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Adsorption of Copper (II) Ions from Aqueous Solution onto Activated Carbon Prepared from Cane Papyrus Full text
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.
Show more [+] Less [-]Daytime Ozone Variation in Surface Air in a Subtropical Mangrove Estuary at Manakudy, South India Full text
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
Show more [+] Less [-]Upgrading the Performance of Urban Wastewater Facultative Ponds by changing to Attached Baffled Process Full text
2018
Sasani, Hossein | Mehrdadi, Naser | Aminzadeh, Behnoush | Takdastan, Afshin
This study aims at evaluating the improved facultative ponds performance in pilot scale. Wastewater has been collected from primary settling basins of Ahvaz wastewater treatment plant. Treatment efficacy of the four systems (three systems in parallel with a control system) has been evaluated over a period of 12 months at various hydraulic retention times (HRT) and organic loading rates (OLR). There has been no baffle and no attached growth media (AGM) in the control system (S0), while other three systems (S2, S3, and S4) have been equipped with different numbers of baffles and AGM packages, containing the mineral shells. Results show that efficiency of BOD5 removal for S0, S2, S3, and S4 are 53.4%, 60.8%, 64.7%, and 67.6%, respectively, while for COD these rates alter to 28.1%, 37.7%, 45.8%, and 50.1 % and of coliform to 66.7%, 76.6%, 80.7%, and 83.4%. Filtered BOD5 in the effluent of S0, S2, S3, and S4 is 32.5, 27.6, 24.6, and 22.3 mg/l, respectively and 60.2, 52.1, 47, and 44.3 mg/l for TSS. Also the 10-day HRT has been optimum among applied HRTs. As such, attached growth-baffled ponds function better than conventional ones, making the technique, examined in the present paper a low-cost process to establish new wastewater treatment plants or upgrading the existent WSPs, especially in case of warm areas of southwestern Iran.
Show more [+] Less [-]Estimation of Annual Effective Dose of 222 Rn and 220 Rn in indoor Air of Rohilkhand region, Uttar Pradesh state, India Full text
2018
Rastogi, N. | Singh, I. | Goswami, V.
The annual exposure to indoor radon and thoron imparts a major contribution to inhalation doses received by the public. In this study, we report results of time integrated passive of indoor radon and thoron concentrations that were carried out in Rohilkhand region with health risk to the dwellers in the region. In present study, Solid State Nuclear Track Detectors (SSNTDS ) based twin chamber dosimeter with LR-115 track detector were used for estimating Radon (222Rn) and Thoron (220Rn) gas concentration levels in the dwellings of Moradabad city. The average Radon and thoron concentration levels in the studied dwellings were found to vary from 13.5 to 21.8 Bq m-3 and thoron concentrations is found to vary from 11.7 to 19.5 Bqm-3 and its corresponding geometric mean of equilibrium-equivalent 222Rn and 220Rn concentration were found 7.07 to 1.7 Bqm-3 . The total annual effective dose due to the exposure to radon and thoron was found to vary from3.7 to 6.2 mSv/y whereas from thoron found to vary from 0.3 to 0.61 mSv/y.
Show more [+] Less [-]Evaluation of natural radioactivity of soil samples from different regions of Wassit governorate Full text
2017
Najam, Laith | Karim, Mahmood | Hameed, Taghreed
The present paper measures natural radioactivity in different areas of Wassit governorate, using (HPGe) detector. Gamma spectrum analysis for each sample along with caululated specific activity show that the average concentrations of U-238, Th-232, and K-40 have been 19.420±4.7 Bq/kg, 18.487±5.05 Bq/kg, and 204.266±46.9 Bq/kg respectively, which is lower than the worldwide average value. While the average value of Radium equivalent, absorbed dose, indoor and outdoor annual effective dose, activity index, and internal and external hazard index for each sample have been found to be 85.182 Bq/kg, 39.962 nGy/h, 0.196 mSv/y, 0.049 mSv/y, 0.374, 0.313, 0.309, and 0.230 respectively, all of them are lower than the permissibility limit value.
Show more [+] Less [-]Determination of nitrate utilization efficiency of selective strain of Bacillus sp. isolated from Eutrophic Lake, Theerthamkara, Kasaragod, Kerala Full text
2017
Usharani, K. | Sruthilaya, K. | Divya, K.
Nitrate pollutants increase the growth of algal bloom, resulting in fresh water eutrophication. The high nitrogen level in wastewater has become a growing concern, which has risen the necessity to develop efficient nitrogen removal techniques. Biological denitrification, which is the reduction of oxidized nitrogen compounds like nitrate or nitrite to gaseous nitrogen compounds, is the most important and widely used method to treat nitrate wastes as it enables the transformation of nitrogen compounds into harmless nitrogen gas. As such, this study collected samples from Eutrophic Lake, picking isolates of bacterial strain with good growth rates in the nitrate medium. The selected bacterial strains were cultured on media 1and 2 and by means of UV-visible spectrophotometer, the nitrate removal efficiency and growth were detected at 410 nm and 600 nm OD respectively. After comparing three bacterial strains, it was found that RN1 had a higher efficiency in nitrate removal at 1000ppm nitrate concentration. At an optimum temperature of 37°C, pH of 7, and agitation of 121 rpm, after 432 hrs of the treatment, RN1 showed an optimum growth, equal to 0.1859 OD in 1000ppm nitrate solution with dextrose. Also the spectral analysis of RN1 strain showed 85% removal efficiency, thus making this strain the best one. Confirmed and identified as Bacillus species, it can be recommended for the bioremoval process of nitrate from wastewater.
Show more [+] Less [-]Growth-phase dependent biodesulfurization of Dibenzothiophene by Enterobacter sp. strain NISOC-03 Full text
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.
Show more [+] Less [-]Evaluating the application of wastewater in different soil depths (Case study: Zabol) Full text
2017
Shojaee, Saeed | Zehtabian, Gholamreza | Jafary, Mohammad | Khosravi, Hasan
Water scarcity, its necessity in food production, and environmental protection in the world have forced human beings to seek new water sources. Nowadays, application of unconventional water resources (wastewater) has been proposed in countries facing the crisis of water resources shortage; however, a few studies have dealt with this issue. The present study has evaluated the changes in the elements of the soil, irrigated with wastewater. For so doing, an experiment has been conducted on a randomized complete block design with three replications. Soil samples have been collected from the studied regions at two depths of 0-30 cm and 30-60 cm and the studied parameters have included sodium, total calcium, magnesium, some acidity, and electrical conductivity of the soil. Three regions of study (namely no irrigation, irrigation with treated wastewater, and irrigation with river waters) have been taken into consideration. Results have shown increased calcium, magnesium, and pH of the effluent from Zabol Wastewater Treatment Plant compared to the control; however, electrical conductivity and chloride have decreased in wastewater-irrigated soil. The electrical conductivity in the surface layer of wastewater samples, treated with an amount of 2.25 (ds/m), has had the most significant difference to the control and other treatments. It can be concluded that wastewater increases some soil properties, contributing to its restoration.
Show more [+] Less [-]Tropospheric Ozone Pollution in Some Major Cities of West Africa and its Relationship with Atmospheric Circulations Full text
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.
Show more [+] Less [-]Community’s perception of utilization and disposal of plastic bags in Eastern Ethiopia Full text
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.
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