Determination of head loss progress in dual-media BOPS-sand filter using numerical modeling incorporated with matrix approach

2011 ◽  
Vol 32 (1-3) ◽  
pp. 33-41 ◽  
Author(s):  
Ahmad Jusoh ◽  
M.N.A. Rajiah ◽  
A. Nora'aini ◽  
E. Azizah
2014 ◽  
Vol 3 (2) ◽  
pp. 276-286 ◽  
Author(s):  
Daneshi Navab ◽  
Banejad Hossein ◽  
Pirtag Hamedany Reza ◽  
Daneshi Vahab ◽  
Farokhi Maedeh

Along with the technology development and increasing consumption of water resources, we are experiencing low qualities in the mentioned resources. Copper brings about serious environment al pollution, threatening human health and ecosystem. This metal found variously in water resources and industrial activities. Therefore, it needs to treat the water resources from these excessive amounts. Different methods have used for this reason but the most used method during recent years has been the absorption by economic absorbers such as sand. Rapid sand filters usually used in water and wastewater treatment plants for water clarification. In this research, a single layer gravity rapid sand filter has used to reduce different concentrations of copper. sediment value and head loss arising in filter media is simulated by using combination of Carman-Kozeny, Rose and Gregory models in different discharges of rapid sand filter. Results have shown that with increasing in discharge and decreasing in input copper concentration, arriving time to given head loss, is increasing. In addition, results demonstrated that with increasing in copper concentration in influent, removal efficiency is decreasing somewhat. Results of this research can applied in an appropriate design of rapid sand filter to copper removal, a prediction of rapid sand filter ability to copper removal and an estimation of arising head loss during filter work thus evaluating of time interval backwash. DOI: http://dx.doi.org/10.3126/ije.v3i2.10641 International Journal of the Environment Vol.3(2) 2014: 276-286


2021 ◽  
Vol 31 (3) ◽  
pp. 118-133
Author(s):  
Assia Bellayoune ◽  
Salah Messast ◽  
Marc Boulon

Abstract The evaluation of friction is an important element in the verification of stability and the determination of the bearing capacity of piles. In the case of cyclic stress, the soil-pile interface has a relaxation which corresponds to a fall in the horizontal stress which represents the normal stress at the lateral surface of the pile. This paper presents an explicit formulation to express the degradation of the normal stress after a large number of shear cycles as a function of cyclic parameters. In this study we are interested in the exploitation of the cyclic shear tests carried out by Pra-ai [1] with imposed normal rigidity (CNS) in order to demonstrate the phenomenon of falling of the normal stress. The approach presented in this paper consists in proposing a simple expression for estimating the degradation of normal stress as a function of cyclic shear parameters after a large number of cycles. The validation of this approach is verified by the application of this formulation to a real case where the comparison of the simulations made by this approach with those recorded on site shows the good adaptation of this approach to this type of problems.


Author(s):  
M. I. Epov ◽  
◽  
V. N. Glinskikh ◽  
M. N. Nikitenko ◽  
K. V. Sukhorukova ◽  
...  

The work is devoted to the substantiation of new geophysical technology for mapping the Bazhenovskaya Formation based on an impulsive electromagnetic sounding from wells. Theoretically shown the possibility of its application to study the formation from highly inclined and subhorizontal wells drilled in the Upper and Middle Jurassic formations. Numerical modeling of the signals in realistic geoelectric models of the Bazhenov Formation with real well trajectories is carried out on the example of the East Surgut field. The calculations have established that the determination of spatial locations of the top and bottom of the beds is possible when using different-length sondes. Zones of high sensitivity of the full magnetic field matrix to the boundaries with a sufficient signal level at considerable distance, even with a small sonde length, are determined. It is theoretically established that pulsed sounding of the Bazhenov Formation from the Upper and Middle Jurassic reservoirs is feasible for both mapping the boundaries of the formation and tracing its lateral variability.


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