scholarly journals Interaction of Titanium Dioxide with Formaldehyde in the Presence of Quartz Sand under Static and Dynamic Conditions

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1420
Author(s):  
Anthi S. Stefanarou ◽  
Constantinos V. Chrysikopoulos
Keyword(s):  
Experimental Data ◽  
Titanium Dioxide ◽  
Kinetic Model ◽  
Quartz Sand ◽  
Order Kinetic ◽  
Aqueous Samples ◽  
Sorption Mechanism ◽  
Effective Removal ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Formaldehyde (FA) is an extremely active compound that is widely used in numerous applications. Given that FA is a known carcinogen, it is essential to remove it from the environment. Titanium dioxide (TiO2), due to its special physicochemical properties, is a promising adsorbent for the removal of specific organic compounds from aqueous solutions. In this study, the interaction of TiO2 with FA in the presence and absence of quartz sand, the most common mineral on the Earth’s surface, was investigated under static and dynamic (batch) conditions, at 25 °C. The experimental data suggested that the sorption of FA onto TiO2 can be described adequately by a pseudo-second order kinetic model, indicating that the main sorption mechanism was chemisorption. It was observed that the combination of TiO2 and quartz sand could1 lead up to effective removal of FA from aqueous samples.

scholarly journals Development of Cerium Oxide/Corncob Nanocomposite: A Cost-Effective and Eco-Friendly Adsorbent for the Removal of Heavy Metals

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4464
Author(s):  
Sidra Gran ◽  
Rukhsanda Aziz ◽  
Muhammad Tariq Rafiq ◽  
Maryam Abbasi ◽  
Abdul Qayyum ◽  
...  
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Contact Time ◽  
Cost Effective ◽  
Particle Diffusion ◽  
Order Kinetic ◽  
Removal Of Heavy Metals ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model ◽  
Pseudo Second Order

This research aims to assess the efficiency of the synthesized corncob as a cost-effective and eco-friendly adsorbent for the removal of heavy metals. Therefore, to carry out the intended research project, initially, the corncob was doped with nanoparticles to increase its efficiency or adsorption capacity. The prepared adsorbent was evaluated for the adsorption of cadmium (Cd) and chromium (Cr) from aqueous media with the batch experiment method. Factors that affect the adsorption process are pH, initial concentration, contact time and adsorbent dose. The analysis of Cd and Cr was performed by using atomic absorption spectrometry (AAS), while the characterization of the adsorbent was performed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that there is a significant difference before and after corncob activation and doping with CeO2 nanoparticles. The maximum removal for both Cd and Cr was at a basic pH with a contact time of 60 min at 120 rpm, which is 95% for Cd and 88% for Cr, respectively. To analyze the experimental data, a pseudo-first-order kinetic model, pseudo-second-order kinetic model, and intra-particle diffusion model were used. The kinetic adsorption studies confirmed that the experimental data were best fitted with the pseudo-second-order kinetic model (R2 = 0.989) and intra-particle diffusion model (R2 = 0.979). This work demonstrates that the cerium oxide/corncob nanocomposite is an inexpensive and environmentally friendly adsorbent for the removal of Cd and Cr from wastewater.

Synthesis of Functionalized Magnetite Titanium Dioxide Nanocomposite for Removal of Acid Fuchsine Dye

2018 ◽  
Vol 21 (8) ◽  
pp. 583-593 ◽  
Author(s):  
Sara Rahnama ◽  
Shahab Shariati ◽  
Faten Divsar
Keyword(s):  
Titanium Dioxide ◽  
Removal Efficiency ◽  
Magnetic Core ◽  
Fractional Factorial ◽  
Order Kinetic ◽  
Sorption Data ◽  
Salt Addition ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Objective: In this research, a novel magnetite titanium dioxide nanocomposite functionalized by amine groups (Fe3O4@SiO2@TiO2-NH2) was synthesized and its ability for efficient removal of Acid Fuchsine as an anionic dye from aqueous solutions was investigated. Method: The core-shell structure of Fe3O4@SiO2@TiO2 was prepared using Fe3O4 as magnetic core, tetra ethyl orthosilicate as silica and tetra butyl titanate as titanium source for shell. The synthesized nanocomposites (particle size lower than 44 nm) were characterized by FT-IR, XRD, DRS, SEM and TGA instruments. The various experimental parameters affecting dye removal efficiency were investigated and optimized using Taguchi fractional factorial design. Results: The synthesized adsorbent showed the highest removal efficiency of Acid Fuchsine (99 %) at pH= 3.5, without salt addition and during stirring at contact times less than 10 minutes. The study of kinetic models at two concentration levels showed the fast dye sorption on the surface of proposed nanocomposites with pseudo second order kinetic model (R2=1). Also, the fitting of Acid Fuchsine sorption data to Freundlich, Langmuir and Temkin isotherms suggested that Freundlich model gave a better fitting than other models (R2=0.9936, n=2). Conclusion: Good chemical stability, excellent magnetic properties, very fast adsorption kinetics and high removal efficiency make the synthesized nanocomposite as a proper recoverable sorbent for removal of Acid Fuchsine dye from wastewaters.

Dyeing mechanism and photodegradation kinetics of gardenia yellow natural colorant

2020 ◽  
pp. 004051752095848
Author(s):  
Huiyu Jiang ◽  
Xiaodong Hu ◽  
Asfandyar Khan ◽  
Jinbo Yao ◽  
Muhammad Tahir Hussain
Keyword(s):  
Kinetic Model ◽  
Cotton Fabric ◽  
Reaction Rate Constant ◽  
Second Order ◽  
Order Kinetic ◽  
Natural Colorant ◽  
Yellow Solution ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Dyeing Rate

In this study, gardenia yellow solution is used to dye 100% cotton fabric. The dyeing rate curve and adsorption isotherms were recorded to explore the thermodynamic model and to calculate the corresponding parameters. A definite concentration of gardenia yellow solution was placed under the xenon arc lamp for irradiation to test its photodegradability. Absorbance of the solution was measured at different degradation times and the corresponding varying curve of the absorbance was drawn to explore the photodegradation reaction order of the natural colorant and consistent parameters were calculated. The experimental results proved that the dyeing of cotton fabric with gardenia yellow colorant followed the pseudo second order kinetic model whereas adsorption isotherm followed the Langmuir model and the photodegradation process followed the second order kinetic model. Values of different parameters were calculated: reaction rate constant k = 2.26 × 10–3 (mg · L−1)1−m h−1, the correlation coefficient R2 = 0.994, and half decay time t1/2 = 5.82 h.

Second-Order Kinetic Model for the Sorption of Cu(II) Ions in Aqueous Solutions of Zeolite NaA

2012 ◽  
Vol 560-561 ◽  
pp. 1174-1177 ◽  
Author(s):  
Dimitar Petrov Georgiev ◽  
Bogdan Iliev Bogdanov ◽  
Yancho Hristov ◽  
Irena Markovska
Keyword(s):  
Kinetic Model ◽  
Aqueous Solutions ◽  
Kinetic Parameters ◽  
Linear Equations ◽  
Linear Method ◽  
Second Order ◽  
Order Kinetic ◽  
Zeolite Naa ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study, the sorption of Cu(II) ions in aqueous solutions of Zeolite NaA by performing batch kinetic sorption experiments. The equilibrium kinetic data were analyzed using the pseudo-second-order kinetic model. A comparison was made of the linear least-squares method and nonlinear method of the widely used pseudo-second-order kinetic model for the sorption of Cu(II) ions of Zeolite . Four pseudo-second-order kinetic linear equations are discussed. Kinetic parameters obtained from the four kinetic linear equations using the linear method differed but they were the same when using the non-linear method. Kinetic parameters obtained from four kinetic linear equations using the linear method differed. Equation type 1 pseudo-second-order kinetic model very well represented the kinetic of the adsorption Cu(II) ions by Zeolite NaA. Equation type 4 exhibited the worst fit. Present investigation showed that the non-linear method may be a better way to determine the kinetic parameters.

scholarly journals Adsorption of tricresyl phosphate onto graphene nanomaterials from aqueous solution

2017 ◽  
Vol 76 (6) ◽  
pp. 1565-1573 ◽  
Author(s):  
Jun Liu ◽  
Siying Xia ◽  
Xiaomeng Lü ◽  
Hongxiang Shen
Keyword(s):  
Experimental Data ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Tricresyl Phosphate ◽  
Batch Mode ◽  
Order Kinetic Model ◽  
Endothermic Process ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Increasing Temperature

Phosphorus flame retardant tricresyl phosphate (TCP) adsorption on graphene nanomaterials from aqueous solutions was explored using batch and column modes. Comparative studies were performed regarding the kinetics and equilibrium of TCP adsorption on graphene oxide (GO) and graphene (G) in batch mode. The adsorption kinetics exhibited a rapid TCP uptake, and experimental data were well described by the pseudo-second-order kinetic model. Adsorption isotherm data of TCP on the two adsorbents displayed an improved TCP removal performance with increasing temperature at pH 5, while experimental data were well described by the Langmuir isotherm model with a maximum adsorption capacity of 87.7 mg·g−1 for G, and 30.7 mg·g−1 for GO) at 303 K. The thermodynamic parameters show that the adsorption reaction is a spontaneous and endothermic process. In addition, dynamic adsorption of TCP in a fixed G column confirmed a faster approach to breakthrough at high flow rate, high influent TCP concentration, and low filling height of adsorbent. Breakthrough data were successfully described by the Thomas and Yoon-Nelson models.

scholarly journals Comparison of Adsorptive Removal of Total Nitrogen (T-N) and Total Phosphorous (T-P) in Aqueous Solution using Granular Activated Charcoal (GAC)

2013 ◽  
Vol 9 (1) ◽  
pp. 1822-1836
Author(s):  
Keon Sang Ryoo ◽  
Jong-Ha Choi ◽  
Yong Pyo Hong
Keyword(s):  
Aqueous Solution ◽  
Kinetic Model ◽  
Adsorption Capacity ◽  
Total Nitrogen ◽  
Activated Charcoal ◽  
Adsorption Equilibrium ◽  
Order Kinetic ◽  
Total Phosphorous ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The present study is to explore the possibility of utilizing granular activated charcoal (GAC) for the removal of total phosphorous (T-P) and total nitrogen (T-N) in aqueous solution. Batch adsorption studies were carried out to determine the influences of various factors like initial concentration, contact time and temperature. The adsorption data showed that GAC has a similar adsorption capacity for both T-N and T-P. The adsorption degree of T-N and T-P on GAC was highly concentration dependent. It was found that the adsorption capacity of GAC is quite favorable at a low concentration. At concentrations of 1.0 mg L-1 of T-P and 2.0 mg L-1 of T-N, approximately 97 % of adsorption was achieved by GAC. The equilibrium data were fitted well to the Langmuir isotherm model. The pseudo-second-order kinetic model appeared to be the better-fitting model because it has higher R2 compared with the pseudo-first-order and intra-particle kinetic model. The theoretical adsorption equilibrium qe,cal from pseudo-second-order kinetic model were relatively similar to the experimental adsorption equilibrium qe,exp. To evaluate the effect of thermodynamic parameters at different temperatures, the change in free energy ΔG, the enthalpy ΔH and the entropy ΔS were estimated. Except for adsorption of T-P at 278 K, the ΔG values obtained were all negative at the investigated temperatures. It indicates that the present adsorption system occurs spontaneously. The adsorption process of T-N by GAC was exothermic in nature, whereas T-P showed endothermic behavior. In addition, the positive values of ΔS imply that there was the increase in the randomness of adsorption of T-N and T-P at GAC-solution interface.  

scholarly journals Adsorptive Studies for the Removal of Crystal Violet Dye from Aqueous Solution by Using Cicca Acida L. Stem - Activated Carbon

2021 ◽  
Vol 16 (2) ◽  
pp. 436-443
Author(s):  
Sharmila Ramasamy ◽  
Anbarasu Kaliyaperumal ◽  
Thamilarasu Pommanaickar
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Kinetic Model ◽  
Crystal Violet ◽  
Order Kinetic ◽  
Human Beings ◽  
Crystal Violet Dye ◽  
Before And After ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Textile industries discharge wastewater containing various dyes including Crystal Violet dye. These dyes are very harmful for human beings, animals and plants. Therefore, the attempt is made for adsorption framework on elimination of crystal violet dye by using Cicca acida L. stem-activated carbon from aqueous solution carried out under various experimental methods and optimization conditions. Adsorption data modeled with Freundlich, Langmuir and Tempkin adsorption isotherms. Thermodynamic factors like as ∆Ho, ∆So and ∆Go were calculated, which indicated that the adsorption was spontaneous and endothermic nature. Based on kinetic study, pseudo-second order kinetic model was fit compared to the pseudo-first order kinetic model. The adsorbent has been characterized by SEM before and after adsorption of crystal violet dye solution.

scholarly journals Microstructural and Equilibrium Adsorption Study of the System of Waste Foundry Molding Sand/Cu (II) Ions

2016 ◽  
Vol 61 (4) ◽  
pp. 1805-1812
Author(s):  
A. Strkalj ◽  
Z. Glavas ◽  
L. Slokar
Keyword(s):  
Experimental Data ◽  
Adsorption Process ◽  
Order Kinetic ◽  
Molding Sand ◽  
Adsorption Study ◽  
Eds Analysis ◽  
Adsorption Capacities ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Casting Production

Abstract This paper deals with the waste foundry molding sand which originally comes from the casting production. Adsorption of Cu (II) ions on the waste foundry molding sand was studied. Experimental data were processed using adsorption isotherms. Obtained results show that the experimental data are best described by the Langmuir isotherm. The following adsorption capacities are obtained: 7.153 mg/g to 293 K, 8.403 mg/g at 333 K and 9.208 mg/g at 343 K. The kinetics and thermodynamics of the process were analysed. The obtained results indicate that the adsorption process takes place according to the pseudo second order kinetic model with the following constants: 0.438 g/mg min at 293 K, 0.550 g/mg min at 333 K and 1.872 g/mg min at 343 K. The following values of ΔG° were obtained: − 95.49 J/mol at 293 K, − 736.99 J/mol at 333 K and − 1183.46 J/mol at 343 K. The value of ΔH° is − 4.16 kJ/mol and the value of ΔS° is 15.17 J/molK. These results were confirmed by microscopic examinations. The results indicate that the adsorption process of Cu (II) ions on waste foundry molding sand is possible. Results of microscopic examinations show the homogeneity of the surface, which is proof of the chemisorption. Cu (II) ions on the surface of the waste foundry molding sand were detected after adsorption by EDS analysis, which proves the existence of the adsorption process.

scholarly journals Removal of COD from Groundwater in and Around Industrial Areas - Using Activated Carbon Powder Prepared by Groundnut Foliage and Groundnut Husk

2021 ◽  
Vol 37 (4) ◽  
pp. 922-927
Author(s):  
A. Kistan ◽  
V. Kanchana ◽  
N. K. Geetha ◽  
G. Infant Sujitha
Keyword(s):  
Activated Carbon ◽  
Kinetic Model ◽  
Adsorption Process ◽  
Oxygen Demand ◽  
Carbon Powder ◽  
Order Kinetic ◽  
Industrial Areas ◽  
Sem Image ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The following study explains that the adsorption efficiency of activated carbon used by Groundnut foliage and groundnut husk for the deportation of COD (Chemical Oxygen demand) from groundwater collected from in and around industrial areas of Vellore district was investigated with different activating conditions (Activating agent- KOH, ZnCl2 and H3PO4; Impregnation ratio-1:1,1:2,1:2; and activation temeperture-500-700°C. The activated carbon prepared based on optimized condition has well-developed pore structure and functional groups which is confirmed from SEM image and FTIR analysis respectively. The adsorption equilibrium was reached in 240 min with the isotherm data fitted well in both the model such as Langmuir model and Freundlich’s model indicating chemisorption’s adsorption for the activated carbon. Moreover, the adsorption process was exothermic accompanied by a decrease in irregularity. Furthermore, the adsorption kinetic study indicated that the adsorption process of the prepared sample follows the pseudo-second-order kinetic model compare to the pseudo-first -order kinetic model

scholarly journals Sorption of Cd2+ and Pb2+ on Aragonite Synthesized from Eggshell

2020 ◽  
Vol 12 (3) ◽  
pp. 1174 ◽  
Author(s):  
Lulit Habte ◽  
Natnael Shiferaw ◽  
Mohd Danish Khan ◽  
Thenepalli Thriveni ◽  
Ji Whan Ahn
Keyword(s):  
Experimental Data ◽  
Synthetic Wastewater ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Solution Ph ◽  
Surface Precipitation ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
High Sorption ◽  
Pseudo Second Order

In the present work, waste eggshells were used as a precursor for the synthesis of aragonite crystals through the wet carbonation method. Cadmium (Cd2+) and lead (Pb2+) were removed by the synthesized aragonite from synthetic wastewater. The influence of initial solution pH, contact time, Cd2+ and Pb2+ concentration, and sorbent dosage were evaluated. The major sorption was observed in the first 100 mins and 360 mins for Pb2+and Cd2+ respectively reaching sorption equilibrium at 720 mins (12 hr). The sorption capacity toward Pb2+ was much higher than toward Cd2+. Both heavy metals displayed high sorption capacities at initial pH 6. The pseudo-second-order kinetic model fits well with the experimental data with a higher correlation coefficient R2. Two isotherm models were also evaluated for the best fit with the experimental data obtained. Langmuir isotherm best fits the sorption of the metals on aragonite synthesized from eggshells. X-ray diffraction (XRD) and Scanning electron microscopy (SEM) results of sorbent after sorption showed that the mechanism of sorption was dominated by surface precipitation. Therefore, aragonite crystals synthesized from waste eggshells can be a potential substitute source for the removal of Cd2+ and Pb2+ from contaminated water.

Sign in / Sign up

Export Citation Format

Share Document