Study on Adsorption and Desorption of Suspended Sediments to Phosphorus in Ganjiang River

2012 ◽  
Vol 599 ◽  
pp. 669-672 ◽  
Author(s):  
Qiu Lin Ouyang ◽  
Gui Qing Gao ◽  
Su Su Liu ◽  
Xiao Ling Shi ◽  
Hai Yan Ju
Keyword(s):  
Suspended Sediments ◽  
Sediment Concentration ◽  
Isothermal Adsorption ◽  
Phosphorus Adsorption ◽  
Kinetic Experiment ◽  
Desorption Process ◽  
Desorption Kinetic ◽  
Adsorption And Desorption ◽  
Phosphorus Desorption ◽  
Adsorption Desorption

Based on isothermal adsorption experiment and adsorption/desorption kinetic experiment,the adsorption and desorption characteristics of suspended sediments in Ganjiang River to phophorus was studied.The results show the phosphorus adsorption of sediment reaches balance basically in 2~4h; the adsorption capacity is increased with the increment of the initial concentration of phosphorus,and decreased with the increment of sediment conentration. The isothermal adsorption of phosphorus by sediment can be fitted preferably by Langmuir and Freundlic model. The adsorption and desorption process can be fitted by Langmuir equation.The phosphorus desorption of sediment reaches balance basically in about 14h. The phosphorus desorption capacity of sediment is decreased with the increment of sediment concentration.

Study on Characters of Nitrogen Adsorption and Desorption of Sediment in Ganjiang River

2012 ◽  
Vol 212-213 ◽  
pp. 391-394
Author(s):  
Qiu Lin Ouyang ◽  
Gui Qing Gao ◽  
Su Su Liu ◽  
Xiao Ling Shi
Keyword(s):  
Theoretical Basis ◽  
Poyang Lake ◽  
Nitrogen Adsorption ◽  
Sediment Concentration ◽  
Isothermal Adsorption ◽  
Desorption Process ◽  
Adsorption And Desorption ◽  
Nitrogen Desorption ◽  
Adsorption Of Nitrogen ◽  
Desorption Capacity

Sediment has the function of adsorption and desorption of the nitrogen in water body. This study provides the theoretical basis of calculating the nitrogen content discharged into the Poyang Lake. The results show the nitrogen adsorption of sediment reaches balance basically in about 4~ 6h, the adsorption capacity is increased with the increment of the initial concentration of nitrogen, and decreased with the increment of sediment conentration.The isothermal adsorption of nitrogen by sediment can be fitted preferably by Henry and Langmuir equation.The adsorption and desorption process can be fitted by Langmuir equation.The nitrogen desorption of sediment reaches balance basically in about 8~14h.The nitrogen desorption capacity of sediment is decreased with the increment of sediment concentration.

scholarly journals STUDY OF CARBON DIOXIDE ADSORPTION ON CHROMOXIDE CATALYST ON NON-STATIONARY CONCENTRATIONS

2018 ◽  
Vol 61 (7) ◽  
pp. 37 ◽  
Author(s):  
Nikolay I. Kol'tsov ◽  
Vladislav Kh. Fedotov
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Chemical Kinetics ◽  
Carbon Dioxide Adsorption ◽  
Dissociative Mechanism ◽  
Simple Method ◽  
Desorption Process ◽  
Adsorption And Desorption ◽  
Additional Information ◽  
Adsorption Desorption

Investigation of the regularities of chemical processes, not only near but also far from the stationary state, gives additional information on their mechanisms. In this paper, we present a new method for estimating rate constants of adsorption-desorption processes from the experimentally measured values of the nonstationary concentrations of an adsorbed substance, based on calculating the instantaneous rates of the adsorption (or desorption) process. This method allows to connect unknown kinetic parameters of adsorption (desorption) of a substance on the catalyst surface for various most probable assumed mechanisms with the calculated values of the instantaneous rates of adsorption-desorption processes. As a consequence, the method makes it possible to solve two types of inverse problems of chemical kinetics: calculate point and interval values of rates constants of adsorption and desorption; determine the most likely mechanism from several proposed mechanisms of implementation of these processes. Using this method, point and interval values of the rates constants of adsorption and desorption of carbon dioxide were determined on the base of nonstationary experimental data on adsorption on the assumption of carbon dioxide adsorption on a chromoxide catalyst to three proposed mechanisms: linear, bimolecular and dissociative. Based on the results of calculations, the corresponding non-stationary dependences of carbon dioxide adsorption were restored, which were compared with the experimental data. The obtained results confirm that the previously established dissociative mechanism of adsorption of carbon dioxide on the chromoside catalyst is the most probable. The developed simple method does not require the use of complex optimization calculations and can be used to solve the inverse problem of chemical kinetics associated with the determination of mechanisms and the estimation of the rates constants of adsorption and desorption of substances on various catalysts.Forcitation:Kol’tsov N.I., Fedotov V.Kh. Study of carbon dioxide adsorption on chromoxide catalyst on non-stationary concentrations. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 37-42

Characterising the Differences between the Adsorption and Desorption Processes in a Desiccant Layer by Detailed Numerical Modelling

2012 ◽  
Vol 326-328 ◽  
pp. 690-695
Author(s):  
C.R. Ruivo ◽  
J.J. Costa ◽  
A.R. Figueiredo
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Channel Wall ◽  
Water Adsorption ◽  
Sorption Isotherms ◽  
Transfer Coefficients ◽  
Desorption Process ◽  
Adsorption And Desorption ◽  
Adsorption Desorption ◽  
Simultaneous Heat

In this paper, the performance of a channel element of a hygroscopic matrix is evaluated by detailed numerical modeling. The adopted physical model takes into account the gas-side and solid-side resistances to heat and mass transfer, as well as the simultaneous heat and mass transfer occurring simultaneously with the water adsorption/desorption process in the desiccant porous channel wall domain. The desiccant medium is silica gel RD, the equilibrium being characterized by sorption isotherms. Appropriate convective transfer coefficients are taken into account for the calculation of the heat and mass transfer phenomena between the airflow and the channel wall. The response of the channel element to a step change in the airflow states is simulated, the results enabling the investigation of some differences between the adsorption and desorption processes.

Research on Desorption of Suspended Sediments to TN and TP in Waizhou Reach

2014 ◽  
Vol 641-642 ◽  
pp. 1155-1158
Author(s):  
Gui Qing Gao ◽  
Hai Yan Ju ◽  
Hao Zhou ◽  
Su Su Liu
Keyword(s):  
Ph Value ◽  
Correlation Coefficients ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Langmuir Model ◽  
Second Step ◽  
Desorption Process ◽  
Basic Equilibrium ◽  
Desorption Experiment ◽  
Physical And Chemical

The physical and chemical characteristics of suspended sediment in Waizhou reach are studied.The particle size is between 0.005-0.75mm.The pH value of sediment sample is 7.1.The desorption experiment after adsorbing total nitrogen(TN) and total phosphorus(TP) saturated was carried out.The experimental results show the desorption of sediment on TN and TP reaches basic equilibrium about 8h.Desorption capacity decreases with the increase of sediment concentration.Desorption process is completed by two steps.The first step is physical desorption process quickly.The second step is chemical desorption and belongs to the process of slow response.Using the Langmuir model can better simulate the process of desorbing.The correlation coefficients of fitting with TN and TP are above 0.8 and 0.75 respectively.The higher the sediment concentration, the better fitting effect.

scholarly journals THE DEVELOPMENT OF A NEW ADSORPTION-DESORPTION DEVICE

2020 ◽  
Vol 60 (6) ◽  
Author(s):  
Ľudmila Gabrišová ◽  
Peter Peciar ◽  
Oliver Macho ◽  
Martin Juriga ◽  
Paulína Galbavá ◽  
...  
Keyword(s):  
Distilled Water ◽  
Water Mixture ◽  
Desorption Process ◽  
Water Vapour Sorption ◽  
Adsorption And Desorption ◽  
Volatile Organic ◽  
Preliminary Study ◽  
Adsorption Desorption ◽  
Granulated Activated Carbon

The aim of this work was to construct a new adsorption-desorption device based on the principle of separation of volatile organic compounds, e.g., ethanol. As an adsorbent, it is possible to use granulated activated carbon (GAC) in the adsorption and desorption process. In this study, two kinds of GACs were used and marked as GAC1 and GAC2. A particle size distribution and water vapour sorption for the selected GACs were measured. An experiment with distilled water was performed as a preliminary study of the new device’s functionality. After the determination of the time necessary for the adsorption and desorption, the experiments were carried out with a model mixture (5% v/v ethanol-water mixture), which resulted in a product with the ethanol content of 39.6 %. The main advantage of this device would be the potential competition of conventional distillation.

scholarly journals Getting information on suspended sediments in a large river from acoustic backscatter

2018 ◽  
Vol 40 ◽  
pp. 04017
Author(s):  
Adrien Vergne ◽  
Céline Berni ◽  
Jérôme Le Coz
Keyword(s):  
Suspended Sediment Concentration ◽  
Spatial Information ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Large River ◽  
Acoustic Backscatter ◽  
Qualitative Information ◽  
Sediment Size ◽  
The Common

There has been a growing interest in the last decade in extracting information on Suspended Sediment Concentration (SSC) from acoustic backscatter in rivers. Quantitative techniques are not yet effective, but acoustic backscatter already provides qualitative information on suspended sediments. In particular, in the common case of a bi-modal sediment size distribution, corrected acoustic backscatter can be used to look for sand particles in suspension and provide spatial information on their distribution throughout a river crosssection. This paper presents a case-study where these techniques have been applied.

Adsorption–Desorption Characteristics of ss-DNA on 2D TpTta-COF Studied by Fluorescently Labeled Oligonucleotides

NANO ◽  
2021 ◽  
pp. 2150050
Author(s):  
Zhaoyu Han ◽  
Sen Li ◽  
Shaoxian Yin ◽  
Zhi-Qin Wang ◽  
Yanfei Cai ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Kinetic Mechanism ◽  
Optical Biosensors ◽  
Desorption Kinetic ◽  
Wide Range ◽  
Potential Applications ◽  
Fluorescently Labeled Oligonucleotides ◽  
Adsorption Desorption ◽  
Physical And Chemical ◽  
And Chemical Properties

Being the newest member of the 2D materials family, 2D-nanosheet possesses many distinctive physical and chemical properties resulting in a wide range of potential applications. Recently, it was discovered that 2D COF can adsorb single-stranded DNA (ss-DNA) efficiently as well as usefully to quench fluorophores. These properties make it possible to prepare DNA-based optical biosensors using 2D COF. While practical analytical applications are being demonstrated, the fundamental understanding of binding between 2D COF and DNA in solution received relatively less attention. In this work, we carried out a systematic study to understand the adsorption and desorption kinetic, mechanism, and influencing factors of ss-DNA on the surface of 2D COF. We demonstrated that shorter DNAs are adsorbed more rapidly and bind more tightly to the surface of 2D COF. The adsorption is favored by a higher pH. The different buffer types also can affect the adsorption. In Tris-HCl solution, the adsorption reached highest efficiency. By adding the complementary DNA (cDNA), desorption of the absorbed DNA on 2D COF can be achieved. Further, desorption efficiency can also be exchanged by various surfactant in solution. These findings are important for further understanding of the interactions between DNA and COFs and for the optimization of DNA and COF-based devices and sensors.

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