langmuir equation
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2021 ◽  
Vol 18 (4(Suppl.)) ◽  
pp. 1536
Author(s):  
Yuni Retnaningtyas ◽  
Ganden Supriyanto ◽  
Roedi Irawan ◽  
Siswandono Siswodihardjo

Molecularly imprinted polymers (MIPs) are an effective method for separating enantiomeric compounds. The main objective of this research is to synthesize D-arabinitol MIPs, which can selectively separate                  D-arabinitol and its potential application to differentiate it from its enantiomer compound through a non-covalent approach. A macroporous polymer was synthesized using D-arabinitol as a template, acrylamide as a functional monomer, ethylene glycol dimethacrylate (EGDMA) being a cross-linker, dimethylsulfoxide (DMSO) being a porogen, as well as benzoyl peroxide being an initiator. After polymer synthesis,                  D-arabinitol was removed by a mixture of methanol and acetic acid (4:1, v/v). Fourier-Transform Infrared spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) distinguished the MIPs and NIPs.                     A selectivity test of MIPs against its enantiomers (L-arabinitol, xylitol, adonitol, and glucose) was carried out using the batch rebinding method. The binding site was quantitatively determined using the Langmuir equation. The results of the selectivity test showed that the MIPs produced was quite selective toward its enantiomer and could potentially be used to separate D-arabinitol from its enantiomer.


2021 ◽  
Vol 12 (2-2021) ◽  
pp. 87-91
Author(s):  
P. E. Evstropova ◽  

The process of sorption of lead, zinc, cadmium and cobalt ions from aqueous solutions on titanium-containing sorbents of various compositions is studied. Langmuir, Freundlich and Temkin models were used to determine sorption equilibrium. It was found that the process of sorption of metal ions on sorbents is described with the maximum probability by the Langmuir equation. The data obtained made it possible to determine the affinity of the metal to the sorbent and to compose a selectivity series.


2021 ◽  
Author(s):  
Wen Wang ◽  
Liqiang Qi ◽  
Pan Zhang ◽  
Jichen Luo ◽  
Jingxin Li

Abstract In order to investigate the effective method of COD removal from desulfurization wastewater, acid-modified fly ash (AFA) and base-modified fly ash (BFA) were prepared by impregnation method. Then, magnetic coagulants (Fe-AFA, Fe-BFA) were prepared by mixing the modified fly ash with magnetic components. The structural characterization results showed that the specific surface area and the porosity of fly ash were obviously increased after modification. Fe-AFA magnetic coagulant has the best performance and superparamagnetism. Under the same experimental conditions, the maximum COD removal amounts of FA, BFA, AFA, Fe-BFA and Fe-AFA were 2.180, 3.209, 4.631, 3.710 and 5.687 mg/g, respectively. The COD removal amount of Fe-AFA was increased by 112.43% compared with the raw FA. The quasi-second-order kinetic and Langmuir equation could well fit the COD coagulation process of five coagulants. After five cycles, the COD removal amount of Fe-AFA was 2.735 mg/g, and the removal rate still reached 67.53%. These findings provide a feasible method for the treatment of fly ash from coal-fired power plants and the preparation of highly efficient COD trapping magnetic coagulants.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Beifeng Lv ◽  
Wenjie Yu ◽  
Jiale Luo ◽  
Biao Qian ◽  
Mulugeta Belete Asefa ◽  
...  

To remove graphene oxide from wastewater, we used batch experiments with calcareous sand to recover GO. The adsorption properties and mechanisms of GO by calcareous sand were investigated by different characterization techniques. In this paper, the relationship between the coagulation of GO on calcareous sand and pH, calcareous sand content, GO initial concentration, and temperature was studied. The results show that calcareous sand can effectively adsorb GO from aqueous solution, the interaction of GO with calcareous sand achieved interaction equilibrium in 5 h, and the adsorption of GO by calcareous sand strongly depends on pH. The isotherm data fitted to a Langmuir equation. A possible mechanism can be expressed from FT-IR, XRD, Raman spectra, SEM, EDS, TEM, AFM, and XPS results. The test results indicate that calcareous sand is a potentially recoverable GO material.


2021 ◽  
Vol 2070 (1) ◽  
pp. 012180
Author(s):  
S Rajalingam ◽  
A Alaguraj ◽  
K Vijays Siva ◽  
S Vanitha ◽  
A Malathy ◽  
...  

Abstract In this study Moringa Oleífera (MO) leaves and pods are utilized for the treatment of Methylene Blue (MB) dye solution. The uptake of pollutants by MO leaves and pods are assessed by varying dosages from 0.01g to 0.1g with different agitation time of 5min to 30 min. From the observed results, the maximum removal (96%) occurs by adding MO leaves at 0.08g dosage at the time period of 15minutes. MO pods removes maximum of 45% at the dosage of 0.1g at 30 minutes. It is found that MO leaves are better in removing organic dye than MO pods. The Scanning Electron Microscope (SEM) and Energy Dispersive X Ray (EDX) analysis are carried out to identify the morphological character and elemental composition of the MO leaves and pods. The result shows that the leaves contain more carbon content (33%) than pods (20.3%). Similarly the amount of oxygen is least in leaves thus enhancing the removal of dye particles. The SEM result indicates that the pore development is more in leaves than pods. Finally, Isotherm model was developed for pods and leaves; it is found that MO pods follow Freundlich equation whereas MO leaves follow Langmuir equation.


2021 ◽  
Vol 3 ◽  
pp. 47-57
Author(s):  
M.K. Kurmanaliev ◽  
◽  
J. Jenisbek ◽  

In the work, the regularities of the process of sorption of copper and nickel ions from model solutions by low-base anionites containing coordination secondary groups are investigated. The main kinetic and concentration coordination characteristics of the process of complexation of copper and nickel ions with ligand groups of a low-base sorbent are determined.Potentiometric titration shows that anionite contains low-base functional groups, the pK of which is equal to 7.2.It is established that the process of sorption of copper ions by low-base macroporous anionite is characterized by a high initial rate and rapid achievement of equilibrium, which ensures absorption of copper ions about 70% of the equilibrium values in the first 10- 15 minutes.The main parameters of the sorption process are determined. Analytical description of sorption isotherm in coordinates of Langmuir equation is carried out. It was shown that due to high rates, the degree of extraction from solutions with a concentration of 10- 15 mmol/l under equilibrium conditions reaches 99.6-98.3%.Studies of the sorption process in a dynamic mode showed the possibility of separating heavy metal ions from aqueous solutions on new low-base anionites.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5511
Author(s):  
Eduard Tokar ◽  
Konstantin Maslov ◽  
Ivan Tananaev ◽  
Andrei Egorin

An Se-derivative of amidoxime was synthesized for the first time as a result of the reaction of oxidative polycondensation of N’-hydroxy-1,2,5-oxadiazole-3-carboximidamide with SeO2: its elementary units are linked to each other due to the formation of strong diselenide bridges. The element composition of the material was established, and the structure of the elementary unit was suggested. The sorption-selective properties were evaluated, and it was found that the adsorbent can be used for the selective recovery of U (VI) from liquid media with a pH of 6–9. The effect of some anions and cations on the efficiency of recovery of U (VI) was estimated. Composite materials were fabricated, in which silica gel with a content of 35, 50, and 65 wt.% was used as a matrix to be applied in sorption columns. The maximum values of adsorption of U (VI) calculated using the Langmuir equation were 620–760 mg g−1 and 370 mg g−1 for the composite and non-composite adsorbents, respectively. The increase in the kinetic parameters of adsorption in comparison with those of the non-porous material was revealed, along with the increase in the specific surface area of the composite adsorbents. In particular, the maximum sorption capacity and the rate of absorption of uranium from the solution increased two-fold.


2021 ◽  
Vol 5 (1) ◽  
pp. 31
Author(s):  
Paryanto Paryanto ◽  
Ayu Mustika Wijaya ◽  
Dwi Bagas Ongko Widodo ◽  
Sonia Waluya ◽  
Wahyu Daut Utomo

<p>The textile industry in Indonesia is growing rapidly, this is confirmed by data from the Badan Pusat Statistik (BPS) which shows that the production of the clothing industry has experienced a significant growth of 15.29 percent in 2019. The use of textile dyes will cause waste problems in the environment. So we need natural dyes as a safer and environmentally friendly alternative. The purpose of this study was to obtain data analysis and to determine the adsorption equilibrium value of the natural dye solution of mangrove <em>Rhizophora stylosa</em> and tingi bark with variations in the amount of dyeing in primisima cloth by comparing it with the Langmuir and Freundlich equations and knowing the role of tunjung and alum in the process of fixing dyes into cloth. This study used a solid-liquid extraction method and then tested by spectrophotometry to obtain initial concentration data. Next, pour the dye that has been tested for its tannin content into a measuring cup and insert the cloth as a medium for mass transfer of tannins from liquid to solid. Samples were taken for each dyeing and tested for tannin content by spectrophotometry and the Ca value was obtained. Isotherm pattern testing. The adsorption test for the absorption process of tannins in natural dyes by cloth was carried out by calculating using the Langmuir and Freundlich equation. Furthermore, the cloth that has been dyed is fixed by tunjung and alum.The most suitable determination of the adsorption capacity of the cloth against natural dyes <em>Rhizopora stylosa</em> and tingi bark is by using the Freundlich adsorption equation compared to the Langmuir equation. This is evidenced by the error value of the Freundlich equation is smaller than the Langmuir equation by showing the value of R<sup>2</sup> which is close to number 1. The constant value of the Langmuir equation tingi bark for three times of dyeing obtained the b value is 0.2338 mg/gr and the k value is 0.00517 L/gr. For five of dyeing, the b value is 0.10817 mg/gr and the k value is 0.00421 L/gr. For the seven times of dyeing, the b value is 0.0670 mg/gr and the k value is 0.003899 L/gr. Whereas in the Freundlich equation for tingi bark for three times of dyeing, the n value is 0.4312 mg/g and the k value is 0.36374 x 10<sup>3</sup> L/gr. For five of dyeing, the n value is 0.30114 mg/g and the k value is 0.99586 x 10<sup>5</sup> L/g. For seven of dyeing, the n value is 0.2424 mg/g and the k value is 0.9354 x 10<sup>7</sup> L/g. The constant value of the Langmuir <em>Rhizopora stylosa</em> equation for three times of dyeing, the b value is 0.15635 mg / gr and the k value is 0.005224 L/gr. For five of dyeing, the b value is 0.08141 mg/gr and the k value is 0.004415 L/gr. For the seven of dyeing, the b value is 0.04909 mg/gr and the k value is 0.00408 L/gr. Whereas in the Freundlich equation for  <em>Rhizopora stylosa</em> for three times of dyeing, the n value is 0.3862 mg/g and the k value is 0.1090 x 10<sup>4</sup> L/g. For five of dyeing, the n value is 0.2733 mg/g and the k value is 0.4355 x 10<sup>6</sup> L/g. For seven of dyeing, the n value is 0.2126 mg/g and the k value is 0.1545 x 10<sup>9</sup> L/g. It can be concluded that the more dyeing, the less the absorbency of the cloth on tannins. The color change of fixation the cloth in the dyeing of <em>Rhizopora stylosa</em> extract with tunjung is from brown to grayish brown, while with alum from brown to dark brown. The color change of fixation the cloth in the dyeing of tingi bark extract with alum is from brown to black, while with alum from brown to dark brown.</p>@font-face {font-family:"Cambria Math"; panose-1:2 4 5 3 5 4 6 3 2 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:-536869121 1107305727 33554432 0 415 0;}@font-face {font-family:Garamond; panose-1:2 2 4 4 3 3 1 1 8 3; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:647 2 0 0 159 0;}p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-unhide:no; mso-style-qformat:yes; mso-style-parent:""; margin-top:0cm; margin-right:0cm; margin-bottom:0cm; margin-left:.5pt; text-align:justify; text-justify:inter-ideograph; text-indent:-.5pt; line-height:103%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Garamond",serif; mso-fareast-font-family:Garamond; mso-bidi-font-family:Garamond; color:black; mso-ansi-language:EN-US; mso-fareast-language:EN-US;}.MsoChpDefault {mso-style-type:export-only; mso-default-props:yes; font-size:11.0pt; mso-ansi-font-size:11.0pt; mso-bidi-font-size:11.0pt; font-family:"Calibri",sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:DengXian; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-ansi-language:EN-US; mso-fareast-language:EN-US;}.MsoPapDefault {mso-style-type:export-only; margin-bottom:8.0pt; line-height:107%;}div.WordSection1 {page:WordSection1;}


2021 ◽  
Vol 14 (16) ◽  
Author(s):  
Huanyu Shi ◽  
Zhibao Dong ◽  
Nan Xiao ◽  
Qinni Huang

2021 ◽  
Vol 6 (3) ◽  
pp. 181-188
Author(s):  
Gatut Ari Wardani ◽  
Ega Maulana Qudsi ◽  
Anindita Tri Kusuma Pratita ◽  
Keni Idacahyati ◽  
Estin Nofiyanti

The use of activated charcoal from sawdust as an adsorbent of tetracycline hydrochloride compounds has been successfully carried out. Sawdust activated charcoal was carbonized at 450°C for 40 minutes with a charcoal size of 100 mesh and activated using H3PO4 solution. The characteristics of active sawdust charcoal showed that water content, iodine adsorption, and methylene blue adsorption had met SNI 06-3730-1995 regarding technical activated charcoal. Testing the morphology of charcoal using a Scanning Electron Microscope showed that the charcoal pores were opened through the activation process. In the functional group analysis test using infrared spectroscopy, the active group contained in charcoal after being activated contained carbon atoms that were purer than sawdust. The adsorption process of tetracycline hydrochloride using sawdust activated charcoal is known to follow Ho orPseudo second-order (K = 0.0039 g/mg.min), while the adsorption isotherm follows the Langmuir equation, KL = 0.0076 L/mg and adsorption capacity amounting to 242.1307 mg/g. Thermodynamically, the adsorption process occurs not spontaneously with a Gibbs free energy value of 120.8949 kJ/mol and occurs by chemisorption.


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