scholarly journals Adsorption of Cr(VI) onto cross-linked chitosan-almond shell biochars: equilibrium, kinetic, and thermodynamic studies

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Türkan Altun ◽  
Hüseyin Ecevit ◽  
Yakup Kar ◽  
Birsen Çiftçi
Keyword(s):  
Particle Diffusion ◽  
Order Kinetic ◽  
Almond Shell ◽  
Film Diffusion ◽  
Composite Adsorbents ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model ◽  
Pseudo Second Order

AbstractIn this study, to remove Cr(VI) from the solution environment by adsorption, the almond shell was pyrolyzed at 400 and 500 °C and turned into biochar (ASC400 and ASC500) and composite adsorbents were obtained by coating these biochars with chitosan (Ch-ASC400 and Ch-ASC500). The resulting biochars and composite adsorbents were characterized using Fourier transform infrared (FTIR) spectroscopy; Brunauer, Emmett, and Teller (BET) surface area; scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX); and the point of zero charge pH (pHpzc) analyses. The parameters affecting the adsorption were examined with batch adsorption experiments and the optimum parameters for the efficient adsorption of Cr(VI) in 55 mg L−1 solution were determined as follows; adsorbent dosages: 5 g L−1 for biochars, 1.5 g L−1 for composite adsorbents, contact time: 120 min, pH: 1.5. It was seen that the temperature did not affect the adsorption much. Under optimum conditions, Cr(VI) adsorption capacities of ASC400, ASC500, Ch-ASC400, and Ch-ASC500 adsorbents are 11.33, 11.58, 37.48, and 36.65 mg g−1, respectively, and their adsorption percentages are 95.2%, 97.5%, 94.3%, and 94.0%, respectively. Adsorption data were applied to Langmuir, Freundlich, Scatchard, Dubinin-Radushkevic, and Temkin isotherms and pseudo-first-order kinetic model, pseudo-second-order kinetic model, intra-particle diffusion model, and film diffusion model. The adsorption data fitted well to the Langmuir isotherm and pseudo-second-order kinetic models. From these results, it was determined that chemical adsorption is the dominant mechanism. Also, both intra-particle diffusion and film diffusion is effective in the adsorption rate. For all adsorbents, the Langmuir isotherm proved to be the most appropriate model for adsorption. The maximum monolayer adsorption capacities calculated from this model are 24.15 mg g−1, 27.38 mg g−1, 54.95 mg g−1, and 87.86 mg g−1 for ASC400, ASC500, Ch-ASC400, and Ch-ASC500, respectively. The enthalpy change, entropy change, and free energy changes during the adsorption process were calculated and the adsorption was also examined thermodynamically. As a result, adsorption occurs spontaneously for all adsorbents.

scholarly journals Development of Cerium Oxide/Corncob Nanocomposite: A Cost-Effective and Eco-Friendly Adsorbent for the Removal of Heavy Metals

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4464
Author(s):  
Sidra Gran ◽  
Rukhsanda Aziz ◽  
Muhammad Tariq Rafiq ◽  
Maryam Abbasi ◽  
Abdul Qayyum ◽  
...  
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Contact Time ◽  
Cost Effective ◽  
Particle Diffusion ◽  
Order Kinetic ◽  
Removal Of Heavy Metals ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model ◽  
Pseudo Second Order

This research aims to assess the efficiency of the synthesized corncob as a cost-effective and eco-friendly adsorbent for the removal of heavy metals. Therefore, to carry out the intended research project, initially, the corncob was doped with nanoparticles to increase its efficiency or adsorption capacity. The prepared adsorbent was evaluated for the adsorption of cadmium (Cd) and chromium (Cr) from aqueous media with the batch experiment method. Factors that affect the adsorption process are pH, initial concentration, contact time and adsorbent dose. The analysis of Cd and Cr was performed by using atomic absorption spectrometry (AAS), while the characterization of the adsorbent was performed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that there is a significant difference before and after corncob activation and doping with CeO2 nanoparticles. The maximum removal for both Cd and Cr was at a basic pH with a contact time of 60 min at 120 rpm, which is 95% for Cd and 88% for Cr, respectively. To analyze the experimental data, a pseudo-first-order kinetic model, pseudo-second-order kinetic model, and intra-particle diffusion model were used. The kinetic adsorption studies confirmed that the experimental data were best fitted with the pseudo-second-order kinetic model (R2 = 0.989) and intra-particle diffusion model (R2 = 0.979). This work demonstrates that the cerium oxide/corncob nanocomposite is an inexpensive and environmentally friendly adsorbent for the removal of Cd and Cr from wastewater.

scholarly journals Characterization and Pb(II) removal potential of corn straw- and municipal sludge-derived biochars

2017 ◽  
Vol 4 (9) ◽  
pp. 170402 ◽  
Author(s):  
Shujuan Wang ◽  
Wei Guo ◽  
Fan Gao ◽  
Rui Yang
Keyword(s):  
Aqueous Solutions ◽  
Surface Complexation ◽  
Order Kinetic ◽  
Municipal Sludge ◽  
Corn Straw ◽  
Ph Values ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Corn straw- and municipal sludge-derived biochars (CS-BC and MS-BC, respectively) were used to remove Pb(II) from aqueous solutions. Despite being pyrolysed at the same temperature (723 K), MS-BC showed higher porosity and hydrophobicity than CS-BC. The optimum biochar loading and pH values allowing efficient Pb(II) removal (greater than 80%) were 0.2 g l −1 and 7.0, respectively. The presence of PO 4 3− (greater than 0.01 mol l −1 ) significantly affected the adsorptive performance of Pb(II) on the biochar samples. The adsorption data fitted well to a pseudo-second-order kinetic model and a Langmuir model, and the maximum Pb(II) adsorption capacities were 352 and 387 mg g −1 for CS-BC and MS-BC, respectively. The main mechanisms involved in the adsorption of Pb(II) on biochar were electrostatic attraction and surface complexation. When comparing both biochars, CS-BC showed better cost-effectiveness for the removal of Pb(II) from aqueous solutions.

REMOVAL OF STRONTIUM (II) FROM AQUEOUS SOLUTION USING FUNCTIONALIZED CARBON NANOTUBES

2012 ◽  
Vol 11 (02) ◽  
pp. 1250019 ◽  
Author(s):  
RAJESH KUMAR ◽  
S. K. JAIN
Keyword(s):  
Carbon Nanotubes ◽  
Polluted Water ◽  
Order Kinetic ◽  
Environmental Application ◽  
Functionalized Carbon Nanotubes ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

This study was carried out to evaluate the environmental application of functionalized carbon nanotubes through the experimental removal of strontium (II) from water. The aim was to find the optimal condition for the removal of strontium from water under different conditions such as initial concentration of strontium, contact time and neutral pH. The functionalized multi wall carbon nanotubes (f-MWCNT) were characterized by FT-IR and scanning electron microscopy (SEM). The adsorption isotherms were correlated to Freundlich and Langmuir models and it was found that the adsorption data could be fitted better by Langmuir model than Freundlich one. The kinetic data shows that the adsorption describes well with the pseudo-second order kinetic model. Functionalized MWCNT can be used as good adsorbent for the removal of the strontium ions from polluted water according to results.

scholarly journals Simultaneous removal of cationic and anionic dyes from aqueous solution by double functional groups modified bagasse

2020 ◽  
Vol 82 (10) ◽  
pp. 2159-2167
Author(s):  
Ru-yi Zhou ◽  
Jun-xia Yu ◽  
Ru-an Chi
Keyword(s):  
Aqueous Solution ◽  
Functional Groups ◽  
Order Kinetic ◽  
Anionic Dyes ◽  
Adsorption Capacities ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Amine Groups ◽  
Modified Adsorbents ◽  
Zeta Potential Analysis

Abstract Double functional groups modified bagasse (DFMBs), a series of new zwitterionic groups of carboxyl and amine modified adsorbents, were prepared through grafting tetraethylenepentamine (TEPA) onto the pyromellitic dianhydride (PMDA) modified bagasse using the DCC/DMAP method. DFMBs' ability to simultaneously remove basic magenta (BM, cationic dye) and Congo red (CR, anionic dye) from aqueous solution in single and binary dye systems was investigated. FTIR spectra and Zeta potential analysis results showed that PMDA and TEPA were successfully grafted onto the surface of bagasse, and the ratio of the amount of carboxyl groups and amine groups was controlled by the addition of a dosage of TEPA. Adsorption results showed that adsorption capacities of DFMBs for BM decreased while that for CR increased with the increase of the amount of TEPA in both single and binary dye systems, and BM or CR was absorbed on the modified biosorbents was mainly through electrostatic attraction and hydrogen bond. The adsorption for BM and CR could reach equilibrium within 300 min, both processes were fitted well by the pseudo-second-order kinetic model. The cationic and anionic dyes removal experiment in the binary system showed that DMFBs could be chosen as adsorbents to treat wastewater containing different ratios of cationic and anionic dyes.

scholarly journals Karekterisasi, Kinetika, dan Isoterm Adsorpsi Limbah Ampas Kelapa sebagai Adsorben Ion Cu(II)

SAINTIFIK ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 104-115
Author(s):  
Agusriyadin Agusriyadin
Keyword(s):  
Adsorption Capacity ◽  
Ph Effect ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Optimum Conditions ◽  
Langmuir Adsorption ◽  
Adsorbent Surface ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Penelitian ini bertujuan untuk menguji kemampuan AK dan AKPM dalam mengadsorpsi ion Cu (II), pengaruh parameter adsorpsi dan mekanisme adsorpsi. AK dan AKP Madsorben dibuat dari residu ampas kelapa. Adsorben dikarakterisasi dengan FTIR, SEM dan EDS. Pengaruh parameter adsorpsi seperti pH awal, dosis adsorben, waktu kontak dan konsentrasi ion Cu (II) awal diperiksa untuk menentukan kondisi optimum serapan tembaga (II). Ion Cu (II) yang teradsorpsi diukur berdasarkan pada konsentrasi Ion Cu (II) sebelum dan sesudah adsorpsi menggunakan metode AAS. Hasil karakterisasi menunjukkan bahwa struktur pori dan gugus fungsi tersedia pada permukaan adsorben. Menurut percobaan efek pH, kapasitas adsorpsi maksimum dicapai pada pH 7. Waktu kontak optimal dan konsentrasi tembaga awal (II) ditemukan masing-masing pada 120 menit dan 100 mg L-1. Data eksperimental sesuai dengan model kinetik orde dua orde dua, dan Langmuir isoterm adsorpsi yang diperoleh paling sesuai dengan data adsorpsi. Kapasitas adsorpsi maksimum adsorben ditemukan menjadi 4,73 dan 6,46 mg g-1 pada kondisi optimal. The results of characterization showed that the pore structure and the functional groups were available on adsorbent surface. According to the pH effect experiments, the maximum adsorption capacity was achieved at pH 7. Optimum contact time and initial copper(II) concentration were found at 120 min and 100 mg L-1, respectively. The experimental data were comply with the pseudo-second-order kinetic model, and Langmuir adsorption isotherm obtained best fitted the adsorption data. The maximum adsorption capacity of the adsorbents was found to be 4.73 and 6.46 mg g-1 at optimum conditions.

Equilibrium and Kinetic Studies for the Biosorption of Aqueous Nickel(II) Ions onto the Pseudomonas alcaligenes Biomass

2010 ◽  
Vol 171-172 ◽  
pp. 41-44
Author(s):  
Xiao Cun Xiao ◽  
Gai Xia Fang ◽  
Er Li Zhao ◽  
Lv Bin Zhai ◽  
Jun Shuai Shi
Keyword(s):  
Industrial Wastewater ◽  
Chemical Interaction ◽  
Kinetic Studies ◽  
Synthetic Wastewater ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Pseudomonas Alcaligenes ◽  
Batch Biosorption

The objective of this study is to assess the environmentaly friendly Ni(II) adsorption from synthetic wastewater using Pseudomonas alcaligenes biomass (PA-2). The ability of PA-2 to remove the Ni(II) ions was investigated by using batch biosorption procedure. The effects such as pH, dosage of biosorbent, Ni(II) initial concentration and sorbate–sorbent contact time and agitating speed on the adsorption capacities of PA-2 were studied. Biosorption equilibriums were rapidly established in about 60 min and the adsorption kinetics followed the pseudo-second order kinetic model. The maximum Ni(II) adsorption capacity determined from Langmuir isotherm were 82.23 mg/g PA-2 at pH 5.0, at 25±2°C and shaker speed 150 rpm, respectively. The carboxyl , hydroxyl and amino groups of the PA-2 were involved in chemical interaction with the Ni(II) ions depicted by Fourier transform infrared spectroscopic (FTIR) results. The study points to the potential of new use of Pseudomonas alcaligenes biomass as an effective biosorbent for the removal of Ni(II) and from environmental and industrial wastewater.

scholarly journals Adsorption of Cr(VI) ions onto goethite, activated carbon and their composite: kinetic and thermodynamic studies

2020 ◽  
Vol 10 (9) ◽  
Author(s):  
G. B. Adebayo ◽  
H. I. Adegoke ◽  
Sidiq Fauzeeyat
Keyword(s):  
Activated Carbon ◽  
Heavy Metal Contamination ◽  
Stem Bark ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Optimum Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Daniellia Oliveri ◽  
Kinetic And Thermodynamic Studies

Abstract Hexavalent chromium was adsorbed from aqueous solution with three prepared and characterized adsorbents, namely goethite (G), activated carbon (AC) and their composite (GAC). The goethite particle was synthesized using the precipitation methods, and activated carbon was prepared from the stem bark of Daniellia oliveri tree and composite in a ratio of 1:5 goethite–activated carbon. The adsorption capacities of G, AC and GAC for Cr(VI) are 6.627, 5.455 and 6.354 mg/g with 0.02 g adsorbent within contact time of 60, 180 and 30 min for G, AC and GAC, respectively, for Cr(VI) adsorption at optimum pH of 3. The isotherm studied was best explained by Langmuir adsorption isotherm and fitted with the pseudo-second-order kinetic model. Desorption studies showed that 1.0 M HNO3 was a better desorbing agent than 0.1 M HNO3, 0.1 M HCl and 1.0 M HCl. Chromium was most desorbed (94.60% in Cr//G using 1 M HNO3). The result obtained revealed that goethite and activated carbon produced are favourable adsorbents and the composite of the two adsorbents gives a more favourable, economical and affordable adsorbent for the clean-up of heavy metal contamination.

Biosorption of hexavalent chromium from aqueous solution by polyethyleneimine-modified ultrasonic-assisted acid hydrochar from Sargassum horneri

2020 ◽  
Vol 81 (6) ◽  
pp. 1114-1129 ◽  
Author(s):  
Jun Wang ◽  
Qinglong Xie ◽  
Ao Li ◽  
Xuejun Liu ◽  
Fengwen Yu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Batch Adsorption ◽  
Crosslinking Reaction ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Initial Ph ◽  
Ultrasonic Assisted ◽  
Order Kinetic Model ◽  
Pseudo Second Order

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.

scholarly journals Adsorption characteristics of Pb(II) using biochar derived from spent mushroom substrate

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Qianlan Wu ◽  
Yang Xian ◽  
Zilin He ◽  
Qi Zhang ◽  
Jun Wu ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Raw Materials ◽  
Edible Mushroom ◽  
Bet Surface Area ◽  
Order Kinetic ◽  
The Sustainable Development ◽  
Adsorption Capacities ◽  
Small Pore ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract As a multifunctional material, biochar is considered a potential adsorbent for removing heavy metals from wastewater. Most biochars with high adsorption capacities have been modified, but this modification is uneconomical, and modifying biochar may cause secondary pollution. Thus, it is necessary to develop an efficient biochar without modification. In this study, spent P. ostreatus substrate and spent shiitake substrate were used as the raw materials to prepare biochar. Then, the physicochemical properties of the biochars and their removal efficiencies for Pb(II) were investigated. The results showed that the physicochemical properties (e.g., large BET surface area, small pore structure and abundant functional groups) contributed to the large adsorption capacity for Pb(II); the maximum adsorption capacities were 326 mg g−1 (spent P. ostreatus substrate-derived biochar) and 398 mg g−1 (spent shiitake substrate-derived biochar), which are 1.6–10 times larger than those of other modified biochars. The Pb(II) adsorption data could be well described by the pseudo-second-order kinetic model and the Langmuir model. This study provides a new method to comprehensively utilize spent mushroom substrates for the sustainable development of the edible mushroom industry.

scholarly journals The Presence of Cu Facilitates Adsorption of Tetracycline (TC) onto Water Hyacinth Roots

2018 ◽  
Vol 15 (9) ◽  
pp. 1982 ◽  
Author(s):  
Xin Lu ◽  
Beibei Tang ◽  
Qi Zhang ◽  
Lizhu Liu ◽  
Ruqin Fan ◽  
...  
Keyword(s):  
Water Hyacinth ◽  
Freundlich Isotherm ◽  
Root Surface ◽  
Interactive Effects ◽  
Order Kinetic ◽  
Batch Experiments ◽  
Adsorption Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ph Range

Batch experiments were conducted to investigate the adsorption characteristics of tetracycline (TC), and the interactive effects of copper (Cu) on the adsorption of TC onto water hyacinth roots. TC removal efficiency by water hyacinth roots was ranging from 58.9% to 84.6%, for virgin TC, 1:1 TC-Cu and 1:2 TC-Cu. The Freundlich isotherm model and the pseudo-second-order kinetic model fitted the adsorption data well. Thermodynamics parameters ΔG0 for TC were more negative in the TC plus Cu than the TC-only treatments, indicating the spontaneity of TC adsorption increased with increasing of Cu concentrations. An elevated temperature was associated with increasing adsorption of TC by water hyacinth roots. The additions of Cu(II) significantly increased TC adsorption onto water hyacinth roots within the pH range 4 to 6, because copper formed a strong metal bridge between root surface and TC molecule, facilitating the adsorption of TC by roots. However, Cu(II) hindered TC adsorption onto water hyacinth roots on the whole at pH range from 6–10, since the stronger electrostatic repulsion and formation of CuOH+ and Cu(OH)2. Therefore, the interaction between Cu(II) and TC under different environmental conditions should be taken into account to understand the environmental behavior, fate, and ecotoxicity of TC.

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