Adsorption, Kinetics and Equilibrium Studies on Removal of Catechol and Resorcinol from Aqueous Solution Using Low-Cost Activated Carbon Prepared from Sunflower (Helianthus annuus) Seed Hull Residues

Vunain, Ephraim; Houndedjihou, Dègninou; Monjerezi, Maurice; Muleja, Adolph Anga; Kodom, BarthélémyTomkouani

doi:10.1007/s11270-018-3993-9

Cited by 21 publications

(7 citation statements)

References 49 publications

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“…Temkin isotherm model postulates that because of indirect adsorbate/sorbate interactions, the heat of adsorption of the atoms adsorbed would linearly decrease with coverage. It also suggests that the adsorption process is characterized by a uniform distribution of binding energies at the adsorbent surface [35]. The Temkin isotherm linearized equation is given as equation (6) below: (6) Q e = B ln K T + B ln C e . …”

Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of Activated Carbon from Agrowastes for the Removal of Acetic Acid from an Aqueous Solution

Njewa

Biswick

Vunain

et al. 2022

Adsorption Science & Technology

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In this study, activated carbons prepared from agrowastes by chemical activation were used to remove acetic acid from an aqueous solution through a batch process. The prepared adsorbents were characterized by SEM, XRD, FT-IR, and point of zero charge (pHpzc). The effects of adsorbent dosage, initial concentration, and contact time were considered. Equilibrium data was tested using Langmuir, Freundlich, Temkin, and Frenkel–Halsey–Hill models. The degree of adsorption of acetic acid increased for both adsorbents as contact time, and adsorbent dosage and initial concentration were increased. The adsorption data were described well by the (Freundlich=Frenkel–Halsey–Hill) models with the highest regression coefficient of R 2 = 0.9961 and R 2 = 0.9951 for Rice Husk Activated Carbon (RH-AC) and Potato Peels Activated Carbon (PP-AC), respectively. This suggests a multilayer through the existence of a heterogeneous pore distribution in the adsorbent surface. Kinetic data agreed well with pseudosecond-order ( R 2 = 0.999 and R 2 = 0.994 ) RH-AC and PP-AC, correspondingly. This indicates that the adsorption process was chemisorption in nature. The regeneration studies showed that the adsorbents prepared could be renewed and reused before losing their adsorbing affinity for acetic acid.

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Section: Resultsmentioning

confidence: 99%

Synthesis and Characterization of Activated Carbon from Agrowastes for the Removal of Acetic Acid from an Aqueous Solution

Njewa

Biswick

Vunain

et al. 2022

Adsorption Science & Technology

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“…Alkali and alkaline earth metals, and some acids, are normally used as activating agents. Examples include potassium hydroxide (KOH) (Fu et al 2019;Seo et al 2019;Yang et al 2019), phosphoric acid (H 3 PO 4 ) (Kang et al 2018;Wu et al 2018;Baek et al 2019), potassium carbonate (K 2 CO 3 ) (Zhou et al 2012;Garba et al 2015;Oliveira et al 2018), zinc chloride (ZnCl 2 ) (Vunain et al 2018;Laverde et al 2019;Ma et al 2019) and sodium hydroxide (NaOH) (Laverde et al 2019;Hasanzadeh et al 2020;Zhang et al 2020).…”

Section: Strategies In Chemical Activationmentioning

confidence: 99%

Effects of chemical activating agents on physical properties of activated carbons – a commentary

Amran

Zaini

2020

Water Practice and Technology

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Well-developed surface areas and porous structures that render high adsorption capacity are necessary for pollutant removal from wastewater by activated carbons. Activated carbons from natural resources, and agricultural and industrial waste materials are produced using chemical agents, including KOH, H3PO4, K2CO3, ZnCl2 and NaOH. This study is intended to highlight the effects of those agents on the physical properties of the activated carbons. The operating conditions, i.e., temperature, time and ratio show an interplay towards the physical properties at varying degree. The yield, pore size, mesoporosity and surface area of activated carbons derived using different chemical agents correlate well with the impregnation ratio. Generally, the pore size, mesoporosity and surface area increase, while the yield decreases with increasing ratio (over a given range). Higher ratio and temperature are recommended for KOH, K2CO3 and NaOH activation, to endow activated carbons with greater surface area.

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“…The chemical processes and extraction methods of industrial production of l -DOPA are unsustainable because of the environmental damage and limitation of raw materials. , The reaction catalyzed by tyrosine phenol lyase (TPL) is considered most effective in producing l -DOPA . Due to the irreversible inhibition on TPL and toxicity of substrate catechol, the process mass intensity (PMI) significantly increased in biocatalyst preparation and waste treatment. , Therefore, screening efficient and irreversible biocatalysts with nontoxic substrates can further enhance the advantages of biotechnological progress. In previous studies, the biosynthesis of l -DOPA, a case of white biotechnology, took Escherichia coli, Aspergillus niger PA2, and Aspergillus oryzae as chassis cells, with tyrosinase or p -hydroxyphenylacetate 3-hydrolase (PHAH) expression, which is excellent research in the process of biotechnology.…”

Section: Introductionmentioning

confidence: 99%

Combining Precursor-Directed Engineering with Modular Designing: An Effective Strategy for De Novo Biosynthesis of l-DOPA in Bacillus licheniformis

et al. 2022

ACS Synth. Biol.

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3-Hydroxy-L-tyrosine (L-DOPA) is a promising drug for treating Parkinson's disease. Tyrosine hydroxylase catalyzes the microbial synthesis of L-DOPA, which is hindered by the efficiency of catalysis, the supply of cofactor tetrahydrobiopterin, and the regulation of the pathway. In this study, the modular engineering strategy in Bacillus licheniformis was identified to effectively enhance L-DOPA production. First, the catalytic efficiency of biocatalyst tyrosine hydroxylase from Streptosporangium roseum DSM 43021 (SrTH) was improved by 20.3% by strengthening its affinity toward tetrahydrobiopterin. Second, the tetrahydrobiopterin supply pool was increased by bottleneck gene expression, oxygen transport facilitation, budC (encoding meso-2,3butanediol dehydrogenase) deletion, and tetrahydrobiopterin regeneration using a native YfkO nitroreductase. The strain 45AB v C successfully produced tetrahydrobiopterin, which was detected as pterin (112.48 mg/L), the oxidation product of tetrahydrobiopterin. Finally, the yield of precursor L-tyrosine reached 148 mg/g DCW , with an increase of 71%, with the deletion of a novel spliced transcript 41sRNA associated with the regulation of the shikimate pathway. The engineered strain 45AB v CS::PD produced 167.14 mg/L (2.41 times of wild-type strain) and 1290 mg/L L-DOPA in a shake flask and a 15 L bioreactor, respectively, using a fermentation strategy on a mixture of carbon sources. This study holds great potential for constructing a microbial source of L-DOPA and its high-value downstream pharmaceuticals.

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Adsorption, Kinetics and Equilibrium Studies on Removal of Catechol and Resorcinol from Aqueous Solution Using Low-Cost Activated Carbon Prepared from Sunflower (Helianthus annuus) Seed Hull Residues

Cited by 21 publications

References 49 publications

Synthesis and Characterization of Activated Carbon from Agrowastes for the Removal of Acetic Acid from an Aqueous Solution

Synthesis and Characterization of Activated Carbon from Agrowastes for the Removal of Acetic Acid from an Aqueous Solution

Effects of chemical activating agents on physical properties of activated carbons – a commentary

Combining Precursor-Directed Engineering with Modular Designing: An Effective Strategy for De Novo Biosynthesis of l-DOPA in Bacillus licheniformis

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