Experimental Design of Surface Modification of Expanded Obsidian and Determination of Water Sorption Capacity

2014 ◽  
Vol 1020 ◽  
pp. 823-826
Author(s):  
G.Sh. Hovsepyan ◽  
M.A. Kalantaryan ◽  
T.V. Yedoyan
Keyword(s):  
Experimental Data ◽  
Surface Modification ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Structural Changes ◽  
Ir Spectrometry ◽  
Water Capacity ◽  
Series Of Experiments ◽  
Water Sorption Capacity

The aim of this paper is to study the possibility of expanded obsidian and its modified product use for oil sorption, in that tetraethoxisilane (TEOS) has been used as a modifier. The optimal concentration of the modifier was determined by 50 per cent weight of expanded obsidian. The expanded obsidian was previously activated with 0,1 M solution of hydrochloric acid. IR spectrometry was used to characterise structural changes in the modified expanded obsidian samples. To determine water sorption capacity a series of experiments has been carried out. The analysis of obtained experimental data showed that after surface modification of expanded obsidian water capacity is reduced 3 times after the surface modification of EO.

scholarly journals Experimental and Modelling Studies of Water Sorption Properties of Cellulosic Derivative Fibers.

2021 ◽  
Author(s):  
MATHILDE SIMON ◽  
RENE FULCHIRON ◽  
FABRICE GOUANVE
Keyword(s):  
Water Sorption ◽  
Sorption Properties ◽  
Hydroxyl Groups ◽  
Vapor Sorption ◽  
Dynamic Vapor Sorption ◽  
Kinetic Rate ◽  
Modelling Studies ◽  
Kinetic Sorption ◽  
Water Sorption Capacity

Abstract The objective of this study was to understand the chemical modification impact on interactions between water and cellulosic fiber. In that respect, cotton (C), flax (F), viscose (V) and cellulose acetate (CA) were analyzed by using a dynamic vapor sorption analysis. The sorption and desorption isotherms and kinetic curves were modelled using the Park model and the “Parallel Exponential Kinetics” (PEK) model-which allowed an accurate fitting on the whole range of water activity. The obtained sorption properties were correlated to the accessibility and the amount of sorption sites and also to the crystallinity level of the fibers. It was found that V exhibited the highest water sorption capacity due to a higher hydroxyl groups accessibility and a high amorphous fraction, followed up by F, C and CA. In contrast, higher kinetic sorption rate was obtained for CA due to a decrease of the hydroxyl groups within the fibers. Regardless the fiber, the determination of characteristic times showed that the kinetic rate was higher for sorption than desorption.

scholarly journals Assessment of Performance of Posidona oceanica (L.) as Biosorbent for Crude Oil-Spill Cleanup in Seawater

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Senda Ben Jmaa ◽  
Amjad Kallel
Keyword(s):  
Crude Oil ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Pure Water ◽  
Water System ◽  
Oil Concentration ◽  
Oil Water ◽  
Mixed Oil ◽  
The Impact ◽  
Water Sorption Capacity

The marine environment is constantly at risk of pollution by hydrocarbon spills that requires its cleanup to protect the environment and human health. Posidonia oceanica (L.) (PO) beach balls, which are characteristic of the Mediterranean Sea and abundant on the beaches, are used as biosorbent to remove hydrocarbons from the sea. The impact of several factors such as oil concentration, time sorption, and weight sorbent was investigated to determine the oil and water sorption capacity for raw and milled P. oceanica fibers. The study of kinetic models for initial crude oil concentration of 2.5, 5, 8.8, 10, 15, 20, 30, and 40 g/L revealed that crude uptake followed the pseudo-first-order model while, for isotherm models, the crude uptake onto the P. oceanica tended to fit the Langmuir model. Experiments were performed according to two systems: a pure oil and pure water system and a mixed oil/water system. For the dry system (pure oil and pure water), the maximum oil and water sorption capacity of raw and milled fibers was found to be 5.5 g/g and 14 g/g for oil and 14.95 g/g and 15.84 g/g for water, respectively, whereas, in the mixed oil/water system, the maximum oil and water sorption capacity was estimated as 4.74 g/g, 12.80 g/g and 7.41 g/g, 8.31 g/g, respectively. The results showed that, in spite of their absorbency of a lot of water, the milled fibers with grain size ranging between 0.5 mm and 1 mm might be the relevant sorbent for the elimination of crude oil from seawater thanks to its efficient sorption capacity and low cost.

scholarly journals Sorption of Hydrocarbons on Peat, and Possibilities for Using Peat-Based Oil Sorbent for Treatment of Polluted Areas

2017 ◽  
pp. 1032-1045
Author(s):  
Dmitry Porshnov ◽  
Maris Klavins
Keyword(s):  
Sorption Capacity ◽  
Structural Changes ◽  
Oil Spills ◽  
Low Cost ◽  
Oil Sorption ◽  
High Moor ◽  
Oil Sorbent ◽  
Water Sorption Capacity ◽  
Sorption Characteristics ◽  
High Moor Peat

The growing use and transport of crude oil and oil products has led to an increasing amount of spillages of various scales. In the event of an oil spill, it is important to stop the spill from spreading and to clean up the polluted environment. One of the possible ways of treating the polluted areas is the use of oil sorbents. The sorbents used for collecting oil in case of oil spills are mostly synthetic, which limits the possibilities of their disposal. The aim of our study is to investigate the possible use of peat and its modification products for oil and other hydrocarbon sorption. Peat is a prospective material for oil sorption because it has such advantages as low cost, biodegradability and relatively high parameters of specific surface area and porosity. At the same time, peat also has disadvantages, such as poor buoyancy characteristics, relatively low oil sorption capacity and low hydrophobicity. We have studied the sorption characteristics of native high-moor peat with different botanical compositions and levels of decomposition, as well as the effect of thermal treatment on the oil sorption capacity, buoyancy and water sorption capacity of peat in comparison with the effect achieved by means of two other methods of chemical modification: silylation and methylation. We have determined the optimal conditions for thermal modification of peat to have an effect on hydrocarbon sorption characteristics. Using the method of IR spectroscopy, we have investigated specific structural changes in peat, which resulted in the improvement of its sorptive characteristics.

scholarly journals Comparison of Hydraulic Conductivity Values Obtained from Empirical Formulae and Laboratory Experiments

2020 ◽  
Vol 68 (4) ◽  
pp. 669-678
Author(s):  
Mario Hala ◽  
Lubomír Petrula ◽  
Zakaraya Alhasan
Keyword(s):  
Experimental Data ◽  
Hydraulic Conductivity ◽  
Laboratory Experiments ◽  
Internal Erosion ◽  
Variable Porosity ◽  
Groundwater Flow Regime ◽  
Series Of Experiments ◽  
Different Grain Size ◽  
Good Agreement

Hydraulic conductivity determination plays an essential role in the investigation of groundwater flow regime which can then influence many field problems such as pumping capabilities in the area, transport of contaminant or heat and soil internal erosion. Numerous equations based on dimensional analysis or experimental measurements have been published since the end of the 19th century for the determination of hydraulic conductivity. However, not all of these formulae are applicable for every material and all of them bring some uncertainty in the value of hydraulic conductivity. This paper contains a description of experimental research carried out concerning the determination of hydraulic conductivity for four types of sand with different grain size distribution curves and variable porosity. Obtained values of hydraulic conductivity ranged from 1 × 10-4 to 4 × 10-3 according to the sample porosity. The series of experiments consisted of 160 separate tests conducted in order to obtain relevant statistical sets. In this paper, the experimental data are discussed and compared with hydraulic conductivities obtained from 6 empirical formulae recommended in a previous study. The comparison showed that some empirical formulae provide a good agreement with the experimental data (the most precise were formulae published by Terzaghi and by Sauerbrey). However, some formulae showed high deviation from measured data (formula published by Zamarin).

scholarly journals The influence of the ammonia concentration and the water content on the water sorption behavior of ambient pressure dried silica xerogels

2020 ◽  
Vol 96 (1) ◽  
pp. 197-206
Author(s):  
Lukas Huber ◽  
Silvia Paz Comesaña ◽  
Matthias M. Koebel
Keyword(s):  
Water Content ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Ambient Pressure ◽  
Ammonia Concentration ◽  
Silica Xerogel ◽  
Sorption Behavior ◽  
Relative Pressure ◽  
Silica Xerogels ◽  
Water Sorption Capacity

Abstract Porous silica xerogels were synthesized within 10 h by a two-step sol–gel process under atmospheric conditions. In the first step, tetraethylorthosiloxane (TEOS) was hydrolyzed with water using sulfuric acid as a catalyst. In the second step, water and ammonia were added to the prehydrolyzed silica sol prior to the drying of the samples at 150 °C. The influence of the ammonia concentration and the water content on the physicochemical properties and the water sorption behavior of silica xerogels produced in the aforementioned way was investigated. The resulting silica xerogels were characterized by helium pycnometry, scanning electron microscopy, fourier-transform infrared spectroscopy, nitrogen sorption, and water sorption. It was shown that a higher ammonia concentration leads to an increased pore size of the silica xerogel which starts to adsorb water at a higher relative pressure. With an increased water content during gelation, the silica xerogel has a higher specific surface area and a higher water sorption capacity. Furthermore, silica xerogels can be tailored by a controlled addition of ammonia and water to have a higher water sorption capacity than the reference silica gel over the whole range of relative pressure.

scholarly journals New Composite Water Sorbents CaCl2-PHTS for Low-Temperature Sorption Heat Storage: Determination of Structural Properties

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 27 ◽  
Author(s):  
Alenka Ristić ◽  
Nataša Zabukovec Logar
Keyword(s):  
Electron Microscopy ◽  
Calcium Chloride ◽  
Structural Properties ◽  
Sorption Capacity ◽  
Water Uptake ◽  
Water Sorption ◽  
Heat Storage ◽  
Impregnation Method ◽  
Sorption Heat ◽  
Water Sorption Capacity

Sorption heat storage, as one of low-energy consuming technologies, is an approach to reduce CO2 emissions. The efficiency of such technology is governed by the performance of the applied sorbents. Thus, sorbents with high water sorption capacity and regeneration temperature from 80 to 150 °C are required. Incorporation of hygroscopic salt such as calcium chloride into porous materials is a logical strategy for increasing the water sorption capacity. This work reports the study on the development of composites with PHTS (plugged hexagonal templated silicate) matrix with an average pore size of 5.7 nm and different amounts of calcium chloride (4, 10, 20 wt.%) for solar thermal energy storage. These composites were prepared by wetness incipient impregnation method. Structural properties were determined by X-ray diffraction (XRD), nitrogen physisorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). CaCl2 was confined in micro- and mesopores of the matrix. The resulting CaCl2-PHTS materials were used for water sorption at 40 °C, showing an increase of maximal water uptake with higher amount of calcium chloride from 0.78 g/g to 2.44 g/g of the dry composite. A small reduction in water uptake was observed after 20 cycles of sorption/desorption between temperatures of 140 °C and 40 °C, indicating good cycling stability of these composites under the working conditions.

An “on–off” switchable cubic phase with exceptional thermal stability and water sorption capacity

2017 ◽  
Vol 53 (99) ◽  
pp. 13217-13220 ◽  
Author(s):  
K. N. Grafskaia ◽  
D. V. Anokhin ◽  
B. I. Zimka ◽  
I. A. Izdelieva ◽  
X. Zhu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Sorption Capacity ◽  
Water Sorption ◽  
Columnar Structure ◽  
Cubic Phase ◽  
Water Sorption Capacity

A wedge-shaped mesogen reveals structural bistability; the gyroid phase exhibits exceptional water sorption capacity whereas the columnar structure does not swell.

scholarly journals Assessment of empirical formulae for determining the hydraulic conductivity of glass beads

2018 ◽  
Vol 66 (3) ◽  
pp. 337-347 ◽  
Author(s):  
Jaromír Říha ◽  
Lubomír Petrula ◽  
Mario Hala ◽  
Zakaraya Alhasan
Keyword(s):  
Experimental Data ◽  
Hydraulic Conductivity ◽  
Glass Bead ◽  
Glass Beads ◽  
Experimental Measurements ◽  
Variable Porosity ◽  
Porosity Function ◽  
Series Of Experiments ◽  
Best Fit

Abstract Empirical formulae are often used in practice to quickly and cheaply determine the hydraulic conductivity of soil. Numerous relations based on dimensional analysis and experimental measurements have been published for the determination of hydraulic conductivity since the end of 19th century. In this paper, 20 available empirical formulae are listed, converted and re-arranged into SI units. Experimental research was carried out concerning hydraulic conductivity for three glass bead size (diameters 0.2 mm, 0.5 mm and 1.0 mm) and variable porosity. The series of experiments consisted of 177 separate tests conducted in order to obtain relevant statistical sets. The validity of various published porosity functions and empirical formulae was verified with the use of the experimental data obtained from the glass beads. The best fit was provided by the porosity function n3/(1-n)2. In the case of the estimation of the hydraulic conductivity of uniform glass beads, the best fit was exhibited by formulae published by Terzaghi, Kozeny, Carman, Zunker and Chapuis et al.

Sign in / Sign up

Export Citation Format

Share Document