An evaluation of coal fly ash as an adsorbent for the removal of methylene blue from aqueous solutions: kinetic and thermodynamic studies

Karaca, Hüseyın; Altıntığ, Esra; Türker, Devrim; Teker, Murat

doi:10.1080/01932691.2018.1462191

Cited by 28 publications

(4 citation statements)

References 37 publications

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“…9 Therefore, to make it viable, use of low-cost adsorbents has been prospected for wastewater remediation. 10 Various mineral systems like zeolites, 11 kaolinite, 12 illite-kaolinite, 13 fly ash, 14 halloysite, 15 sepiolite, 16,17 montmorillonite, 18 and clinoptilolite 19 have been used for dye adsorption. The favorable dye adsorption using these minerals is due to their attributes like high surface area and molecular sieve structure.…”

Section: Introductionmentioning

confidence: 99%

Effect of temperature and fly ash content on the catalytically pyrolyzed rice straw biochar–fly ash composites for methylene blue adsorption

Bhardwaj

Nag

Hussain

et al. 2022

Asia-Pacific J Chem Eng

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Rice straw and fly ash are the wastes produced in abundance which need immediate attention for their management. In the present study, the in situ pyrolysis of rice straw in presence of fly ash was carried out and the resultant composites were studied for adsorption of methylene blue (MB). Slow pyrolysis of rice straw in presence of fly ash is evaluated using thermogravimetric analysis (TGA) and Coats-Redfern equation for pseudo-first-order reaction kinetics, respectively. The activation energy (E a ) for the pyrolysis of rice straw was 41.75 kJ/mol which was lowered to 37.39 kJ/mol in presence of fly ash. Biochar fly ash composites BFA4 1-3 , BFA5 1-3 , and BFA6 1-3 were prepared at three 400 C, 500 C, and 600 C pyrolysis temperature, respectively, the subscript indicating three different ratios of rice straw and fly ash (1:3, 1:1, and 3:1 w/w ratio). The composites BF4-6 1-3 were neutral to alkaline in pH, due to the presence of basic oxide and carbonates minerals. BFA4-6 1-3 was studied for batch adsorption of MB and optimized for pH, dose, and initial concentration of adsorbate. The maximum MB adsorption capacity of 25.91 mg/g was reported for the composite BFA4 1 . MB adsorption efficiency (q e ) followed the trend BFA4 1-3 > BFA5 1-3 > BFA6 1-3 , which indicates a strong influence of biochar surface functional groups on dye adsorption, as reiterated by the multiple linear regression (MLR) analysis. Stripping of MB was achieved using methanol as a stripping agent for MB-adsorbed BFA4-6 1-3 with desorption efficiency of 7% to 11% in the first cycle and 23% to 100% in the second cycle.Thus, the biochar fly ash composite with optimum ion exchangeable functional organic moieties would be suitable for dye remediation and waste generated in the process could find application in soil amelioration. K E Y W O R D S adsorption-desorption, composite biochar, dye, thermogravimetric analysis Akanksha Bhardwaj and Shilpa Nag have equal contributions to the paper.

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Section: Introductionmentioning

confidence: 99%

Effect of temperature and fly ash content on the catalytically pyrolyzed rice straw biochar–fly ash composites for methylene blue adsorption

Bhardwaj

Nag

Hussain

et al. 2022

Asia-Pacific J Chem Eng

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“…This explains that the adsorption between MB dye and parenchyma fibre based AC favours chemisorption over physisorption 52 . A previous study showed that pseudo second order kinetic model was favoured for the adsorption of methylene blue dye by fly ash as the adsorbent surface is primarily occupied by the dye molecules, leading to a competitive adsorption scenario with water due to the surface being covered by water 53 . The value of rate constant, k 2 , decreased with increasing initial dye concentration for all temperatures.…”

Section: Adsorption Isotherms Kinetics and Thermodynamicsmentioning

confidence: 99%

Sustainable oil palm trunk fibre based activated carbon for the adsorption of methylene blue

Gayathiri,

Pulingam,

Lee

et al. 2023

Sci Rep

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Activated carbon (AC) is becoming the limelight due to its widespread application as an adsorbent for wastewater treatment, gases, and catalysis. However, its high consumption and price have drawn more attention to the sustainable use of natural resources as precursor for AC production. This study focuses on synthesising AC from two types of oil palm trunk (OPT) fibres, a significant agricultural waste products produced by Malaysia's thriving palm oil industries. The BET surface area of about 2057.9 m2 g−1 was achieved by chemical activation with phosphoric acid (H3PO4). The efficiency of the synthesised AC was critically analysed based on the adsorption experiments with methylene blue (MB) by varying several parameters (dosage of adsorbent, pH, initial dye concentration, and temperature of the solution) to elucidate the adsorption mechanism(s). A maximum adsorption capacity of 320.4 mg g−1 at 50 °C was achieved, and the Temkin (r2 = 0.98, 0.95, 0.95) and Langmuir (r2 = 0.94, 0.93, 0.95) isotherm models fitted the adsorption process better than the Freundlich (r2 = 0.95, 0.90, 0.86) model. Besides, the pseudo-second-order model (r2 > 0.90) best described the adsorption process, favouring chemisorption over physisorption. Thermodynamics showed MB adsorption on AC was spontaneous except at the highest dye concentration. It was exothermic at lower dye concentrations (50 and 100 mg L−1) and endothermic at higher ones (300, 500, and 700 mg L−1). In a nutshell, this study reveals that OPT fibre is a promising precursor for synthesising highly porous AC for the adsorption of MB dye.

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“…Setelah itu, dilakukan proses hidrotermal menggunakan reaktor autoclave stainless steel dan dioven pada suhu 160 °C selama 7 jam untuk adsorben AHMW. Abu layang dicuci hingga pH netral, disaring, dikeringkan pada 105 °C selama 24 jam (Karaca et al, 2018) dan didinginkan sampai suhu kamar untuk selanjutnya dikararkterisasi. Karakteristik gugus fungsi dan luas permukaan AMW dan AHMW menggunakan FTIR, XRD, dan SAA dengan metode Brunauer-Emmett-Teller (BET).…”

Section: Preparasi Dan Aktivasi Abu Layangunclassified

Adsorpsi Metilen Biru oleh Abu Layang Batu Bara yang Teraktivasi Menggunakan Proses Hidrotermal dengan Bantuan Gelombang Mikro

et al. 2021

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Metilen biru (MB) merupakan pewarna kationik yang paling sering digunakan sebagai zat warna, hal tersebut dapat menyebabkan masalah lingkungan perairan dan bersifat toksik. Abu layang dapat dimanfaatkan sebagai adsorben karena memiliki sifat ramah lingkungan dan kelimpahannya sebagai limbah yang perlu dimanfaatkan. Tujuan penelitian ini adalah untuk mengetahui karakteristik abu layang dan mengetahui kondisi optimum proses adsorpsi MB oleh abu layang yang diaktivasi. Abu layang diaktivasi secara kimia dengan NaOH dan secara fisika menggunakan gelombang mikro (AMW) dan aktivasi hidrotermal dengan bantuan gelombang mikro (AHMW). Hasil karakterisasi menggunakan FTIR, adsorben AMW dan AHMW memiliki gugus fungsi yaitu gugus O‒H pada pita 3435 cm-1 dan 3435,16 cm-1, gugus T‒O‒T (T=Si atau Al) pada pita 10039,20 cm-1 dan 1007,82 cm-1, dan gugus O‒Si‒O atau Al‒O‒Al pada pita 772,5 cm-1 dan 720,62 cm-1. Hasil difraktogram sinar-X menunjukkan puncak yang khas yaitu Quartz (SiO2) pada 2θ 16° dan 21° dan Mullite (3Al2O3.2SiO2) 33° dan 40° pada kedua adsorben. AMW memiliki luas permukaan sebesar 37,87 m2/g dan AHMW sebesar 53,76 m2/g dengan SAA. Kedua adsorben terklasifikasi sebagai material mesopori dengan ukuran diameter pori 2,32 nm dan 19,10 nm. Adsorpsi MB oleh AMW optimum pada pH 9 selama 90 menit, AHMWoptimum pada pH 9 selama 120 menit dengan konsentrasi awal optimum 200 mg/L pada keduanya. Hasil kinetika adsorpsi metilen biru menggunakan AMW dan AHMW mengikuti pola kinetika pseudo orde dua Ho dan McKay dengan nilai k2 masing-masing sebesar 0,0429 dan 0,0116 g mg-1 min‑1. Kapasitas adsorpsi MB menggunakan abu layang tanpa aktivasi sebesar 3,59 mg/g, sedangkan kapasitas adsorpsi MB menggunakan AMW dan AHMW mengikuti pola isoterm Langmuir berturut-turut sebesar 37,87 dan 53,76 mg/g.Methylene Blue Adsorption by Activated Coal Fly Ash Using Microwave-Assisted Hydrothermal Process. Methylene blue (MB) is a cationic dye that is most often used as a dye, that can cause aquatic environmental problems and is toxic. Fly ash can be used as an adsorbent because of its environmentally friendly properties and its abundance as waste that needs to be utilized. The purpose of this study was to determine the characteristics of fly ash and to determine the optimum conditions for the MB adsorption process by activated fly ash. Fly ash is activated chemically with NaOH and physically using microwaves (AMW) and hydrothermal activation with the help of microwaves (AHMW). The results of characterization using FTIR, two adsorbents have functional groups, namely O‒H groups in the 3435 cm-1 and 3435.16 cm-1 bands, T‒O‒T groups (T=Si or Al) in the 10039.20 cm-1 and 1007.82 cm-1, and O‒Si‒O or Al‒O‒Al groups in the bands 772.5 cm-1 and 720.62 cm-1. The results of the X-ray diffractogram showed typical peaks, namely Quartz (SiO2) at 2θ 16° and 21° and Mullite (3Al2O3. 2SiO2) 33° and 40° on both adsorbents. AMW has a surface area of 37.87 m2/g and AHMW is 53.76 m2/g with SAA. Both adsorbents are classified as mesoporous materials with pore diameters of 2.32 nm and 19.10 nm. The optimum adsorption of MB by AMW was at pH 9 for 90 minutes, AHMW was optimum at pH 9 for 120 minutes with the optimum initial concentration of 200 mg/L in both. The results of methylene blue adsorption kinetics using AMW and AHMW followed the pseudo second order kinetic pattern of Ho and McKay with k2 values of 0.0429 and 0.0116 g mg-1min-1. MB adsorption capacity in fly ash without activation was 3.59 mg/g, while its adsorption capacity in AMW and AHMW were respectively 37.87 and 53.76 mg/g, which follow the Langmuir isotherm pattern.

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An evaluation of coal fly ash as an adsorbent for the removal of methylene blue from aqueous solutions: kinetic and thermodynamic studies

Cited by 28 publications

References 37 publications

Effect of temperature and fly ash content on the catalytically pyrolyzed rice straw biochar–fly ash composites for methylene blue adsorption

Effect of temperature and fly ash content on the catalytically pyrolyzed rice straw biochar–fly ash composites for methylene blue adsorption

Sustainable oil palm trunk fibre based activated carbon for the adsorption of methylene blue

Adsorpsi Metilen Biru oleh Abu Layang Batu Bara yang Teraktivasi Menggunakan Proses Hidrotermal dengan Bantuan Gelombang Mikro

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