Removal of 2,4-D, glyphosate, trifluralin, and butachlor herbicides from water by polysulfone membranes mixed by graphene oxide/TiO2 nanocomposite: study of filtration and batch adsorption

Graphene oxide/Chitosan (GOCH) composite was synthesized by hydrothermal method and structurally characterized by FT-IR, RAMAN, XRD and BET analyses which provide support for graphene oxide and chitosan incorporation. The synthesized composite was employed for the removal of direct red 7 (DR7) by batch adsorption process. Langmuir, Freundlich, Temkin, Dubinin-Radushkevic, Harkin-Jura, Scatchard plot analysis and Hasley isotherms were used to elucidate adsorption mechanism. The value of R2 revealed that isotherm was well explained by Langmuir model. The extent of monolayer adsorption capacity of GOCH was calculated as 34.2 mg/g. The pseudo first order kinetic studies were in agreement with experimental data. Thermodynamic parameters such as activation energy (Ea = 8.405 KJ/mol), enthalpy (ΔH = 89.417 KJ/mol), free energy change (ΔG) and entropy (ΔS = 0.2971 KJ/mol) were calculated. It propounded that the adsorption of DR7 on GOCH was favorable, spontaneous and an endothermic process.

Download Full-text

Alkaline deoxygenated graphene oxide as adsorbent for cadmium ions removal from aqueous solutions

Water Science & Technology ◽

10.2166/wst.2015.124 ◽

2015 ◽

Vol 71 (11) ◽

pp. 1611-1619 ◽

Cited By ~ 4

Author(s):

Jun Liu ◽

Hongyan Du ◽

Shaowei Yuan ◽

Wanxia He ◽

Pengju Yan ◽

...

Keyword(s):

Graphene Oxide ◽

Aqueous Solutions ◽

Batch Adsorption ◽

Maximum Adsorption Capacity ◽

Order Kinetic ◽

Transmission Electron ◽

Equilibrium Data ◽

Order Kinetic Model ◽

Pseudo Second Order ◽

Ft Ir

Alkaline deoxygenated graphene oxide (aGO) was prepared through alkaline hydrothermal treatment and used as adsorbent to remove Cd(II) ions from aqueous solutions for the first time. The characterization results of transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and Fourier transform infrared (FT-IR) spectra indicate that aGO was successfully synthesized. The batch adsorption experiments showed that the adsorption kinetics could be described by the pseudo-second-order kinetic model, and the isotherms equilibrium data were well fitted with the Langmuir model. The maximum adsorption capacity of Cd(II) on aGO was 156 mg/g at pH 5 and T = 293 K. The adsorption thermodynamic parameters indicated that the adsorption process was a spontaneous and endothermic reaction. The mainly adsorption mechanism speculated from FT-IR results may be attributed to the electrostatic attraction between Cd2+ and negatively charged groups (–CO−) of aGO and cation-π interaction between Cd2+ and the graphene planes. The findings of this study demonstrate the potential utility of the nanomaterial aGO as an effective adsorbent for Cd(II) removal from aqueous solutions.

Download Full-text

Nitrogen-Doped Porous Carbon Materials Derived from Graphene Oxide/Melamine Resin Composites for CO2 Adsorption

Molecules ◽

10.3390/molecules26175293 ◽

2021 ◽

Vol 26 (17) ◽

pp. 5293

Author(s):

Like Ouyang ◽

Jianfei Xiao ◽

Housheng Jiang ◽

Shaojun Yuan

Keyword(s):

Graphene Oxide ◽

Surface Area ◽

Porous Carbon ◽

Carbon Materials ◽

Co2 Adsorption ◽

Formaldehyde Resin ◽

Batch Adsorption ◽

Nitrogen Doped ◽

Porous Carbon Materials ◽

Adsorption Sites

CO2 adsorption in porous carbon materials has attracted great interests for alleviating emission of post-combustion CO2. In this work, a novel nitrogen-doped porous carbon material was fabricated by carbonizing the precursor of melamine-resorcinol-formaldehyde resin/graphene oxide (MR/GO) composites with KOH as the activation agent. Detailed characterization results revealed that the fabricated MR(0.25)/GO-500 porous carbon (0.25 represented the amount of GO added in wt.% and 500 denoted activation temperature in °C) had well-defined pore size distribution, high specific surface area (1264 m2·g−1) and high nitrogen content (6.92 wt.%), which was mainly composed of the pyridinic-N and pyrrolic-N species. Batch adsorption experiments demonstrated that the fabricated MR(0.25)/GO-500 porous carbon delivered excellent CO2 adsorption ability of 5.21 mmol·g−1 at 298.15 K and 500 kPa, and such porous carbon also exhibited fast adsorption kinetics, high selectivity of CO2/N2 and good recyclability. With the inherent microstructure features of high surface area and abundant N adsorption sites species, the MR/GO-derived porous carbon materials offer a potentially promising adsorbent for practical CO2 capture.

Download Full-text

(3-Aminopropyl) Triethoxysilane (APTES) Functionalized Magnetic Nanosilica Graphene Oxide (MGO) Nanocomposite for the Comparative Adsorption of the Heavy Metal (Pb(II), Cd(II) and Ni(II)) ions from Aqueous Solution

10.21203/rs.3.rs-1184162/v1 ◽

2021 ◽

Author(s):

C Donga ◽

S Mishra ◽

A Aziz ◽

L Ndlovu ◽

A Kuvarega ◽

...

Keyword(s):

Aqueous Solution ◽

Graphene Oxide ◽

Metal Ion ◽

Ion Concentration ◽

Batch Adsorption ◽

Solution Ph ◽

Magnetic Graphene Oxide ◽

Equilibrium Data ◽

Langmuir Isotherm Model ◽

Adsorption Equilibrium Data

Abstract (3-aminopropyl) triethoxysilane (APTES) modified magnetic graphene oxide was synthesized and applied in the adsorption of three heavy metals, Pb(II), Cd(II) and Ni(II) from aqueous solution. An approach to prepare magnetic GO was adopted by using (3-aminopropyl) triethoxysilane (APTES) as a functionalizing agent on magnetic nanosilica coupled with GO to form the Fe3O4@SiO2-NH2/GO nanocomposite. FT-IR, XRD, BET, UV, VSM, SAXS, SEM and TEM were used to characterize the synthesized nanoadsorbents. Batch adsorption studies were conducted to investigate the effect of solution pH, initial metal ion concentration, adsorbent dosage and contact time. The maximum equilibrium time was found to be 30 min for Pb(II), Cd(II) and 60 min for Ni(II). The kinetics studies showed that the adsorption of Pb(II), Cd(II) and Ni(II) onto Fe3O4@SiO2-NH2/GO followed the pseudo-second-order kinetics. All the adsorption equilibrium data were well fitted to Langmuir isotherm model and maximum monolayer adsorption capacity for Pb(II), Cd(II) and Ni(II) were 13.46, 18.58 and 13.52 mgg-1, respectively. The Fe3O4@SiO2-NH2/GO adsorbents were reused for at least 7 cycles without the leaching of mineral core, showing the enhanced stability and potential application of Fe3O4@SiO2-NH2/GO adsorbents in water/wastewater treatment.

Download Full-text