Preparation, uranium (VI) absorption and reuseability of marine fungus mycelium modified by the bis-amidoxime-based groups

2019 ◽  
Vol 108 (1) ◽  
pp. 37-49 ◽  
Author(s):  
Dianxiong He ◽  
Ni Tan ◽  
Xiaomei Luo ◽  
Xuechun Yang ◽  
Kang Ji ◽  
...  
Keyword(s):  
Orthogonal Experiment ◽  
Model Fitting ◽  
Freundlich Isotherm ◽  
Marine Fungus ◽  
Absorption Capacity ◽  
Adsorption Model ◽  
Characterization Methods ◽  
Before And After ◽  
Functionalized Materials ◽  
Fungus Mycelium

Abstract Bis-amidoxime-based claw-like-functionalized marine fungus material (ZZF51-GPTS-DCDA-AM) was prepared for study to absorb the low concentration uranium (VI) from aqueous solution. A series of characterization methods such as SEM, TGA and FT-IR were applied for the functionalized materials before and after modification and adsorption. The experimental results suggested that the amidoxime groups were successfully grafted onto the surface of mycelium powder and provided the special binding sites for the absorption of uranium (VI). In the absorption research, uranium (VI) initial concentration, pH and equilibrium time were optimized as 40 mg L−1, 6.0, and 110 min by L43 orthogonal experiment, respectively, and the maximum absorption capacity of the prepared material was 370.85 mg g−1 under the optimum batch conditions. After five cycling process, the desorption rate and regeneration efficiency of the modified mycelium were found to be 80.29 % and 94.51 %, respectively, which indicated that the material had an adequately high reusability property as a cleanup tool. The well known Langmuir and Freundlich isotherm adsorption model fitting found that the modified materials had both monolayer and bilayer adsorption to uranium (VI) ions. Simultaneously, the pseudo-second-order model was better to illustrated the adsorption kinetics process. The enhanced adsorption capacity of uranium (VI) by the modified fungus materials over raw biomass was mainly owing to the strong chelation of amidoxime groups and uranium (VI) ions.

scholarly journals Cementitious Composites Reinforced with Polypropylene, Nylon and Polyacrylonitile Fibres

2012 ◽  
Vol 730-732 ◽  
pp. 271-276
Author(s):  
H.R. Pakravan ◽  
M. Jamshidi ◽  
M. Latifi ◽  
F. Pacheco-Torgal
Keyword(s):  
Absorption Capacity ◽  
Cement Matrix ◽  
Cementitious Composites ◽  
Scanning Electron Micrographs ◽  
Energy Absorption Capacity ◽  
Cement Ratio ◽  
Pull Out ◽  
Water To Cement Ratio ◽  
Before And After ◽  
Scanning Electron

This paper compares the adhesion strength between three polymeric fibres (polypropylene (PP), nylon66 (N66) and polyacrylonitrile (PAN)) embedded in a cement paste. The specimens were prepared at a water to cement ratio (w/c) of 0.5 and tested after 7, 14 and 28 curing days. It was found that although the adhesion between the polymeric fibres to the cement matrix is an important factor, the energy absorption capacity or energy dissipation ability of the fibres, plays a more important role in the improvement of the cementitious composites fracture toughness. Scanning electron micrographs were used to characterize the fibres surface before and after the Pull-out tests.

scholarly journals Adsorption Study of Soluos Dumpsite Leachate Treatment Using Musa sapientum Peels as Biosorbent

2021 ◽  
pp. 26-35
Author(s):  
L. Salami ◽  
D. O. Olumuyiwa ◽  
E. A. Alfred ◽  
O. S. Olakanmi
Keyword(s):  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Coefficient Of Determination ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Adsorption Model ◽  
Leachate Treatment ◽  
Adsorbent Dosage ◽  
Musa Sapientum ◽  
Pass Through

Dumpsite leachate has the potential to pollute ground and surface water as well as vegetation within the vicinity of the dumpsite.  Its treatment therefore needs adequate attention. The aim of this work is to study the adsorption of Soluos dumpsite leachate treatment using Musa sapientum peel as biosorbent with a view of establishing the adsorption isotherm model. Musa sapientum peels sourced from Ayetoro market in Epe area of Lagos State, Nigeria were used to prepare the adsorbent. Batch adsorption was carried out with various dosage of the prepared absorbent in leachate collected from Soluos dumpsite in Lagos. The adsorption data obtained were fitted into Linear, Freundlich, Langmuir, Temkin and Hasley isotherm models. The results showed that the concentration of total dissolved solids (TDS) in the dumpsite leachate decreased as the adsorbent dosage increased. At adsorbent dosage of 10 g/L, the concentration of TDS in the leachate was 485.7 mg/L which was less than the 500 mg/L stipulated by National Environmental Standard and Regulatory Agency (NAESRA) for the discharge of wastewater. The coefficient of determination (R2) values for Linear, Freundlich and Hasley, Langmuir and Temkin isotherm models were 0.9944, 0.9936, 0.8562 and 0.9723 respectively. Linear isotherm model was jettisoned because the plot did not pass through the origin and Freundlich isotherm model was ignored as a result of N value which was less than unity hence Hasley isotherm model was adopted in this work. A good correlation existed between the experimental and predicted values, having a R2 value of 0.9965 which further validated the Hasley isotherm model as the best adsorption model for the treatment of Soluos dumpsite leachate using Musa sapientum peel as biosorbent. It was concluded that Musa sapientum peel as biosorbent can be used for treatment of Soluos dumpsite leachate.

scholarly journals Synthesis of zeolite L using rice husk ash silica for adsorption of methylene blue: kinetic and adsorption isotherm

2018 ◽  
Vol 197 ◽  
pp. 05002 ◽  
Author(s):  
Citra Deliana Dewi Sundari ◽  
Soni Setiadji ◽  
Yusuf Rohmatullah ◽  
Sanusi Sanusi ◽  
Denia Febby Nurbaeti ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Rice Husk ◽  
Adsorption Process ◽  
Rice Husk Ash ◽  
Freundlich Isotherm ◽  
Particle Morphology ◽  
Absorption Capacity ◽  
Molar Ratio ◽  
Blue Dye ◽  
Zeolite L

Rice husk has a high silica content, so it can be utilized as silica source for zeolite synthesis. In this research, synthesis of zeolite L has been done using silica from rice husk ash without organic template. The synthesized zeolite L is then used as an adsorbent to adsorb methylene blue dye. The steps of zeolite L synthesis include: silica extraction from rice husk ash using NaOH and zeolite L synthesis using hydrothermal method with molar ratio 10 SiO2: Al2O3: 4 K2O: 100 H2O at 170°C for 24 hours. The resulting Zeolite L was then characterized by XRD and SEM. The absorption capacity of methylene blue solution by zeolite L was observed experimentally through the effect of pH of the solution, contact time, and initial concentration of the solution, then determining the isotherm and its absorption kinetics. From XRD and SEM results of zeolite L sample, it is shown that zeolite L has been formed and its particle morphology is a hollow cylinder with cylinder diameter of 0.049 - 0.123 μm. The adsorption process refers to the Freundlich isotherm model which provides the highest correlation coefficient. The methylene blue adsorption process by zeolite L follows pseudo second-order kinetics.

scholarly journals Adsorption Behavior and Relative Distribution of Cd2+ Adsorption Mechanisms by the Magnetic and Nonmagnetic Biochars Derived from Chicken Manure

2020 ◽  
Vol 17 (5) ◽  
pp. 1602 ◽  
Author(s):  
Fei Huang ◽  
Lu Zhang ◽  
Ren-Ren Wu ◽  
Si-Ming Zhang ◽  
Rong-Bo Xiao
Keyword(s):  
Ion Exchange ◽  
Magnetic Separation ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Chicken Manure ◽  
Relative Distribution ◽  
Order Kinetic ◽  
Practical Applications ◽  
Adsorption Mechanisms ◽  
Before And After

The present study investigated the adsorption of Cd2+ by nonmagnetic and magnetic biochars (CMB and M-CMB) derived from chicken manure, respectively. The adsorption characteristics were investigated as a function of initial pH, contact time, initial Cd2+ concentration and magnetic separation. Adsorption process of both biochars were better described by Pseudo-second-order kinetic equation and Freundlich isotherm model, which were spontaneous and endothermic in nature. It was found that maximum capacities were 60.69 and 41.07 mg/g obtained at the initial Cd2+ concentration of 180 mg/L for CMB and M-CMB, and the turbidity of adsorption-treated solution was reduced from 244.3 to 11.3 NTU after magnetic separation of 0.5 min. These indicated that M-CMB had lower adsorption capacity of Cd2+ than CMB, though it was successfully separated from the treated solutions. Furthermore, both biochars before and after adsorption were analyzed by SEM-EDS, XRD and FTIR. Adsorption mechanisms mainly included precipitation, ion-exchange, complexation and Cπ-coordination, in which precipitation and ion-exchange dominated the adsorption process by CMB, while in M-CMB, precipitation was always predominant mechanism, followed by ion-exchange. The two other mechanisms of complexation and Cπ-coordination were trivial in both biochars, jointly contributing 7.21% for CMB and 5.05% for M-CMB to total adsorption. The findings deepen our understanding of the mechanisms governing the adsorption process, which are also important for future practical applications in the removal of heavy metals from wastewater by the biochars.

scholarly journals The Synthesis and Effect of Silver Nanoparticles on the Adsorption of Cu2+ from Aqueous Solutions

2020 ◽  
Vol 10 (14) ◽  
pp. 4840
Author(s):  
Ghadah M. Al-Senani ◽  
Nada Al-Kadhi
Keyword(s):  
Aqueous Solution ◽  
Freundlich Isotherm ◽  
Spherical Particles ◽  
Convolvulus Arvensis ◽  
X Ray ◽  
Nanoparticle Surface ◽  
Before And After ◽  
Adsorption Processes ◽  
Sem Analyses

The adsorption of Cu2+ ions from an aqueous solution using AgNPs synthesized from Convolvulus arvensis leaf extract was investigated. The characterization of AgNPs was investigated before and after the adsorption of Cu2+ ions via Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) analyses. The adsorbent contained various functional groups in addition to the AgNPs, which contributed to the Cu2+ ions adsorption. The silver nanoparticle surface consisted of spherical particles and deep pores, which adsorbed numerous Cu2+ ions. The influences of dosage, pH, and contact time on adsorption of 10 and 50 mg/L Cu2+ at 298 K, and initial Cu2+ concentrations at 298 and 323 K were studied. It was found that the highest percentage of Cu2+ ions adsorbed from an aqueous solution was 98.99%; the aqueous solution had 10 mg/L of Cu2+ ions and 0.2 g of AgNPs, at pH 12 and 298 K. A pseudo-second kinetics model offered the most accurate description of the process of adsorption. The process of Cu2+ adsorption more resembled a Langmuir rather than a Freundlich isotherm model, including chemical and physical mixed adsorption (mixed adsorption) processes, and was exothermic and spontaneous.

scholarly journals Uptake of Cationic Dyes by Cement Kiln Dust: Sorption Mechanism and Equilibrium Isotherm

2002 ◽  
Vol 20 (7) ◽  
pp. 657-668 ◽  
Author(s):  
Mamdouh M. Nassar ◽  
Abd. El Hakim A. Daifullah ◽  
Yehia H. Magdy ◽  
Ebrahiem E. Ebrahiem
Keyword(s):  
Sodium Silicate ◽  
Active Sites ◽  
Freundlich Isotherm ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
X Ray Diffraction ◽  
Exchange Reactions ◽  
Sorptive Capacity ◽  
Before And After ◽  
Kiln Dust

The mechanistic aspects of the sorption of Basic Blue-3 and Basic Red-22 on to cement kiln dust (CKD) have been investigated. The by-pass kiln dust before and after washing with water was characterized by X-ray diffraction methods, IR spectroscopy and elemental analysis. Two forms of by-pass kiln dust were used in this study without any treatment, i.e. in powder and pelletized form (the latter being achieved using water or sodium silicate). Equilibrium isotherms to assess the maximum capacity of the two basic dyes on the two forms of CKD were evaluated using a computer program. This allowed two-, three- and four-parameter adsorption models to be studied; it was found that the piecewise Freundlich isotherm yielded an excellent overall fit. Washing with water led to the loss of some active sites responsible for the sorptive capacity. The increase in capacity observed after pelletization with water rather than with sodium silicate could be explained by an increase in hydroxy moieties that undergo exchange reactions. In both cases of pelletization, the adsorption capacity was less than for the unwashed powdered form. The uptake order was found to be: unwashed powder > pellets with water > pellets with sodium silicate.

Removal of the Endocrine Disrupting Chemicals Nonylphenol from Water by Activated Carbon

2012 ◽  
Vol 178-181 ◽  
pp. 520-525
Author(s):  
Xiao Dong Wang ◽  
Yu Feng Xiao
Keyword(s):  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Pore Volume ◽  
Ph Value ◽  
Absorption Capacity ◽  
Carbon Surface ◽  
Drinking Water Source ◽  
Adsorption Model ◽  
Average Pore ◽  
Endocrine Disrupting

Nonylphenol(NP) have endocrine disrupting effects and exist generally in drinking water source. Physical properties including surface area, average pore-diameter, and micro-pore volume and chemical structure of the activated carbon was characterized by N2 adsorption experiment and X-ray photoelectron spectroscopy (XPS). Pore volume could be the most important for adsorption. The high O content of carbon surface lead a negative effect to absorption capacity and low pH value, low temperature lead a positive effect to adsorption. The effect of humus in water to the removal was also studied and EDCs-humus bi-component adsorption model was established, it was found that there is strong competition between EDCs and humus. Due to the competition adsorption capacity of NP greatly decreased especially when the concentration of NP is very low. The adsorption kinetics test results indicated that the adsorption of NP followed the first-order kinetics and the smaller diameter GAC could increase adsorption velocity.

A Novel Approach of Chitosan Additive to Remove Formaldehyde from Building Materials

2011 ◽  
Vol 335-336 ◽  
pp. 1174-1180
Author(s):  
Huang Chin Wang ◽  
Sy Yuan Kang ◽  
Chao Heng Tseng ◽  
Wen Cheng Shau ◽  
Zhi Yang Chen
Keyword(s):  
Removal Efficiency ◽  
Indoor Air ◽  
Building Materials ◽  
Urea Formaldehyde ◽  
Absorption Capacity ◽  
Structural Element ◽  
Carcinogenic Substance ◽  
Novel Approach ◽  
Before And After ◽  
Industrial Standards

Formaldehyde (HCHO) which emitted from building materials, such as plywood and adhesive, is a carcinogenic substance in indoor air. Chitosan is produced from the structural element in the exoskeleton of crustaceans (such as crabs and shrimp), and has the ability to absorb HCHO. In this study, the HCHO removal efficiency by chitosan additives was evaluated for two building materials - adhesive and plywood. The experiments were performed in a small chamber based on the method of Japanese Industrial Standards (JIS) A1901 to evaluate the HCHO emission from adhesive and plywood before and after the application of chitosan additives. Both the HCHO concentration in the chamber and the HCHO emission factor of two adhesives, urea-formaldehyde (UF) resin and Poly Vinyl Acetate (PVAC) resin, were reduced from 0.02~0.21 ppm and 0.12~1.05 mg/m2h to 0~0.14 ppm and 0.12~0.63 mg/m2h after using chitosan additives. The best HCHO removal efficiency was adding 9% chitosan additives in the adhesives. The amount of absorbed HCHO is proportional to the amount of chitosan additives, and approximate 0.02 mg of HCHO can be absorbed by per mg of chitosan additive (i.e. absorption capacity 0.02 g HCHO/g Chitosan).

Experimental Research on Deep Cryogenic Treatment Process of YT30 Cemented Carbide Inserts

2010 ◽  
Vol 139-141 ◽  
pp. 702-705 ◽  
Author(s):  
Hong Juan Yan ◽  
Hong Hai Xu ◽  
Xin Min Li
Keyword(s):  
Orthogonal Experiment ◽  
Cryogenic Treatment ◽  
Cemented Carbide ◽  
Deep Cryogenic Treatment ◽  
Tempering Temperature ◽  
Before And After ◽  
Orthogonal Experiment Method ◽  
Enhance Wear Resistance ◽  
Carbide Inserts ◽  
Cemented Carbide Inserts

Deep Cryogenic treatment (DCT) is a one time permanent process, carried out in such a way that the material is slowly cooled down to the cryogenic temperature, after which it is held at that temperature for a specified period of time and is heated back to room temperature at slow rate followed by low temperature tempering. In this study, the orthogonal experiment method was used to study the DCT process of YT30 cemented carbide inserts. The primary relation of the different factors of DCT was analyzed. TH300 sclerometer was used to measure the hardness of inserts. The microscopes were used to observe the wearing profiles of inserts and microstructures before and after DCT. The orthogonal experiment results show that the effect of soaking temperature on the properties of inserts is the first factor, the soaking time is second one, the cooling rate is third one, and the last one is the tempering temperature. DCT improves the multi-type martensite transformation of Co. Therefore DCT increases hardness and enhance wear resistance of the cemented carbide inserts.

scholarly journals Effect of Organic and Mineral Soil Fractions on Sorption Behaviour of Chlorophenol and Triazine Micropollutants

2009 ◽  
Vol 60 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Sanja Stipičević ◽  
Sanja Fingler ◽  
Vlasta Drevenkar
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Mineral Soil ◽  
Freundlich Isotherm ◽  
Sorption Process ◽  
Mineral Surface ◽  
Sorption Behaviour ◽  
Soil Fractions ◽  
Before And After ◽  
Sorption Intensity

Effect of Organic and Mineral Soil Fractions on Sorption Behaviour of Chlorophenol and Triazine MicropollutantsThis article compares the sorption behaviour of 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol, chlorotriazine atrazine, methylthiotriazine ametryn, methoxytriazine atratone, hydroxyatrazine, and didelakylated atrazine in a topsoil and an aquifer sediment before and after removal of sorbent organic matter and in humic acid. Freundlich isotherm coefficients Kf and 1/n and free energy change (δG°) were calculated for all compounds in all sorbents. According to sorbent pH values, chlorophenolate anions and uncharged triazine species dominated in all sorption experiments with topsoil and aquifer sediment. In experiments with humic acid, chlorophenols, atrazine, and didealkylated atrazine existed almost completely as neutral species, whereas protonated species dominated for hydroxyatrazine, atratone, and ametryn. In addition to a hydrophobic partition, sorption of all compounds in native soil and sediment sorbents includes specific, more polar interactions, which greatly depend on sorbate acidity/basicity, specific properties of the sorbent organic matter and of mineral surface, as well as on the system pH. A significantly greater sorption intensity of all compounds in "organic-free" than in the native aquifer sediment confirmed the importance and possible dominance of mineral surface in the sorption process. Sorption intensity of chlorophenol and triazine compounds in humic acid was closely related to compound hydrophobicity. Greater sorption of almost completely protonated hydroxyatrazine than of the more hydropohobic but uncharged atrazine indicated different humic acid reaction sites for two compounds and consequently different sorption mechanisms.

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