scholarly journals Biosorption of methylene blue by nonliving biomass of the brown macroalga Sargassum hemiphyllum

2017 ◽  
Vol 76 (6) ◽  
pp. 1574-1583 ◽  
Author(s):  
Jianfeng Liang ◽  
Jianrong Xia ◽  
Jianyou Long

The ability of Sargassum hemiphyllum to remove methylene blue (MB) from aqueous solution was evaluated. Batch experiments were conducted to examine the effects of parameters such as initial pH, contact time, biomass dose and initial dye concentration on adsorption capacity. S. hemiphyllum before and after MB adsorption was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The Langmuir isotherm model provided the best correlation with experimental data, and the monolayer biosorption capacity was 729.93 mg·g−1 within 120 min using 0.5 g·L−1 algal biomass and pH of 5. The pseudo-second-order kinetic model accurately described the adsorption kinetics data. Thermodynamic parameters (ΔG0, ΔH0 and ΔS0) at temperature ranges of 293–313 K demonstrated that biosorption is an endothermic and spontaneous reaction. FT-IR analysis showed that the hydroxyl, amine and carboxyl functional groups on the surface of the algae were the most important functional groups for biosorption of MB. XPS analysis indicated that the algal biomass combined with MB molecules through –NH2 groups. These results suggest that S. hemiphyllum is a favorable biosorbent for removing MB dye from wastewater.

2020 ◽  
Vol 81 (6) ◽  
pp. 1114-1129 ◽  
Author(s):  
Jun Wang ◽  
Qinglong Xie ◽  
Ao Li ◽  
Xuejun Liu ◽  
Fengwen Yu ◽  
...  

Abstract In this study, an efficient route to synthesizing polyethyleneimine-modified ultrasonic-assisted acid hydrochar (PEI-USAH) is developed and reported. Ultrasonic irradiation technique was used as surface modification method to shorten the crosslinking reaction for hydrochar and polyethyleneimine (PEI). The PEI-USAH showed an excellent adsorption capacity for Cr(VI) from aqueous solution. The physicochemical properties of this PEI-modified adsorbent were comparatively characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis and CNHS analysis. The effects of contact time, initial pH, and biosorbent dose on adsorption capacities were investigated. The batch adsorption experiments showed that PEI-USAH possessed the maximum adsorption capacities of 94.38 mg/g and 330.84 mg/g for initial Cr(VI) concentration of 100 mg/L and 500 mg/L, respectively. Furthermore, this adsorption process could be fitted to Langmuir adsorption and described by the pseudo second order kinetic model. Based on the above findings, PEI-USAH could be used as a potential adsorbent for removal of Cr(VI) from wastewater.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaodong Li

Using straw and urea as raw materials, biochar (BC) and g-C3N4 were prepared by oxygen-free pyrolysis at 300°C and 550°C. BC/g-C3N4 was prepared by loading different amounts of g-C3N4 onto the surface of biochar and characterized by SEM and FT-IR. The adsorption effect on methylene blue (MB) was investigated from the aspects of dosage and pH. The studies of adsorption equilibrium isotherms and the kinetic and the thermodynamic parameters on the BC/g-C3N4 adsorbents are discussed. The results showed that BC/g-C3N4 0.16 g/L with a doping ratio of 1 : 3 was added to the MB solution with an initial concentration of 50 mg/L and pH=11. The adsorption rate and adsorption amount were 96.72% and 302.25 mg/g, respectively. The adsorption process included surface adsorption and intraparticle diffusion, which conformed to the pseudo-second-order kinetic model and Langmuir-Freundlich model. Thermodynamic parameters (ΔG0<0, ΔH0>0, and ΔS0>0) showed that the adsorption reaction is spontaneous, which positively correlated with temperature.


2019 ◽  
Vol 62 (3) ◽  
Author(s):  
Naereh Besharati ◽  
Nina Alizadeh ◽  
Shahab Shariati

Abstract. This study was focused on the adsorption of methylene blue (MB) as a cationic dye on magnetite nanoparticles loaded with coffee (MNLC) and magnetite nanoparticles loaded with peanut husk (MNLPH) as naturally cheap sources of adsorbent. Coffee and Peanut husk were magnetically modified by contact with water-based magnetic fluid. These new type of magnetically natural materials can be easily separated by means of magnetic separators. They were characterized with Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) instruments. Different parameters affecting MB removal efficiency such as contact time, pH of solution and amount of adsorbents were studied and optimized. Dye adsorption process was studied from both kinetic and equilibrium point. The studies of MB sorption kinetic showed rapid dynamic sorption with second-order kinetic model, suggesting chemisorption mechanism with R2 = 0.9988, qeq=10.28 mg g-1 and R2=0.9967, qeq=128.20 mg g-1, respectively. Equilibrium data were fitted well to the Langmuir isotherm more than Freundlich and Temkin isotherm. The modified adsorbents showed MB removal with 88.49 and 74.62 mg g-1 sorption capacity for MNLC and MNLPH, respectively. This study showed a simple, efficient and reliable method for removal of MB from aqueous solutions with MNLC and MNLPH as efficient adsorbents. Resumen. Este estudio se centró en la adsorción de azul de metileno (MB) como un colorante catiónico en nanopartículas de magnetita cargadas con café (MNLC) y nanopartículas de magnetita cargadas con cáscara de cacahuete (MNLPH) como fuentes de adsorbente naturalmente económicas. El café y la cáscara de maní se modificaron magnéticamente por contacto con un fluido magnético a base de agua. Este nuevo tipo de materiales magnéticamente naturales se puede separar fácilmente mediante separadores magnéticos. Se caracterizaron con espectroscopia infrarroja de transformada de Fourier (FT-IR), difracción de rayos X en polvo (DRX) y microscopía electrónica de barrido (SEM). Se estudiaron y optimizaron diferentes parámetros que afectan la eficiencia de eliminación de MB, como el tiempo de contacto, el pH de la solución y la cantidad de adsorbentes. Se estudió el proceso de adsorción de tinte desde el punto de equilibrio y cinético. Los estudios de cinética de absorción de MB mostraron una absorción dinámica rápida con un modelo cinético de segundo orden, lo que sugiere un mecanismo de quimiosorción con R2= 0.9988, qeq= 10.28 mg g-1 y R2= 0.9967, qeq= 128.20 mg g-1, respectivamente. Los datos de equilibrio se ajustaron bien a la isoterma de Langmuir más que a la isoterma de Freundlich y Temkin. Los adsorbentes modificados mostraron eliminación de MB con 88.49 y 74.62 mg g-1 de capacidad de absorción para MNLC y MNLPH, respectivamente. Este estudio mostró un método simple, eficiente y confiable para la eliminación de MB de soluciones acuosas con MNLC y MNLPH como adsorbentes eficientes.


Author(s):  
Chunlian Hu ◽  
Wei Zhang ◽  
Yuantao Chen ◽  
Na Ye ◽  
DaWa YangJi ◽  
...  

Abstract Herein adsorption studies were proposed on a carboxylated sludge biochar (CSB) material modified by HNO3 to assess its capacity in the removal of cobalt from aqueous solution. The as-prepared sludge biochar material were characterized by Brunaure-Emmett-Teller (BET), Fourier transform infrared (FT-IR), Thermogravimetric analysis (TGA), Energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The isotherm process could be well described by Langmuir isotherm model. The adsorption kinetics indicated that cobalt adsorption followed pseudo-second-order kinetic model. The mechanism between Co(II) and biochar involved electrostatic interaction, ion exchange, surface complexation and physical function. The adsorption capacity on CSB was as high as 72.27 mg·g−1, surpassing original sludge biochar (SB). This is due to the fact that CSB had abundant oxygen-containing functional groups and many hydroxyls, as well as, the BET surface areas increased when SB was modified by HNO3, which stimulate adsorption effect. Therefore, this work shows that CSB could be used as an efficient adsorbent to remove Co(II) in the wastewater.


2020 ◽  
Vol 82 (8) ◽  
pp. 1535-1546
Author(s):  
Dajun Ren ◽  
Hongyan Yu ◽  
Jian Wu ◽  
Zhaobo Wang ◽  
Shuqin Zhang ◽  
...  

Abstract In this study, rice straw was used to prepare biomass carbon, which was modified with KOH and cetyltrimethylammonium bromide (CTAB) to obtain modified biomass carbon (MBC). The biomass carbon (BC) before and after modification was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR), and the surface morphology, crystal structure and surface group characteristic BC were explored. The specific surface area and micropores of the modified biomass carbon increased significantly, the crystallinity was higher, and the pore structure was more clearly found. The adsorption performance of MBC for 2,4-dichlorophenol (2,4-DCP) was investigated. The results showed that under the best adsorption conditions ((2,4-DCP concentration (200 mg/L), MBC dosage (50 mg), pH (5.5), and loading time (60 min), temperature (room temperature)), the removal rate of 2,4-DCP was up to 42.5%, and adsorption capacity was 85.13 mg/g. The adsorption of 2,4-DCP on MBC materials was better explained by the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model. It was believed that the adsorption of 2,4-DCP by MBC was the monolayer adsorption process on the uniform surface of MBC at high concentration, and there was no interaction between the 2,4-DCP and MBC adsorbate during this process.


2015 ◽  
Vol 76 (13) ◽  
Author(s):  
Ahmed Salisu ◽  
Mohd Marsin Sanagi ◽  
Khairil Juhanni Abd Karim ◽  
Neda Pourmand ◽  
Wan Aini Wan Ibrahim

In this study, the removal of methylene blue (MB) dye using alginate-graft-poly (methyl methacrylate) beads was investigated. The effects of adsorption parameters namely initial pH and initial dye concentration were studied. The removal efficiency of the beads has been found to be dependent on initial dye concentration and initial pH. The experimental equilibrium data was fitted successfully to Langmuir isotherm model with the maximum monolayer coverage of 5.25 mg g−1 and adsorption kinetics data has been well fitted by a pseudo-second-order kinetic model. The alginate based beads could be used as low-cost and eco-friendly adsorbent for removal of trace amount of methylene blue from aqueous solution.


2014 ◽  
Vol 675-677 ◽  
pp. 647-653
Author(s):  
Hong Bin Lv ◽  
Yao Li ◽  
Wan You Zhang ◽  
Li Juan Xi

Mg-Fe hydrotalcite-like compounds (Mg-Fe-HTLCs) were synthesized via hydrothermal method, and characterized by XRD and FT-IR. The roasted products were used to remove sulfate ions by the adsorptive ability from aqueous solution. The effects of adsorbent dosage, initial pH and temperature on the sulfate ions removal were fully investigated, and the adsorption kinetics and adsorption isotherms were also studied. Results showed that the synthesized materials with CO32- as the interlayer anions had fine crystallinity. The materials of Mg-Fe hydrotalcite-like compounds had a very good adsorption capacity for aqueous solution with the initial sulfate ions concentration was 500mg/L, pH range from 4 to 8 and temperature of 35°C. Moreover, the adsorption equilibrium was about 90 min under the optical condition. The experimental data showed a good compliance with the pseudo-second-order kinetic model, and the adsorption isotherm data met Langmuir models well. It was found that the maximal adsorption capacity reached 151.51mg/g.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
I. Osasona ◽  
A. O. Adebayo ◽  
O. O. Ajayi

Biosorption of Pb(II) ions from aqueous solution by cow hooves (CHs) was investigated as a function of initial pH, contact time, and biosorbent dosage through batch studies. Equilibrium experiments were performed at three different temperatures (298, 308, and 318 K) using initial Pb2+ concentration ranging from 15 to 100 mgg−1. This study revealed that maximum uptake (96.2% removal) of Pb2+ took place within 30 minutes of agitation, and the process was brought to equilibrium within 60 minutes of equilibration. The equilibrium data were modelled using Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models. The Langmuir isotherm model fitted the data best at all temperatures considered. The Lagergren second-order kinetic model fitted the biosorption process better than the first-order model. The negative values obtained for both Gibb’s free energy change and enthalpy change are an indication of the spontaneous and exothermic nature of the sorption of Pb2+ onto CH. A study of the FTIR spectral obtained before and after Pb2+ sorption showed that carbonyl, hydroxyl, amino, and carboxyl groups were involved in the sorption process.


2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.


2018 ◽  
Vol 21 (8) ◽  
pp. 583-593 ◽  
Author(s):  
Sara Rahnama ◽  
Shahab Shariati ◽  
Faten Divsar

Objective: In this research, a novel magnetite titanium dioxide nanocomposite functionalized by amine groups (Fe3O4@SiO2@TiO2-NH2) was synthesized and its ability for efficient removal of Acid Fuchsine as an anionic dye from aqueous solutions was investigated. Method: The core-shell structure of Fe3O4@SiO2@TiO2 was prepared using Fe3O4 as magnetic core, tetra ethyl orthosilicate as silica and tetra butyl titanate as titanium source for shell. The synthesized nanocomposites (particle size lower than 44 nm) were characterized by FT-IR, XRD, DRS, SEM and TGA instruments. The various experimental parameters affecting dye removal efficiency were investigated and optimized using Taguchi fractional factorial design. Results: The synthesized adsorbent showed the highest removal efficiency of Acid Fuchsine (99 %) at pH= 3.5, without salt addition and during stirring at contact times less than 10 minutes. The study of kinetic models at two concentration levels showed the fast dye sorption on the surface of proposed nanocomposites with pseudo second order kinetic model (R2=1). Also, the fitting of Acid Fuchsine sorption data to Freundlich, Langmuir and Temkin isotherms suggested that Freundlich model gave a better fitting than other models (R2=0.9936, n=2). Conclusion: Good chemical stability, excellent magnetic properties, very fast adsorption kinetics and high removal efficiency make the synthesized nanocomposite as a proper recoverable sorbent for removal of Acid Fuchsine dye from wastewaters.


Sign in / Sign up

Export Citation Format

Share Document