scholarly journals Sorption of Monothioarsenate to the Natural Sediments and Its Competition with Arsenite and Arsenate

2021 ◽  
Vol 18 (23) ◽  
pp. 12839
Author(s):  
Huimei Shan ◽  
Jinxian Zhang ◽  
Sanxi Peng ◽  
Hongbin Zhan ◽  
Danxue Liao
Keyword(s):  
Sorption Isotherm ◽  
Freundlich Isotherm ◽  
Arsenic Species ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
High Concentration ◽  
Competitive Effects ◽  
Subsurface Environment ◽  
Intermediate Time ◽  
Langmuir Isotherm Model

Monothioarsenate (MTAsV) is one of the major arsenic species in sulfur- or iron-rich groundwater, and the sediment adsorption of MTAsV plays an important role in arsenic cycling in the subsurface environment. In this study, batch experiments and characterization are conducted to investigate the sorption characteristic and mechanism of MTAsV on natural sediments and the influences of arsenite and arsenate. Results show that MTAsV adsorption on natural sediments is similar to arsenate and arsenite, manifested by a rapid early increasing stage, a slowly increasing stage at an intermediate time until 8 h, before finally approaching an asymptote. The sediment sorption for MTAsV mainly occurs on localized sites with high contents of Fe and Al, where MTAsV forms a monolayer on the surface of natural sediments via a chemisorption mechanism and meanwhile the adsorbed MTAsV mainly transforms into other As species, such as AlAs, Al-As-O, and Fe-As-O compounds. At low concentration, MTAsV sorption isotherm by natural sediments becomes the Freundlich isotherm model, while at high concentration of MTAsV, its sorption isotherm becomes the Langmuir isotherm model. The best-fitted maximum adsorption capacity for MTAsV adsorption is about 362.22 μg/g. Furthermore, there is a competitive effect between MTAsV and arsenate adsorption, and MTAsV and arsenite adsorption on natural sediments. More specifically, the presence of arsenite greatly decreases MTAsV sorption, while the presence of MTAsV causes a certain degree of reduction of arsenite adsorption on the sediments before 4 h, and this effect becomes weaker when approaching the equilibrium state. The presence of arsenate greatly decreases MTAsV sorption and the presence of MTAsV also greatly decreases arsenate sorption. These competitive effects may greatly affect MTAsV transport in groundwater systems and need more attention in the future.

Thermodynamic Studies for Adsorption of Cd2+ and Pb2+ from Waster Water on Modified Walnut Shell

2015 ◽  
Vol 737 ◽  
pp. 622-626
Author(s):  
Shao Hua He ◽  
Dan Wang ◽  
Qing Qiu Kong ◽  
Xi Wu
Keyword(s):  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Walnut Shell ◽  
Isotherm Models ◽  
Model Parameters ◽  
Maximum Adsorption Capacity ◽  
Adsorption Data ◽  
Batch Technique ◽  
Adsorption Processes ◽  
Langmuir Isotherm Model

The adsorption isothermal curve and thermodynamic adsorption of Cd2+ and Pb2+ on modified walnut shell from waster water were investigated using batch technique. The equilibrium adsorption data are fitted to Langmuir and Freundlich isotherm models and the model parameters are evaluated. The Langmuir isotherm model shows a better fit to adsorption data than the Freundlich isotherm model for the sorption of Cd2+ and Pb2+ on modified walnut shell. The maximum adsorption capacity of Cd2+ and Pb2+ by modified walnut shell is found to be 32.68 mg·g-1 and 84.75 mg·g-1 at 298K temperature, respectively. The adsorption processes of Cd2+ and Pb2+ has feasibility and spontaneous nature. Thermodynamic parameters depict the endothermic nature of sorption and the process is spontaneous and favorable.

scholarly journals Preparation of ureido-functionalized PVA/silica mesoporous fibre membranes via electrospinning for adsorption of Pb2+ and Cu2+ in wastewater

2017 ◽  
Vol 76 (9) ◽  
pp. 2526-2534 ◽  
Author(s):  
Meimei Zhou ◽  
Weizhen Tang ◽  
Pingping Luo ◽  
Jiqiang Lyu ◽  
Aixia Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Adsorption Capacity ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption

Abstract Ureido-functionalized mesoporous polyvinyl alcohol/silica composite nanofibre membranes were prepared by electrospinning technology and their application for removal of Pb2+ and Cu2+ from wastewater was discussed. The characteristics of the membranes were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and N2 adsorption-desorption analysis. Results show that the membranes have long fibrous shapes and worm-like mesoporous micromorphologies. Fourier transform infrared spectroscopy confirmed the membranes were successfully functionalized with ureido groups. Pb2+ and Cu2+ adsorption behavior on the membranes followed a pseudo-second-order nonlinear kinetic model with approximately 30 minutes to equilibrium. Pb2+ adsorption was modelled using a Langmuir isotherm model with maximum adsorption capacity of 26.96 mg g−1. However, Cu2+ adsorption was well described by a Freundlich isotherm model with poor adsorption potential due to the tendency to form chelating complexes with several ureido groups. Notably, the membranes were easily regenerated through acid treatment, and maintained adsorption capacity of 91.87% after five regeneration cycles, showing potential for applications in controlling heavy metals-related pollution and metals reuse.

scholarly journals Isolasi Kitosan Dari Tudung Jamur Merang (Vollvariella Volvaceae) Dan Aplikasinya Sebagai Absorben Logam Timbal (Pb)

2018 ◽  
Vol 6 (1) ◽  
pp. 44-50
Author(s):  
Matheis F.J.D.P. Tanasale ◽  
Adriani Bandjar ◽  
Natasya Sewit
Keyword(s):  
Experimental Data ◽  
Molecular Weight ◽  
Adsorption Capacity ◽  
Langmuir Isotherm ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
Langmuir Isotherm Model ◽  
Ftir Spectrophotometry ◽  
Chitin And Chitosan

Chitosan isolated from mushroom (Vollariella volvaceae) as adsorbent of lead (Pb) metal has been done.  The isolation of chitosan was obtained 2.94% from total weight of mushroom.  Fungtional groups of chitin and chitosan were indentified by using FTIR spectrophotometry.  The chitosan had 74.66% degree of deacetylation and 2.09 x 104 g/mol viscosity molecular weight.  The experimental data of the chitosan as adsorbent for Pb metal were correlated with the Langmuir and Freundlich isotherm model.  The maximum adsorption capacity of Pb based on the Langmuir isotherm model was 2.66 mg/g.

scholarly journals SORPTION STUDIES OF CRUDE OIL ON ACETYLATED SAWDUST

2018 ◽  
Vol 54 (2A) ◽  
pp. 201 ◽  
Author(s):  
Nguyen Trung Duc
Keyword(s):  
Crude Oil ◽  
Oil Spill ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Sorption Kinetics ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
Aqueous Environment ◽  
Experimental Conditions ◽  
Langmuir Isotherm Model

Acetylated sawdust (AS) has been studied as sorbent for crude oil spill clean-up operations in the aqueous environment. Sorption kinetics and isotherm studies were carried out under various experimental conditions. The experimental data were particularly tested using the Langmuir isotherm model and the Freundlich isotherm model. The results showed that the acetylation of sawdust enhanced the equilibrium sorption capacity of biomass towards the crude oil. Kinetic studies have shown that the data better fitted the Langmuir moldel than the Freundlich model. The maximum adsorption capacity of AS was 7.9 g/g of crude oil. These values indicated that the acetylated sawdust is a suitable sorbent with potential for further development for oil spill treatment.

Adsorption and Deposition of Cu (II) on Modified Valonia Tannin

2009 ◽  
Vol 620-622 ◽  
pp. 555-558
Author(s):  
Yi Li ◽  
Xue Gang Luo ◽  
Zhao Liu ◽  
Yan Huang ◽  
Xiao Yan Long
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Mannich Reaction ◽  
Langmuir Isotherm ◽  
Freundlich Isotherm ◽  
Heterogeneous Surface ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model

The modified valonian tannin was prepared through sulfonated-mannich reaction and used to adsorb Cu (II) from the aqueous solutions. The adsorption capacity rapidly reached equilibrium within 2 hours. The effect of pH on adsorption was apparent, the amount of adsorption increased significantly as the pH increased from 2.0 to 4.0 and then leveled off at pH 4.0-6.0. Equilibrium data fitted well with Freundlich isotherm model compared to Langmuir isotherm model, indicating that adsorption takes place on heterogeneous surface of the modified valonia tannin. The adsorption capacity was increased by increasing initial concentrations. The maximum adsorption capacity of cooper ion was determined to be 56.200 mg/g at 100 mg/L concentration.

scholarly journals Fabrication of Carboxymethylcellulose/Metal-Organic Framework Beads for Removal of Pb(II) from Aqueous Solution

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 942 ◽  
Author(s):  
Huo-Xi Jin ◽  
Hong Xu ◽  
Nan Wang ◽  
Li-Ye Yang ◽  
Yang-Guang Wang ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Langmuir Isotherm ◽  
Adsorption Equilibrium ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Metal Organic ◽  
Langmuir Isotherm Model

The ability to remove toxic heavy metals, such as Pb(II), from the environment is an important objective from both human-health and ecological perspectives. Herein, we describe the fabrication of a novel carboxymethylcellulose-coated metal organic material (MOF-5–CMC) adsorbent that removed lead ions from aqueous solutions. The adsorption material was characterized by Fourier-transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy. We studied the functions of the contact time, pH, the original concentration of the Pb(II) solution, and adsorption temperature on adsorption capacity. MOF-5–CMC beads exhibit good adsorption performance; the maximum adsorption capacity obtained from the Langmuir isotherm-model is 322.58 mg/g, and the adsorption equilibrium was reached in 120 min at a concentration of 300 mg/L. The adsorption kinetics is well described by pseudo-second-order kinetics, and the adsorption equilibrium data are well fitted to the Langmuir isotherm model (R2 = 0.988). Thermodynamics experiments indicate that the adsorption process is both spontaneous and endothermic. In addition, the adsorbent is reusable. We conclude that MOF-5–CMC is a good adsorbent that can be used to remove Pb(II) from aqueous solutions.

scholarly journals Sorption of Ni(II) and Cr(III) ions by the Chironomus yoshimatsui larvae from wastewater

2018 ◽  
Vol 15 (1) ◽  
pp. 6062-6069
Author(s):  
Keon Sang Ryoo
Keyword(s):  
Freundlich Isotherm ◽  
Sorption Kinetics ◽  
Isotherm Model ◽  
Sorption Data ◽  
First Order ◽  
Batch System ◽  
Survival Capacity ◽  
Langmuir Isotherm Model ◽  
Treatment Technologies ◽  
Kinetics Of

In this study, Chironomus yoshimatsui larvae were applied to remove Ni(II) and Cr(III) ions from wastewater. The sorption studies were carried out using laboratory-reared C. y. larvae. It was found that C. y. larvae are very susceptible to Cr(III) as compared to Ni(II). The survival capacity of C. y. larvae was sharply reduced when exposed to even low Cr(III) concentration. Sorption isotherm and kinetics of C. y. larvae for Ni(II) were determined by means of controlled experiments in a batch system. It was observed that sorpyion efficiency of Ni(II) was largely concentration dependent and more effective at lower concentration. At each equilibrium, Ni(II) was removed up to roughly 44∼80 %. Sorption data were better fitted to the Langmuir isotherm model because of its correlation coefficient R2 value greater than that of the Freundlich isotherm model. The sorption kinetics by C. y. larvae for Ni(II) was well described a pseudo-first-order rate expression. C. y. larvae have enormous potential for application in wastewater treatment technologies because they are widespread and abundant all around the world and can be easily kept in culture.

Synthesis, Characterization and Adsorption Property of Expanded Graphite/Conducting Polymer Composite

2011 ◽  
Vol 322 ◽  
pp. 93-97 ◽  
Author(s):  
Min Cong Zhu ◽  
Wei Qi ◽  
Yan Jie Mao ◽  
Yin Hu ◽  
Xin Qing ◽  
...  
Keyword(s):  
Adsorption Property ◽  
Expanded Graphite ◽  
Freundlich Isotherm ◽  
Reactive Dye ◽  
Isotherm Model ◽  
Freundlich Isotherms ◽  
Pani Composite ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Ir Analysis

In the present work, expanded graphite (EG) was prepared by microwave irradiation. Then, the expanded graphite/polyaniline (EG/PANi) composite was synthesized in the typical method. The samples of EG and EG/PANi were characterized by SEM and IR analysis techniques. Adsorption property of EG/PANi composite for removing the dye, reactive brilliant red K-2BP, from aqueous solution was investigated. The effects of initial dye concentration and contact time, pH, sorbent dosage on the adsorption process were studied. Experimental data were modelled by Langmuir and Freundlich isotherms. Langmuir isotherm model fitted well the equilibrium data for EG/PANi composite comparing to the Freundlich isotherm model. The uptake capacity of EG/PANi for K-2BP was found to be 1.03047 mg/g. The results indicated that EG/PANi composite is not an ideal sorbent used for reactive dye removal.

scholarly journals Adsorption Properties of Ni(II) by D301R Anion Exchange Resin

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Song Xiuling ◽  
Du Huipu ◽  
Liu Shijun ◽  
Qian Hui
Keyword(s):  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Bending Vibration ◽  
Freundlich Model ◽  
Diffusion Controlled ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model

The adsorption of Ni(II) with D301R resin was investigated in this paper. The results showed that the saturated extent of adsorption Ni(II) by the resin was 84.3 mg/g. The equilibrium data of Ni(II) sorption was better described by Langmuir isotherm model (r2=0.994) while that of Ni(II) sorption also fitted in Freundlich isotherm model within the experimental concentration range. The amount of the constant (q0) of Ni(II) under 298 K in Langmuir model was 76.92 mg/g, which was close to the experimental results. The constant n was within 2–10 in Freundlich model; it was shown that adsorption of Ni(II) by the resin was easy to take place. The uptake kinetics followed the Lagergren pseudo-first-order rate equation (r2=0.9813). The particle diffusion controlled the adsorption process of Ni(II). The coefficient of the intraparticle diffusion increased with the increase of the pH values and the concentration of Ni(II) in aqueous solution. There was a drop of 20.1 cm−1for the bending vibration frequency of N–H bond. Results showed that the adsorption of Ni(II) by D301R anion exchange resin was the surface complexation through the infrared spectrum analysis.

scholarly journals Evaluation of Lagergren Kinetics Equation by Using Novel Kinetics Expression of Sorption of Zn2+ onto Horse Dung Humic Acid (HD-HA)

2018 ◽  
Vol 16 (3) ◽  
pp. 338 ◽  
Author(s):  
Bambang Rusdiarso ◽  
Rahmat Basuki ◽  
Sri Juari Santosa
Keyword(s):  
Humic Acid ◽  
Kinetic Model ◽  
Sorption Capacity ◽  
Complex Function ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Extraction And Purification ◽  
Langmuir Isotherm Model ◽  
Desorption Rate Constant ◽  
Kinetic Expression

Extraction and purification of humic acid from dry horse dung powder (HD-HA) was performed successfully and the purified HD-HA was then applied as sorbent to adsorb Zn2+. Extraction and purification were performed based on procedure of Stevenson (1994) under atmospheric air. Parameters investigated in this work consist of effect of medium sorption acidity, sorption rate (ka) and desorption rate constant (kd), Langmuir (monolayer) and Freundlich (multilayer) sorption capacities, and energy (E) of sorption. The ka and kd were determined according to the kinetic model of second order sorption reaching equilibrium, monolayer sorption capacity (b) and energy (E) were determined according to Langmuir isotherm model, and multilayer sorption capacity (B) was determined based on Freundlich isotherm model. Sorption of Zn2+ on purified HD-HA was maximum at pH 5.0. The novel kinetic expression resulted from proposed kinetic model has been shown to be more applicable than the commonly known Lagergren equation obtained from the pseudo-first order sorption model. The application of the equation revealed that the intercept of Lagergren equation, ln qe was more complex function of initial concentration of Zn2+ (a), Langmuir sorption capacity (b), and sorbed Zn2+ at equilibrium (xe).

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