breakthrough time
Recently Published Documents


TOTAL DOCUMENTS

167
(FIVE YEARS 52)

H-INDEX

11
(FIVE YEARS 4)

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 584
Author(s):  
Agnieszka Brochocka ◽  
Aleksandra Nowak ◽  
Paweł Kozikowski

In this article, we present polymer non-woven fabrics with the addition of carbon sorbents being tested to estimate the breakthrough time and efficient protection against vapors present in smog. For this purpose, three substances were selected, which constitute an inhalation hazard and are smog components: cyclohexane, toluene, and sulfur dioxide. It was demonstrated that an increased quantity of carbon sorbent in polymeric filters significantly prolongs the breakthrough time. However, high sorbent quantities may increase the filter surface mass and air flow resistance. To optimize the protective parameters with functionality, a compromise between the two has to be found. By comparing the breakthrough times for different carbon sorbent quantities, the optimal filter composition was elaborated. The analyzed non-woven fabrics were manufactured by the melt-blown process and filled with ball-milled carbon sorbents supplied directly into the fabric blowing nozzle. Both protective performance and textural properties were analyzed for two commercially available carbon sorbents. Furthermore, it was proven that high values of sorbent-specific surface area translates directly into greater filter performance.


Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 86
Author(s):  
Adeleke A. Oyekanmi ◽  
Mohammed B. Alshammari ◽  
Mohamad Nasir Mohamad Ibrahim ◽  
Marlia Mohd Hanafiah ◽  
Ashraf Y. Elnaggar ◽  
...  

The reduction of chemical oxygen demand (COD) from palm oil mill effluent (POME) is very significant to ensure aquatic protection and the environment. Continuous adsorption of COD in a fixed bed column can be an effective treatment process for its reduction prior to discharge. Adsorption capacity of bone derived biocomposite synthesized from fresh cow bones, zeolite, and coconut shells for the reduction in the organic pollutant parameter was investigated in this study in a fixed bed column. The effect of influent flow rate (1.4, 2.0, and 2.6 mL/min) was determined at an influent pH 7. The optimum bed capacity on the fabricated composite of surface area of 251.9669 m2/g was obtained at 1.4 mL/min at breakthrough time of 5.15 h influent POME concentration. The experimental data were fitted to Thomas, Adams–Bohart, and Yoon–Nelson models fixed bed adsorption models. It was revealed that the results fitted well to the Adams Bohart model with a correlation coefficient of R2 > 0.96 at different influent concentration. Adsorption rate constant was observed to increase at lower flow rate influent concentration, resulting in longer empty bed contact time (EBCT) for the mass transfer zone of the column to reach the outlet of the effluent concentration. In general, the overall kinetics of adsorption indicated that the reduction in COD from POME using a bone-biocomposite was effective at the initial stage of adsorption. The pore diffusion model better described the breakthrough characteristics for COD reduction with high correlation coefficient. Shorter breakthrough time compared to EBCT before regeneration indicated that the bone composite was suitable and effective for the reduction in COD from POME using fixed bed column adsorption.


Author(s):  
Megat Ahmad Kamal Megat Hanafiah ◽  
Shariff Ibrahim ◽  
Nur Izah Fasihah Mohamad Subberi ◽  
Nesamalar Kantasamy ◽  
Is Fatimah

The feasibility of Mengkuang leaves (Pandanus atrocarpus) as a non-conventional low-cost adsorbent for the removal of an anionic dye, Reactive Orange 16 (RO16), was investigated. Among the dyes that have been commonly used in the Batik industry was reactive dye. In this study, Mengkuang leaves were chemically modified with cetyltrimethylammonium bromide (CTAB), a cationic surfactant, to improve their adsorption performance toward anionic dyes. The adsorbent’s morphological characteristics were analyzed using a scanning electron microscope (SEM). The surface of modified Mengkuang leaves seems to be irregular and uneven, with more porous structures than raw Mengkuang leaves. Adsorption of RO16 dye in fixed bed column using modified Mengkuang leaves adsorbent indicated the breakthrough time increased at higher bed height and lower flow rate. The breakthrough times for bed height of 0.5, 2, and 4 cm were at 16, 68, and 165 min, respectively. Meanwhile, breakthrough time for the flow rate of 2,5 and 7 mL.min-1 were at 327, 104, and 43 min, respectively. However, the study utilizing raw Mengkuang leaves showed no significant removal of RO16. Thus, it can be concluded that the cationic surfactant modification of Mengkuang leaves is advantageous for anionic dye removal. This anionic dye removal is significantly influenced by column parameters such as bed height and flow rate as the plotted breakthrough curves obtained from experimental data were similar to the typical breakthrough curve. When applied to the Yoon-Nelson model, the adsorption data provided the best fit with the R2 value above 0.95. The time taken for the breakthrough is very similar to model prediction values. Experiments with real batik dye wastewater showed the immense potential of modified Mengkuang leaves where total removal of real Batik wastewater was instantaneous.


2021 ◽  
Vol 902 ◽  
pp. 127-132
Author(s):  
Marvin U. Herrera ◽  
Ronniel D. Manalo ◽  
Monet C. Maguyon-Detras ◽  
Mary Donnabelle L. Balela

Kapok fibers were used as a filtering medium in a column-type filtration set-up to separate diesel from water molecules in dynamic conditions. The amount of diesel flowing out the filtration system with respect to time was monitored. The times wherein the diesel first came out the filtering system (breakthrough time) were shorter at higher influent concentration and faster flow rate. Meanwhile, the total sorbed diesel molecules in the filtering system were increasing with the influent concentration while invariant with flow rate. The shorter breakthrough time was associated with the higher amount of diesel molecules that could be sorbed at a shorter time and the rate at which the overall processes of sorption-desorption-resorption proceeded. On the other hand, the sorption capacity of the system was viewed to be affected by the amount of moving diesel molecules that would interact with the kapok fibers and/or surface-sorbed diesel molecules but not by the contact time.


Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1887
Author(s):  
Santiago Céspedes ◽  
Alejandro Molina ◽  
Betiana Lerner ◽  
Maximiliano S. Pérez ◽  
Camilo A. Franco ◽  
...  

A selection flowchart that assists, through Computational Fluid Dynamics (CFD) simulations, the design of microfluidic experiments used to distinguish the performance in Chemical Enhanced Oil Recovery (CEOR) of two surfactants with very similar values of interfacial tension (IFT) was proposed and its use demonstrated. The selection flowchart first proposes an experimental design for certain modified variables (: porosity, grain shape, the presence of preferential flowing channels, and injection velocity). Experiments are then performed through CFD simulations to obtain a set of response variables (: recovery factor, breakthrough time, the fractal dimension of flow pattern, pressure drop, and entrapment effect). A sensitivity analysis of regarding the differences in the interfacial tension (IFT) can indicate the CFD experiments that could have more success when distinguishing between two surfactants with similar IFTs (0.037 mN/m and 0.045 mN/m). In the range of modifiable variables evaluated in this study (porosity values of 0.5 and 0.7, circular and irregular grain shape, with and without preferential flowing channel, injection velocities of 10 ft/day and 30 ft/day), the entrapment effect is the response variable that is most affected by changes in IFT. The response of the recovery factor and the breakthrough time was also significant, while the fractal dimension of the flow and the pressure drop had the lowest sensitivity to different IFTs. The experimental conditions that rendered the highest sensitivity to changes in IFT were a low porosity (0.5) and a high injection flow (30 ft/day). The response to the presence of preferential channels and the pore shape was negligible. The approach developed in this research facilitates, through CFD simulations, the study of CEOR processes with microfluidic devices. It reduces the number of experiments and increases the probability of their success.


2021 ◽  
Vol 10 (2) ◽  
pp. 75-83
Author(s):  
Dike Fitriansyah Putra ◽  
Mursyidah Umar ◽  
Lazuardhy Vozika Futur ◽  
Aznil Arif Rahman

This study aims to determine the benefits of the interwell tracer test technique in improving the streamline simulation on the existing array's re-look. It also analyses the best scheme for the injection spot to enhance oil recovery. This study's subject parameters are limited to the tracer's breakthrough time, produced concentration, cumulative production, and pathline movement. The results showed that previous studies distinguished the correlation between injectors and producers with the development of a new pathline that conveys a scheme of water-flood for the application. Furthermore, several developments of water-flood schemes have been executed for better oil recovery in the mature fields worldwide. The vigorous simulation model is an effort to imitate the actual field capable of enhancing the character's understanding and helping the waterflood to rinse the oil trap or the unswept pocket. Unlike a Cartesian model, the streamline conveys an enhanced portrait of the transmissibility reservoir in terms of pressure-driven. The streamline model suggests the injector's preferred position to unlock any unswept oil in the formation and minimize the water path conflict, which leads to over injection in some regions. The expected outcome is the ultimate oil increment with the original technique associated with re-patterning the wells appropriately to gain residual oil saturation in the virgin alleyway.


2021 ◽  
Author(s):  
Sidra Shaoor Kiani ◽  
Atif Ullah ◽  
Amjad Farooq ◽  
Masroor Ahmad ◽  
Naseem Irfan ◽  
...  

Abstract In order to provide protection against extremely toxic gases Activated Carbon (AC) adsorption has long been regarded to be a useful technology in terms of gas removal. AC without chemical impregnation has been considerably less effective than impregnated ACs. AC in present use was modified with an organic amine i.e. triethylenediamine (TEDA) to enhance the physical and chemical properties of AC in order to remove specific poisonous gases. Purpose of this study was to assess the TEDA impregnated AC in terms of adsorption capability for simulant gas like SO2. Analysis was done in a properly designed setup. By using the scheme reported here, significant adsorption of toxic gas was obtained. Maximum removal capability observed by AC-4 for SO2 gas was 3.74 g/g-C and its breakthrough time was 264 minutes. Breakthrough time and adsorption capacity of AC-4 was found to be 25 times and 10 times greater as compared to raw AC. Different characterization techniques were also used to study impregnated AC. It was found that chemical adsorption was the crucial means by which TEDA impregnated AC removed the simulant gas. Langmuir model was best to represent equilibrium and adsorption kinetics follow second order model. The process was endothermic, favorable and spontaneous.


2021 ◽  
Vol 11 (6) ◽  
Author(s):  
Nouria Nabbou ◽  
Elhassan Benyagoub ◽  
Meriem Belhachemi ◽  
Mustapha Boumelik ◽  
Moncef Benyahia

AbstractThis present work is a part of the liquid discharges treatment topic by studying the removal performance for thermotolerant coliforms (FC) and fecal streptococci (F.Strep) by a local natural light green clay from Kenadsa (Bechar-Algeria) under continuous adsorption processes in a fixed-bed column. The study estimated the clay adsorbing efficiency by the adsorption technique for bacteria contaminating the dairy effluent by determining the bacterial load before and after treatment. The mean log counts per 100 ml for FC and F.Strep were assessed by MPN method on liquid medium. The clay material characterizations were made through X-ray diffraction, X fluorescence spectrometry and Fourier transform infrared spectroscopy analysis. Besides, some parameters were estimated such as the breakthrough time tb (clay filter breakdown); the amount of the contaminating bacteria that was removed at the breakthrough time Xb and the exhaustion of disinfection capacity Xe; the total amount of contaminating bacteria flowing through the column Xtotal; and the total removal efficiency (Y). According to the XRD, XRF and FTIR results, the predominant mineral constituents were silicon dioxide, aluminum oxide, ferric oxide and magnesium oxide with rates of 59,44; 18,09; 7,79; and 3,87%, respectively, and hence, their classification among non-swelling clay minerals, illite is the major mineral group of this material. The results of the bacteriological analysis of raw dairy effluents showed an average bacterial load of 3,88 Log10 and 4,1 Log10 CFU/100 mL for FC and F.Strep, respectively, exceeding the thresholds set by the national and the international regulations. The results of the dairy effluents treated by the tested material have shown that the used clay has a relatively high adsorption property for the clay fixed-bed system (3 cm of bed height), expressed by a total removed efficiency Y (%) of FC and F.Strep used to evaluate the column performance ranging from 55 to 84%. It gives a higher log removal for FC and F.Strep (0.98–1.65 Log10) reported from the first adsorption process, and a breakthrough time ranged from 100 to 250 min, which was inversely proportional to the initial bacterial load of discharges and also linked to the nature of the bacterial contaminants. When the breakthrough occurs earlier, the column service life will be shortened. For the studied parameters, the results of treated effluent complied with national and WHO regulations for unrestricted agricultural irrigation, otherwise, as authorized effluents to be discharged into nature without risks. These preliminary results are very promising at laboratory scale as an innovative green technology, treatment method respecting the environment and opens up prospects for the future, where the modification or the optimization of operating conditions such as the bed height of the fixed bed for adsorption, the volumetric flow rate or the clay structure like the particle size distribution of the adsorbents, known as one of the adsorbent classes endowed with an antimicrobial property, can improve the column performance, and further, the removal or even more the disinfection process by adsorption method.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Suran Wang ◽  
Yuhu Bai ◽  
Bingxiang Xu ◽  
Ling Chen ◽  
Wenlan Li ◽  
...  

Water breaks through along fractures is a major concern in tight sandstone reservoirs with a bottom aquifer. Analytical models fail to handle the three-dimensional two-phase flow problem for partially penetrating inclined fractures, so time-consuming numerical simulation are often used for this problem. This paper presents an efficient semianalytical model for this problem considering three-dimensional fractures and two-phase flow. In the model, the hydraulic fracture is handled discretely with a numerical discrete method. The three-dimensional volumetric source function in real space and superposition principle are employed to solve the model analytically for fluid flow in the reservoir. The transient flow equations for flow in three-dimensional inclined fractures are solved by the finite difference method numerically, in which two-phase flow and stress-dependent properties are considered. The eventual solution of the model and transient responses are obtained by coupling the model for flow in the reservoir and discrete fracture dynamically. The validation of the semianalytical model is demonstrated in comparison to the solution of the commercial reservoir simulator Eclipse. Based on the proposed model, the effects of some critical parameters on the characteristics of water and oil flow performances are analyzed. The results show that the fracture conductivity, fracture permeability modulus, inclination angle of fractures, aquifer size, perforation location, and wellbore pressure drop significantly affect production rate and water breakthrough time. Lower fracture conductivity and larger inclination angle can delay the water breakthrough time and enhance the production rate, but the increment tends to decline gradually. Furthermore, water breakthrough will occur earlier if the wellbore pressure drop and aquifer size are larger. Besides, the stress sensitivity and perforation location can delay the water breakthrough time.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Meltem Bilici Baskan ◽  
Seçil Hadimlioglu

AbstractIn this study, graphene oxide (GO), iron modified clinoptilolite (FeZ), and composites of GO-FeZ (GOFeZA and GOFeZB) were synthesized and characterized using SEM, EDS, XRF, FTIR, and pHpzc. The arsenate uptake on composites of GOFeZA and GOFeZB was examined by both kinetic and column studies. The adsorption capacity increases with the increase of the initial arsenate concentration at equilibrium for both composites. At the initial arsenate concentration of 450 μg/L, the arsenate adsorption on GOFeZA and GOFeZB was 557.86 and 554.64 μg/g, respectively. Arsenate adsorption on both composites showed good compatibility with the pseudo second order kinetic model. The adsorption process was explained by the surface complexation or ion exchange and electrostatic attraction between GOFeZA or GOFeZB and arsenate ions in the aqueous solution due to the relatively low equilibrium time and fairly rapid adsorption of arsenate at the beginning of the process. The adsorption mechanism was confirmed by characterization studies performed after arsenate was loaded onto the composites. The fixed-bed column experiments showed that the increasing the flow rate of the arsenate solution through the column resulted in a decrease in empty bed contact time, breakthrough time, and volume of treated water. As a result of the continuous operation column study with regenerated GOFeZA, it was demonstrated that the regenerated GOFeZA has lower breakthrough time and volume of treated water compared to fresh GOFeZA.


Sign in / Sign up

Export Citation Format

Share Document