scholarly journals GO/PAMAM as a High Capacity Adsorbent for Removal of Alizarin Red S: Selective Separation of Dyes

2020 ◽  
Vol 67 (4) ◽  
pp. 1124-1138
Author(s):  
Mohammad Rafi ◽  
Babak Samiey ◽  
Chil-Hung Chen
Keyword(s):  
Adsorption Capacity ◽  
High Capacity ◽  
Pamam Dendrimer ◽  
Alizarin Red S ◽  
Alkaline Media ◽  
Maximum Adsorption Capacity ◽  
Alizarin Red ◽  
Adsorption Sites ◽  
Diffusion Controlled ◽  
Amine Groups

Adsorption of Alizarin Red S (ARS) on graphene oxide/poly(amidoamine) (GO/PAMAM) was studied at different ARS initial concentrations, temperatures, pHs, shaking rates and contact times. Adsorption sites of GO/PAMAM were phenolic –OH (Ph) group of GO and amine groups (–NH2, –NH+ 3 and –NHR+2) of PAMAM dendrimer moieties of GO/PAMAM. At pH = 2 and 318 K, maximum adsorption capacity (qe,max) of the adsorbent was 1275.2 mg g–1 which is one of the highest capacity in the literature. Thus, GO/PAMAM in this work acted as a superadsorbent for ARS. At the incipient of adsorption, ARS– molecules were adsorbed on Ph sites that was reaction-controlled step, (Ea = 114.5 kJ mol–1). Adsorption of ARS–on the remaining sites was diffusion–controlled. In alkaline media, two other types of ARS molecules were identified during that were adsorbed on Ph and –NH+ 3 sites. Further increasing the pH of the solution, decreased the number these two sites and yielded a reduced adsorption capacity (qe,max). Methylene blue (MB), thionine (Th), pyronin Y (PY), acridine orange (AO), methyl blue (MEB) and janus green (JG) dyes were selectively separated from their mixtures with ARS molecules using GO/PAMAM at pH of 2. The used adsorbent was recycled fficiently by using ethylenediamine very fast.

Preparation of Graphene Oxide Modified Rice Husk for Cr(VI) Removal

2019 ◽  
Vol 19 (11) ◽  
pp. 7035-7043 ◽  
Author(s):  
Tong Ouyang ◽  
Jidan Tang ◽  
Fang Liu ◽  
Chang-Tang Chang
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Rice Husk ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Sites ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Alkaline Conditions ◽  
Rice Husk Biochar

The objective of this paper is to study the removal of Cr(VI) in aqueous solution by using a new graphene oxide-coated rice husk biochar composite (GO-RHB). GO-RHB is a synthetic material having a porous structure with lots of oxygen-containing functional groups and a large surface area that provide effective adsorption sites. Experiments showed that GO-RHB had higher adsorption capacity under acidic than under alkaline conditions. At pH of 2, GO-RHB has the maximum adsorption capacity(48.8 mg g−1). Equilibrium data obtained by fitting with the Langmuir and Freundlich models indicate that the reaction process was monolayer adsorption. The adsorption of Cr(VI) followed the pseudo-second-order kinetic model that illustrates chemical adsorption. Intraparticlediffusion studies further revealed that film diffusion was taking place. Moreover, the results of thermodynamics showed that the adsorption process was endothermic and spontaneous in nature. The removal mechanism of Cr(VI) was also explained in detail. The prepared adsorbent is highly efficient and might be useful than many other conventional adsorbent used for the removal of Cr(VI) from wastewater.

scholarly journals The Triple Mechanisms of Atenolol Adsorption on Ca-Montmorillonite: Implication in Pharmaceutical Wastewater Treatment

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2858 ◽  
Author(s):  
Po-Hsiang Chang ◽  
Wei-Teh Jiang ◽  
Binoy Sarkar ◽  
Wendong Wang ◽  
Zhaohui Li
Keyword(s):  
Adsorption Capacity ◽  
Clay Mineral ◽  
Basal Spacing ◽  
Maximum Adsorption Capacity ◽  
Pharmaceutical Wastewater ◽  
Absorption Bands ◽  
Adsorption Mechanisms ◽  
Adsorption Sites ◽  
Dioctahedral Smectite ◽  
Β Receptor

The adsorption of atenolol (AT) from aqueous solutions by Ca-montmorillonite (SAz-2) was investigated in batch studies under different physicochemical conditions. The AT existed in neutral un-dissociated form at pH 10, and was adsorbed on dioctahedral smectite (SAz-2) obeying the Langmuir isotherm with a maximum adsorption capacity of 330 mmol/kg. The kinetic adsorption suggested that both strong and weak adsorption sites existed on SAz-2 and participated in the adsorption mechanisms. The amount of exchangeable cations desorbed from SAz-2 during AT adsorption was linearly correlated with the amounts of adsorbed AT having slopes of 0.43, which implied that a cation exchange based adsorption mechanism was also in place. A comprehensive basal spacing change of SAz-2 was observed after AT adsorption on the clay mineral when tested with or without AT recrystallization. The intercalation of AT into the SAz-2 interlayers did not result in swelling due to the low adsorption capacity of the drug. Prominent interactions between the pharmaceutical molecule and SAz-2 were evidenced by apparent shifts of the infrared absorption bands after adsorption. The interlayer configurations and hydrogen bonding of AT on SAz-2 were also supported by infrared, X-ray diffraction and thermogravimetric analyses. This study suggested that SAz-2 is an excellent material to remove not only AT from pharmaceutical wastewater, but can potentially remove many other β-receptor blocker drugs. The results helped us to understand the possible interlayer configurations and adsorption mechanisms of the drugs on natural clay mineral based adsorbents.

scholarly journals Effects of Cu(II) on the Adsorption Behaviors of Cr(III) and Cr(VI) onto Kaolin

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Juanjuan Liu ◽  
Xiaolong Wu ◽  
Yandi Hu ◽  
Chong Dai ◽  
Qin Peng ◽  
...  
Keyword(s):  
Distribution Coefficient ◽  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Saturation Index ◽  
Surface Complexation ◽  
Maximum Adsorption Capacity ◽  
Positive Correlation ◽  
Adsorption Sites ◽  
Ph Values ◽  
Adsorption Behaviors

The adsorption of Cr(III) or Cr(VI) in the absence and presence of Cu(II) onto kaolin was investigated under pH 2.0–7.0. Results indicated that the adsorption rate was not necessarily proportional to the adsorption capacity. The solutions’ pH values played a key role in kaolin zeta potential(ζ), especially the hydrolysis behavior and saturation index of heavy metal ions. In the presence of Cu(II),qmixCr(III)reached the maximum adsorption capacity of 0.73 mg·g−1at pH 6.0, while the maximum adsorption capacity for the mixed Cr(VI) and Cu(II) system (qmixCr(VI)) was observed at pH 2.0 (0.38 mg·g−1). Comparing the adsorption behaviors and mechanisms, we found that kaolin prefers to adsorb hydrolyzed products of Cr(III) instead of Cr3+ion, while adsorption sites of kaolin surface were occupied primarily by Cu(II) through surface complexation, leading to Cu(II) inhibited Cr(VI) adsorption. Moreover, Cr(III) and Cr(VI) removal efficiency had a positive correlation with distribution coefficientKd. Cr(III) and Cr(VI) removal efficiency had a positive correlation with distribution coefficientKdand that of adsorption affinities of Cr(III) or Cr(VI) on kaolin was found to beKdCr(III) <KdCr(III)-Cu(II) andKdCr(VI) >KdCr(VI)-Cu(II).

scholarly journals Study of adsorption mechanism of Congo Red on graphene oxide/PAMAM nanocomposite

2021 ◽  
Author(s):  
Mohammad Rafi ◽  
Babak Samiey ◽  
Chil-Hung Cheng
Keyword(s):  
Graphene Oxide ◽  
Kinetic Parameters ◽  
Congo Red ◽  
Kinetic Data ◽  
Pamam Dendrimer ◽  
Maximum Adsorption Capacity ◽  
Hydroxyl Groups ◽  
Experimental Conditions ◽  
Adsorption Sites ◽  
Rate Controlling Step

Graphene oxide/poly(amidoamine) (GO/PAMAM) nanocomposite adsorbed high quantities of congo red (CR) anionic dye in 0.1 M NaCl solution, with the maximum adsorption capacity of 198 mg·g−1. The kinetics and thermodynamics of adsorption were investigated to elucidate the effects of pH, temperature, shaking rate, ionic strength, and contact time. Kinetic data were analyzed by the KASRA model and the KASRA, ISO, and pore-diffusion equations. Adsorption adsorption isotherms were studied by the ARIAN model and the Henry, Langmuir, and Temkin equations. It was shown that adsorption sites of GO/PAMAM at experimental conditions were phenolic hydroxyl groups of GO sheets and terminal amine groups of PAMAM dendrimer. Analysis of kinetic data indicated that amine sites were located on the surface, and that hydroxyl sites were placed in the pores of adsorbent. CR molecules interacted with the adsorption sites via hydrogen bonds. The molecules were adsorbed firstly on the amine sites, and then on the internal hydroxyl sites. Adsorption kinetic parameters indicated that the interaction of CR to the –NH3+ sites was the rate-controlling step of adsorption of CR on this site and adsorption activation energies calculated for different parts of this step. On the other hand, kinetic parameters showed that the intraparticle diffusion was the rate-controlling step during the interaction of CR molecules to –OH sites and activation energy of this step was not calculable. Finally, the used GO/PAMAM was completely regenerated by using ethylenediamine.

Removal properties of arsenic compounds with synthetic hydrotalcite compounds

2005 ◽  
Vol 5 (5) ◽  
pp. 75-81 ◽  
Author(s):  
Y. Kiso ◽  
Y. J. Jung ◽  
T. Yamada ◽  
M. Nagai ◽  
K. S. Min
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Inorganic Arsenic ◽  
Underground Water ◽  
Experimental Result ◽  
Maximum Adsorption Capacity ◽  
Arsenic Compounds ◽  
Adsorption Sites ◽  
Effects Of Ph ◽  
Very High

The contamination of underground water with inorganic arsenic compounds has caused serious problems, particularly in developing countries. For water containing low-level arsenic compounds, an adsorption process may be more effective than other processes such as RO membrane and precipitation. In this study, the removal performance for arsenic compounds was examined with synthetic hydrotalcite (HTAL) compounds as an adsorbent process from the following viewpoints: the adsorption capacity, adsorption isotherm, the effects of pH and co-existing anions. The HTAL-Cl, which contains Cl− ions as an intercalate, showed very high adsorption capacity in the neutral pH region. The maximum adsorption capacity was 105 mg-As(V) g−1. The adsorption isotherm was approximated by the following modified Langmuir equation:The equation suggests that one mol of As(V) occupies two adsorption sites of HTAL-Cl, and the experimental result indicated that 2.64 mol of Cl− ions in the HTAL-Cl were substituted with one mol of As(V). The interfering effects of co-existing anions were relatively low, and the magnitude of the effects was observed in the order of HCO3− &gt; HPO42− &gt; SO42− &gt; Cl−.

scholarly journals Three-dimensional double-network hydrogels of graphene oxide, alginate, and polyacrylonitrile for copper removal from aqueous solution

2019 ◽  
Vol 25 (6) ◽  
pp. 924-929 ◽  
Author(s):  
Jung-Weon Choi ◽  
Hee Jin Kim ◽  
Hayeon Ryu ◽  
Sanghwa Oh ◽  
Sang-June Choi
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Adsorption Equilibrium ◽  
Three Dimensional ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Double Network ◽  
Adsorption Sites ◽  
Pseudo Second Order ◽  
Ft Ir

Three-dimensional (3D) double-network graphene oxide/alginate-polyacrylonitrile (GO/Ca-Alg2-PAN) composite hydrogels were synthesized via surface functionalization of GO to activate adsorption sites. The morphology and structure of the GO/Ca-Alg2-PAN were analyzed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA-DSC). The results of the physicochemical analyses indicated that GO/Ca-Alg2-PAN was successfully synthesized by the combination of a 2D-structured graphene oxide with the alginate which was functionalized with the PAN polymer to generate the 3D double network composites. This functionalization approach contributed to an increase in Cu<sup>2+</sup> ion adsorption capacity. The maximum adsorption capacity of the GO/Ca-Alg2-PAN for Cu<sup>2+</sup> was 5.99 mmol/g. The results of adsorption kinetic experiments indicated that the GO/Ca-Alg2-PAN reached adsorption equilibrium within 147 mins at 2 mM Cu<sup>2+</sup> in accordance with a pseudo-second-order model.

scholarly journals Removal Efficiency of Textile Dyes from Aqueous Solutions Using Calcined Waste of Eggshells as Eco-friendly Adsorbent

2021 ◽  
Vol 35 (1) ◽  
pp. 43-56
Author(s):  
Rachid Slimani ◽  
Hasnaa Hiyane ◽  
Mohammadine El Haddad ◽  
Said Lazar ◽  
Said El Antri ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Rhodamine B ◽  
Low Cost ◽  
Textile Dyes ◽  
Alizarin Red S ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Alizarin Red ◽  
Eggshell Waste ◽  
Regeneration Study

This research investigates the removal of textile dyes (Rhodamine B and Alizarin Red S) from aqueous solution by a low-cost adsorbent prepared from eggshell waste. Batch adsorption experiments were conducted in order to determine the effect of different parameters such as pH, dye concentration, contact time, adsorbent dosage, particle <br /> size, and temperature. The best correlation was found by Langmuir model, and the maximum adsorption capacity was 175.58 mg g–1 for Rhodamine B and 156.56 mg g–1 for Alizarin Red S. Thermodynamic studies showed that the adsorption of Rhodamine B and Alizarin Red S were feasible, spontaneous, and exothermic in nature. Regeneration study conducted to test the reusability (five cycles) and comparison of adsorption capacities of Rhodamine B and Alizarin Red S showed that calcined eggshell adsorbent could potentially be used for the removal of dyes from aqueous solutions.

Kinetics and Isotherm Studies of Methyl Orange Adsorption Using Polyethyleneimine-Graphene Oxide Polymer Nanocomposite Beads

2019 ◽  
Vol 801 ◽  
pp. 304-310
Author(s):  
Jirah Emmanuel T. Nolasco ◽  
Elaine Nicole O. Cañeba ◽  
Karl Michael V. Edquila ◽  
Joel Ian C. Espita ◽  
Jem Valerie D. Perez
Keyword(s):  
Graphene Oxide ◽  
Methyl Orange ◽  
Adsorption Capacity ◽  
Kinetic Studies ◽  
Polymer Nanocomposite ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Sites ◽  
Wide Ph Range

Nanocomposite beads containing 2% chitosan (CS), 2% polyethyleneimine (PEI), and 1,500 ppm graphene oxide (GO) were synthesized for the removal of methyl orange (MO) from water. Characterization of the CS-PEI-GO beads using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) showed favorable adsorbent properties as given by the presence of numerous surface functional groups and a porous structure. Effects of different parameters such as pH, contact time, and initial concentration on the percentage removal of MO and adsorption capacity of the beads were investigated by performing batch adsorption experiments. MO removal of more than 85% was achieved by the beads across a wide pH range. Kinetic studies were performed and a pseudo-second order kinetic equation with R2 of 0.9999 was obtained. Furthermore, adsorption equilibrium data for MO were best described by the Toth isotherm model (R2 = 0.9644), suggesting multilayer adsorption on heterogeneous adsorption sites with a maximum adsorption capacity of 421.51 mg/g. Finally, FTIR and SEM analyses after adsorption confirmed the presence of MO on the surface of the beads and revealed an intact and stable structure. Overall, the excellent adsorption capability and multi-functionality demonstrated in this study show great potential of the synthesized material for wastewater treatment applications.

Sign in / Sign up

Export Citation Format

Share Document