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Particluate matter: research and management; Proceedings from the 2nd WeBIOPATR Workshop, Mokra Gora, Serbia 31.8.-2.9.2009 Полный текст
2009
Bartonova, Alena | Jovasevic-Stojanovic, Milena
The aim of the workshop was to provide a forum for discussion of new research results regarding particulate matter (PM), and atmospheric PM monitoring and management. Participants came from Serbia, Montenegro, Bosnia Herzegovina, Croatia, Turkey, Portugal, Hungary and Norway, representing research, managers and authorities. The workshop had four sessions: PM sources and source apportionment, Pollution trends and levels, Exposure and health, Air Quality Management. Inall, over 40 participants presented papers and posters from authors from 16 countries. A special number of the Serbian journal Chemical Industry and Chemical Engineering is being prepared. The workshop was supported from the We BIOPATR project (Research Council of Norway), and from the grant of the Ministry of Science and Technological Development of the Republic of Serbia.
Показать больше [+] Меньше [-]Longitudinal Survey of Female Faculty in Biological and Agricultural Engineering Полный текст
2009
Abadie, A. | Christy, A. | Jones, J. | Wang, J. | Lima, M.
Female faculty in biological and agricultural engineering (BAE) were surveyed in 1998 to examine their professional experiences, motivations, and insights. Approximately 7% of all BAE faculty were women in 1998, and the total number of women in the population was 57. Results, based on a 61% response rate, showed that 60% of the population was at the assistant professor rank. Respondents reported that BAE departments provided a supportive environment and believed that the attraction of women to BAE was due to its emphasis on biological systems, as well as biological engineering's relative newness and lack of long-standing stereotypes of male dominance. Full results of the original survey were published in the Journal of Women and Minorities in Science and Engineering in 2000. We re-surveyed the population of women in BAE in 2006 because we believe that longitudinal data on this population will provide interesting insights into this group and its experiences in the profession, and may suggest ways to increase female representation among engineering faculty. The population is now comprised of 89 women and represents approximately 11% of BAE faculty. Approximately 85% of all women in the original 1998 survey population are included in the current population. Reasons given by those exiting the population include staying in academia but moving to non-BAE departments such as chemical engineering or bioengineering, being promoted to academic leadership positions without retaining primary BAE status, or pursuing other non-academic professional opportunities. Forty-nine percent of the population are now assistant professors, and the number of BAE full professors increased from 10% in 1998 to 19% in 2006. A significant number of women BAE faculty have engineers and/or faculty members within their immediate families; two respondents are second-generation women engineers. The reported self-confidence level of women faculty is 65%, the same as the 1998 survey. Ninety-five percent of respondents act as mentors to others (up from 72% in 1998). Eighty-four percent of respondents do not feel that they have experienced space inequities, and 73% do not believe they have experienced salary inequities. Lack of support for dual-career couples and other family issues were mentioned by 48% of respondents as issues that could be addressed to improve the climate for women faculty in BAE; these issues were mentioned more often in 2006 than in 1998.
Показать больше [+] Меньше [-]Micromechanics of granular materials with capillary effects | Micromécanique des matériaux granulaires avec effets capillaires Полный текст
2009
Scholtes, Luc | Chareyre, B. | Nicot, François | Darve, F. | Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP) | Érosion torrentielle, neige et avalanches (UR ETGR (ETNA)) ; Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE | International audience | Based on discrete element simulations and micro-mechanical calculations, this paper presents studies on the shear strength properties of unsaturated granular materials with capillary effects. Capillary forces are described on the local scale, depending on the water content, and are superimposed on the standard dry particle interaction that is currently described through an elastic-plastic relation. Simulations of triaxial compression tests at several water-content levels in the pendular regime are used to investigate the macroscopic consequences of this local description. The two methods are in rather good agreement, both reproducing the dependency of shear strength on water content, as classically observed in laboratory experiments. For the water-content levels considered, a nonlinear evolution of the cohesion with the water content is obtained, resulting in shear-strength saturation with increasing water content. Moreover, the computations allow a capillary stress tensor to be exhibited from capillary forces, directly related to the cohesion of the material. Finally, emphasising this capillary stress contribution, the generalised effective stress concept is reviewed, with a conclusion on the limitations of the classical macroscopic description of water effects in unsaturated granular materials.
Показать больше [+] Меньше [-]Effect of Dye Concentration on Sequencing Batch Reactor Performance Полный текст
2009
Vaigan, A. A. | Moghaddam, M. R. Alavi | Hashemi, H.
Reactive dyes have been identified as problematic compounds in textile industries wastewater as they are water soluble and cannot be easily removed by conventional aerobic biological treatment systems. The treatability of a reactive dye (Brill Blue KN-R) by sequencing batch reactor and the influence of the dye concentration on system performance were investigated in this study. Brill Blue KN-R is one of the main dyes that are used in textile industries in Iran. Four cylindrical Plexiglas reactors were run for 36 days (5 days for acclimatization of sludge and 31 days for normal operation) at different initial dye concentrations. The dye concentrations were adjusted to be 20, 25, 30 and 40 mg/L in the reactors R1, R2, R3 and R4, respectively. In all reactors, effective volume, influent wastewater flowrate and sludge retention time were 5.5 L, 3.0 L/d and 10 d, respectively. According to the obtained data, average dye removal efficiencies of R1, R2, R3 and R4 were 57% ± 2, 50.18% ± 3, 44.97% ± 3 and 30.98% ± 3, respectively. The average COD removal efficiencies of all reactors were 97% ± 1, 97.12% ± 1, 96.93% ± 1 and 97.22% ± 1, respectively. The dye removal efficiency was decreased by increasing the dye concentration with the correlation coefficient of 0.997.
Показать больше [+] Меньше [-]Performance Evaluation Of Wastewater Stabilization Ponds In Arak-iran Полный текст
2009
Naddafi, K. | Hassanvand, M.S. | Dehghanifard, E. | Razi, D. Faezi | Mostofi, S. | Kasaee, N. | Nabizadeh, R. | Heidari, M.
Arak waste stabilization pond facilities consist of two stabilization pond systems, module 1 and module 2. The existing facilities have had several problems in their operation. The objectives of this research were to evaluate the performance of stabilization ponds in wastewater treatment of the city of Arak, because of several problems in their operation, and to prepare a scheme of its upgrading, if necessary. Within the period of May to September 2007, analyses were carried out for both raw and treated wastewaters. Results of these investigations showed that the average effluent concentrations of BOD5, COD and SS taken from primary and secondary facultative ponds of module 1 were 91.5, 169, 114; and 70, 160, 123 mg/L, respectively. These results indicated that the effluent of the primary facultative ponds of module 1 were complied with the Iranian treated wastewater standards for agricultural reuse in terms of BOD5 and COD concentrations; hence the secondary facultative ponds could be changed to other primary facultative ponds in order to increase the capacity of wastewater treatment plant. For module 2, BOD5, COD, and SS average concentrations of treated wastewater for the secondary and tertiary facultative ponds were obtained as 69, 101, 77; and 76, 127, 78 mg/L, respectively. Thus the effluent of the secondary facultative pond was complied with the considered standards in terms of all studied parameters. Consequently, the tertiary facultative pond could be changed to other secondary facultative pond to upgrade both the quality and the quantity of treated wastewater.
Показать больше [+] Меньше [-]TiO2-Based Heterogeneous Photocatalytic Treatment Combined With Ozonation For Carbendazim Degradation Полный текст
2009
Rajeswari, R. | Kanmani, S.
The degradation of pesticide Carbendazim was investigated by combination of TiO2-based photocatalysis and ozonation. A batch annular photoreactor has been used for carrying out the combined process and the influence of TiO2 concentration, ozone dose and pH were investigated. The results showed that the removal rate increased with increase in ozone dosage upto 0.48 g/h and decreased above 1g/L of TiO2. At optimum pH=6, with 1g/L TiO2 and with 0.48g/h ozone dose, 88% COD removal was achieved in 3 hours by the combined photocatalytic ozonation process, where as 54% and 67% COD removal was observed with each photocatalysis and ozonation process, respectively. BOD5/COD ratio was enhanced to 0.38 and TOC removal was 80% in 180 min of combined treatment. Carbendazim was quickly degraded by the combined photocatalytic ozonation process and followed pseudo-first order kinetics. The kinetic study showed that degradation rate constant of Carbendazim with TiO2/UV/O3 to be 1.5 times higher than that & O3 with the same ozone dose and 2.2 times higher than that of TiO2/UV. A mechanism involving the formation of an ozonide radical previous to the generation of hydroxyl radicals is suggested to explain the synergistic effect between ozone and TiO2 under illumination. The laboratory study has also demonstrated that a combination of TiO2-based photocatalysis and ozonation will overcome the disadvantage of the selectivity of ozonation and the lower efficiency of TiO2 photocatalysis.
Показать больше [+] Меньше [-]Determination Of Heavy Metals In Fish, Water And Sediments Of Avsar Dam Lake In Turkey Полный текст
2009
Öztürk, M. | Özözen, G. | Minareci, O. | Minareci, E.
In the present study, some heavy metals (Cd, Cr, Cu, Fe, Ni and Pb) were seasonally determined in water, sediment and some tissues of Cyprinus carpio from Avsar Dam Lake, which is an important water source for irrigation and drinking in Turkey. Heavy metal levels in water, sediment and fish samples were analyzed by inductively coupled plasma spectroscopy (ICP/AES). The obtained results showed that the average values of Fe in water samples were higher than the respective reference values for fresh water. Results for levels in water were compared with national and international water quality guidelines, as well as literature data reported for the lakes. The analysis of heavy metals in sediments indicated that among the six heavy metals tested, Fe was maximally accumulated, followed by Ni, Cu, Cr, Pb and Cd. Heavy metal concentrations were found to decrease in sequence of the Cyprinus carpio samples, in the muscle and stomach-intestine as Fe > Cu > Pb> Ni > Cr > Cd; in the gill, heart and liver as Fe > Cu > Ni > Pb > Cr > Cd and in the air sac as Fe > Cu > Ni > Pb > Cd >Cr. In the fish samples, cadmium, chromium, nickel and lead concentrations exceeded the tolerable values provided by international institutions.
Показать больше [+] Меньше [-]Endocrine Disrupting Contaminants In Water Resources And Sewage In Hamadan City Of Iran Полный текст
2009
Jafari, A. J. | Abasabad, R. Pourkabireh | Salehzadeh, A.
Many chemicals which are released into the environment have the potential to disrupt the function of endocrine systems. They pose a growing threat to human and wildlife health. These chemicals have been characterized as endocrine disrupting chemicals. Some phenolic chemicals, such as bisphenol A, have been measured in surface water, sediments and sewage sludge. The objective of this study was to investigate endocrine-disrupting agents in drinking, surface and groundwaters sources and also sewage in the city of Hamadan, in the west of Iran. Samples from all sources were collected during April-September and October-March, extracted by solid phase method and analyzed by HPLC-UV in the wave length of 270nm for estrol, 210 nm for ethinyl estradiol and 280 nm for other compounds. The results showed that presence of bisphenol A with concentrations ranging 0.002 to 1μg/L, 0-0.002 μg/L in drinking and groundwaterfor nonylphenol and 0.001 - 10ng/L for 17-beta estradiol. Estron was not detected in drinking water during October-March. The concentration levels of pollutants in wastewater were tens times higher than the water. Analysis of different types of water showed that concentration levels of pollutants were higher during April-September comparing with October-March (Pvalue <0.005), which may be due to the changes of environmental conditions. The widespread use of birth control pills formulated with these potent estrogenic chemicals appear to be the major route for the release of estrogenic substances into the aquatic environment.
Показать больше [+] Меньше [-]Biosorption Of Iron From Aqueous Solution By Dried Biomass Of Activated Sludge Полный текст
2009
Shokoohi, R. | Saghi, M. H. | Ghafari, H. R. | Hadi, M.
This study was conducted to investigate the removal of iron by dried biomass of activated sludge. Dried activated sludge, prepared as a powder, was tested as a sorbent for the removal of iron from aqueous solutions. The effects of various experimental parameters including initial iron concentration, mass of biomass and contact time were examined and optimal experimental conditions were obtained. The equilibrium time for iron adsorption onto biomass was determined as 150 min. The rate of iron removal was directly correlated to biomass amount and contact time. Increasing contact time from 0.5h to 2.5h resulted in 25% improvement in iron removal efficiency. When the weight of the biomass increased from 0.1g to 0.9 g, the iron removal efficiency increased from 62% to 95%. High initial iron concentration had an adverse effect on iron removal efficiency. Increasing initial iron concentration from 2 to 10 (mg/L) caused declining the iron removal efficiency from 70% to 56%. Freundlich, Langmuir, Dubinin-Radushkevich and Temkin isotherm models could describe the adsorption equilibrium of the iron onto the activated sludge. Meanwhile, Freundlich isotherm represented a better correlation compared to other isotherms (R2 < 0.999). Also Elovich kinetic models fits well with experimental data (R2<0.997).
Показать больше [+] Меньше [-]Airborne Polybrominated Diphenyl Ethers In A Computer Classroom Of College In Taiwan Полный текст
2009
Chang, F. H. | Yang, C. R. | Tsai, C. Y. | Lin, W. C.
This study characterized the airborne exposure of students to thirty polybrominated diphenyl ether congeners inside and outside a computer classroom in a southern Taiwan college. Arithmetic mean values of total indoor and outdoor polybrominated diphenyl ether concentrations were 125.0 pg/m3 (89.8 to 203.9 pg/m3) and 110.3 pg/m3 (83.5 to 157.0 pg/m3), respectively. Total indoor polybrominated diphenyl ether concentrations were one order of magnitude lower than those detected in homes in Birmingham, United Kingdom and in Ottawa, Canada but were several times higher than those measured in the ambient air in Ottawa, Canada and from the Bohai Sea to the Arctic. The five highest indoor concentrations of polybrominated diphenyl ether congeners were decabromodiphenyl ether (23.0 pg/m3), 4,4'-dibromodiphenyl ether (15.9 pg/m3), 2,2',3,4,4',5,5',6-octabromodiphenyl ether (10.6 pg/m3), 2,4-dibromodiphenyl ether (10.3 pg/m3) and 2,2',3,4,4',5',6-heptabromodiphenyl ether (10.0 pg/m3). Although indoor and outdoor total polybrominated diphenyl ether concentrations did not significantly differ, the indoor concentrations of 2,4-dibromodiphenyl ether, 2,2',4-tribromodiphenyl ether, 2,4,4'-tribromodiphenyl ether, 2,2',4,5'-tetrabromodiphenyl ether and 2,3',4',6-tetrabromodiphenyl ether were significantly higher than their outdoor concentrations. This study suggests the following measures: 1) to increase the air exchange rate and open classroom doors and windows for several minutes before classes to reduce indoor PBDE concentrations; 2) to reduce polybrominated diphenyl ether emissions from new devices, it's better to use computer-related products that meet the Restriction of Hazardous Substances Directive adopted by the European Union.
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