scholarly journals Adsorption behavior of Fe (III) in aqueous solution on melamine

2020 ◽  
Vol 82 (9) ◽  
pp. 1848-1857
Author(s):  
Hao Peng ◽  
Jing Guo ◽  
Bingqing Wang
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Processing Parameters ◽  
Adsorption Behavior ◽  
Experimental Conditions ◽  
Optimal Processing ◽  
Waste Effluents ◽  
Pseudo Second Order ◽  
Standard Enthalpy Change

Abstract This paper focused on the adsorption behavior of Fe (III) in aqueous solution on melamine. The effects of experimental conditions including dosage of melamine, reaction time and reaction temperature were investigated. The results showed that nearly 99% Fe (III) was adsorbed under the optimal conditions: melamine dosage (mole ratio) at n(C3H6N6)/n(Fe) = 3.5:1, reaction time of 60 min and reaction temperature of 90 °C. The optimal processing factors were obtained from response surface methodology and the effects of processing parameters on the removal efficiency of Fe (III) followed the order: mole ratio (n(C3N6H6):n(Fe)) > reaction temperature > reaction time. The adsorption kinetics behavior was fitted well with the pseudo-second-order model. The thermodynamic study showed that the adsorption process was unspontaneous and endothermic. The value of free energy change and standard enthalpy change disclosed that the mechanism of adsorption onto melamine was physisorption. The results will be useful for further applications of system design in the treatment of practical waste effluents.

The Adsorption Behavior of Reactive Dye on Magnetic Chitosan Coated Cotton Fibers

2011 ◽  
Vol 396-398 ◽  
pp. 2198-2201
Author(s):  
Xue Mei He ◽  
Kong Liang Xie
Keyword(s):  
Aqueous Solution ◽  
Crosslinking Agent ◽  
Reactive Dye ◽  
Adsorption Behavior ◽  
Experimental Conditions ◽  
Magnetic Chitosan ◽  
Pseudo Second Order ◽  
Basic Solutions ◽  
Kinetics Of ◽  
Coated Cotton

A new composite magnetic chitosan coated cotton (MSCC) fiber with 3-glycidyloxypropyltrimethoxysilane (GPTMS) as a crosslinking agent was prepared for the adsorption of C.I. Reactive red 194 from aqueous solution. The structure and morphology of MSCC fibers were analyzed by FTIR and SEM. The adsorption behavior of C.I. Reactive red 194 from aqueous solution onto MSCC fibers was investigated under various experimental conditions such as initial concentration of the dyes, temperature, pH and adsorb time. Experimental data indicated that the adsorption capacity of MSCC fibers on C.I. Reactive red 194 was higher in acidic rather than in basic solutions. A rise of temperature accelerates mass transfer of dyes into the MSCC fibers. The kinetics of the interactions was best described by pseudo-second-order mechanism.

Study on Synthesis of the High Aspect Ratios Nesquehonite Whiskers

2011 ◽  
Vol 239-242 ◽  
pp. 1118-1122 ◽  
Author(s):  
Ping Ke Yan ◽  
Bin Wang ◽  
Yu Juan Gao
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Low Temperature ◽  
Growth Mechanism ◽  
Reaction Temperature ◽  
Solution Method ◽  
Temperature Reaction ◽  
Aspect Ratios ◽  
Whisker Length ◽  
Aqueous Solution Method

In this paper, nesquehonite whiskers were synthesized by low-temperature aqueous solution method, and the impacts of reaction temperature, reaction time and surfactant dosage and other factors on the maximum whisker length and high aspect ratios of nesquehonite whiskers were also investigated. Results showed that under the conditions that the reaction temperature was 40 – 50 °C the reaction time was 50 – 60min and the amount of surfactant dosage was 1% (by mass), high aspect ratios nesquehonite whisker products can be synthesized. On this basis, growth mechanism of the nesquehonite whiskers was discussed.

Study on the Preparation of Chitosan-Based Resin

2010 ◽  
Vol 160-162 ◽  
pp. 1810-1815
Author(s):  
Jing Xian Li ◽  
Juan Qin Xue ◽  
Ming Wu ◽  
Yu Jie Wang ◽  
Wei Bo Mao
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Experimental Results ◽  
Raw Material ◽  
Cross Linking ◽  
Reactant Ratio ◽  
Experimental Conditions ◽  
Stirring Rate ◽  
Formaldehyde Crosslinking ◽  
New Type

With chitosan as the raw material, a new type of resin material is synthesized through formaldehyde crosslinking. The effects of the reactant ratio, the reaction temperature, the reaction time, the stirring rate and the system pH on the cross-linking rate are studied in detail. The resin material is then characterized by means of IR. The experimental results show that the reaction occurs mainly on the amino and the hydroxyl of chitosan. The chitosan-based resin material with good properties of sphericity and acidresistivity can be prepared under the optimal experimental conditions, which are found to be 1:5 for the ratio of chitosan and formaldehyde, 60°C for the temperature, 1 h for the reaction time, 440r/min for the stirring rate and 10 for the pH.

scholarly journals Investigating the zinc ion adsorption capacity of a chitosan/β-cyclodextrin complex in wastewater

2020 ◽  
Vol 143 ◽  
pp. 02006
Author(s):  
Jiaxin Liu ◽  
Siqi Wang ◽  
Xiuqing Ding ◽  
Jingyi Fu ◽  
Jun Zhao
Keyword(s):  
Reaction Time ◽  
Adsorption Capacity ◽  
Reaction Temperature ◽  
Zinc Ion ◽  
Mass Ratio ◽  
Industrial Waste Water ◽  
Cyclodextrin Complex ◽  
Experimental Conditions ◽  
Polyethylene Glycol 400 ◽  
Adsorption Rates

To decrease the amount of Zn2+ in industrial waste water, in this study, β-cyclodextrin (β-CD) was first modified and then used to obtain a β-cyclodextrin polymer (β-CDP). The effects of reaction temperature and reaction time of β-CD with citric acid (CA), polyethylene glycol 400 (PEG-400), and disodium hydrogen phosphate (NaH2PO4) on the amount of β-CDP produced were investigated. The results showed that at a reaction temperature of 145 °C and a reaction time of 4.5 h, 6.58 g of β-CDP was produced. Then, chitosan (CTS) was crosslinked with β-CDP using glutaraldehyde to prepare a chitosan/β-cyclodextrin (CTS/β-CDP) complex. The mass ratio of CTS to β-CDP, reaction temperature, reaction time, and amount of added glutaraldehyde were used as the main variables to examine the Zn2+ adsorption rate and adsorption capacity of the composites prepared in this study. The optimum experimental conditions were as follows: a mass ratio of 3:10, a reaction temperature of 80 °C, a reaction time of 90 min, and 2 mL of glutaraldehyde. Under these optimal conditions, the adsorption amount and adsorption rates of Zn2+ using CTS/β-CDP complex were respectively 97.70 mg·g-1 and 78.92%.

Degradation of herbicides (ametryn and isoproturon) during water disinfection by means of two oxidants (hypochlorite and chlorine dioxide)

1997 ◽  
Vol 35 (4) ◽  
pp. 129-136 ◽  
Author(s):  
A. Lopez ◽  
G. Mascolo ◽  
G. Tiravanti ◽  
R. Passino
Keyword(s):  
Aqueous Solution ◽  
Reaction Time ◽  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Hydrolysis Product ◽  
Water Disinfection ◽  
Experimental Conditions ◽  
Molar Ratios ◽  
Chemical Structures ◽  
Opposite Trend

The paper reports the results of an investigation aimed to find out the number and the chemical structures of byproducts which form during the reactions occurring in aqueous solution between two very common disinfectants, sodium hypochlorite (NaClO) and chlorine dioxide (ClO2), and two herbicides widely used in agriculture and frequently found in groundwaters: ametryn and isoproturon. Under controlled experimental conditions [T=20°C, pH=7, reaction-time = 48h, herbicide/disinfectant molar ratios: 0.05 and 0.05×10−2], ametryn reactions with chlorine dioxide much slower than with sodium hypochlorite, whereas the opposite trend has been observed for isoproturon. In any case, however, the higher the reagents concentration the faster the reactions. As for reaction byproducts, they have been detected by HPLC and identified by HPLC-MS. In particular, ametryn (R-S-CH3) reaction with NaClO gives rise to the consecutive formation of four derivatives: the sulphoxide (R-SO-CH3), the sulphone (R-SO2-CH3), the sulphonate ester (R-O-SO2-CH3) and its hydrolysis product (R-OH). Within the fixed reaction time (48h), ametryn reaction with ClO2 forms only the sulphoxide derivative (R-SO-CH3). As for isoproturon, it reacts with both oxidants forming aromatic-ring substituted derivatives. In particular, during the reactions with NaClO and ClO2, four and two (chlorinated and/or hydroxylated) derivatives are respectively formed.

Thermal Activation of Brazilian Smectite Clay (Primavera) and its Application for the Removal of Cadmium from Aqueous Solution

2020 ◽  
Vol 07 ◽  
Author(s):  
Marta Lígia Pereira da Silva ◽  
Tellys Lins Almeida Barbosa ◽  
Meiry Gláucia Freire Rodrigues
Keyword(s):  
Aqueous Solution ◽  
Kinetic Constant ◽  
Second Order ◽  
Order Kinetic ◽  
Experimental Conditions ◽  
X Ray ◽  
Thermally Activated ◽  
Study Results ◽  
Water Cleaning ◽  
Pseudo Second Order

Background: Region-based solutions for water cleaning could be critical to tackle the water challenges faced in enhancing the in the future. Brazilian Primavera clay is cheap, abundant, and an untested material that has the potential to be used for water cleaning. Objective: the objective of the present work was to thermally activate and characterize the Brazilian clay and then determine the potential to remove Cd2+ from an aqueous solution. Methods: Primavera clay was thermally activated at 300 oC and characterized using X ray diffraction, X-ray Spectroscopy Energy Dispersive, and N2 adsorption. Sorption equilibrium was determined using the following experimental conditions: constant pH 4.5, 5 h, and 27 oC. Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherms models were applied in order to determine the efficiency of clay used as an adsorbent. Adsorption kinetics was analyzed using the pseudo-second-order kinetic model. Results: In this study, results revealed that even though the heat treatment did not cause profound alterations on the clay structure(smectite) and surface area (78 m2 /g), a pseudo-second-order kinetic constant of 0.5563 mg/g/min was found for the cadmium removal. Conclusion: The mathematical models of the Langmuir and Temkin showed a better fit to the experimental data. A high affinity between the cadmium and the thermally activated Primavera clay was found up to 88 % with removal efficiencies.

scholarly journals Obtaining adsorbents from acid and acid-thermal activation of bentonite for chlorothalonil pesticide removal

2020 ◽  
Vol 15 (3) ◽  
pp. 812-825
Author(s):  
Nadia Boudouara ◽  
Réda Marouf ◽  
Jacques Schott
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Thermal Activation ◽  
X Ray Diffraction ◽  
Acid Attack ◽  
Experimental Conditions ◽  
X Ray ◽  
Pesticide Removal ◽  
Freundlich Equation ◽  
Pseudo Second Order

Abstract Bentonite samples collected from M'Zila of Mostaganem (Algeria) were treated in first protocol with sulfuric acid at concentrations 1, 3 and 6N. The second protocol concerns the acid attack of bentonite combined with thermal treatment at temperatures of 100 and 200 °C. The obtained adsorbents were characterized by different analyses techniques such as chemical composition, X-ray diffraction (XRD), specific surface area and pHPZC. The modified bentonites were used for removal of Chlorothalonil (Chl) from aqueous solution. The adsorption behavior of the pesticide was studied under different experimental conditions of pH, contact time, concentration of Chl and temperature of solution. The adsorption of Chl followed pseudo-second order kinetics and was described by the Freundlich equation. Thermodynamic study revealed that Chl adsorption was endothermic and physical in nature.

Magnesium Recovery from Desiliconization Slag of Nickel Laterite Ores by Carbonization

2013 ◽  
Vol 813 ◽  
pp. 255-258 ◽  
Author(s):  
Wen Ning Mu ◽  
Shuang Zhi Shi ◽  
Yu Chun Zhai
Keyword(s):  
Reaction Time ◽  
Reaction Temperature ◽  
Flow Rate ◽  
Temperature Reaction ◽  
Nickel Laterite ◽  
Experimental Conditions ◽  
Solid Ratio ◽  
Carbonation Process ◽  
Laterite Ores ◽  
Orthogonal Experiments

This work examines the recovery of magnesium from desiliconization slag of nickel laterite ores by carbonation process. The effects of reaction temperature, reaction time, liquid/solid ratio and CO2 flow rate on magnesium dissolution are investigated. The optimized experimental conditions of recovering magnesium were gained by the analysis of orthogonal experiments.

scholarly journals Uptake of phenol from aqueous solution by burned water hyacinth

2008 ◽  
Vol 10 (2) ◽  
pp. 43-49 ◽  
Author(s):  
Mohammed Uddin ◽  
Mohammed Islam ◽  
Mohammed Islam ◽  
Mohammed Abedin
Keyword(s):  
Aqueous Solution ◽  
Water Hyacinth ◽  
Second Order ◽  
Point Of Zero Charge ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Experimental Conditions ◽  
Adsorption Models ◽  
Adsorption Sites ◽  
Pseudo Second Order

Uptake of phenol from aqueous solution by burned water hyacinth The potential of burned water hyacinth (BWH) for phenol adsorption from aqueous solution was studied. Batch kinetic and isotherm studies were carried out under varying experimental conditions of contact time, phenol concentration, adsorbent dosage and pH. The pH at the point of zero charge (pHPZC) of the adsorbent was determined by the titration method and the value of 8.8 ± 0.2 was obtained. The FTIR of the adsorbent was carried out in order to find the potential adsorption sites for the interaction with phenol molecules. The Freundlich and Langmuir adsorption models were used for the mathematical description of adsorption equilibrium and it was found that the experimental data fitted very well to the Langmuir model. Maximum adsorption capacity of the adsorbent was found to be 30.49 mg/g. Batch adsorption models, based on the assumption of the pseudo-first-order and pseudo-second-order models, were applied to examine the kinetics of the adsorption. The results showed that kinetic data closely followed the pseudo-second-order model.

Bioenergy II: Effect of Experimental Conditions on the Slow Batch Pyrolysis of Mixtures of Plastics, Tyres and Forestry Biomass Wastes

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Filipe Paradela ◽  
Filomena Pinto ◽  
Isabel Cabrita ◽  
Ibrahim Gulyurtlu ◽  
Ana M. Ramos
Keyword(s):  
Reaction Time ◽  
Gas Phase ◽  
Reaction Temperature ◽  
Liquid Fraction ◽  
Initial Pressure ◽  
Initial Mixture ◽  
Experimental Conditions ◽  
Product Yields ◽  
Liquid Yield

This work aimed to study the recovery of three types of waste by the process of pyrolysis: biomass, plastics and used tyres. The effects of experimental conditions in products yield and composition were studied. The increase of reaction time increased alkane content both in gas phase from 53% to 70% v/v and in liquid fraction from 48% to 60% w/w. The rise of reaction temperature led to a decrease of liquid yield (from 82% to 73% w/w), which was followed by the increase of solids and gases. The increase of reaction temperature also allowed the increase of the alkane content in gas phase from 39% to 70% v/v. The increase of initial pressure did not lead to appreciable variations in product yields or composition. The parameter that most affected products yield and composition was plastics content on the wastes initial mixture. The enhancement of this parameter increased liquids yield from 33% to 92% w/w, at the expenses of solids and gases contents and also decreased aromatics contents from 52% to 28% w/w.

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