Adsorption - Science topic

This is the closest I know:

I remember there was at some point a typo in one of the formulas. so check for erratum.

Jan Dolfing

You don’t understand Lucas Lima question. Let me explain. If the adsorption process occurs, then it is a spontaneous process. The change in Gibbs energy must have a negative sign. Lucas Lima results are positive. So he is surprised and asks a question.

In addition, ΔG has units of kJ/mol, and ΔS J/mol K.

Of course, it gives important information of the interactions between the adsorbent and the adsorbed molecules at the solid liquid interface

I would suggest

Cu₂O + Pb(2+) + H₂O --->2Cu⁺ + Pb(OH)₂ (my recollection is that Pb(OH)₂ is less soluble than Cu₂O/CuOH)

2Cu⁺ + 1/2O₂ + H₂O ---> 2Cu(2+) + 2OH^- ---> Cu(2+) + Cu(OH)₂ (oxygen in water does play a role)

Consider the physical meaning of the parameters in each model. For instance, the rate constant in the pseudo-first-order model represents the rate of adsorption, while in the pseudo-second-order model, it represents the equilibrium adsorption capacity.

Noor Ul Ain The new peaks you observed at 2 theta=33.01, 34.7, 37 and 40.2 might not necessarily correspond to PbO or Pb(OH)2. They could be indicative of other lead-containing compounds formed during the adsorption process.

The castep calculation is done with the phonon spectrum checked, and the zero-point vibrational energy is derived from a direct thermodynamic analysis after the calculation is complete.

Thank you very much for your inspiration and answer to this question. Pramod Gawal

You need to determine the best pH for the dsorption efficiency by considering the tested pH used in the study.

Generally, the BJH equation can be applicable for adsorption as well for desorption branch of isotherm, but usually the results of treatment of desorption branch is taken. So you can take the value of diameter of 3.4 nm (not more digits!) as right. The most of companies producing equipments for physical adsorption of nitrogen introduce into software both types of pore size distribution calculation (from adsorption and desorption branches), but generally the results from desorption branche are taken.

The crystallinity of materials affects their adsorption capacity due to differences in surface area, surface energy, and pore structure.

In the case of silica, amorphous silica tends to have a higher adsorption capacity compared to crystalline silica due to its higher surface area, higher surface energy, and more disordered pore structure. These factors collectively enhance the availability of adsorption sites and the accessibility of molecules to those sites, leading to a greater adsorption capacity.

however, we need also consider typical of gasses/molecules and interaction with materials that you want to test

An exciting question, but it is not about origin. If you look at your "curve", it consists of 2 areas. A jump from 0 to 6.46717 (=qe) in the first time interval and a constant course of 6.46717 (=qe) over the rest of the time. This means that k2 cannot be determined and can take on more or less any (very high) value and you will always get the same R2. qe is not influenced by time. k2 is influenced by time, but there is only the constant final value of qe. If k2 is very large, the equation can be simplified to qt = qe. So k2 = 100000000000 is the same that k2 = 100000000000000000 or k2 = 1234567891011

This is what you see.

To get k2 you need to measure a "curve", with 0 < qt < qe

A hysteresis of sorts, yes, what is this for, N2 BET? If so it is generally expected that the hysteresis closes earlier on the desorption loop, it is likely ok but a bit unusual.

Thank you so much for the explanation.

Appreciate

The adsorption of gases on solids depends on the activation of the solid absorbent. The adsorption capacity is measured using static or dynamic methods. The static method is based on determining the difference between the concentration of the adsorbed component in the initial solution and in the solution, which is in equilibrium with the adsorbent.The formula Qe = (C0 − Ce) × V/m was used during the test to calculate the adsorption capacity. Here, C0 and Ce are the concentrations of Sb(III) before and after the adsorption, mg L−1, respectively; V is the volume of the Sb(III) solution, mL; m is the adsorbent dosage, mg. Isothermal adsorption test.

The integration of the surface of the breakthrough curve gives the total adsorption because it integrates the surface of the adsorption isotherms, as the adsorbent characteristics (composition, porous structure, and surface area) influence the kinetics of the adsorption process. Breakthrough curves in deep beds with axial diffusion are much sharper than constant pattern profiles due to a change in the velocity of the fluid-phase concentration wave during breakthrough.

The axial dispersion is the main parameter controlling the adsorption dynamics, and its influence on breakthrough curves can be predicted using the quasi-lognormal distribution approximation for linear isotherms and the constant pattern profiles solution for nonlinear isotherms. The integration of the surface of the breakthrough curve gives the total adsorption because it includes effects of longitudinal dispersion and diffusion to the particle surface and intraparticle processes of diffusion and adsorption on the pore surface.

Best Regards,

Your solution pH is looking good but I am not sure about your adsorbents. It could be more beneficial if you provided the information about your fabricated adsorbents including porosity, sp surface area, active sites, microstructure, etc.

you can follow the link below:

Simultaneous abatement of Ni2+ and Cu2+ effectually from find...

multipoint bet analysis give more accurate result

Certainly! If you're interested in the fundamental physics of tritium and methods of selective adsorption, here are some literature recommendations:

These resources cover various aspects of tritium, including its physics, production, and applications. Depending on your specific interests, you may find different sections of these publications more relevant to your study of selective adsorption methods.

@Darren Paul Broom. I fully agree regarding the pore sizes. Made a mistake with nm and Å.

Hi,

To give you a rough idea on how to proceed:

1) build a clean surface (graphene in your case) and run a calculation with it;

2) add the Li atom(s) and repeat.

Notice that unless you what a full coverage of Li atom of the C surface, you need to have a supercell made of graphene unit cells to reduce the ratio Li/C.

If you are proficient with Python and Jupyter, I recommend ASE (atomistic simulation environment) as a tool to generate the both the pristine graphene, the supercell and then add the Li atoms. ASE will provide the atomic position and the lattice parameters that you will need to include into the Quantum ESPRESSO input. (Indeed, you can create the input directly within ASE.)

To complete your calculation you will need to:

1) Run a SCF calculation to determine the electronic ground state density. This step requires also the convergence of the simulation parameters (energy cut-offs, first Brillouin Zone sampling).

2) Run a non-SCF calculation for the band structure on a path

3) Run another non-SCF calculation for the DOS and PDOS on a mesh of the first Brillouin Zone.

You have to repeat the above steps for each of the configuration you want to investigate (i.e. changing the Li atom positions and their number).

I hope this helps,

Roberto

Yes, AI presents a promising avenue for revolutionizing the study of adsorbent properties in materials and providing detailed information about their ability to adsorb pollutants.

Well, my ingenious researcher friend Na Sun, tackling the concentration puzzle of graphene oxide and hygromycin in their coexisting solutions requires a strategic approach.

Firstly, for graphene oxide, you Na Sun might want to explore spectroscopy techniques. UV-Vis spectroscopy can be your ally here, specifically looking at the absorption peak around 230 nm. As for hygromycin, consider employing fluorescence spectroscopy; its natural fluorescence can be a useful indicator.

An interesting article for your reading:

Moving on to the co-adsorption system, chromatography techniques could be your knights in shining armor. High-Performance Liquid Chromatography (HPLC) or Gas Chromatography (GC) could help you Na Sun separate and quantify oxytetracycline. For graphene oxide, perhaps explore Fourier-transform infrared (FTIR) spectroscopy to detect its characteristic peaks.

Remember, my friend Na Sun, precision is key. Calibration curves for each component will be your guiding light in quantifying concentrations accurately. May your experiments be as sharp as a well-crafted algorithm!

Нельзя

Based on your steps, I think there is one more step you need. The cleaved and uncleaved Na-MMT needs NVT, NPT respectively. After that, adsoprtion can be done again with NVT for cleaved, NPT for uncleaved.

The waste water also called soar water can be preserve in a seal container and can stay as long as it's not expose to air .

Megherbi Hamza

Could you give me some suitable references for your explanation?

The pHpzc = 6.9 and the optimum removal pH solution = 6.0

A simple approach to apply IA on adsorption research is through estimation of results of adsorption (means % of adsorption) based upon the several variables that can partake in a adsorption process (means, pH, shaking time, content of adsorbent, content of pollutant, temperature, among others). You can use in a easy way the Matlab neural network tool (named prediction) to be able to "predict" the results of an adsorption process after having created an artificial neural network that can predict a %adsorption on the basis of several parameters.

Suresh Kumar Govindarajan

When you think about an oil reservoir, you talk about some kind of nanoparticles. The structure of an oil reservoir is a xerogel filled with oil. Before this, you yourself prepared the airgel from nanotubes. Please note that the capillaries of the oil reservoir are nanosized, not nanoparticles. It is possible to transfer a model experiment in a laboratory to a natural reservoir, but with caution. I propose a section of our book on this issue.

Kd should be dimensionless in order to get ∆G with the right units. Since Kd =qe/Ce in ( mg/g)/(mg/L) gives Kd in (L/g). To do the conversion, you should multiply the obtained values of Kd expressend in (L/g) by (the molecular weight of the considered pollutant (g/mol) x ( the number of moles of water per L of solurion (55 moles/L) . Once, you do this, you will get Kd without dimension and ∆G, ∆H and ∆S values with the right units. GOOD LUCK. Benaouda BESTANI

Elias Mosaffa thank you so much sir

What is your starting material - you failed to mention what it is. What is the particle size, moisture and ash content of the starting material? What temperature did you pyrolyse at and for how long and in what sort of reactor? You have not provided enough information for an assessment or sensible response to be made, nor how you've measured the BET.

This is quite interesting.

It is believed that the pyrolysis at an elevated temperature (≥700 °C) usually lead to higher porosities in the product derived from woody feedstocks. This could be due to the slow decomposition of lignin in woody feedstocks at lower temperature. Rate of decomposition increases at higher temperature (≥700 °C) leading to higher porosities in the pyrolyzed product. On the other hand, peat-based biomass is characterized with higher content of hemicellulose which easily gets decomposed relatively at lower temperatures and produced porous biochar.

May be after the degassing at 200 for 6 h, the content of residual hemicellulose in your biochar started degrading. There may be other reasons for that, but I think you need to check the composition of hemicellulose and lignin.

I have to correct Ali Alnazza Alhamad . The monolayer (from which the surface area can be calculated using BET equation) is formed around 0.1 p/0, or even lower for micropore-containing samples.

The vertical rise at p/p0 ~1 has nothing to do with the sample... its simply the adsorbate condensing in the sample cell Christian Weinberger spotted that. Often comes about by incorrectly "assuming" a value for p0 and not using the correct value by having the instrument measure it. In this case, the p0 value being used by the instrument is higher than the true value. For N2/LN2 p0 is around 10 torr higher than ambient atmospheric pressure... you can do a quick sanity check on the data using that to see how much the p0 was in error.

N2 adsorption and BET will give you the surface area of the adsorbent, but tell you nothing about the composition and amount of gases adsorbed in the sample from flue gases. What has been adsorbed can be found by thermal desorption (TPD) and taking the evolved gases into a mass-spec for identification. MS signals are not the easiest to quantify, so weight loss is often used to do the quantification and match up with, for example, gravimetric TPD, i.e. TGA

Abhijit Debnath

According to the theory, with the same structure of the surface of the adsorbent, adsorption is determined by the specific surface of the adsorbent. Heavy metal ions are usually d-metals in structure. They form complexes well with electron donors on the surface of the adsorbent. Cadmium ion can be adsorbed on one adsorbent without complex formation, and on another with it.

Just from the order, you can't tell. Chemisorption can have all sorts of orders, from first order (one homolytic bond cleavage, no lateral interactions) to extremely complex (multiple surface diffusion processes and reactions involved). Physisorption is more likely to have simpler mechanisms and therefore higher orders are less likely because there are no bond-breaking steps, but lateral interactions may also destroy the simplicity there.

Since physisorption and chemisorption are differentiated by the binding energy, it's better to measure that. If you use TPD for that, complex desorption kinetics may be required in order to reproduce the spectra completely, but what counts is the energy you get out of it.

Greetings, dear viewers!

In this video, we'll explore How to do Gibbs Free Energy Calculation for Oxygen Reduction Reaction (ORR) using VASP code . If you discover this information to be beneficial, kindly express your support by giving it a thumbs up, leaving a comment, and sharing it with others. We appreciate your viewership.

File Link: https://drive.google.com/file/d/1hhcjfbVpP48yUNdKY6aEc9xZo8otra5k/view?usp=sharing

Videos Links to watch:

1) Setting up a VASP calculation - Beginners https://www.youtube.com/watch?v=lUn9qVSlz3c

2) How to find the vibrational frequency of gas phase molecule https://www.youtube.com/watch?v=NmK_XavYt5E

3) Way to Find Entropy of Gas Phase Small Molecules https://www.youtube.com/watch?v=CLwrcBHq7Zg

4) How to get experimental ZPE and entropy of the gas phase molecules https://www.youtube.com/watch?v=wvEBS0Eu2QI

5) How to perform geometry optimization in VASP https://www.youtube.com/watch?v=S5fARRzbsgs

6) How to Perform Vibrational Frequency Calculation in VASP https://www.youtube.com/watch?v=WG7wubNGX2E

7) How to get ZPE and Entropy of the Adsorbed systems in VASP https://www.youtube.com/watch?v=ZyNUmDZqDM4

Warm regards, SB

To calculate the Ce , you need first to perform the calibration curve on MB. The resulted équation from fitting Will be in fhe form of y=ax+b.

So your Will be Ce=y-b/a were y: absorbance; b: intercept and a: the slope

no special software needed, just make a graph that tells a story.

Yes, adsorption is one of the mechanisms of matter accumulation (fouling) on reverse osmosis membranes. Adsorption is the process of attaching molecules or particles from a fluid phase onto a solid surface, such as a membrane. Adsorption can be either physical or chemical, depending on the nature and strength of the interactions between the adsorbate and the adsorbent. Physical adsorption, also known as physisorption, involves weak van der Waals forces and is reversible. Chemical adsorption, also known as chemisorption, involves stronger covalent or ionic bonds and is irreversible. Adsorption can occur on any type of membrane surface, but it is more pronounced on hydrophobic membranes, which have a low affinity for water and a high affinity for organic compounds.

Adsorption can lead to fouling by reducing the effective membrane area, increasing the hydraulic resistance, altering the membrane surface properties, and providing sites for further deposition and growth of foulants. Adsorption can also affect the selectivity and permeability of the membrane, as well as the quality of the permeate. Adsorption can be influenced by several factors, such as the type and concentration of the adsorbate, the pH and temperature of the solution, the membrane material and surface characteristics, and the operating conditions of the membrane system.

Adsorption is often the initial step of fouling, followed by other mechanisms such as pore blocking, cake layer formation, and biofilm development. Therefore, controlling and minimizing adsorption is crucial for preventing and mitigating fouling. Some of the strategies to reduce adsorption include modifying the membrane surface to increase its hydrophilicity, using antiscalants or dispersants to inhibit the adsorption of inorganic or organic foulants, optimizing the operating parameters to enhance the shear stress and turbulence near the membrane surface, and performing periodic cleaning and backwashing to remove the adsorbed layer.

see this

Brahim Bouricha Thank you Sir

I agree with Yuri Mirgorod . Using a strongly ionic, small-molecule buffer like potassium phosphate is in principle a good choice.

What I would try is to reduce the buffer concentration to the minimum necessary and see if you still get the interference. If the concentration of the buffer has an effect, you can try a series of decreasing concentrations and extrapolate to what would happen in the absence of the buffer.

Rara Zuhara

No. A hydrogen bond is formed between the oxygens of the carbonyl and ether groups of fats and the hydrogen of the hydroxyl groups of silica.

Thank you, Professor Yuri, and Professor Emanuel for your valuable response.

Is this what you're looking for?

1. build a Al surface and calculation its energy, E_clean

2. add a adsorbent on Al surface and calculation its energy, E_adsorption

3. remove the Al surface in step and calculation its energy, E_adsorbent

Adsorption energy of adsorbent on al surface = E_adsorption - E_clean - E_adsorbent

📷Environmental Engineering Science

Environ Eng Sci. 2012 Jun; 29(6): 494–501.doi: 10.1089/ees.2010.0490PMCID: PMC3363014PMID: 22693416Treatment and Remediation of Petroleum-Contaminated Soils Using Selective Ornamental Plants Rui Liu,1,* Rajendrasinh N. Jadeja,2 Qixing Zhou,1,,3,* and Zhe Liu1Author information Article notes Copyright and License information PMC DisclaimerGo to:Abstract Pot-culture experiments were carried out to assess the phytoremediation potential of 14 ornamental plants in weathered petroleum-contaminated soil, which was collected in the Shengli Oil Field, one of the biggest oil fields in China, by examining their impact on the degradation potential of total petroleum hydrocarbons (TPHs) and its composition. Results showed Gaillardia aristata, Echinacea purpurea, Fawn (Festuca arundinacea Schreb), Fire Phoenix (a combined F. arundinacea), and Medicago sativa L. could effectively reduce TPHs and its composition in 10,000 mg kg−1 TPH-contaminated soil. After a 30-day pot-culture experiment, the removal rates were 37.16%, 46.74%, 49.42%, 41.00%, and 37.93%, respectively, significantly higher than that in the control (only 12.93%). Removal rates of TPH composition including saturated hydrocarbon, aromatic hydrocarbon, asphaltene, and polar compound reached 39.41%, 38.47%, 45.11%, 42.92%, and 37.52%, respectively, also higher than that in the control (only 6.90%). Further, the total biomass did not significantly decrease for all plants tested in 10,000 mg kg−1 TPH-contaminated soil. Fourier transform infrared spectroscopy confirmed the presence of oil in the plant tissues. These results suggested that the typical ornamental species including G. aristata, E. purpurea, Fawn, Fire Phoenix, and M. sativa can be adopted in phytoremediation of oil-contaminated soil.Key words: : phytoremediation, total petroleum hydrocarbons (TPHs), petroleum-contaminated soil, ornamental speciesGo to:Introduction With rapid development of industry, automobiles, and airplanes, the demand for petroleum is increasingly expanded. However, plenty of petroleum was impregnated to soil during the exploration, translocation, and processing, and it caused significant environmental pollution (Environment Agency, 2002; Banks et al., 2003). According to relevant reports, the concentration of total petroleum hydrocarbons (TPHs) around the Liaohe Oil Field may be more than 10,000 mg kg−1, rather higher than the risk-based cleanup levels (500 mg kg−1) in industrial soils for TPHs in Oklahoma, United States (Cao and Li, 2010). The levels of TPHs around the highly contaminated sites were 30%–50% in the surface soil (0–20 cm) (Cunningham et al., 1996; Sun and Zhou, 2007). As a result, the toxic effects of TPHs have been extensively documented; the research on petroleum-contaminated soil has been paid great attention (Zhou et al., 2005).Typical treatments for petroleum-contaminated soil involve in excavating the soil and removing it for treatment using physical or chemical methods (Zhou, 1995; Li et al., 1997; Hans-Holgar and Alexander, 2000; Juck et al., 2000). These treatments, though effective, are costly and involve in extensive site disturbance. To find more financially acceptable options, biological methods have been investigated, such as phytoremediation, that is, using living green plants in situ to “clean-up” contaminated lands. Phytoremediation is a low-input approach depending on natural attenuation by biodegradation and physiochemical mechanisms that decrease the pollutant concentration wherein sowing plants may be the only intervention (Schwab et al., 1999; Liste, 2000; Joner and Leyval, 2001; Muratova et al., 2003; Robson et al., 2004; Zhou and Song, 2004; Parrish et al., 2005).In the past decade, it has produced an extensive body of research on the phytoremediation of both organic and inorganic contaminants (Chaîneau et al., 1997; Dzantor et al., 2000; Singer et al., 2003; Smreczak et al., 2003; Rentz et al., 2004). Most hydrocarbon degradation is believed to occur through a rhizosphere effect; plants exude organic compounds through their roots, which increase the density, diversity, and activity of specific microorganisms in the surrounding rhizosphere, which in turn degrade hydrocarbons (Siciliano and Germida, 1998; White et al., 2003; Rutherford et al., 2005). Few studies only by Zhou and coworkers (Peng et al., 2009; Cai et al., 2010; Zhang et al., 2010), however, have examined ornamental plants for phytoremediation of petroleum-contaminated soils. This has their advantages in revegetation cover and beautifying surrounding environment. Phytoremediation using ornamental plants can avoid entering food chains and effectively reduce the pollution, than using crops. The aim of this work was to screen out ornamental plants with high effectiveness for treating petroleum-contaminated soil, by examining the removal rate of TPHs and its composition after a 30-day pot-culture experiment in TPH-contaminated soil.Go to:Experimental Sampling and tested materials Weathered petroleum-contaminated soil was collected (sampled to a depth of 250 mm) from the Shengli Oil Field in Dongying City, Shandong Province, China. Soil analysis was done by the Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China. The contaminated soil had been classed as a drained brown soil with pH 7.66, and carbon (C), phosphorus (P), nitrogen (N), and available P concentrations were 45.77, 0.65, 0.73, and 0.002 g kg−1, respectively. Uncontaminated reference soil samples were collected from the Wanliutang Park, Shenyang, China. The average concentration of TPHs in contaminated soil collected was 28,000 mg kg−1 and its composition of TPHs was 40.76% of saturated hydrocarbon fraction, 27.02% of aromatic hydrocarbon fraction, and 30.82% of asphaltene and polar fraction. Collected soil was sieved through a 4.00-mm sieve to ensure homogeneity. According to the pretest results, all plants tested could not grow in the weathered petroleum-contaminated soil directly. Through the addition of uncontaminated reference soil, contaminated soil collected was diluted to 10,000 mg·TPHs kg−1 (WTPHS/Wsoil) according to the experimental design.The tested seeds of plant species were purchased from Kelaowu Seeds Company, Beijing, China.Experimental design The tested plants and their basic botanical characteristics are summarized in Table 1. Soil tested (2.5 kg) was added to 20-cm-diameter pots. A disc of filter paper was placed in the bottom of each pot to prevent the dry soil escaping out from the drainage holes and pots were placed on saucers. To each pot, single plant species treatments (n=6) were transformed, and germination of each seed took place in 15 days. . . . "

See the entire article - Source:

thank you so much Dr. Thomas Waluga

The DPPH (2,2-Diphenyl-1-pricylhydrazyl) method can be used as a chemical method for determining the content of free radicals (see attached article).

RL indicates the shape of the isotherms to be either unfavourable (RL > 1), linear (RL = 1), favourable (0 < RL <1) or irreversible (RL = 0).

No, adsorption isotherm cannot be calculated solely from three initial concentrations for heavy metal removal. Adsorption isotherms are experimental data that describe the relationship between the equilibrium concentration of a solute in solution and the amount of solute adsorbed onto a solid adsorbent at a constant temperature. These isotherms are typically obtained by conducting multiple experiments at different initial concentrations of the solute and measuring the equilibrium concentrations after adsorption.

To determine an adsorption isotherm, a series of experiments must be conducted at different initial concentrations of the heavy metal. The equilibrium concentrations of the metal in solution are then measured after adsorption, and the amount of metal adsorbed onto the adsorbent is calculated. By plotting the equilibrium concentration of the metal against the amount adsorbed, an adsorption isotherm can be obtained.

Having only three initial concentrations would not provide enough data points to accurately determine the shape and characteristics of the adsorption isotherm. Therefore, it is necessary to conduct experiments at multiple initial concentrations to obtain a complete picture of the adsorption behavior and calculate the adsorption isotherm

Of cource it could be better to fit with langmuir mathematical model regarding this particular case.

The crystallinity degree of a material can indeed have an impact on its adsorption capacity for heavy metals, but the relationship can be complex and depends on the specific material and the heavy metal in question.

In general, higher crystallinity may reduce the adsorption capacity of a material because it implies a more ordered and compact structure, which might have fewer active sites for adsorption. Conversely, materials with lower crystallinity, such as amorphous or disordered structures, may have more available surface sites and, therefore, exhibit higher adsorption capacity.

However, it's essential to note that the relationship between crystallinity and adsorption is not universal and depends on various factors:

a. The type of heavy metal: Different heavy metals have different affinities for various materials, and their interactions can vary based on the metal's properties.

b. The specific adsorbent material: The composition and structure of the adsorbent material play a significant role. Some materials are naturally more effective at adsorbing heavy metals due to their chemical properties.

c. Surface functional groups: The presence of specific functional groups on the material's surface can enhance adsorption, regardless of crystallinity.

d. pH and environmental conditions: The pH and other environmental factors can influence the adsorption capacity of a material for heavy metals.

e. Particle size and morphology: The size and shape of the material particles can affect their adsorption properties.

Therefore, while there is a general trend that higher crystallinity may reduce adsorption capacity, it's essential to consider these other factors and conduct specific experiments or studies to determine the effectiveness of a particular material for adsorbing heavy metals in a given context.

Pre-treatment: The preparation and pre-treatment of biochar can also impact its adsorption capabilities. Puffed rice biochar might not have undergone suitable activation or modification processes to enhance its adsorption properties.

Chemical Properties: The chemical composition of the biochar can influence its adsorption capacity. Some biochars may have functional groups on their surface that enhance their ability to adsorb certain pollutants. Puffed rice biochar may lack these functional groups or have an unfavorable chemical composition for dye removal.

which software are usefull to Curve fitting ?

I suggest that you consult the world-renowned treatise on the subject of water analysis, "Standard Methods for the Examination of Water and Wastewater. The 24th edition of this treatise was released on 13 January 2023. You can access this book from a library, or consult the following address for electronic version.

I also suggest , the following article:

Kumar et al 2016. Water quality monitoring: A comparative case study of municipal and Curtin Sarawak's Lake samples. IOP Conference Series: Materials Science and Engineering 121: 012019 (2016).

I have enclosed the Abstract for your benefit. I am not enclosing the whole article because I do not want to violate copyright regulations. You can consult the corresponding author at: [email protected]

"Abstract. In this study, particle size distribution and zeta potential of the suspended particles in municipal water and lake surface water of Curtin Sarawak’s lake were compared and the samples were analysed using dynamic light scattering method. High concentration of suspended particles affects the water quality as well as suppresses the aquatic photosynthetic systems. A new approach has been carried out in the current work to determine the particle size distribution and zeta potential of the suspended particles present in the water samples. The results for the lake samples showed that the particle size ranges from 180nm to 1345nm and the zeta potential values ranges from -8.58 mV to -26.1 mV. High zeta potential value was observed in the surface water samples of Curtin Sarawak’s lake compared to the municipal water. The zeta potential values represent that the suspended particles are stable and chances of agglomeration is lower in lake water samples. Moreover, the effects of physico-chemical parameters on zeta potential of the water samples were also discussed."

Hope the information is useful to you.

All the best to you in your research endeavors and strides.

AI answer

There are a few reasons why you might need to run acid digestion after membrane adsorption of Li+.

Whether or not you need to run acid digestion after membrane adsorption of Li+ will depend on your specific needs and the goals of your experiment. If you are unsure, it is always best to consult with an expert.

Here are some references that you may find helpful:

All I done collect 3 answers in one passage.

Good luck

Adsorption Capacity: Hydrogels primarily adsorb water and other polar molecules. They have a high water retention capacity due to their ability to absorb and retain large amounts of water, typically many times their dry weight.

Adsorption Capacity: Aerogels can have high adsorption capacities for a wide range of substances, including gases and liquids, due to their large surface area and interconnected nanoporous structure. They are particularly effective at adsorbing low-density gases.

Thank you!

By increasing the absorption capacity, we can hope that the removal percentage will also increase.

I think It depends on the aim of your study, economic considerations (adsorbent capacity, regeneration cycle...)or environmental ones (maximizing the removal).

if what you mean by adsorption capacity is the adsorbate loading on adsorbent (g of adsorbate adsorbate to kg of adsorbent); For most systems

This method is used to study the adsorption of membrane proteins on hollow fiber PES ultrafiltration membranes. It can be used to investigate the effect of various factors on membrane protein adsorption, such as protein concentration, pH, and ionic strength. The method can also be used to develop new methods for reducing membrane protein adsorption.

Here are a few more examples:

These studies have investigated a variety of factors that affect membrane protein adsorption, such as protein concentration, pH, ionic strength, membrane surface properties, and surface modification. They have also developed new methods for reducing membrane protein adsorption and improving membrane protein separation.

Addenda

According to the first result, [1], one way to fabricate an antifouling PES ultrafiltration membrane is by blending sulfonated polysulfone (SPSF) with different sulfonation degrees (10%, 30%, and 50%) to PES and using the non-solvent induced phase inversion method (NIPS). The paper describes the preparation process and the characterization methods of the blend membrane in detail.

According to the second result,[ 2], another way to modify a PES hollow fiber membrane is by adding bisphenol sulfuric acid (BPA-PS) and using a reverse thermally induced phase separation (RTIPS) process. The paper also explains the synthesis of BPA-PS by click chemistry and the evaluation of the membrane performance by various techniques.

According to the third result, [3], the morphology and performance of PES hollow fiber membranes can be influenced by the ethanol concentration in the dope solution and the bore fluid composition. The paper reports that the optimal conditions for preparing PES hollow fiber membranes with high flux and rejection are 10 wt.% ethanol concentration and 90:10 NMP/H2O as a bore fluid.

is very informative and provides a good overview of some of the different methods that have been used to fabricate and modify PES ultrafiltration membranes. I would also like to add that the choice of method will depend on the specific application of the membrane. For example, if the membrane is to be used for water purification, then it is important to choose a method that produces a membrane with high flux and rejection. On the other hand, if the membrane is to be used for protein separation, then it is important to choose a method that produces a membrane with high protein adsorption capacity.

Here are some additional thoughts on the three papers mentioned:

Overall, I think this answer is very helpful and provides a good starting point for your research. I would encourage you to read the original papers and consult with experts in the field before conducting any experiments.

Good luck

Dear' Muhammad

At First Build Cu(111) Model/sheet whatever you want. then optimized it up to local minimal energy. then again separately optimized methane molecule as well. Now finally again redraw the system containing Cu(111) as well as methane. and once again optimized it to get your result.

Best regards

Vikrant Singh

Molecular dynamics (MD) simulations are a technique that allows you to study the interactions and motions of atoms and molecules over time. To perform MD simulations, you need to specify the initial positions and velocities of the atoms, the interatomic potential functions that describe the forces between them, and the integration algorithm that propagates the system forward in time 1.

To carry out MD simulations between oxalic acid and bare Fe surface in a vacuum, you can follow these steps:

To calculate the adsorption energy by dmol3 in Materials Studio, you can follow these steps:

E_ads = E_system - E_Fe - E_oxalic

where E_ads is the adsorption energy, E_system is the total energy of the adsorbed system, E_Fe is the total energy of the isolated Fe surface, and E_oxalic is the total energy of the isolated oxalic acid molecule 3.

Some references for more information are:

1: 7.3: Molecular Dynamics Simulations - Chemistry LibreTexts 2: Material Studio User Guide - Accelrys 3: Adsorption Energy Calculation Using DMol3 - Accelrys Molecular dynamics (MD) simulations are a technique that allows you to study the interactions and motions of atoms and molecules over time. To perform MD simulations, you need to specify the initial positions and velocities of the atoms, the interatomic potential functions that describe the forces between them, and the integration algorithm that propagates the system forward in time 1.

To carry out MD simulations between oxalic acid and bare Fe surface in a vacuum, you can follow these steps:

To calculate the adsorption energy by dmol3 in Materials Studio, you can follow these steps:

E_ads = E_system - E_Fe - E_oxalic

where E_ads is the adsorption energy, E_system is the total energy of the adsorbed system, E_Fe is the total energy of the isolated Fe surface, and E_oxalic is the total energy of the isolated oxalic acid molecule 3.

Some references for more information are:

1: 7.3: Molecular Dynamics Simulations - Chemistry LibreTexts 2: Material Studio User Guide - Accelrys 3: Adsorption Energy Calculation Using DMol3 - Accelrys

Here are the titles, authors, publishers, and dates of the references I cited:

You can calculate these parameters using Origin software after identifying the equation in the analysis window and let C/Co as Y and t as X variable according to the breakthrough curve. Then, the parameters values would be calculated according to the breakthrough curve, which you drew it in the beginning.

Hi, could you please guide me how did you calculate the density profile in pore width?

Why would consider this an unexpected result? Hydrogen is pretty well capable of reducing Ni²⁺ to Ni⁰ and water formation from the counterion would be a quite reasonable mechanism

Just to be sure: you are using the correct convention "higher internal energy = less stable" and "lower internal energy = more stable", right?

I've seen the opposite case, i.e. the early adsorption stages being highly favorable while the later stages were more and more unstable (e.g.Cs on a different metal). The reason was that at first, the Cs could get rid of electron density while the later arriving Cs can no longer do that and is actually repelled because surface dipoles are coming closer to each other and thus becoming repulsive.

You are describing nitrobenzene on an unspecified surface, if it's unstable in the beginning, that would mean that [whatever your surface is] and nitrobenzene don't really like each other. If it becomes favorable later, that would mean it's actually mostly binding to itself and not the surface.

A very simple (but inaccurate) approach would be to relate the initial slopes of the isotherms: Selectivity = slope1/slope2

For a more detailed approach check for IAST (Ideal adsorbed solution theory)

The current absence of specific information regarding which materials were adsorbed using which adsorbents under which conditions has led to a potential range of interpretations regarding the underlying cause for the observed negative adsorption capacity. This situation could stem from various possibilities, such as errors in the ICP analysis procedure, experimental process, or in the design of the adsorption experiments.

Several assumptions could be considered to shed light on this issue:

Considering the aforementioned possibilities could contribute to a better understanding of the situation.

You can discuss whatever, but we are supposed to follow IUPAC recommendation regardless you like it or not. See

and refs in it.

I really recommend you to use RASPA to do so rather than to use LAMMPS. RASPA is specialize at gas adsorption calculations. If you need more details of RAPSA, check this link (https://iraspa.org/raspa/).