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881.
Srimurali Sampath Govindaraj Shanmugam Krishna Kumar Selvaraj 《Environmental Forensics》2015,16(1):76-87
This study analyzed the seasonal distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs) in the atmospheric environment of Tamil Nadu, India. Passive air sampling was performed at 32 locations during the period from April 2009 to January 2010, and PAHs were quantified using a gas chromatograph-mass spectrometer. Analysis showed that the concentrations of PAHs were in the range of 5–47.5 ng/m3 with uniform distribution in urban areas in all seasons. Pre-monsoon season showed the highest cumulative concentration of PAHs in both agricultural and coastal areas. Among PAHs, phenanthrene, fluoranthene, and pyrene levels were found to be predominant in all the samples, contributing up to 36%, 35.5%, and 24.5% of total PAHs, respectively. The signature of the PAHs obtained through diagnostic ratio and principal component analysis revealed that diesel emissions was the probable source of PAHs in all locations. Based on Word Health Organization guidelines, the human lung cancer risk due to observed level of PAH concentration (i.e., PAHs exposure) is meager. However, the risk is predicted to be more in the coastal area during summer (18 individuals among 0.1 million people). To the knowledge of these authors, this report is the first on the seasonal analysis of PAHs using passive air sampling in India. 相似文献
882.
Chandan Kumar Samanta Manoj Kumar Hota Satya Ranjan Nayak Bijay Ketan Panigrahi 《International Journal of Sustainable Engineering》2014,7(4):352-359
This paper deals with energy management in hybrid electric vehicles. Use of radial basis function neural network (RBFNN) for the problem of energy management gains importance in the present decade. Use of genetic algorithm (GA) and particle swarm optimization (PSO) as optimization algorithms for parameter estimation is also well known. However, none of the researchers in the area tried to use GA and PSO as training algorithms for the problem. Hence in this paper, we propose two novel methods, based on RBFNN. The difference between RBFNN-based approaches in the literature and those used in this paper is the use of GA and PSO (i.e. optimising algorithms) as training algorithm to train RBFNNs. Interestingly, it is seen that the proposed approaches of this paper outperform RBFNN-based approaches in the literature with traditional training. 相似文献
883.
884.
Shalini Singh Prem Dureja Sushil Kumar 《Journal of environmental science and health. Part. B》2013,48(3):337-346
Abstract The degradation of α and β isomers of endosulphan and endosulphan sulphate in four sterilized and non sterilized Indian soils under laboratory conditions was studied. Degradation was found to be more in non‐sterilized as compared to the sterilized soil. The half life of α‐endosulphan, β‐endosulphan and endosulphan sulphate was found to be 136.8, 273 and 301 days in sterilized Alfisol and 55, 256 and 277 days in non‐sterilized Alfisol, respectively. α‐Endosulphan degraded more readily than β‐endosulphan and endosulphan sulphate under both sterilized and non‐sterilized soil conditions. 相似文献
885.
P. Pal R. Kumar N. Srivastava J. Chowdhury 《Environmental science and pollution research international》2014,21(3):1833-1849
A Visual Basic simulation software (WATTPPA) has been developed to analyse the performance of an advanced wastewater treatment plant. This user-friendly and menu-driven software is based on the dynamic mathematical model for an industrial wastewater treatment scheme that integrates chemical, biological and membrane-based unit operations. The software-predicted results corroborate very well with the experimental findings as indicated in the overall correlation coefficient of the order of 0.99. The software permits pre-analysis and manipulation of input data, helps in optimization and exhibits performance of an integrated plant visually on a graphical platform. It allows quick performance analysis of the whole system as well as the individual units. The software first of its kind in its domain and in the well-known Microsoft Excel environment is likely to be very useful in successful design, optimization and operation of an advanced hybrid treatment plant for hazardous wastewater. 相似文献
886.
Ankur Rajpal Renu Bhargava A. K. Chopra Tarun Kumar 《Journal of Material Cycles and Waste Management》2014,16(2):219-226
The aim of the study was to examine safe reuse and recycling of organic waste digestate obtained from a biogas plant (5 % total solid) with enhanced nutrient value through vermitechnology. Two indigenous epigeic earthworm species Perionyx excavates and Perionyx sansibaricus were tried individually for this purpose. The results clearly show a significant increase in pH values from 6.5–7.4, electrical conductivity (21.3–21.7 %), total N (84.5–94.6 %), total P (35.9–47.1 %), total K (49.8–52.6 %), Ca (41.9–41.9 %) and a significant decrease in total organic C (17.1–22.4 %), C/N ratio (7.2–6.9), C/P ratio (20.3–20.6), COD (51.9–55.7 %), BOD (85.5–91.2 %). Similarly, indicator organisms (fecal coliforms and fecal streptococci) showed decrement at the end of the composting period (60 days). Fecal Coliforms reduce to nil, while in fecal streptococci a 6 log reduction was observed. Oxygen uptake rate dropped to 67.4–70 % for vermireactors. Overall, the aforementioned findings highlighted that the indigenous earthworm species could enhance the nutrient value of the anaerobic digestate, which could be utilized as an efficient soil conditioner. 相似文献
887.
Rajendran Muthuraj Manjusri Misra Amar Kumar Mohanty 《Journal of Polymers and the Environment》2014,22(3):336-349
Two biodegradable polyesters, poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) were melt-compounded in a twin screw extruder to fabricate a novel PBS/PBAT blend. The compatibility of the blend was attributed to the transesterification reaction that was confirmed by Fourier transform infrared spectroscopy. The Gibbs free energy equation was applied to explain the miscibility of the resulting blend. Dynamic mechanical analysis of the blends exhibits an intermediate tanδ peak compared to the individual components which suggests that the blend achieved compatibility. One of the key findings is that the tensile strength of the optimized blend is higher than each of the blended partner. Rheological properties revealed a strong shear-thinning tendency of the blend by the addition of PBAT into PBS. The phase morphology of the blends was observed through scanning electron microscopy, which revealed that phase separation occurred in the blends. The spherulite growth in the blends was highly influenced by the crystallization temperature and composition. In addition, the presence of a dispersed amorphous phase was found to be a hindrance to the spherulite growth, which was confirmed by polarizing optical microscopy. Furthermore, the increased crystallization ability of PBAT in the blend systems gives the blend a balanced thermal resistance property. 相似文献
888.
Carine Saison Natasha J. Waller Anu Kumar Rai S. Kookana 《Journal of environmental science and health. Part. B》2013,48(3):226-234
The impact of pesticides, namely thiobencarb (TBC), molinate (MOL) and chlorpyrifos (CPF), on soil microbial processes was studied in two Australian soils. Substrate induced respiration (SIR), substrate induced nitrification (SIN) and phosphatases and chitinase enzymatic activities were assessed during a 30-day microcosm study. The pesticides were applied to soils at recommended rates either alone, or as binary mixtures with TBC. Soil samples were sampled at 5, 15 and 30 days after pesticide treatments. Substrate induced respiration was only transiently affected by pesticides in both soils. In contrast, the process of indigenous nitrification was affected by the presence of pesticides in both soils, especially when the pesticides were applied as binary mixtures. Substrate induced nitrification increased with pesticides in the Griffith soil (except with MOL+TBC after 5 days) whereas SIN values were non-significantly different to the control on the Coleambally soil. The binary mixtures of pesticides with TBC resulted in a decrease in SIN in both soils, but the effects disappeared within 30 days. The enzymatic activities were not consistently affected by pesticides, and varied with the soil and pesticides studied. This study showed that, when applied at recommended application rates, TBC, MOL, and CPF (individually or as binary mixtures), had little or only transitory effects on the functional endpoints studied. However, further investigations are needed to assess the effect on microbial densities and community structure despite the low disturbance to the functions noted in this work. 相似文献
889.
Totan Adak Jitendra Kumar N. A. Shakil S. Walia 《Journal of environmental science and health. Part. B》2013,48(3):217-225
Amphiphilic copolymers, synthesized from poly (ethylene glycols) and various aliphatic diacids, which self assemble into nano-micellar aggregates in aqueous media, were used to develop controlled release (CR) formulations of imidacloprid [1-(6 chloro-3-pyridinyl methyl)-N- nitro imidazolidin-2- ylideneamine] using encapsulation technique. High solubilisation power and low critical micelle concentration (CMC) of these amphiphilic polymers may increase the efficacy of formulations. Formulations were characterised by Infrared (IR) spectroscopy, Dynamic Light Scattering (DLS) and Transmission Electron Microscope (TEM). Encapsulation efficiency, loading capacity and stability after accelerated storage test of the developed formulations were checked. The kinetics of imidacloprid release in water from the different formulations was studied. Release from the commercial formulation was faster than the CR formulations. The diffusion exponent (n value) of imidacloprid, in water ranged from 0.22 to 0.37 in the tested formulations. While the time taken for release of 50 % of imidacloprid ranged from 2.32 to 9.31 days for the CR formulations. The developed CR formulations can be used for efficient pest management in different crops. 相似文献
890.
Swapan Kumar Ghosh Sujoy Pal Sumanta Ray 《Environmental science and pollution research international》2013,20(7):4339-4355
Plastic is a broad name given to the different types of organic polymers having high molecular weight and is commonly derived from different petrochemicals. Plastics are generally not biodegradable or few are degradable but in a very slow rate. Day by day, the global demand of these polymers is sharply increasing; however, considering their abundance and potentiality in causing different environmental hazards, there is a great concern in the possible methods of degradation of plastics. Recently, there have been some debates at the world stage about the potential degradation procedures of these synthetic polymers and microbial degradation has emerged as one of the potential alternative ways of degradation of plastics. Alternatively, some scientists have also reported many adverse effects of these polymers in human health, and thus, there is an immediate need of a potential screening of some potential microbes to degrade these synthetic polymers. In this review, we have taken an attempt to accumulate all information regarding the chemical nature along with some potential microbes and their enzymatic nature of biodegradation of plastics along with some key factors that affect their biodegradability. 相似文献