scholarly journals Adsorption-Desorption Mechanism of Synthesized Benzimidazole Based Fungicide 2-(3’-Pyridyl) on Selected Soil Minerals

2019 ◽  
Vol 10 (2) ◽  
pp. 38-44
Author(s):  
Khuram Shahzad Ahmad ◽  
Shaan Bibi Jaffri ◽  
Saba Gul ◽  
Khadija Ikhlaq ◽  
Maryam Javaid ◽  
...  

The adsorption and desorption phenomenon of synthesized Benzimidazole based fungicide, 2-(3’-pyridyl)benzimidazole (PyBlm), was investigated by batch equilibrium method. Four soil minerals were utilized for thesorption studies including; alumina, silica, muscovite and montmorillonite. Highest value of adsorption coefficient(Kd(ads)), obtained for montmorillonite mineral (Mx (Al, Fe, Mg4) Si8O20 (OH4)) was 2779 µg ml-1. Highest rate ofadsorption is attributable to its considerably large surface area of 628 m2g-1 and highest inter-lattice d-spacing, 10 Å.Highest desorption (Kd(des)) was also observed in montmorillonite mineral (21.45 µg ml-1). Montmorillonite thusdisplayed increased sorption capacity for PyBlm among all tested minerals. Hysteresis coefficient ranged from 0.58 to3. The results were statistically evaluated by using one-way analysis of variance (ANOVA). Furthermore, statisticalevaluation done with the help of Minitab 17 expressed the good fitting of the obtained results, which was shown bymeans of residual plots. Current research which suggests the variable adsorption and desorption of PyBlm expresses theprofound dependence of PyBlm interaction on the physicochemical characteristics of the selected minerals. Allminerals except montmorillonite expressing poor adsorption signifying the percolation of PyBlm through them towardsthe lower soil profiles. Results obtained in the present research show of that montmorillonite in firmly interacting withthe PyBlm molecules and thus alleviating the possibility of PyBlm percolation to lower soil profiles.

Author(s):  
Khuram Shahzad Ahmad ◽  
Shaan Bibi Jaffri ◽  
Saba Gul ◽  
Khadija Ikhlaq ◽  
Maryam Javaid ◽  
...  

The adsorption and desorption phenomenon of synthesized Benzimidazole based fungicide, 2-(3’-pyridyl)benzimidazole (PyBlm), was investigated by batch equilibrium method. Four soil minerals were utilized for thesorption studies including; alumina, silica, muscovite and montmorillonite. Highest value of adsorption coefficient(Kd(ads)), obtained for montmorillonite mineral (Mx (Al, Fe, Mg4) Si8O20 (OH4)) was 2779 µg ml-1. Highest rate ofadsorption is attributable to its considerably large surface area of 628 m2g-1 and highest inter-lattice d-spacing, 10 Å.Highest desorption (Kd(des)) was also observed in montmorillonite mineral (21.45 µg ml-1). Montmorillonite thusdisplayed increased sorption capacity for PyBlm among all tested minerals. Hysteresis coefficient ranged from 0.58 to3. The results were statistically evaluated by using one-way analysis of variance (ANOVA). Furthermore, statisticalevaluation done with the help of Minitab 17 expressed the good fitting of the obtained results, which was shown bymeans of residual plots. Current research which suggests the variable adsorption and desorption of PyBlm expresses theprofound dependence of PyBlm interaction on the physicochemical characteristics of the selected minerals. Allminerals except montmorillonite expressing poor adsorption signifying the percolation of PyBlm through them towardsthe lower soil profiles. Results obtained in the present research show of that montmorillonite in firmly interacting withthe PyBlm molecules and thus alleviating the possibility of PyBlm percolation to lower soil profiles.


2020 ◽  
Vol 19 (1) ◽  
pp. 77-97
Author(s):  
Haji Mwevura ◽  
Peter Nkedi-Kizza ◽  
Michael Kishimba ◽  
Henrik Kylin

Batch adsorption-desorption equilibrium techniques were used to investigate the adsorption capacity and influence of salinity on partitioning of the insecticide chlorpyrifos between water and soil or water and sediments from the Rufiji Delta. The data were fitted to different adsorption-desorption models and the hysteresis index was calculated using the ratio between the Freundlich exponents for desorption and adsorption, and secondly, the difference in area under the normalized adsorption and desorption isotherms using the maximum adsorbed and solution concentrations. The data showed non-linear adsorption and that chlorpyrifos was strongly adsorbed to soil and sediments from the Rufiji Delta. The linearized adsorption coefficient (KD) and Freundlich adsorption coefficient (Kf) correlated significantly with organic carbon content. Chlorpyrifos adsorption as well as hysteresis calculated by both methods decreased with salinity (i.e. the sediment adsorbs increasing amounts of chlorpyrifos with decreasing salinity). This indicates that settling of freshwater sediments is among the major removal pathways of the chemical from the water column, but increased turbulence during high tides may resuspend settled sediment simultaneously increasing salinity and re-dissolve chlorpyrifos. However, discharge of fresh water, particularly during heavy rains, increases the trapping efficiency of the sediments. The theoretical approach developed showed that the Langmuir model describes the desorption data better than the Freundlich model, and that a better index of hysteresis is one that considers areas under the adsorption and desorption isotherms, provided the desorption isotherm is described by the normalized Langmuir isotherm and the adsorption isotherm by the normalized Freundlich isotherm.


2019 ◽  
Vol 10 (2) ◽  
pp. 50-54
Author(s):  
Shaan Bibi Jaffri ◽  
Khuram Shahzad Ahmad ◽  
Mishkat Ul Saba ◽  
Gulistan Sher ◽  
Maham Sharif

Soil and soil minerals are the primary recipients of different contaminates coming in immediate contact.Agricultural practices which are dominated by use of different agrochemicals have further aggravated the soil quality.Fungicides, aimed at the extermination, inhibition and growth retardation of fungal species in agricultural crops havebeen used frequently. Among such fungicides, Benzimidazole based fungicides are of prime significance due to theircomparatively improved annihilatory activity. Despite such frequent utilization, the reports on the reception andconsequent sorption of Benzimidazole fungicides are scarce. Current work has, for the first time, investigated theinteraction of Benzimidazole based fungicide, Mecarzole (metabolite of Benomyl fungicide and also known asCarbendazim) in the selected minerals i.e. corundum (alumina), silica, muscovite and montmorillonite. The interactionwas studied via standard equilibration method established in batches. Adsorption and desorption of Mecarzole in theselected minerals was evaluated by multilayer Linear and Freundlich model for different parameters i.e. Kd, Kf, Kfdesand Kdes. Linearity was exhibited by the minerals for attachment of Mecarzole. The highest values of Kd (6.93 mL. µg-1) and Kf (7.99 mL. µg-1) obtained for muscovite are indicative of the higher affinity of muscovite for Mecarzole incomparison to other three minerals. Excellent adsorption of Mecarzole in muscovite is suggestive of the fact thatMecarzole interacting with muscovite is not a threat towards lower soil profiles since there is a stronger bonding. Incontrast to muscovite, Mecarzole poorly adsorbed in alumina represents a threat to soils due to possible percolation ofpoorly adsorbed Mecarzole molecules.


Author(s):  
Shaan Bibi Jaffri ◽  
Khuram Shahzad Ahmad ◽  
Mishkat Ul Saba ◽  
Gulistan Sher ◽  
Maham Sharif

Soil and soil minerals are the primary recipients of different contaminates coming in immediate contact.Agricultural practices which are dominated by use of different agrochemicals have further aggravated the soil quality.Fungicides, aimed at the extermination, inhibition and growth retardation of fungal species in agricultural crops havebeen used frequently. Among such fungicides, Benzimidazole based fungicides are of prime significance due to theircomparatively improved annihilatory activity. Despite such frequent utilization, the reports on the reception andconsequent sorption of Benzimidazole fungicides are scarce. Current work has, for the first time, investigated theinteraction of Benzimidazole based fungicide, Mecarzole (metabolite of Benomyl fungicide and also known asCarbendazim) in the selected minerals i.e. corundum (alumina), silica, muscovite and montmorillonite. The interactionwas studied via standard equilibration method established in batches. Adsorption and desorption of Mecarzole in theselected minerals was evaluated by multilayer Linear and Freundlich model for different parameters i.e. Kd, Kf, Kfdesand Kdes. Linearity was exhibited by the minerals for attachment of Mecarzole. The highest values of Kd (6.93 mL. µg-1) and Kf (7.99 mL. µg-1) obtained for muscovite are indicative of the higher affinity of muscovite for Mecarzole incomparison to other three minerals. Excellent adsorption of Mecarzole in muscovite is suggestive of the fact thatMecarzole interacting with muscovite is not a threat towards lower soil profiles since there is a stronger bonding. Incontrast to muscovite, Mecarzole poorly adsorbed in alumina represents a threat to soils due to possible percolation ofpoorly adsorbed Mecarzole molecules.


2014 ◽  
Vol 804 ◽  
pp. 149-152 ◽  
Author(s):  
Ji Sun Kim ◽  
Jae Ho Baek ◽  
Myung Hwan Kim ◽  
Seong Soo Hong ◽  
Man Sig Lee

In this study, we confirmed effect of carbon pre-treatment on Pd dispersion in synthesis of Pd/C catalyst. Physical characteristics on the surface of before and after pre-treated carbon were analyzed by nitrogen adsorption-desorption analysis. The dispersion and size of Pd particles were analyzed by XRD, FE-TEM and CO-chemisorption. After pre-treatment, surface area of carbon were decreased. And mesopore area ratio were increased with decreasing micropore area ratio. In the case of pre-treated carbon, we confirmed high dispersion of Pd particles.


2005 ◽  
Vol 494 ◽  
pp. 369-374 ◽  
Author(s):  
M. Milošević ◽  
N. Pejić ◽  
Ž. Čupić ◽  
S. Anić ◽  
Lj. Kolar-Anić

Macroporous cross-linked copolymer of 4-vinylpyridine and 25% (4:1) divinylbenzene is analyzed under open conditions, that is in a continuous well-stirred tank reactor (CSTR). With this aim the appropriate bifurcation diagram is found and the behavior of the system with and without polymer in the vicinity of the bifurcation point is used for the polymer examinations. Two different granulations of polymer are considered. Moreover, some physicochemical characteristics of the polymer, such as specific surface area, skeletal and particle density, are determined.


2013 ◽  
Vol 284-287 ◽  
pp. 230-234
Author(s):  
Yu Jen Chou ◽  
Chi Jen Shih ◽  
Shao Ju Shih

Recent years mesoporous bioactive glasses (MBGs) have become important biomaterials because of their high surface area and the superior bioactivity. Various studies have reported that when MBGs implanted in a human body, hydroxyl apatite layers, constituting the main inorganic components of human bones, will form on the MBG surfaces to increase the bioactivity. Therefore, MBGs have been widely applied in the fields of tissue regeneration and drug delivery. The sol-gel process has replaced the conventional glasses process for MBG synthesis because of the advantages of low contamination, chemical flexibility and lower calcination temperature. In the sol-gel process, several types of surfactants were mixed with MBG precursor solutions to generate micelle structures. Afterwards, these micelles decompose to form porous structures after calcination. Although calcination is significant for contamination, crystalline and surface area in MBG, to the best of the authors’ knowledge, only few systematic studies related to calcination were reported. This study correlated the calcination parameters and the microstructure of MBGs. Microstructure evaluation was characterized by transmission electron microscopy and nitrogen adsorption/desorption. The experimental results show that the surface area and the pore size of MBGs decreased with the increasing of the calcination temperature, and decreased dramatically at 800°C due to the formation of crystalline phases.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Esmael Salimi ◽  
Jafar Javadpour

Wormhole-like mesostructured monetite was successfully synthesized using cetyltrimethylammonium bromide (C19H42BrN, CTAB), as a porosity agent. X-ray techniques and FTIR reveal that the crystalline grains consist of highly crystalline pure monetite phase. Monetite rods with diameter around 20–40 nm and length in the range of 50–200 nm were confirmed by FESEM and TEM. Based on N2adsorption-desorption isotherms investigation, surface area increased up to 31.5 m2/g due to the removal of surfactant after calcinations at 400°C. The results indicate that CTAB can not only affect monetite crystallization but also change particles morphology from plate shape to rod-like.


2021 ◽  
Vol 26 (6) ◽  
pp. 715-726
Author(s):  
Francisco Romero-Gavilán ◽  
Andreia Cerqueira ◽  
Eduardo Anitua ◽  
Ricardo Tejero ◽  
Iñaki García-Arnáez ◽  
...  

AbstractCalcium ions are used in the development of biomaterials for the promotion of coagulation, bone regeneration, and implant osseointegration. Upon implantation, the time-dependent release of calcium ions from titanium implant surfaces modifies the physicochemical characteristics at the implant–tissue interface and thus, the biological responses. The aim of this study is to examine how the dynamics of protein adsorption on these surfaces change over time. Titanium discs with and without Ca were incubated with human serum for 2 min, 180 min, and 960 min. The layer of proteins attached to the surface was characterised using nLC-MS/MS. The adsorption kinetics was different between materials, revealing an increased adsorption of proteins associated with coagulation and immune responses prior to Ca release. Implant–blood contact experiments confirmed the strong coagulatory effect for Ca surfaces. We employed primary human alveolar osteoblasts and THP-1 monocytes to study the osteogenic and inflammatory responses. In agreement with the proteomic results, Ca-enriched surfaces showed a significant initial inflammation that disappeared once the calcium was released. The distinct protein adsorption/desorption dynamics found in this work demonstrated to be useful to explain the differential biological responses between the titanium and Ca-ion modified implant surfaces. Graphic abstract


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