scholarly journals Efficient removal of tetracycline with KOH-activated graphene from aqueous solution

2017 ◽  
Vol 4 (11) ◽  
pp. 170731 ◽  
Author(s):  
Jie Ma ◽  
Yiran Sun ◽  
Fei Yu
Keyword(s):  
Ionic Strength ◽  
High Specific Surface Area ◽  
Order Kinetic ◽  
Liquid Ratio ◽  
Promising Alternative ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Solid Liquid ◽  
Coexisting Ions

Activated graphene absorbents with high specific surface area (SSA) were prepared by an easy KOH-activated method, and were applied in absorbing antibiotics, such as tetracycline (TC). After activation, many micropores were introduced to graphene oxide sheets, leading to higher SSA and many new oxygen-containing functional groups, which gave KOH-activated graphene excellent adsorption capacity (approx. 532.59 mg g −1 ) of TC. Further study on the adsorption mechanism showed that the Langmuir isotherm model and the pseudo-second-order kinetic model fitted with experiment data. To further understand the adsorption process, the effects of solid–liquid ratio, pH, ionic strength and coexisting ions were also investigated. The results revealed that, compared with pH and ionic strength, solid–liquid ratio and coexisting ions (Cu 2+ , CrO 4 2− ) had more significant influence over the adsorption performance. The findings provide guidance for application of KOH-activated graphene as a promising alternative adsorbent for antibiotics removal from aqueous solutions.

scholarly journals Removal of methylene blue by biosorption onto Stipa tenacissima L. (Alfa) plants: Kinetics, equilibrium and thermodynamic studies

2021 ◽  
pp. 33-44
Author(s):  
Samir Ladjali ◽  
Nadjib Dahdouh ◽  
Samira Amokrane ◽  
El Mekatel ◽  
Djamel Nibou
Keyword(s):  
Methylene Blue ◽  
Contact Time ◽  
Blue Dye ◽  
Order Kinetic ◽  
Liquid Ratio ◽  
Stipa Tenacissima ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Solid Liquid

This study examines the ability of Stipa tenacissima L. (Alfa) to biosorb the Methylene Blue dye. Biosorption tests were performed in aqueous solution based on certain essential parameters such as solution?s pH (2-12), solid/liquid ratio (1-6 g/L), initial dye concentration (25-125 mg/L) and contact time (0-300 min). The Langmuir, Freundlich, Temkin and Elovich models were applied. It was found that the equilibrium data could be fitted to the Langmuir isotherm for MB biosorption with a maximum capacity qmax 55, 95 mg/g. The kinetic study shows that the experimental data correspond to the pseudo-second order kinetic model. The negative Gibbs values free energy ?G? reveal the spontaneity of MB biosorption at the surface of Stipa tenacissima L. The positive value of ?H? reveals the endothermic nature of the process.

scholarly journals Fenton-Like Oxidation of Antibiotic Ornidazole Using Biochar-Supported Nanoscale Zero-Valent Iron as Heterogeneous Hydrogen Peroxide Activator

2020 ◽  
Vol 17 (4) ◽  
pp. 1324 ◽  
Author(s):  
Yanchang Zhang ◽  
Lin Zhao ◽  
Yongkui Yang ◽  
Peizhe Sun
Keyword(s):  
Oxidation Process ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
Mass Ratio ◽  
Promising Alternative ◽  
Nanoscale Zero Valent Iron ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
H2o2 System

Biochar (BC)-supported nanoscale zero-valent iron (nZVI-BC) was investigated as a heterogeneous Fenton-like activator to degrade the antibiotic ornidazole (ONZ). The characterization of nZVI-BC indicated that BC could enhance the adsorption of ONZ and reduce the aggregation of nZVI. Thus, nZVI-BC had a higher removal efficiency (80.1%) than nZVI and BC. The effects of parameters such as the nZVI/BC mass ratio, pH, H2O2 concentration, nZVI-BC dose, and temperature were systematically investigated, and the removal of ONZ followed a pseudo-second-order kinetic model. Finally, possible pathways of ONZ in the oxidation process were proposed. The removal mechanism included the adsorption of ONZ onto the surface of nZVI-BC, the generation of •OH by the reaction of nZVI with H2O2, and the oxidation of ONZ. Recycling experiments indicated that the nZVI-BC/H2O2 system is a promising alternative for the treatment of wastewater containing ONZ.

Fast Removal of Pb2+ from Aqueous Solution by Water Insoluble Konjac Glucomannan

2009 ◽  
Vol 610-613 ◽  
pp. 65-68 ◽  
Author(s):  
Xue Gang Luo ◽  
Feng Liu ◽  
Xiao Yan Lin
Keyword(s):  
Aqueous Solution ◽  
Correlation Coefficients ◽  
Konjac Glucomannan ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Equilibrium Process ◽  
Fast Removal

Konjac glucomannan (KGM) was converted into water insoluble konjac glucomannan (WIKGM) by treating with NaOH through completely deacetylated reaction. Adsorption study was carried out for the adsorption of Pb2+ from aqueous solution using water insoluble konjac glucomannan. The influences of pH, contact time, temperature and initial Pb2+ concentration on the absorbent were studied. Results of kinetic data showed that the Pb2+ adsorption rate was fast and good correlation coefficients were obtained for the pseudo second-order kinetic model. The equilibrium process was described well by the Langmuir isotherm model with maximum adsorption capacity of 9.18 mg/g on WIKGM at 25°C.

Removal of fluoride from aqueous solution by adsorption onto Kanuma mud

2010 ◽  
Vol 62 (8) ◽  
pp. 1888-1897 ◽  
Author(s):  
Nan Chen ◽  
Zhenya Zhang ◽  
Chuanping Feng ◽  
Miao Li ◽  
Rongzhi Chen ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Fluoride Concentration ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Solution Ph ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Solid Liquid Interface ◽  
Solid Liquid

Kanuma mud, a geomaterial, is used as an adsorbent for the removal of fluoride from water. The influences of contact time, solution pH, adsorbent dosage, initial fluoride concentration and co-existing ions were investigated by batch equilibration studies. The rate of adsorption was rapid with equilibrium being attained after about 2 h, and the maximum removal of fluoride was obtained at pH 5.0–8.0. The Freundlich isotherm model was found to represent the measured adsorption data well. The negative value of the thermodynamic parameter ΔG suggests the adsorption of fluoride by Kanuma mud was spontaneous, the endothermic nature of adsorption was confirmed by the positive ΔH value. The negative ΔS value for adsorbent denoted decreased randomness at the solid/liquid interface. The adsorption process using Kanuma mud followed the pseudo-second-order kinetic model. Fluoride uptake by the Kanuma mud was a complex process and intra-particle diffusion played a major role in the adsorption process. It was found that adsorbed fluoride could be easily desorbed by washing the adsorbent with a solution of pH 12. This indicates the material could be easily recycled.

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 Utilization of Sawdust Waste Biomass as an Eco-Friendly Biosorbent for Bioremediation of Manganese Pollution in Aqueous Environment

2019 ◽  
Vol 2 (3) ◽  
pp. 823-830
Author(s):  
Fatih Deniz
Keyword(s):  
Operating Conditions ◽  
Aqueous Environment ◽  
Order Kinetic ◽  
Waste Biomass ◽  
Equilibrium Studies ◽  
Manganese Removal ◽  
Removal Capacity ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

In this study, the sawdust waste biomass was used as an eco-friendly biosorbent material for the bioremediation of manganese pollution in aqueous environment. The effects of various environmental variables such as pH, biosorbent amount, metal concentration and contact time on the manganese biosorption were studied in batch operating conditions. The kinetic and equilibrium studies were performed to elucidate the biosorption behavior of biosorbent material. The biosorption capacity of biosorbent was strongly influenced by the operating parameters. The experimental data were more successfully modeled by the pseudo-second-order kinetic model and Langmuir isotherm model compared to other models applied in the study. The maximum manganese removal capacity of biosorbent was found to be 25.655 mg g-1. These findings showed that the sawdust waste biomass can be used as an eco-friendly biosorbent material for the bioremediation of manganese pollution in aqueous environment.

Adsorption of Cu(II), Ni(II) and Zn(II) ions by nano kaolinite: Thermodynamics and kinetics studies

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Adsorption Process ◽  
Ion Concentration ◽  
Order Kinetic ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir

An easy route for preparation emulsion of kaolinite (Al2Si2O5.4H2O) from Sweileh sand deposits, west Amman, Jordan by hydrochloric acid under continuous stirring for 4 h at room temperature was performed and nano kaolinite powder was used as an adsorbent for the removal of Cu(II), Zn(II) and Ni(II) ions. Nano kaolinite was characterized by XRD, FT-IR and SEM techniques. Effect of pH, adsorbent dose, initial metal ion concentration, contact time and temperature on adsorption process was examined. The negative values of ΔGo and the positive value of ΔHo revealed that the adsorption process was spontaneous and endothermic. The Langmuir isotherm model fitted well to metal ions adsorption data and the adsorption capacity. The kinetic data provided the best correlation of the adsorption with pseudo-second order kinetic model. In view of promising efficiency, the nano kaolinite can be employed for heavy metal ions adsorption.

scholarly journals Granules of brick waste (GBW) as low-cost sorbent for removal of Pb+2 ions from aqueous solutions

2020 ◽  
Vol 27 (3) ◽  
pp. 1-8
Author(s):  
Teba H. Mhawesh ◽  
Ziad T. Abd Ali
Keyword(s):  
Aqueous Solutions ◽  
Low Cost ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Sorption Data ◽  
X Ray ◽  
Batch Tests ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The potential application of granules of Granular brick waste as a low-cost sorbent for removal of Pb+2 ions from aqueous solutions has been studied. The properties of Granular brick waste were determined through several tests such as X-Ray diffraction , Energy dispersive X-ray, Scanning electron microscopy , and surface area. In batch tests, the influence of several operating parameters including contact time, initial concentration, agitation speed, and the dose of GBW was investigated. The best values of these parameters that provided maximum removal efficiency of lead (89.5 %) were 2.5 hr, 50 mg/L, 250 rpm, and 1.8 g/100mL, respectively. The sorption data obtained by batch experiments subjected to the three isotherm models called Langmuir, Freundlich and   Elovich. The results showed that the Langmuir isotherm model described well the sorption data (R2= 0.9866) in comparison with other models. The kinetic data were analyzed using two kinetic models called pseudo_first_order and pseudo_second_order. The pseudo-second-order kinetic model was found to agree well with the experimental data.

scholarly journals KINETIC AND ISOTHERM STUDY OF CUPPER ADSORPTION FROM AQUEOUS SOLUTION USING WASTE EGGSHELL

2014 ◽  
Vol 22 (2) ◽  
pp. 132-140 ◽  
Author(s):  
Ayben Polat ◽  
Sukru Aslan
Keyword(s):  
Ph Value ◽  
Experimental System ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Isotherm Study ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

The sorption of Cu2+ ions from aqueous solutions by eggshell was investigated in a batch experimental system with respect to the temperature, initial Cu2+ concentrations, pH, and biosorbent doses. The adsorption equilibrium was well described by the Langmuir isotherm model with the maximum adsorption capacity of 5.05 mg Cu2+/g eggshell at 25 °C. The value of qe increased with increasing the temperature while also increases the release of Ca2+ and HCO−3 ions from the eggshell. The highest sorption of Cu onto the waste eggshell was determined at the initial pH value of 4.0. The results confirming that the adsorption reaction of Cu2+ on the eggshell was thought to be endothermic. A comparison of the kinetic models such as pseudo first and second-order kinetics, intraparticle diffusion, and Elovich on the sorption rate demonstrated that the system was best described by the pseudo second-order kinetic model.

scholarly journals Adsorptive Removal of Methylene Blue onto ZnCl2Activated Carbon from Wood Apple Outer Shell: Kinetics and Equilibrium Studies

2011 ◽  
Vol 8 (4) ◽  
pp. 1696-1707 ◽  
Author(s):  
N. Bhadusha ◽  
T. Ananthabaskaran
Keyword(s):  
Methylene Blue ◽  
Outer Shell ◽  
Blue Dye ◽  
Order Kinetic ◽  
Biomass Waste ◽  
Equilibrium Studies ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Limonia Acidissima

Methylene blue dye removal from aqueous solution was investigated using ZnCl2activated carbon prepared from wood apple outer shell (Limonia acidissima, biomass waste). Influence of agitation time, adsorbent dose, dye concentration, pH and temperature were explored. Two theoretical adsorption isotherms namely Langmuir and Freundlich were used to describe the experimental results. The Langmuir adsorption capacity (Qo) was found to be 35.1 mg/g and the equilibrium parameter (RL) values indicate favourable adsorption. The experimental data were well fitted with Langmuir isotherm model and pseudo second order kinetic model. Desorption studies showed that ion exchange mechanism might be involved in the adsorption process.

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