Adsorption Definition and 36 Threads

Summary:: I have an assignment on slurry bed adsorption and would like to know how to calculate residence time as it is not specified. I was also wondering if anyone had any suggestions for another isotherm to try and fit the data to (other than freundlich). Thanks ##\frac {dq} {dt} = \frac...

How the number of the particles in a solution increase the probability to get adsorption on a surface? which physical terms explain this? For example when I increase the concentration of molecules in a solution I can see that the adsorption and the aggregation on the surface happen.

My book states the following: When the concentration of the adsorbate is less on the surface relative to its concentration in the bulk, it is called negative adsorption. I googled it and there are barely any source that talk about negative adsorption. I saw one or two videos and I believe that...

Anybody familiar with aspen adsorption with advance level of simulation? I need some guidance regarding my ongoing project of Nitrogen production via Air sepearation (Pressure Swing Adsorption).

I read somewhere that the "new car smell", which many of us like, is composed of formaldehyde, something that is not good for health. I also learned that it has tendencies to cause pulmonary diseases. A good option to get rid of the smell is to drive with windows down. But doing that in the...

Hello! I have a question about the first problem in Stat Mech (Physical Adsorption) from http://web.mit.edu/physics/current/graduate/exams/gen2_F01.pdf. The solution to it can be found http://web.mit.edu/physics/current/graduate/exams/gen2sol_F01.pdf. I understand the logic they use for the...

The question is: in a total reflection setup, we have an evanescent waves created in the second medium, under the separation surface. If this medium is highly adsorbing, would then affect the reflected light ? Let's say the first medium has adsorption zero, while the second is highly adsorbing...

I am using a Micromeretics ASAP2020 machine. The sample is ~25mg of reduced graphene oxide based film. The problem is I am getting adsorption isotherms showing negative volumes of adsorbate (N2) entering the tube as P/P0 increases. The sample was degassed prior to testing at 250°C for 3...

Let's consider an isotherm isobaric adsorption of gas (A) on the adsorbent (B). There are two phases in the system: - volume phase (1) that consists of gas and adsorbent. - surface phase (2) that contains a layer of adsorbed gas on the surface of adsorbent. When deriving Gibbs adsorption...

we interest one V-Sorb 2800 BET surface area analyzer, using physical adsorption principle to test particles surface area data, if anyone knows this analyzer principle?

I was reading up a bit about adsorption but am stuck at this part. http://www.chem.qmul.ac.uk/surfaces/scc/scat2_4.htm The part I'm confused about is the second last sentence.

Dear Sir/Madam, Im in my final internship for my bachelor mechanical enginering. And i have to design the filter system of a cremation proces. The fluegas is filled with toxic concentrations. Such as mercury, PCDD/PCDF, HCL, NOx The mercury and dioxine i will filter using activated carbon ...

Homework Statement An extract form my textbook: " In general, easily liquefiable gases( ie. with higher critical temperature) are readily adsorbed as van der walls forces are stronger near the critical temperature. Hence 1g of activated charcoal adsorbs more SO2( Tc=630K),than CH4...

Hello, I am trying to come up with a easy method of determining amount of gas, in this case CO2 adsorbed onto a solid adsorbent. The adsorbent i am going to use is microporous polymer (MP). So, if it has to be as simple as it can be, I think I should measure change in weight. At this point I am...

1. Surfactant molecule is made from water-loving head and grease-loving tail (Figure 1). My question: How do we measure the cross-sectional area of the alkyl chain of surfactant? Do we measure it vertically (refer to GREEN DOUBLE ARROWS of Figure 1) or horizontally (refer to RED DOUBLE ARROWS of...

Guys I want to ask that on surface of water there are unbalanced forces in downward direction so adsorption takes place so how they balance the forces in downward direction? I drawn a free body diagram but I still got a force to water molecule in downward direction so how that molecule is stable?

Homework Statement Adsorption, coagulation, and flocculation are all important processes to remove or separate target substances from mixtures. In these processes, we can observe the spontaneous decrease of entropy.; can we therefore conclude that the second law of thermodynamics doesn't always...

I am referring to the paper entitled "New Adsorption Model -Theory, Phenomena and New Concept - " which is published in J. Oleo Sci. (https://www.jstage.jst.go.jp/article/jos/64/1/64_ess14213/_article) I have question on your paper on paragraph 3 page 2 stating "The important finding is that...

Hi all, I want to measure the concentration of benzene or toluene, in water with a GC, FID detectors. I put benzene in water with an adsorbent and after hours I've to test the concentration of benzene. In the lab we've already methanol and toluene, so I'm thinking to use toluene as pollutant...

Why is it that gas with higher critical temperature are adsorbed to greater extent on surface of adsorbent as compared to gas with lower critical temperature?

Homework Statement A dilute solution of surfactants can be regarded as an ideal three-dimensional gas. As surfactant molecules can reduce their energy by contact with air, a fraction of them migrate to the surface where they can be treated as a two-dimensional ideal gas. Surfactants are...

Hi, all, I find that binding energy (Van der Waals) are different from Adsorption Energy determined let's say from desorption spectroscopy. If approaching from 3/2kT = eV -> then at room temperature, it's approximately 25meV. So, for adsorption to occur at room temperature, the binding...

Hi, Suppose I have a dissociative adsorption reaction and want to find the free energy change ΔF, this can be written at constant temperature: \Delta F = \Delta E -T\Delta S Now given the adsorption energy \Delta E_{ads} I would like to extrapolate the Free energy assuming that the adsorbate...

Homework Statement I have an adsorption reaction A+* \leftrightharpoons A^* Then I am to finde the rate constants and these should be given by an Arhennius relation, e.g. from left to right in the reaction: k_+ = f_+\exp(-\Delta E_a/k_bT) where the delta energy is the activation energy and...

Hi everyone, I'm trying to design a simple model by using Comsol Multiphysics. I set an inlet concentration of a species "cp" that will be adsorbed to a circular surface located at the center of the microfluidic cell (I named the concentration of adsorbed protein "cpl" ). I used laminar flow...

Adsorption of Benzene using Activated Carbon - Increase in concentration!? I'm not quite sure where to post but here it goes. I'm performing an adsorption experiment of benzene from solution using commercial activated carbon. It is expected that the concentration of benzene would decrease...

Hello! The other day I was reading about adsorption(gas over solid), and there it stated that it is a spontaneous process. I wanted to know how spontaneous the process is. I therefore took nitrogen adsorption over zeolite as a candidate to find its spontaneity, and to my surprise, my...

Homework Statement Please look at P9 in http://panda.unm.edu/pandaweb/graduate/prelims/SM_S09.pdf "Now consider a metal surface in which the M adhesion sites are comprised of equal populations of sites of two different types..." Homework Equations The entropy and the chemical potential of a...

Heres a short question, How does diffusion affects the rate of adsorption?. If the diffusivity of a fluid increases, will the rate of adsorption increase or decrease? Thanks in advance Cheers

Dear all, I'm trying to relate the concentration of moisture in an external environment with the concentration of moisture on the surface of a polymer. This is an adsorption and is it right to relate it using Henry's law? What is the explanation for this? On a side note, what happens when...

Hi there, I'm having trouble understanding, have adsorption isotherms are determined via Monte-Carlo simulations. What I've learned so far is: - you do a "typical" Monte-Carlo run with translations, rotations and insertions/deletions - the insertion/deletion probability is (mostly)...

What does n/w on the y-axis stand for?

Hi. I'm trying to calculate the adsorption energies at all high symmetry sites on an Aluminium (111) surface (consisting of a few atomic layers). The adsorbates are hydrogen atoms. I make sure that one hydrogen atom per primitive surface cell is adsorbed (i.e. one monolayer of hydrogen atoms...

Air is compressed to 10 atmospheres, cooled to 25 degrees C and passed through a bed of molecular sieve that has an initial moisture content of 8 lb water/100 lb sieve. the saturation vapor pressure of water at 25C is 24 mmHg. Assume M.W of air is 30 and the height of a transfer unit is 3...

Hi! Does anywone knows what happen with ammonia adsorption at pressures of 1-15 bar? thanks.:smile:

How does hydrogen gas get into a piece of palladium metal such that the amount of hydrogen is 900 times the volume of palladium?A strong pump would be required to put 900 times the volume of a gas cylinder into the cylinder or the hydrogen would have to have its temperature lowered first. Heat...