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Impact of fertilizers on the uptake of 226Ra, 232Th, and 40K by pot-grown rice plants
2016
Alsaffar, Mohammed | Suhaimi Jaafar, Mohamad | Ahmad Kabir, Norlaili | Ahmad, Nisar
Fertilizers usually enhance potassium (K) content and other naturally occurring radioactive materials in agricultural fields that eventually enter the human food chain through plants. In this study, pot-grown rice plants planted in soil that is relatively high in natural radioactive content was used to estimate the individual influence of fertilizer applications on the uptake of 226Ra, 232Th, and 40K using gamma-ray spectrometry. Three types of common fertilizers used in rice cultivation (with percentages) 17.5N:15.5P:10K, 17N:3P:25K+2MgO, and 46N (i.e., urea) were separately added to the potted-rice plants which were in three different growth stages: emergence stage (10 days), maximum tillering stage (40 days), and initiation stage (70 days). Fertilizers at various concentrations (0, 100, 200, 300, and 400 mg kg–1) were applied in the first stage of plant growth, whereas only 200 mg kg–1 fertilizer was applied in the second and third stages. Results showed that the uptake of 226Ra, 232Th, and 40K by rice grains was affected by different concentrations of fertilizer and its application time. However, these findings suggested insignificant health risk related to the ingestion dose of grains treated with selected fertilizers.
Показать больше [+] Меньше [-]A prediction distribution of atmospheric pollutants using support vector machines, discriminant analysis and mapping tools (Case study: Tunisia)
2016
Bedoui, Souhir | Gomri, Sami | Samet, Hekmet | Kachouri, Abdennaceur
Monitoring and controlling air quality parameters form an important subject of atmospheric and environmental research today due to the health impacts caused by the different pollutants present in the urban areas. The support vector machine (SVM), as a supervised learning analysis method, is considered an effective statistical tool for the prediction and analysis of air quality. The work presented here examines the feasibility of applying the SVM to predict the ozone and particle concentrations in two Tunisian cities, namely Tunis and Sfax. We used the SVM with the linear kernel, SVM with the polynomial kernel and SVM with the RBF kernel to predict the ozone and particle concentrations in Tunisia for one year. The RBF kernel produced good results for the two pollutants with 0% error rate. Polynomial and linear kernels produced sufficiently low errors for the pollutants, at 9.09% and 18.18%, respectively. Discriminant Analysis (DA) was selected to analyze the datasets of two air quality parameters, namely ozone O3 and Suspended Particles SP. The DA results show that the spatial characterization allows for the successful discrimination between the two cities with an error rate of 4.35% in the case of the linear DA and 0% in the case of the quadratic DA. A thematic map of Tunisia was created using the MapInfo software.
Показать больше [+] Меньше [-]DO-BOD modeling of River Ganga from Devprayag to Roorkee, India using BMKB model
2016
Bhutiani, Rakesh | Khanna, D.R.
The idea of systems analysis and mathematical modeling for formulating and resolving river pollution issues is of relatively recent vintage and has been applied widely in the last 3 decades. The present study illustrates the utility of Beck-modified Khanna–Bhutiani model (BMKB) to determine the pollution load due to the presence of organic matter in River Ganga from its course from Devprayag to Roorkee through the holy city of India, Haridwar. The study was conducted over a period of 3 years between 2010 and 2013. The study was aimed to verify the BMKB model for River Ganga. This model was simulated and calibrated through the data obtained by model by comparing it with the field data observed manually. Paired T-test were performed for dissolved oxygen (DO) and biochemical oxygen demand (BOD) between the titrated value and modelled value to determine if there was any statistically significant difference between the means of respective values. The results of T-test revealed statistically significant difference between DO and BOD, i.e., DO t (11)= 3.819, P= 0.003, BOD t(11)= 14.635, P= 0.000. The model presented with a good agreement between the calibrated and observed data, thereby actualizing the validity of the proposed model.
Показать больше [+] Меньше [-]Analysis of Chemical and Microbial Contents of Public Swimming Pools’ Water in Akwa Ibom State, Nigeria
2016
Antia, Mfon | Umoh, Akaninyene
This study assessed the chemical and microbial contents in the water of public swimming pools in Akwa Ibom State, Nigeria. A total of 16 public pools were selected through probability sampling from the 32 pools that existed in the five urban areas of Akwa Ibom State. Water samples were collected from the sampled pools and tested in the laboratory for chemical and microbial contents. Results showed that the chemical contents of most pools in the study area were less than the values recommended for effective disinfection of the pools. Average free chlorine ranged from 0.05 mg/L to 1.15 mg/L 200 Cfu/ml permissible, except for pools L and M, with 1.8×102 Cfu/ml and 1.7×102 Cfu/ml, respectively. Mean fecal coliform ranged from 2.0×103 Cfu/ml to 4.4×103 Cfu/ml >10 Cfu/100 ml permissible, except for pools L and M, with 0.0 Cfu/ml. It could therefore be concluded that only one out of every eight public swimming pools in Akwa Ibom State meet the minimum requirement for both chemical and microbial contents. This simply implies that most public swimming pools in the study area are not safe for users.
Показать больше [+] Меньше [-]Isolation and characterization of diesel-degrading Pseudomonas strains from diesel-contaminated soils in Iran (Fars province)
2016
Niazy, Zahar | Hassanshahian, Mehdi | Ataei, Ahmad
In this study, among the 21 diesel-degrading bacteria that were isolated from an oil-polluted area in Fars (Iran), 6 bacterial strains were tested for their capability to metabolize and grow on diesel oil by degrading its hydrocarbons content. The biochemical characteristics and 16S rRNA sequence analysis of diesel-degrading bacteria showed that these strains were related to the genus Pseudomonas. Among the six isolates, five strains (L1, I2, D1, D2, and G1) were clustered with Pseudomonas aeruginosa, whereas only one strain (K3) was clustered with Pseudomonas fragi. Gas chromatographic (GC) analysis of the diesel oil that was remaining in the culture medium after 10 days of culture at 30°C showed that P. aeruginosa I2 presented the highest growth rate and diesel-oil degradation (88%) between all isolates. P. aeruginosa I2 also presented the best emulsification activity, but the best hydrophobicity was seen in P. aeruginosa G1. By applying these bacteria in bioremediation processes, diesel oil contamination in soil can be counteracted.
Показать больше [+] Меньше [-]Alterations in the Plasma Thyroid and Cortisol Hormones in Yellowfin Sea bream, Acanthopagrus latus, following exposure to Benzo(α)Pyrene
2016
Alijani Ardeshir, Rashid | Rastgar, Sara | Movahedinia, Abdol-Ali | Yarahmadi, Zahra
The goal of this research is to study the effect of benzo-alpha-pyrene (BαP) as a pollutant on the plasma levels of cortisol, thyroxin (T4), and triiodothyronine (T3) hormones, and the T3/T4 ratio in the yellowfin sea bream, Acanthopagrus latus. The BαP (50 mg kg-1) in vegetable oil was peritoneally injected. Blood samples were obtained from the treated and control groups after 3 and 72 hr, respectively. The amounts of cortisol, T3, and T4 were measured using the ELISA techniques. The results showed that during both the 3 and 72 hr BαP exposures, the T4 hormone levels significantly decreased, although the cortisol levels increased (P<0.05). However, the T3 hormone levels and T3/T4 ratios compared with their control groups showed a significant difference just after 72 hr (P<0.05). The disruptive effects of the BαP exposure on T4 was stronger than that on the T3, being more evident in long-term stress. Thus, the BαP exerts a significant effect on the thyroid endocrine system and consequently on fish metabolism and growth.
Показать больше [+] Меньше [-]Contamination by trace elements of agricultural soils around Sidi Bou Othmane in abandoned mine tailings in Marrakech, Morocco
2016
Yassir, Barkouch | Sana, El Fadili | Alain, Pineau
This study was carried out for the purpose of investigating the issue of tailings dams as a potential source of contamination by trace elements in soils at the Sidi Bou Othmane mine in the Marrakech Region, Morocco. Soil samples taken from depths of up to 15 cm and within a radius of 50 m from the tailings dams, were analyzed for Cd, Cu, Pb and Zn using atomic absorption spectrometry. Average concentrations of Cd, Cu, Pb and Zn in soils around the abandoned tailings dams were, respectively, 157.2±8.8, 969.1±38.7, 1640.7±42.7 and 2846.8±84.6 mg/kg. Soils in the vicinity of the decommissioned tailings dams registered increased values for Cd, Cu, Pb and Zn. Contamination factors (CF) and pollution index (PI) were calculated in order to estimate the anthropogenic contribution of target pollutants which determined Cd, Cu, Pb and Zn as the main pollutants in this region. The results revealed the polluted areas in the vicinity of the mine, especially two rural communities apparently linked to the lack of appropriate measures to counteract the effects of these mine tailings, which were causing a progressive contamination of the soil with residues of heavy metal emissions in this region under study. Improved strategies for the management of tailings, among other factors, might have influenced the reduced level of contamination by trace elements at the abandoned mine tailings dam sites.
Показать больше [+] Меньше [-]Trend of Groundwater Quality Changes, Using Geo Statistics (Case Study: Ravar Plain)
2016
Babakhani, Maral | Zehtabian, Gholamreza | Keshtkar, Amir Reza | Khosravi, Hassan
Groundwater aquifers are an important source of water supply for agriculture, industry and drinking. The present study investigates the changes in the quality of groundwater using geostatistical methods in the Ravar plain during a 10-year period. In this study, after selecting the appropriate spatial interpolation method to draw water quality parameters such as TDS, SAR and EC, zoning maps of Ravar plain were provided for three periods of time: the first period (2002-2005), an intermediate period (2006-2009) and the final period (2010-2012) in two seasons using ArcGIS 10.1. For this purpose, data were evaluated in GS+ 5.1 software, after calculation, the best model with the lowest estimated error was selected for zoning water quality parameters. Because of the lowest estimation error, Kriging, Gaussian and Spherical variogram models were selected as appropriate interpolation method for zoning the quality parameters. The results of the spatial analysis of TDS showed that TDS have been increased in the study area. Due to the amount of dissolved solids, EC amount was highly variable. According to the Wilcox classification, at the end of the period, water quality of agricultural was inappropriate in most of the area which represents the increase of electrical conductivity during the period.
Показать больше [+] Меньше [-]Antibiotics Removal in Biological Sewage Treatment Plants
2016
Ghosh, Gopal | Hanamoto, S. | Yamashita, N. | Huang, X. | Tanaka, H.
This study investigated the occurrence and removal of 12 antibiotics (ciprofloxacin, enrofloxacin, levofloxacin, norfloxacin, nalidixic acid, azithromycin, clarithromycin, roxithromycin, lincomycin, novobiocin, sulfamethoxazole, trimethoprim) at four sewage treatment plants (STPs): two STPs in Kyoto, Japan and two STPs in Beijing, China. The STPs differed in design and operation conditions, utilized a variety of secondary treatment processes. The antibiotics were frequently detected in influents and effluents, and ranged from ng/L up to lower μg/L. In influent, clarithromycin (1.1–1.6 μg/L) and levofloxacin (3.6–6.8 μg/L) were detected in the highest concentration in Japanese and Chinese STPs, respectively. The overall elimination of the antibiotics were differed between STPs and ranged from negative to >90%. These data demonstrate that there are detectable levels of antibiotics are discharging from STPs, and only some of these antibiotics are being removed in a significant proportion by STPs. It was also observed that biological nutrient removal based sewage treatment processes (anaerobic–anoxic–oxic: A2O; and anoxic–oxic: AO) have relatively higher antibiotics removal efficiencies than oxidation ditch (OD) processes.
Показать больше [+] Меньше [-]Municipal Solid Waste Management using GIS Application in Mirpur Area of Dhaka City, Bangladesh
2016
Islam, S. M. | Rahman, Syed | Hassan, Mahmud | Azam, Gausul
Identifying Municipal Solid Waste (MSW) disposal sites and appropriately managing them is a challenging task to many developing countries like Bangladesh. It is a complex issue in an urban area, as increasing population levels, rapid economic growth and rise in community living standard, accelerates the generation rate of MSW. The study area is zone-2 (Mirpur-Pallabi) of Dhaka North City Corporation (DNCC) (10.40 km2) is a residential area, from where about 353.34 ton/day solid waste is generated and among them about 57.43% were managed by DNCC. There are 41 different size containers present at 17 locations in study area. The existing site and waste collecting containers are not sufficient, which deteriorates the environment due to illegal waste dumping and about 15 illegal dumping sites were identified. To identify proper waste dumping site and prevent contamination, Geographical Information System (GIS) was used to propose an efficient scenario with relocating the existing waste collecting containers and another scenario was proposed with number of containers (73) to attain an 93.68% waste collection efficiency including optimization and selection of waste collecting routes for the study area. This study also indicate that the application of GIS is an efficient and low cost tool to study and select appropriate dumping site so as to facilitate decision making processes.
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