Analysis of fluid discharge from a hanging geotextile bag

The aim of the study was to describe in a mathematical manner the hydraulic capacity of textile filters for wastewater treatment at changeable wastewater levels during a period between consecutive doses, taking into consideration the decisive factors for flowconditions of filtering media. Highly changeable and slightly changeable flow-conditions tests were performed on reactors equipped with non-woven geo-textile filters. Hydraulic conductivity of filter material coupons was determined. The dry mass covering the surface and contained in internal space of filtering material was then indicated and a mathematical model was elaborated. Flow characteristics during the highly changeable flow-condition test were sensitivity to differentiated values of hydraulic conductivity in horizontal zones of filtering layer. During the slightly changeable flow-conditions experiment the differences in permeability and hydraulic conductivity of different filter (horizontal zones) height regions were much smaller. The proposed modelling approach in spite of its simplicity provides a satisfactory agreement with empirical data and therefore enables to simulate the hydraulic capacity of vertically oriented textile filters. The mathematical model reflects the significant impact of the filter characteristics (textile permeability at different filter height) and operational conditions (dosing frequency) on the textile filters hydraulic capacity.M. Spychała, M. Pawlak, T. Nawrot 422There are many factors and conditions related to non-woven geo-textile hydraulic conductivity and clogging. Some of these are well known: fibre density [Marks 1975], filtered suspension particle size [Gourc and Faure 1990] and organic material growth or deposition [Hoogerdendorn and Van der Meulen 1977].The studies conducted thus far [Spychała et al. 2013] showed a satisfactory pollution removal by textile filters for wastewater treatment (TFWT).The average values of removal efficiencies can seem to be relatively low, however much higher values were observed occasionally under slightly changeable conditions (inflow concentrations): up to 89% for COD, 80% for ammonium nitrogen and up to 48% for total phosphorus. Taking into consideration that this type of filter operates without forced (energy consuming) aeration and sophisticated solutions are not applied, it can be considered as satisfactory in its performance.TFTW hydraulic conditions are complex due to the dosing regimen related to changeable wastewater surface level (which causes changeable hydrostatic pressure). Another flow-related condition is the stratification of biomass (the mixture of live organisms and solids originated from wastewater) concentration and their resistance along the filter layer height (filtering surface is oriented vertically) due to the clogging process. However it is worth noting that the TFWT is a specific filtering medium operating under specific conditions and therefore both internal clogging and surface accumulation (in the form of filter cake) occurs.The form of biomass inside th...

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“…The elaborated modelling approach corresponds to the study carried out by Weggel et al [2011] and Weggel and Dorth [2012].…”

Section: Hydraulic Model Elaborationmentioning

confidence: 99%

Capacity of Textile Filters for Wastewater Treatment at Changeable Wastewater Level – A Hydraulic Model

Spychała

Pawlak

Nawrot

2016

ASP.FC

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“…Furthermore, Malik et al [6] studied the influence of the filling sand density on the dewatering performance of the geotubes. With the results of the hanging bag tests, Weggel et al [7][8][9] analyzed the dewatering process of the geotubes, and established the analytical model of geotubes dewatering.…”

Section: Introductionmentioning

confidence: 99%

Effect of silt content in filling sand on the geotubes dewatering performance by hanging bag tests

Man¹,

Hu²,

Wang³

2020

J. meas. eng.

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The dewatering performance of geotubes is affected by the silt content of filling sand, which limits the construction speed of geotubes. In order to evaluate the effect of silt content of filling sand on the dewatering performance of geotubes, a series of hanging bag tests were carried-out by varying filling sand with five different silt content. In the tests, the variation of the water loss, soil loss and soil particles grading with time were studied. And the relationship between the silt content and the rate of water loss was analyzed. The research results show that the dewatering process could be divided into three stages, when the powder content is more than 20 %. Otherwise, the dewatering process only includes two stages. Three different bell-shaped function relationships exist between the percentage content of silt particles, median particle size and nonuniformity coefficient with the rate of water loss respectively. Furthermore, the different relationships were simplified into 3 different linear functions correspondingly. The research results could be used as a reference for geotubes engineering practice.

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“…Geotextile tubes have been of interest in various studies due to its wide applications in civil engineering. Evaluation results on the permeability and retention characteristics of geotextile tubes can be found in the studies of Moo-Young et al (2002), Koerner and Koerner (2006) and Weggel et al (2011). Model tests and large-scale experiments on geotextile tubes can be found in the literature (Recio and Oumeraci, 2009, Kriel 2012, Kim et al 2013b, 2014a.…”

Section: Introductionmentioning

confidence: 99%

Stress and strain behavior investigation on a scale model geotextile tube for Saemangeum dike project

Kim¹,

Lee²,

Jo³

et al. 2014

Ocean Systems Engineering

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Geotextile tubes are basically a huge sack filled with sand or dredged soil. Geotextile tubes are made of permeable woven or non-woven synthetic fibers (i.e., polyester or PET and polypropylene or PP). The geotextile tubes' performances in strength, dewatering, retaining solid particles and stacked stability have been studied extensively in the past. However, only little research has been done in the observation of the deformation behavior of geotextile tubes. In this paper, a large-scale apparatus for geotextile tube experiment is introduced. The apparatus is equipped with a slurry mixing station, pumping and delivery station, an observation station and a data station. For this study the large-scale apparatus was utilized in the studies regarding the stresses on the geotextile and the deformation behavior of the geotextile tube. Model tests were conducted using a custom-made woven geotextile tubes. Load cells placed at the inner belly of the geotextile tube to monitor the total soil pressure. Strain gauges were also placed on the outer skin of the tube to measure the geotextile strain. The pressure and strain sensors are attached to a data logger that sends the collected data to a desktop computer. The experiment results showed that the maximum geotextile strain occurs at the sides of the tube and the soil pressure distribution varies at each geotextile tube section.

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Analysis of fluid discharge from a hanging geotextile bag

Cited by 21 publications

References 5 publications

Capacity of Textile Filters for Wastewater Treatment at Changeable Wastewater Level – A Hydraulic Model

Capacity of Textile Filters for Wastewater Treatment at Changeable Wastewater Level – A Hydraulic Model

Effect of silt content in filling sand on the geotubes dewatering performance by hanging bag tests

Stress and strain behavior investigation on a scale model geotextile tube for Saemangeum dike project

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