scholarly journals Coffee residue-based activated carbons for phenol removal

Author(s):  
Hemavathy Palanisami ◽  
Mohamad Rafiuddin Mohd Azmi ◽  
Muhammad Abbas Ahmad Zaini ◽  
Zainul Akmar Zakaria ◽  
Muhd Nazrul Hisham Zainal Alam ◽  
...  

Abstract This work was aimed to evaluate the adsorptive properties of activated carbons from coffee residue for phenol removal. The coffee residue was activated using H3PO4 and KOH, and the resultant activated carbons were characterized for surface area and functional groups. The values of surface area were recorded as 1,030 m2/g and 399 m2/g for H3PO4- and KOH-activated carbons, respectively. The maximum capacity for phenol removal is comparable for both activated carbons at 43 mg/g. The pores might be inaccessible due to electrostatic repulsion by surface functional groups and hydroxyl anions. The second stage in a two-stage adsorber design is necessary to accomplish the process with high performance and minimum dosage of activated carbon. Coffee residue is a promising activated carbon precursor for phenol removal.

2017 ◽  
Vol 4 (2) ◽  
pp. 186-194 ◽  
Author(s):  
Tan I. A. W. ◽  
Abdullah M. O. ◽  
Lim L. L. P. ◽  
Yeo T. H. C.

Activated carbon derived from agricultural biomass has been increasingly recognized as a multifunctional material for various applications according to its physicochemical characteristics. The application of activated carbon in adsorption process mainly depends on the surface chemistry and pore structure which is greatly influenced by the treatment method. This study aims to compare the textural characteristics, surface chemistry and surface morphology of coconut shell-based activated carbon modified using chemical surface treatments with hydrochloric acid (HCl) and sodium hydroxide (NaOH). The untreated and treated activated carbons were characterized for their physical and chemical properties including the Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and textural characterization. The FTIR spectra displayed bands confirming the presence of carboxyl, hydroxyl and carbonyl functional groups. The Brunauer–Emmett–Teller (BET) surface area of the untreated activated carbon was 436 m2/g whereas the surface area of the activated carbon modified using 1M NaOH, 1M HCl and 2M HCl was 346, 525 and 372 m2/g, respectively. SEM micrographs showed that many large pores in a honeycomb shape were clearly found on the surface of 1M HCl sample. The pore structure of the activated carbon treated with 2M HCl and NaOH was partially destroyed or enlarged, which decreased the BET surface area. The modification of the coconut shell-based activated carbon with acidic and alkaline treatments has successfully altered the surface functional groups, surface morphology and textural properties of the activated carbon which could improve its adsorptive selectivity on a certain adsorbate.


2020 ◽  
Vol 998 ◽  
pp. 102-107
Author(s):  
Ria Grace Abdon ◽  
Top Archie Dela Peña ◽  
Camille Punongbayan ◽  
John Achilles Ricafrente

Commercial activated carbon (CAC) was modified using low-pressure radio frequency nitrogen plasma discharge (NPD) operating at 0.3 mbar and 40 kHz. The surface chemistry of CAC was modified using HNO3 pre-oxidation to possibly influence the reactivity of NPD. The results of x-ray photoelectron spectroscopy (XPS) suggested that pre-oxidation reduces aromaticity, generates aliphatic carbons (C-C and C-H), and increases carboxylic functional groups (COOH) which probably enhances the nitrogen plasma functionalization based on the N/C ratio for CAC-O-P (4.29 %) compared to CAC-P (2.88 %). FTIR was used to confirm such effects of pre-oxidation from the functional groups present on the carbon surface. The total surface area was identified using Langmuir and Brunauer–Emmett–Teller (BET) N2 adsorption isotherms at 77 K. Both pre-oxidation and plasma treatment caused an increase in the surface area of CAC up to 150 percent. Carbon t-plot method was used to determine the micropore volume, micropore area, and external surface area. The total surface area of each activated carbon was mostly constituted of micropore area which was identified to be directly proportional to the micropore volume. Scanning electron microscope (SEM) confirms the destruction of the surface morphology for CAC-O that might have caused the increase in surface area. Development of surface threadlike structures were observed for the NPD treated CAC-O. NPD favors the development of NH2 functionalities and reduces the aromaticity of activated carbons while enhancing the surface morphology and the surface area.


Author(s):  
T.V. Nagalakshmi ◽  
K.A. Emmanuel ◽  
Ch. Suresh Babu ◽  
Ch. Chakrapani ◽  
P. Paul Divakar

Jackfruit PPI-1 variety was selected as source of lignocellulose material. Its rind and pulp waste was used as precursor for preparation of activated carbon. K2CO3 was selected as activating agent to prepare activated carbon. Various carbons were prepared by changing the impregnation ratio (IR) at different temperatures. Activated carbon prepared at 600°C and at IR1 had good BET surface area (987m2 g-1) and yield (61.97%). In order to introduce different functional groups, this carbon was divided into two parts. One part was subjected to liquid phase oxidation with 0.1N HNO3 and the other part was soaked in 0.1N KOH for 3hours. SEM, FTIR, TPD, XRD and TGA analyses were done to identify surface morphological changes, nature of functional groups and thermal stability of activated carbons.


1989 ◽  
Vol 6 (4) ◽  
pp. 182-191 ◽  
Author(s):  
S. Biniak ◽  
J. Kaźmièrczak ◽  
A. Swiatkowski

The effect of the chemical character of the surface of an activated carbon on phenol adsorption from aqueous solutions is described. The adsorbents used consisted of five types of activated carbon obtained by modification of the raw material. The results obtained indicate that the principal factor influencing adsorption is the oxygen contained in those surface functional groups which exhibit an acidic character. Moderately and slightly acidic groups are the most important in this context.


2018 ◽  
Vol 13 (1) ◽  
pp. 153-159
Author(s):  
Sahira Joshi

 This paper presents the comparative study on the adsorption capacity of activated carbons prepared from Lapsi (Choerospondias axillaris) seed stone and Betel (Areca catechu) nut. Activated carbons (ACs) were prepared from Lapsi seed stone (LSS) and Betel Nut (BN) by chemical activation with H3PO4 (in the ratio of 1:1 by weight) at 400°C. The pore structure of activated carbons was determined by iodine number and methylene blue number. Surface morphology of ACs was studied by scanning electron microscopy (SEM). Surface functional groups were analyzed by Fourier Transform Infra Red Spectroscopy (FTIR). As indicated by TGA analysis, the appropriate temperature required for carbonization was 400 ºC. Betel nut AC showed high iodine number and methylene number of 888 mg/gm and 369 mg/gm respectively. SEM micrographs of Betel nut AC show the presence of well developed pores on its surface. FTIR result indicated that both ACs contain −OH, >C=O groups as oxygen containing surface functional groups. Based on the result, the AC prepared from betel nut by activation with H3PO4 is comparable with commercial activated carbon and could be used as potential adsorbent for removal of pollutants from water and waste water.Journal of the Institute of Engineering, 2017, 13(1): 153-159


2011 ◽  
Vol 64 (10) ◽  
pp. 2059-2065 ◽  
Author(s):  
Cínthia S. Castro ◽  
Anelise L. Abreu ◽  
Carmen L. T. Silva ◽  
Mário C. Guerreiro

The present work highlights the preparation of activated carbons (ACs) using spent coffee grounds, an agricultural residue, as carbon precursor and two different activating agents: water vapor (ACW) and K2CO3 (ACK). These ACs presented the microporous nature and high surface area (620–950 m2 g−1). The carbons, as well as a commercial activated carbon (CAC) used as reference, were evaluated as phenol adsorbent showing high adsorption capacity (≈150 mg g−1). The investigation of the pH solution in the phenol adsorption was also performed. The different activating agents led to AC with distinct morphological properties, surface area and chemical composition, although similar phenol adsorption capacity was verified for both prepared carbons. The production of activated carbons from spent coffee grounds resulted in promising adsorbents for phenol removal while giving a noble destination to the residue.


2017 ◽  
pp. 96-103 ◽  
Author(s):  
Gillian Eggleston ◽  
Isabel Lima ◽  
Emmanuel Sarir ◽  
Jack Thompson ◽  
John Zatlokovicz ◽  
...  

In recent years, there has been increased world-wide concern over residual (carry-over) activity of mostly high temperature (HT) and very high temperature (VHT) stable amylases in white, refined sugars from refineries to various food and end-user industries. HT and VHT stable amylases were developed for much larger markets than the sugar industry with harsher processing conditions. There is an urgent need in the sugar industry to be able to remove or inactivate residual, active amylases either in factory or refinery streams or both. A survey of refineries that used amylase and had activated carbon systems for decolorizing, revealed they did not have any customer complaints for residual amylase. The use of high performance activated carbons to remove residual amylase activity was investigated using a Phadebas® method created for the sugar industry to measure residual amylase in syrups. Ability to remove residual amylase protein was dependent on the surface area of the powdered activated carbons as well as mixing (retention) time. The activated carbon also had the additional benefit of removing color and insoluble starch.


Author(s):  
Kaixiang Zou ◽  
Yuanfu Deng ◽  
Weijing Wu ◽  
Shiwei Zhang ◽  
Guohua Chen

High performance carbon-based materials are ideal electrode materials for Li-ion capacitors (LICs), but there are still many challenges such as the complicated preparation preocesses, high cost and low yield. Also,...


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