.
The present study evaluates the suitability ofactivated carbon, prepared from Cane Papyrus, a plant that grows naturally and can be found quite easily, which serves as a biological sorbent for removal of Cu2+ ions from aqueous solutions. Fourier transform infra-red analysis for the activated carbon, prepared fromCane Papyrus confirms the presence of amino (–NH), carbonyl (–C=O), and hydroxyl (–OH) functional groups with Bath mode getting used to investigate the effects of the following parameters: adsorbent dosage (among the rates of 10, 20, and 30 g/L), pH values, Cu2+ initial concentration, and contact time. Results reveal higher efficiency (98%) of powdered adsorbent for removal of Cu2+ ions, which is found at pH=6 with 30 g/L activated carbon, prepared from Cane Papyrus, for a duration of 2 hours. The Freundlich isotherm model with linearized coefficient of 0.982 describes the adsorption process more suitably than the langmuir model, in which this rate equals to 0.899. Pseudo-second order kinetic equation best describes the kinetics of the reaction. Furthermore, it has been found that 0.5M HCl is a better desorbing agent than either 0.5 M NaOH or de-ionized water. The experimental data, obtained, demonstrate that the activated carbon prepared from Cane Papyrus can be used as a suitable adsorbent for Copper(II) ion removal from aqueous solutions.
اظهر المزيد [+] اقل [-]Industrial waste disposal alternatives in the process of aromatic compounds in petrochemical industry (case study: Nouri petrochemical complex, Asaluyeh, Iran
2018
Heidari, L. | Jalili Ghazizade, M. | Salemi, A.
Application of aromatic compounds has dramatically increased as raw materials in various industries and different factories have been established to produce aromatic compounds. The current research aims at characterizing industrial waste generation in aromatics production process in petrochemical industries and determining the best feasible alternative for waste disposal. For this purpose, the world’s biggest aromatic producer, i.e. Nouri Petrochemical Complex (NPC), located in Asaluyeh, Iran, has been selected as case study. Firstly, different waste streams, generated during aromatics production, have been determined through a specific checklist. Spent industrial soil, catalyst, spent sieve, and Normal-Formyl-Morpholine (NFM) solvent are the most important identified wastes in NPC, with the former being the most generated waste in NPC with a rate of 600 tons per year. Afterwards, the mentioned waste has been sampled and important physicochemical specification such as heavy metals and organic compounds has been measured. Ni, Cu, and As are remarkable trace heavy metals, observed in all kinds of generated waste. In the next step, industrial waste classification and coding has been done, based on different guidelines. Finally different feasible alternatives like material recovery, sanitary landfill, and incineration have been compared, based on conventional economic, technical, and environmental indices. The best feasible waste disposal methods are the extraction of heavy metals from spent catalysts, recycling of spent molecular sieves and spent industrial soil as additives to building materials, and recovery of thermal energy by incineration of spent NFM solvent.
اظهر المزيد [+] اقل [-]Daytime Ozone Variation in Surface Air in a Subtropical Mangrove Estuary at Manakudy, South India
2018
Krishna Sharma, R. | Chithambarathau, T | Elampari, K. | Nagaveena, S.
Surface ozone (SOZ) can be very harmful if it exceeds the threshold limit. It can accumulate over sea and can return back to the land along with the breeze. Rural and vegetation rich areas often record elevated levels of surface ozone because of the variations in Volatile Organic Compound (VOC) levels, wind velocity and direction. Similarly methane is also an important greenhouse gas and plays a vital role in the atmospheric budget. In this work, ozone and methane levels measured during daytime in a mangrove estuary near Manakudy(8.0911 N, 77.477 E),kanyakumari, South India for a period of ten months from March 2014 to December 2014 are analyzed.SOZ showed an imprecise diurnal pattern with an early morning peak whereas methane recorded an apparent diurnality. The maximum value of SOZ was around 50 ppb. Summer months recorded high levels of SOZ followed by Southwest monsoon (SWM) and Northeast monsoon (NEM).High levels of methane were found in SWM followed by NEM and low concentration during summer. The correlation between SOZ and methane was found as r = -0.257, p
اظهر المزيد [+] اقل [-]Anthropogenic share of metal contents in soils of urban areas
2018
Fazeli, G. | Karbassi, A.R. | khoramnejadian, Sh. | Nasrabadi, T.
In the present investigation, 41 soil samples were subjected to single step chemical partitioning to assess the lithogenic and non-lithogenic portions of metals in Tehran's soils. The share of various studied metals in the anthropogenic portion ranges from as low as 0.2% to as high as 85% of bulk concentration. Geo-accumulation index (Igeo) showed that Cd falls within "heavily contaminated" soils. It might be inferred that Ni, Cu, Cr, Zn, Co and Ca fall within "Deficient to minimal" class in accordance with enrichment factor (EF) classification.. Enrichment factor values (to some extents) match with the chemical partition studies results (except for Ni and Cr). The very low Ca content of soil samples could be indicative of low biological productivity in the Tehran's soil. Also the very low concentrations of Mn could be indicative of reducing environment in soils of Tehran.
اظهر المزيد [+] اقل [-]Levels of natural radioactivity in environment in residential area of Moradabad District, Western Uttar Pradesh
2017
Rastogi, Nikhil | Singh, Indu
Indoor radon and thoron have been measured in the houses ofMoradabad District, Uttar Pradesh India, by means of solid state nuclear trackdetectors. Radon, an invisible radioactive gas, occurs naturally in indooratmospheres and along with thoron is the most important contribution of humanexposure to natural sources. Radon exists in soil gas building materials and indooratmosphere to name but a few. Risk of lung cancer depends on the concentrationof radon and thoron and their decay products in the environment aboverecommended levels. The present article measures the concentration of indoorradon and thoron in 60 dosimeters by means of a solid state nuclear track detectorin different house types of Moradabad district, Uttar Pradesh. The measurementshave been carried out in residential buildings at a height of 2 m from the sea level,using a twin chamber radon dosimeter. The value of radon concentration in thepresent study varies between 10.5 Bq/m3 and 29.5 Bq/m3 with an average of 19.8Bq/m3 while that of thoron is between 5.6 Bq/m3 and 24 Bq/m3 with an average of14.9 Bq/m3 respectively. Results, obtained with twin cup radon/thoron dosimeter,show that the concentration of indoor radon and thoron have been within therecommended level, with all the values staying under the safe limits, decreed bythe International Commission on Radiological Protection (ICRP) and UnitedNations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR).
اظهر المزيد [+] اقل [-]Evaluation of Cadmium Removal from the Water in Phytoremeiation Process Using Eichhornia crassipes
2017
Asrari, Elham | Avatefi Nezhad, Goltab
Conserving water resources and protecting them from pollution are of high account in the natural cycle of our life. This study has tried to determine the refining potential and capacity of water hyacinth (Eichhornia crassipes) in order to remove the cadmium from water, studying the influence of factors such as initial concentration of cadmium, contact time, absorbent mass, and pH. Results have shown that the best efficiency of cadmium, more than 99%, was obtained in the optimum conditions (i.e. retention time of 30 hours, adsorbent dose of three plants (12 stems), and pH=6.6). By increasing the initial concentration of cadmium from 0.28 to 8.28 mg/L, the elimination efficiency did not change; moreover, by increasing the absorbent mass, the elimination efficiency increased from 98.4 to 99.8 and the lowest retention time was obtained for the balance. All experiments have been repeated three times, showing in the end that water hyacinth is able to absorb cadmium up to 8.28 mg/L. This process follows Freundlich isotherm (R2=0.98). Results of this study indicate that this plant can grow well at high levels of cadmium and the growth of water hyacinth is better in the presence of cadmium than control conditions (city water). Finally, it can be concluded that it is necessary to provide a reliable, cheap, and fast method to eliminate pollution. Eichhornia crassipes, a promising plant with great functionality, can be used as a refiner in order to eliminate the heavy metals in wastewater (sewage) effluents, particularly industrial sewage.
اظهر المزيد [+] اقل [-]Utilization of temple floral waste for extraction of valuable products: A close loop approach towards environmental sustainability and waste management
2017
Singh, Pardeep | Borthakur, A. | Singh, R. | Awasthi, Sh. | Pal, D.B. | Srivastava, P. | Tiwary, D. | Mishra, P.K.
This study presents the natural dye recovery from various biodegradable temple and household wastes. The raw material for colour extraction consisted residual flowers and garlands from various temples as well as onion and vegetables peels from vegetable markets, university hostels, and households, which were washed, dried, crushed, and sieved. The extracted natural colours were produced by means of ultra-sonication, and were dried in the spray drier, being characterized by FT-IR and UV-Vis Spectrophotometers. They were used to dye various fabrics such as cotton, silk, and wool, not to mention different mordents. It was found out that the remaining residue, left after dye extraction, was rich in nutrients, hence, it could be further used as the resource material, itself. As a result, we explored these residual wastes for vermicomposting and biochar production, which can be further employed as an organic fertilizer for agriculture. Overall, the present waste management approach will lead to a closed-loop environmental management through waste reduction and reutilization. It will also provide value-added materials for economic gains from waste. Thus, it can be promoted as a potential mechanism to maintain the environmental sustainability at wider scales.
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