scholarly journals Adsorption Characteristics and Molecular Simulation of Malachite Green onto Modified Distillers’ Grains

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 171
Author(s):  
Chengtao Li ◽  
Deyi Kong ◽  
Xiaolong Yao ◽  
Xiaotao Ma ◽  
Chunhui Wei ◽  
...  

Adsorbent material was prepared using distillers’ grains (DG), which is a waste product of distilleries. The DG was pre-treated with NaOH and esterification-modified with CS2, which is a commonly used anionic modifier. The structure and morphology of the adsorbent was characterized by FTIR, XRD, EDS, SEM, BET, and zeta potential. The related mechanism of adsorption of malachite green (MG) onto modified distiller’s grains (MDG) was studied by adsorption experiments and molecular simulation techniques. The experimental results showed that CS2 successfully modified the DG fiber, and simultaneously yielded the MDG with a uniform pore distribution. MDG had a considerable adsorption capacity of 367.39 mg/g and a maximum removal rate of 96.51%. After eight adsorption–desorption cycle experiments, the adsorption removal rate of MDG to MG dye remained at 82.6%. The adsorption process could be fitted well by a pseudo-second-order kinetic model (the correlation coefficient R2 > 0.998) and Freundlich isotherm adsorption equation (the correlation coefficient R2 > 0.972). Moreover, the adsorption of MG dye by MDG is a spontaneous, endothermic, and increased entropy process. The results of molecular simulation showed that the mechanism of MG molecules onto MDG was mainly chemical adsorption. The adsorption performance of MG onto MDG was better and more stable than DG. Molecular simulation also provided a theoretical guidance of MDG adsorption–desorption for the research on recycling of DG resources.

2018 ◽  
Vol 77 (6) ◽  
pp. 1734-1743 ◽  
Author(s):  
Abhay Prakash Rawat ◽  
D. P. Singh

Abstract Adsorption behavior of mentha (mint) plant biochar (MPB) in removal of malachite green (MG) dye from aqueous solution was analyzed as a function of different pH (4.0–10.0), initial dye concentration (20–100 mg/L), contact time (0–45 min) and dose of adsorbent (0.05–0.3 g/100 mL). The zeta potential of the MPB particles was found to be −37.9 mV, indicating a negatively charged sorption surface of MPB particles. MPB was found to be more effective in removal of MG dye at pH 6.0 due to combined action of physico-chemisorption and a reductive electron transfer reaction. Results on the Brunauer–Emmett–Teller (BET) analysis of the N2 adsorption–desorption isotherm of MPB as adsorbent showed sigmoidal shape similar to the type IV isotherm and mesoporous nature. The cyclic voltammetric analysis of MG dye showed a reversible, coupled redox reaction at the interface of dye molecules and MPB particles. The maximum monolayer adsorption capacity (qmax) of MPB was found to be 322.58 mg g−1. The separation factor (RL) value was between 0 and 1, indicating a favourable adsorption of MG dye onto MPB. The results fitted well to a pseudo-second-order kinetic model. Further results from desorption experiments showed recovery of MG dye by about 50% in the presence of 1 N HCl.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 6100-6120
Author(s):  
Yinan Hao ◽  
Yanfei Pan ◽  
Qingwei Du ◽  
Xudong Li ◽  
Ximing Wang

Armeniaca sibirica shell activated carbon (ASSAC) magnetized by nanoparticle Fe3O4 prepared from Armeniaca sibirica shell was investigated to determine its adsorption for Hg2+ from wastewater. Fe3O4/ASSAC was characterized using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), and BET (Brunauer–Emmett–Teller). Optimum adsorption parameters were determined based on the initial concentration of Hg2+, reaction time, reaction temperature, and pH value in adsorption studies. The experiment results demonstrated that the specific surface area of ASSAC decreased after magnetization; however the adsorption capacity and removal rate of Hg2+ increased 0.656 mg/g and 0.630%, respectively. When the initial concentration of Hg2+ solution was 250 mg/L and the pH value was 2, the adsorption time was 180 min and the temperature was 30 °C, and with the Fe3O4/ASSAC at 0.05 g, the adsorption reaching 97.1 mg/g, and the removal efficiency was 99.6%. The adsorption capacity of Fe3O4/ASSAC to Hg2+ was in accord with Freundlich isotherm models, and a pseudo-second-order kinetic equation was used to fit the adsorption best. The Gibbs free energy ΔGo < 0,enthalpy change ΔHo < 0, and entropy change ΔSo < 0 which manifested the adsorption was a spontaneous and exothermic process.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2479
Author(s):  
Hua Jing ◽  
Lili Ji ◽  
Zhen Wang ◽  
Jian Guo ◽  
Shiyao Lu ◽  
...  

Spartina alterniflora is an invasive plant from coastal wetlands, and its use in applications has garnered much interest. In this study, a composite photocatalyst (ZnO@BC) was synthesized by preparing zinc oxide (ZnO) nanoparticles with S. alterniflora extracts, S. alterniflora, and one-step carbonization, which was characterized using scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), Raman, X-ray photoelectron spectroscopy, ultraviolet–visible spectroscopy (UV–vis DRS), photoluminescence (PL) and N2 adsorption–desorption isotherm. The degradation capacity and mechanism of malachite green (MG) using ZnO@BC were analyzed under visible irradiation, and the degradation products of malachite green were detected by LC–MS. The results show that ZnO@BC has a larger surface area (83.2 m2/g) and various reactive groups, which enhance its photocatalytic efficiency, with the presence of oxygen vacancy further improving the photocatalytic activity. The total removal rate of malachite green (400 mg/L) using ZnO@BC is up to 98.38%. From the LC–MS analysis, it could be concluded that malachite green is degraded by demethylation, deamination, conjugate structure and benzene ring structure destruction. This study provides a novel idea for the high-value utilization of S. alterniflora.


Author(s):  
Vijayakumar Govindasamy ◽  
Renganathan Sahadevan ◽  
Sivanesan Subramanian ◽  
Dharmendira Kumar Mahendradas

Perlite was utilized as an adsorbent for the removal of malachite green from their aqueous solution. The effects of the initial dye concentration, contact time, adsorbent dose, pH, and temperature were studied for the adsorption of malachite green in batch mode. The dye adsorption equilibrium was rapidly attained after 40 min of contact time. Adsorbent was characterized by FTIR, XRD and SEM. The Langmuir and Freundlich isotherm described the adsorption data over the concentration range (20 – 100 mg/L). The rate parameters of the intra particle diffusion were calculated and compared to identify the adsorption mechanisms. The thermodynamic parameters such as entropy change, enthalpy change, and energy of adsorption were calculated to know the nature of adsorption. The negative values of energy of adsorption and the positive values of enthalpy change suggested that the adsorption process is spontaneous and exothermic. Kinetic studies showed that the adsorption process obeyed the pseudo first-order kinetic model.


2014 ◽  
Vol 633 ◽  
pp. 165-168 ◽  
Author(s):  
Li Wang ◽  
Wen Juan He ◽  
Yu Feng He ◽  
Hong Li ◽  
Rong Min Wang

Loess based copolymer (L/CoPolym), a typical silicate minerals / copolymer composite, was used as polymer adsorbent for removing basic fuchsin (BF) in wastewater. Under the optimal condition of adsorption, the removal rate of BF reached to 98.2%, and the adsorption capacity got to 565.0 mg/g. Adsorption dynamics were consistent with pseudo-second-order kinetic model and isotherm model can meet the Freundlich isotherm.


2014 ◽  
Vol 71 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Kiran Aftab ◽  
Kalsoom Akhtar ◽  
Fozia Anjum

The objective of this study was to assess the removal and recovery of Pb-II from industrial wastewater using a locally isolated strain of Aureobasidium sp. RBSS-303. The initial Pb2+ concentration of 600 mg/L resulted in maximum uptake capacity (Qmax 235.1 ± 0.3 mg/g). The biosorbent revival was attained by contacting with HCl (0.01 M), with 75.3% recovery of Pb2+. The Freundlich isotherm best explains the Pb2+ sorption performances. Maximum adsorption distribution coefficient of 1,309.6 mg metal/mL was observed at initial Pb2+ concentration value of 100 mg/L. Evaluation of nine kinetic models showed the removal rate of Pb2+ was reliant on diffusion control pseudo-second-order and saturation-mixed-order kinetic models with a high correlation coefficient value (R = 0.99). Fourier transform infrared spectroscopy analysis showed the major contribution of –NH2 and –CN ligands of Aureobasidium sp. RBSS-303 in the sorption phenomenon of Pb2+. The biosorption assays carried out with effluent of the paint industry showed 76.8% efficiency for Pb2+ removal by the candidate biosorbent, regardless of the complex composition of the industrial effluent.


Nova Scientia ◽  
2019 ◽  
Vol 11 (23) ◽  
pp. 01-25 ◽  
Author(s):  
Rafael Romero Toledo ◽  
Víctor Ruiz Santoyo ◽  
Luis M. Anaya Esparza ◽  
Alejandro Pérez Larios ◽  
Merced Martínez Rosales

Arsenic is a toxic element for human health. It persists in the environment as a result of natural and anthropic contamination, generating nocive effects for consumers. Some of them can be cancer, cardiovascular disorders, hypotension, metabolic disease and peripheral neuropathy. Adsorption is considered to be one of the most effective technologies widely used in global environmental protection areas. The objective of this study was to generate a low cost agglomerated alumina adsorbent (A-1) for the effective removal of arsenic (V) from water and its comparison with a commercial agglomerated alumina (A-2). Both of them of 5 mm of diameter. The physicochemical properties of the adsorbents were characterized by various techniques, such as: XRF, zeta potential, XRD, adsorption-desorption of N2 and FE-SEM/EDS. Batch experiments were performed to evaluate the efficiency of removal of As (V) from water by A-1 and A-2. The point of zero charge of A-1 and A-2 was at pH 8.5 and 8.1, respectively. The experimental results in batches indicated that agglomerate A-1 has a higher adsorption capacity than A-2 (1.212 mg∙g-1; 1.058 mg∙g-1) in similar conditions, concentration of 15 mg∙L-1 of As (V), temperature (20± 2 °C) and pH 7. The adsorption processes of As (V) in A-1 and A-2 followed the kinetics of Pseudo-first order kinetic and the Freundlich isotherm. The results showed that the agglomerate A-1 is an attractive adsorbent for the effective removal of As (V) from water.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4402
Author(s):  
Qingqing Cao ◽  
Siqi Lu ◽  
Wenjun Yin ◽  
Yan Kang ◽  
Naihao Yang ◽  
...  

High-ring polycyclic aromatic hydrocarbons (PAHs, Benzo[b]fluorathene (BbFA), etc.) are difficult to biodegrade in the water environment. To address this issue, an innovative method for the preparation of MnO2 nanoflower/graphene oxide composite (MnO2 NF/GO) was proposed for adsorption removal of BbFA. The physicochemical properties of MnO2 NF/GO were characterized by SEM, TEM, XRD, and N2 adsorption/desorption and XPS techniques. Results show that the MnO2 NF/GO had well-developed specific surface area and functional groups. Batch adsorption experiment results showed that adsorption capacity for BbFA was 74.07 mg/g. The pseudo-second-order kinetic model and Freundlich isotherm model are fitted well to the adsorption data. These show electron-donor-acceptor interaction; especially π-π interaction and π complexation played vital roles in BbFA removal onto MnO2 NF/GO. The study highlights the promising potential adsorbent for removal of PAHs.


2021 ◽  
Vol 27 (2) ◽  
pp. 1-12
Author(s):  
Omar Hisham Fadhel ◽  
Mohammed Yaqob Eisa ◽  
Ziad Rafaa Zair

This paper presents the ability to use cheap adsorbent (corn leaf) for the removal of Malachite Green (MG) dye from its aqueous solution. A batch mode was used to study several factors, dye concentration (50-150) ppm, adsorbent dosage (0.5-2.5) g/L, contact time (1-4) day, pH (2-10), and temperature (30-60)   The results indicated that the removal efficiency increases with the increase of adsorbent dosage and contact time, while inversely proportional to the increase in pH and temperature. An SEM device characterized the adsorbent corn leaves. The adsorption's resulting data were in agreement with Freundlich isotherm according to the regression analysis, and the kinetics data followed pseudo-first-order kinetic with a correlation coefficient of 0.9309. The thermodynamic data show that the process is exothermic and reversible. The highest removal of MG was 91%, which gave proof that the corn leaves as adsorbent material have the capability of adsorbing the MG dye for aqueous solutions


2013 ◽  
Vol 807-809 ◽  
pp. 521-525
Author(s):  
Hui Juan Wang ◽  
Xiao Li Wang ◽  
Li Xiang Wang

The alkali heat modification used in coal gangue. And the adsorption effect of MB on original gangue and modified gangue were observed. The results were showed that removal rate of MB was 96.87% and 45.45% by modified gangue and original gangue under the conditions of MB initial concentration 50mg·L-1. The adsorption mechanism was discussed based on Freundlich isotherm model and Langmuir isotherm model. It was proved that MB was easy to be adsorbed by modified coal gangue and the adsorption was belong to monolayer adsorption.The pseudo-second-order kinetic model was best accord to adsorption. And the rate of absorption was control by intra-particle diffusion.


Sign in / Sign up

Export Citation Format

Share Document