Transient Kinetic and Thermodynamic Behaviour of Langmuir Adsorption in a Flow System

1999 ◽  
Vol 64 (4) ◽  
pp. 726-734 ◽  
Author(s):  
Miloslav Pekař ◽  
Josef Koubek
Keyword(s):  
Adsorption Equilibrium ◽  
Flow System ◽  
Adsorption Rate ◽  
Adsorption Behaviour ◽  
Transient Responses ◽  
Simple Reaction ◽  
Langmuir Adsorption ◽  
Thermodynamic Behaviour

Various kinetic pathways to the adsorption equilibrium in an isothermal differential bed of adsorbent are illustrated on several examples. Discussion is based on the computed transient responses of adsorption rate and distance from adsorption equilibrium to the start of adsorptive feed. It is shown that adsorption behaviour in flow system may not be smooth and very steep changes on the rate responses may appear. Even the simple reaction need not approach equilibrium smoothly but at a jump. The approach assuming "closeness to the equilibrium" should be used very carefully, in this case.

COPPER (Cu2+) REMOVAL FROM WATER USING NATURAL ZEOLITE FROM GEDANGSARI, GUNUNGKIDUL, YOGYAKARTA

2015 ◽  
Vol 2 (2) ◽  
Author(s):  
Wahyu Wilopo ◽  
Septiawan Nur Haryono ◽  
Doni Prakasa Eka Putra ◽  
I Wayan Warmada ◽  
Tsuyoshi Hirajima
Keyword(s):  
Waste Water ◽  
Economic Growth ◽  
Heavy Metals ◽  
Natural Zeolite ◽  
Adsorption Equilibrium ◽  
Waste Water Treatment ◽  
Batch Test ◽  
Maximum Capacity ◽  
Geological Materials ◽  
Langmuir Adsorption

Development of indusrialization and urbanization not only increase economic growth but also contribute to the environmental degradation, especially contamination of heavy metals in water. In other side, there are many geological materials have capability to immobilize heavy metals. Therefore, the objective of this research is to know the maximum capacity of natural zeolite from Trembono area, Gunung Kidul regency to immobilize copper (Cu2+) from water and to understand their mechanism. This experiment was carry out by a batch test. The result showed that the maximum capacity of zeolite to immobilize Cu (qmax) is 63,69 mmolCu/kg Zeolite according to Langmuir adsorption equilibrium model. In addition, the capability to immobilize Cu will increases due to decreasing the grain size. The result of this research can be used as an alternative for waste water treatment, especially Cu. Keywords: Removal, copper (Cu2+), natural zeolite, Langmuir isotherm

Absorption Equilibrium and Thermodynamics of Fenugreek Yellow Pigment on Macroporous Resins

2011 ◽  
Vol 233-235 ◽  
pp. 91-94
Author(s):  
Feng Han ◽  
Wen Hong Li ◽  
Xuan Tang ◽  
Dong Li
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Adsorption Equilibrium ◽  
Yellow Pigment ◽  
Adsorption Models ◽  
Freundlich Model ◽  
Langmuir Adsorption ◽  
Macroporous Resins ◽  
Equilibrium Data

The adsorption equilibrium and thermodynamics of pigment extracted from Fenugreek after degumming on macroporous resins was investigated under differentinitial concentrations. The suitability of the Freundlich and Langmuir adsorption models to the equilibrium data was investigated. The model fitness was determined by R2 . Thermodynamic parameters were calculated by the Van’t Hof equation.The results showed that Freundlich model gave a better fit of adsorption isotherms than Langmuir models. The positive value of enthalpy(∆H) indicated that the adsorption was endothermic, the negative value of Gibbs free energy (∆G) showed the spontaneous and favoured nature of adsorption, and the entropy(∆S) was positive.The resins LS-46 showed an effective adsorbtion for Fenugreek yellow pigment.

The Research for Microwave Modified Vermiculite Adsorption of Zn2+

2014 ◽  
Vol 809-810 ◽  
pp. 493-499
Author(s):  
Li Fang Bao ◽  
Chen Li Wang ◽  
Jin Chuan Gu ◽  
Sheng Zhong ◽  
Rui Wang
Keyword(s):  
Reaction Time ◽  
Correlation Coefficient ◽  
Adsorption Isotherms ◽  
Reaction Temperature ◽  
Room Temperature ◽  
Adsorption Equilibrium ◽  
Adsorption Rate ◽  
Absorption Mechanism ◽  
Initial Concentration ◽  
The Impact

The impact on the adsorption of Zn2+of these factors, initial concentration, modification time, reaction time vermiculite dosage, reaction temperature and pH having, and absorption mechanism are studied . The results show that: microwave modification time 30s, reaction time 40min, modified vermiculite dosage 8g/L, reaction temperature 30°C, reaction pH 6, Zn2+ adsorption rate can reach 97.91%, adsorption isotherms of Zn2+ by microwave modified vermiculite show that the adsorption equilibrium is consistent with Langmuir curves, correlation coefficient reached to 0.997 at room temperature.

Adsorption Equilibrium and Kinetics of Copper from Aqueous Solutions on Steel Slag

2011 ◽  
Vol 354-355 ◽  
pp. 33-36
Author(s):  
Jian Yun Li ◽  
Quan Xian Hua ◽  
Jun Ling Niu ◽  
Jian Wei Tang ◽  
Ke Xu
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Equilibrium ◽  
Steel Slag ◽  
Adsorption Rate ◽  
Batch Adsorption ◽  
Equilibrium And Kinetics ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data ◽  
Kinetics Of

The adsorption of copper in aqueous solutions by steel slag was studied in batch adsorption experiments. The adsorption equilibrium data fitted best with Langmuir and Freundlich equations. The adsorption was preferential type. A comparison of the kinetics models on the apparent adsorption rate showed that the adsorption system was best described by the pseudo-second-order kinetics. The adsorption rate was controlled by both liquid film diffusion and intraparticle dispersion.

scholarly journals Dyeing Property and Adsorption Kinetics of Reactive Dyes for Cotton Textiles in Salt-Free Non-Aqueous Dyeing Systems

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1030 ◽  
Author(s):  
Jiping Wang ◽  
Yuanyuan Gao ◽  
Lei Zhu ◽  
Xiaomin Gu ◽  
Huashu Dou ◽  
...  
Keyword(s):  
Surface Tension ◽  
Adsorption Equilibrium ◽  
Aqueous Media ◽  
Reactive Dyes ◽  
Reactive Dye ◽  
Adsorption Rate ◽  
Order Kinetic ◽  
Cotton Textiles ◽  
Order Kinetic Model ◽  
Large Water

In recent years, new concepts in textile dyeing technology have been investigated which aim to decrease the use of chemicals and the emission of water. In this work, dyeing of cotton textiles with reactive dyes has been investigated in a silicone non-aqueous dyeing system. Compared with conventional aqueous dyeing, almost 100% of reactive dyes can be adsorbed on cotton textiles without using any salts in non-aqueous dyeing systems, and the fixation of dye is also higher (80%~90% for non-aqueous dyeing vs. 40%~50% for traditional dyeing). The pseudo-second-order kinetic model can best describe the adsorption and equilibrium of reactive dyes in the non-aqueous dyeing systems as well as in the traditional water dyeing system. In the non-aqueous dyeing systems, the adsorption equilibrium of reactive dyes can be reached quickly. Particularly in the siloxane non-aqueous dyeing system, the adsorption equilibrium time of reactive dye is only 5–10 min at 25 °C, whereas more time is needed at 60 °C in the water dyeing system. The surface tension of non-aqueous media influences the adsorption rate of dye. The lower the surface tension, the faster the adsorption rate of reactive dye, and the higher the final uptake of dye. As a result, non-aqueous dyeing technology provides an innovative approach to increase dye uptake under a low dyeing temperature, in addition to making large water savings.

Synthesis of a Novel Hexanedioyl Thiourea Resin and its Adsorption Properties for Ag(I)

2012 ◽  
Vol 217-219 ◽  
pp. 1213-1217
Author(s):  
Zhong Nan Wang ◽  
Hong Zhong ◽  
Shuai Wang
Keyword(s):  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Interfacial Polymerization ◽  
Langmuir Adsorption Isotherm ◽  
Adsorption Properties ◽  
Chelating Resin ◽  
Langmuir Adsorption ◽  
Polyethylene Polyamine ◽  
Ft Ir ◽  
Equilibrium Adsorption Capacity

A novel hexanedioyl thiourea chelating resin(HTR) was synthesized through interfacial polymerization of hexanedioyl diisothiocyanate and polyethylene polyamine. Its structure was confirmed by FT-IR. The adsorption properties of HTR for Ag(I) were investigated by batch operation . The results show that the adsorption equilibrium of HTR for Ag(I) is achieved after 12 hour at 20°C, the equilibrium adsorption capacity is 4.56mmol/g and increases as the temperature or pH rises, the adsorption process accords with G. E. Boyd equation and Langmuir adsorption isotherm as well, and the silver-loaded resins can be quantitatively eluted by a solution containing 6% thiourea in 1mol/L HNO3.

High performance of amidoxime/amine functionalized polypropylene for uranyl (VI) from aqueous solution

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Fangting Chi ◽  
Jie Xiong ◽  
Sheng Hu ◽  
Jingwei Hou ◽  
Mei Gu ◽  
...  
Keyword(s):  
High Performance ◽  
Adsorption Equilibrium ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Adsorption Rate ◽  
Polypropylene Fibers ◽  
Amino Groups ◽  
Amine Functionalized ◽  
Grafting Technique ◽  
Group Fourier Transform

Abstract Amidoxime-based adsorbents are widely investigated as the main adsorbent in the recovery of uranium from seawater. However, the adsorption rate and loading capacity of such adsorbents should be further improved due to the economic viability consideration. In this paper, the adsorption properties of amidoxime-based adsorbent were enhanced through the cografting of amino groups. The acrylonitrile (AN) and glycidyl methacrylate (GMA) were firstly cografted onto polypropylene fibers by preirradiation grafting technique. Then the cografted fibers were treated with ethylenediamine to convert GMA to amino group, following treated with hydroxylamine to convert AN groups to amidoxime (AO) group. Fourier transform infrared spectroscopy, scanning electron microscopy and contact angle measurement were used to characterize the structure of the adsorbent. The results showed that the amidoxime and amino groups had been successfully grafted onto the polypropylene fibers. For AO fiber, high adsorption rate was observed within the first 30 min and the plateau value of 42.3% uranium loading (0.0904mg/g) was reached at around 30 min. The AO/amine fibers exhibited a higher adsorption rate. The adsorption equilibrium for AO/amine fiber was attained within 20 min, resulting in the adsorption of 93.3% uranium loading (0.191mg/g). Additionally, AO/amine fibers can avoid pH reducing for better adsorption efficiency.

Synthesis and Adsorption Properties for Ag(I) of Pyridinedicanbnyl Thiourea Resin

2012 ◽  
Vol 581-582 ◽  
pp. 180-184 ◽  
Author(s):  
Zhong Nan Wang ◽  
Hong Zhong ◽  
Shuai Wang
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Langmuir Adsorption Isotherm ◽  
Adsorption Properties ◽  
Chelating Resin ◽  
Batch Operation ◽  
Langmuir Adsorption ◽  
Ft Ir ◽  
Equilibrium Adsorption Capacity

A novel pyridinedicanbnyl thiourea chelating resin(PTR) was synthesized from pyridinedicanbnyl diisothiocyanate and diethylene triarmine , its structure was confirmed by FT-IR. The adsorption properties of PTR for Ag(I) were investigated by batch operation . The results show that the adsorption equilibrium of PTR for Ag(I) is achieved after 14 hour at 25°C, the equilibrium adsorption capacity is 4.73mmol/g, the adsorption process accords with G. E. Boyd equation and Langmuir adsorption isotherm as well,and the silver-loaded resins can be quantitatively eluted by a solution containing 6% thiourea in 1mol/L HNO3.

Fluid Transient Responses With Check Valves in Pipe Flow System With Air Entrainment

1997 ◽  
Author(s):  
T. S. Lee ◽  
L. C. Leow
Keyword(s):  
Transient Flow ◽  
Flow System ◽  
Check Valve ◽  
Air Entrainment ◽  
Pipeline System ◽  
Piping System ◽  
Transient Responses ◽  
Fluid System ◽  
Free System ◽  
Fluid Transient

A common flow system arrangement in piping system consists of a lower reservoir, a group of pumps with a check valve in each branch, and a pipeline discharging into a upper reservoir. In earlier studies of check valves performances in transient flow, none considered the effects of air entrainment into a pipeline system and the subsequent effects on the check valve performances in transient flow. Studies on pressure surges during pump tripped in pumping systems showed that by including an air entrainment variable wave speed model, reasonable predictions of fluid transient responses with proper phasing and attenuation of pressure peaks can be obtained. The most severe case where all the pumps in the station fail simultaneously due to power failure was analysed for their maximum and minimum pressure variation along the pipeline. A numerical model is now set up in the present work to investigate the check valve performances in transient flow for a pumping system with air entrainment. The analyses examine a fluid system with a variable air entrainment content (ε) and studied numerically it effects on the flow reversal time and hence determine the appropriate valve selection for a given fluid system to minimize problems of check valve slamming. Present numerical computations show that the air content in a fluid system can adversely affect the check valve transient responses. With the fluid system operating within a critical range of air entrainment values, analysis showed that there is a possibility of “check valve slamming” when the check valves were selected based on the analysis of an air free system. The above phenomena is confirmed through physical field measurements.

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