The Removal and Inhibitory Effect of CNTs on Model Viruses

2013 ◽  
Vol 743-744 ◽  
pp. 402-408 ◽  
Author(s):  
Shi Yuan Liu ◽  
Xiang Zheng ◽  
Ye Yang ◽  
Jia Liu ◽  
Jie Li

Nanomaterial is becoming an important adsorption or disinfection material for removing virus from drinking water. In this study, static and dynamic tests were used to examine adsorption and inhibition characteristics of carbon nanotubes (CNTs) on two model viruses -- f2 and MS2 bacteriophage. Controlling variate method was used to systematically investigate the adsorption kinetics and adsorption isotherms of CNTs on two model viruses; as well as to find the impact of different CNTs dosages on adsorption effect; and then to study the inhibitory effect of CNTs.The results showed that: (1) The adsorption process of f2 and MS2 bacteriophage on CNTs corresponded well with the pseudo-second-order kinetics equation. Time to reach a saturation equilibrium adsorption is about 30min. (2) Both the Langmuir and Freundlich isotherm adequately described two adsorption processes which indicated that the removal mechanism of virus was a mix of monolayer and multilayer adsorption. (3)The dosage of a single removal system should not be too high in practical application. (4) The inhibition of CNTs on model viruses exhibited.

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2586
Author(s):  
Inas A. Ahmed ◽  
Ahmed H. Ragab ◽  
Mohamed A. Habila ◽  
Taghrid S. Alomar ◽  
Enas H. Aljuhani

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m2/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH0) was 37.7 KJ mol−1 for CR and 8.71 KJ mol−1 for BG, while the entropy change (ΔS0) was 89.1 J K−1 mol−1 for CR and 79.1 J K−1 mol−1 BG, indicating that the adsorption process was endothermic and spontaneous in nature.


Author(s):  
Hadj Daoud Bouras ◽  
Ahmed RédaYeddou ◽  
Noureddine Bouras ◽  
Abdelmalek Chergui ◽  
Lidia Favier ◽  
...  

Aspergillus parasiticus (A. parasiticus) CBS 100926T was used as a biosorbent for the removal of Methylene Blue (MB), Congo Red (CR), Sudan Black (SB), Malachite Green Oxalate (MGO), Basic Fuchsin (BF) and Phenol Red (PR) from aqueous solutions. The batch biosorption studies were carried out as a function of dye concentration and contact time. The biosorption process followed the pseudo-first-order and the pseudo-second-order kinetic models and the Freundlich and Langmuir isotherm models. The resulting biosorbent was characterized by Scanning Electron Microscopy (SEM), X-Ray Diffractometer and Fourier Transformer Infrared Spectroscopy (FTIR) techniques. The results of the present investigation suggest that A. parasiticus can be used as an environmentally benign and low cost biomaterial for the removal of basic and acid dyes from aqueous solution. HIGHLIGHTS Micro-fungi Aspergillus parasiticus CBS100926T was employed as a new biosorbent for the biosorption of six dyes. The maximum dye capacity was found to be 131.58 mg/g. Adsorption processes can reach equilibrium within 120 min. Adsorption processes follow the pseudo-second-order rate equation. The results of equilibrium sorption were described through Freundlich isotherm.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Dan Peng ◽  
Fan Ouyang ◽  
Min Deng ◽  
Lei Nie ◽  
Sifang Kong

Corn stover (CS) is mainly composed of three parts: pith (CSP), rind (CSR), and leaf (CSL). These parts have different lignocellulosic constituents and structural properties. Herein, biosorbents derived from individual corn stover constituents were prepared in an effort to determine the significance of each constituent for multipollutant removal. In this study, SEM, BET, XRD, FTIR, XPS, fibre composition, and contact angle measurements were used to characterize and analyse the physical and chemical properties of the three components of CS and to study their adsorption effects, adsorption isotherms, and kinetics. The lignocellulosic compositions of CSP and CSR were similar, the cellulose content in CSP and CSR was significantly higher than that in CSL, and the hemicellulose content of CSL was much higher than those of CSP and CSR. The minimum lignin content was found in CSP, and the maximum lignin content was found in CSR. The results show that each component had a certain adsorption effect on typical organic pollutants (antibiotics, oils, and dyes). CSP had the strongest oil adsorption capacity, CSR was more suitable for adsorbing antibiotics, and CSL had outstanding adsorption capacity for dye. The pseudo-second-order model and the Langmuir adsorption isotherm model could describe the adsorption processes well, and they consisted of monolayer adsorption accompanied by chemical adsorption reactions. The focus of this study was to provide references for selecting effective adsorbent precursors to remove organic pollutants from wastewater.


2015 ◽  
Vol 1104 ◽  
pp. 111-117
Author(s):  
Wei Mei Shi ◽  
Ye Chun Ding ◽  
Long Huo Wu

Through the experiment of Ciprofloxacin (CIP) adsorption by KMnO4modifiedDurio zibethinusMurr Shell (KDS), the best condition, adsorption kinetics and thermodynamic characteristics were studied. The isotherm parameters were estimated by linear regression analysis with Langmuir isotherm model, Temkin isotherm and Freundlich isotherm model. The equilibrium process was described well by the Freundlich isotherm model, which indicated that the adsorption thermodynamics of CIP on KDS is a multilayer adsorption process.The kinetics of the interactions showed better agreement with the pseudo-second-order model (R2=0.9999). This study demonstrated that KDS could be used for the removal of CIP in water treatment.


2013 ◽  
Vol 781-784 ◽  
pp. 2273-2276
Author(s):  
Shi Yong Wei ◽  
Xu Hong Deng

Hydroxy-iron pillared montmorillonite (Fe-Mont) was prepared and characterized, and the fluoride adsorption capacity of Fe-Mont was investigated. Compared to pure montmorillonite (Mont), the interlayer spacing, specific surface area (SSA), surface fractal dimension and isoelectric point (IEP) of Fe-Mont increased. At pH 4.5, the Langmuir adsorption capacity (qmax) for fluoride of Mont and Fe-Mont was 4.23 and 6.92 mg/g, respectively. The adsorption data for fluoride by Fe-Mont could be fitted by Langmuir model (R2 =0.986) and also by Freundlich isotherm (R2 =0.948), and indicating that the monolayer and multilayer adsorption behaviors are simultaneously involved in the fluoride adsorption processes of Fe-Mont.


2018 ◽  
Vol 36 (3-4) ◽  
pp. 1100-1111 ◽  
Author(s):  
Hua-jun Chen ◽  
Wenjie Tian ◽  
Wuxiu Ding

Herein active manganese dioxide was prepared by different methods using KMnO4 and MnSO4·H2O as inorganic precursors. The impact of preparation methods on morphology and adsorption performance of the synthesized products was investigated. The experimental results show that the reaction temperature and pressure had a great effect on the morphology and adsorption performance of active manganese dioxide. The shape of active manganese dioxide prepared at room temperature and pressure was short rod-like while active manganese dioxide synthesized by hydrothermal method was mesoporous fibers and had better adsorption performance. The adsorption behavior of 2,4-dinitrophenol on mesoporous manganese dioxide was well described by Langmuir and Freundlich isotherm equation ( R2>0.99) and pseudo-second-order kinetic equation ( R2>0.99), so the adsorption process maybe a chemical and monolayer adsorption. The pH of solution had significant effect on the adsorption performance of 2,4-dinitrophenol on mesoporous manganese dioxide. The adsorption capacity was 2.539 mg/g in the condition of pH = 7.


2013 ◽  
Vol 726-731 ◽  
pp. 1827-1832
Author(s):  
Hong Mei Deng ◽  
Yong Heng Chen ◽  
Cui Qin Wu ◽  
Xue Xia Huang ◽  
Tao Liu

Fir sawdust, a low-cost residual agricultural material, was used as adsorbent for the removal of Cu2+from aqueous solutions. Factors affecting the adsorption behavior of Cu2+, such as pH, initial metal concentration, contact time and temperature, have been carried out. The Cu2+removal was pH-dependent, reaching a maximum at pH 5. The adsorption capacity of the fir sawdust from Langmuir adsorption isotherm was 38.6 mg/g at 25°C. The adsorption process followed pseudo-second-order kinetics. The equilibrium data fitted very well to the Freundlich isotherm. The negative ΔGovalues at various temperatures confirm that the adsorption processes are spontaneous.


2011 ◽  
Vol 396-398 ◽  
pp. 2388-2393 ◽  
Author(s):  
Hong Mei Deng ◽  
Yong Heng Cheng ◽  
Xiang Yang Chang ◽  
Jian Gong ◽  
Cui Qin Wu ◽  
...  

Cedar sawdust (Cedrus deodara), an agricultural by-product abundant in China, was used as an adsorbent for the removal of Cu(II) from aqueous solutions. The extent of adsorption was investigated as a function of pH, contact time, adsorbate concentration and reaction temperature. The Cu(II) removal was pH-dependent, reaching a maximum at pH 5. The adsorption process followed pseudo-second-order kinetics and equilibrium was reached at 60 min. The rate constantly increased with the increase of temperature, indicating the endothermic nature of adsorption. The equilibrium adsorption capacity of Cu(II) determined from the Langmuir equation was 64.52 mg/g at 25°C. The equilibrium data fitted very well to the Freundlich isotherm model as compared to the Langmuir isotherm. The negative ΔGo values at various temperatures confirm that the adsorption processes are spontaneous. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) analysis of cedar sawdust, before and after adsorption of Cu(II), suggested that the main mechanisms involved in the removal of Cu(II) might be the ionic exchange and complexation.


2020 ◽  
Vol 2 (1) ◽  
pp. 42
Author(s):  
Giulio Galamini ◽  
Giacomo Ferretti ◽  
Valeria Medoro ◽  
Nicola Tescaro ◽  
Barbara Faccini ◽  
...  

The use of zeolite-rich tuffs is a valid method for recovering nitrogen from wastewaters. This paper aims at describing the NH4+ adsorption processes of an Italian chabazite zeolite tuff used for the treatment of raw liquid swine manure. The effects of temperature, grain size and contact time were investigated. The isothermal analysis showed a multilayer adsorption behavior, well explained by the Harkins–Jura model, while kinetics was explained by pseudo-second-order, Elovich and intraparticle diffusion models. This study highlighted the complexity of the adsorption process from raw liquid manure, as well as the significant differences between tested particle sizes of the same zeolite tuff.


Author(s):  
Mouayed A. Hussein ◽  
Ibtighaa K. Radhi ◽  
Zaki N. Kadhim

Calcium oxide was obtained from eggshell and modified with Sulfur, Nitrogen and, Oxygen. The adsorbents were characterized using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and, scanning electron microscopy (SEM). The adsorbents were used for the removing of the dyes of Nigrosin, Alizarin red S, Indigo carmine, and Acid fuchsin from their aqueous solutions. The adsorption isotherm experiments were studied, and the equilibrium adsorption found either obeyed the Langmuir or Freundlich isotherm depending on the Sips isotherm results. Thermodynamic studies showed that the adsorption processes of the studied dyes were spontaneous, endothermic and randomness increases according to their ΔG, ΔH and ΔS values, respectively. The kinetic studies revealed that the pseudo second-order model best represented adsorption kinetics. Moreover, the photocatalytic ability of adsorbents was investigated under the sunlight, the results revealed the adsorbents have a strong photo-catalytic ability to absorb the dyes, particularly that observed for Acid fuchsin.


Sign in / Sign up

Export Citation Format

Share Document