Physicochemical effect of activation temperature on the sorption properties of pine shell activated carbon

2016 ◽  
Vol 75 (5) ◽  
pp. 1158-1168 ◽  
Author(s):  
Agha Arslan Wasim ◽  
Muhammad Nasiruddin Khan

Activated carbons produced from a variety of raw materials are normally selective towards a narrow range of pollutants present in wastewater. This study focuses on shifting the selectivity of activated carbon from inorganic to organic pollutants using activation temperature as a variable. The material produced from carbonization of pine shells substrate was activated at 250°C and 850°C. Both adsorbents were compared with commercial activated carbon for the sorption of lead, cadmium, methylene blue, methyl blue, xylenol orange, and crystal violet. It was observed that carbon activated at 250°C was selective for lead and cadmium whereas the one activated at 850°C was selective for the organic dyes. The Fourier transform infrared spectroscopy study revealed that AC850 had less surface functional groups as compared to AC250. Point of zero charge and point of zero salt effect showed that AC250 had acidic groups at its surface. Scanning electron microscopy depicted that increase in activation temperature resulted in an increase in pore size of activated carbon. Both AC250 and AC850 followed pseudo-second-order kinetics. Temkin isotherm model was a best fit for empirical data obtained at equilibrium. The model also showed that sorption process for both AC250 and AC850 was physisorption.

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2951
Author(s):  
Mirosław Kwiatkowski ◽  
Jarosław Serafin ◽  
Andy M. Booth ◽  
Beata Michalkiewicz

This paper presents the results of a computer analysis of the effect of activation process temperature on the development of the microporous structure of activated carbon derived from the leaves of common polypody (Polypodium vulgare) via chemical activation with phosphoric acid (H3PO4) at activation temperatures of 700, 800, and 900 °C. An unconventional approach to porous structure analysis, using the new numerical clustering-based adsorption analysis (LBET) method together with the implemented unique gas state equation, was used in this study. The LBET method is based on unique mathematical models that take into account, in addition to surface heterogeneity, the possibility of molecule clusters branching and the geometric and energy limitations of adsorbate cluster formation. It enabled us to determine a set of parameters comprehensively and reliably describing the porous structure of carbon material on the basis of the determined adsorption isotherm. Porous structure analyses using the LBET method were based on nitrogen (N2), carbon dioxide (CO2), and methane (CH4) adsorption isotherms determined for individual activated carbon. The analyses carried out showed the highest CO2 adsorption capacity for activated carbon obtained was at an activation temperature of 900 °C, a value only slightly higher than that obtained for activated carbon prepared at 700 °C, but the values of geometrical parameters determined for these activated carbons showed significant differences. The results of the analyses obtained with the LBET method were also compared with the results of iodine number analysis and the results obtained with the Brunauer–Emmett–Teller (BET), Dubinin–Radushkevich (DR), and quenched solid density functional theory (QSDFT) methods, demonstrating their complementarity.


2021 ◽  
Vol 2 (446) ◽  
pp. 105-109
Author(s):  
A.E. Ilyassov ◽  
A.О. Baikonurova ◽  
B.N. Surimbayev

The article presents the results of a comparison of the sorption characteristics for gold of crushed activated carbon of the foreign Haycarb brand, obtained from expensive raw materials - coconut shells, and crushed activated carbon of the domestic Shubarkol brand, obtained from relatively cheap raw materials - low-ash coking coal. The activated carbon Shubarkol crushed to a class of -3.6+1.0 mm, was produced in Kazakhstan from coking coal by Shubarkolkomir JSC. To test the crushed coal Shubarkol, industrial crushed coal Haycarb, made from coconut shells, was used as a reference sample. This coal is widely used in gold mining enterprises for the sorption of dissolved gold from cyanide solutions and pulps. For research, a productive solution of the process of heap leaching of gold from oxidized ore of one of the deposits of Kazakhstan was used with the composition, mg/L: gold 0.82; silver 0.44; copper 8.34; pH 11.05. Determination of the sorption characteristics of coals was carried out by the method of saturation with gold when changing solutions. The results of changes in the gold content in the mother solution, its extraction and saturation of coals with precious metal after each sorption cycle from the productive heap leaching solution using crushed coals of the Shubarkol and Haycarb brands are presented. It follows from the obtained data that Shubarkol activated carbon has similar sorption characteristics compared to Haycarb activated carbon. The working capacity for gold of Shubarkol coal was 2.28 kg/ton of sorbent, and of Haycarb coal - 2.57 kg/ton. Thus, crushed coal Shubarkol, obtained from relatively cheap raw materials, can be successfully used at industrial facilities instead of foreign sorbent.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Daouda Kouotou ◽  
Horace Ngomo Manga ◽  
Abdelaziz Baçaoui ◽  
Abdelrani Yaacoubi ◽  
Joseph Ketcha Mbadcam

In this study, activated carbons were prepared from oil palm shells by physicochemical activation. The methodology of experimental design was used to optimize the preparation conditions. The influences of the impregnation ratio (0.6–3.4) and the activation temperature between 601°C and 799°C on the following three responses: activated carbon yield (R/AC-H3PO4), the iodine adsorption (I2/AC-H3PO4), and the methylene blue adsorption (MB/AC-H3PO4) results were investigated using analysis of variance (ANOVA) to identify the significant parameters. Under the experimental conditions investigated, the activation temperature of 770°C and impregnation ratio of 2/1 leading to the R/AC-H3PO4of 52.10%, theI2/AC-H3PO4of 697.86 mg/g, and the MB/AC-H3PO4of 346.25 mg/g were found to be optimum conditions for producing activated carbon with well compromise of desirability. The two factors had both synergetic and antagonistic effects on the three responses studied. The micrographs of activated carbons examined with scanning electron microscopy revealed that the activated carbons were found to be mainly microporous and mesoporous.


CERNE ◽  
2017 ◽  
Vol 23 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Gregório Mateus Santana ◽  
Roberto Carlos Costa Lelis ◽  
Emerson Freitas Jaguaribe ◽  
Rayssa de Medeiros Morais ◽  
Juarez Benigno Paes ◽  
...  

ABSTRACT Considering the water scarcity problems facing many countries, the need for water reuse can make activated carbon (AC) an essential product for modern society. In this context, to contribute with better activated carbons that could be used to serve in water treatment, this article discusses these materials production, using bamboo as raw material, and analyses their application effectiveness. The bamboo was collected, transformed into activated carbon, by simultaneous chemical and physical activations, and named H3PO4/H2OAC. The obtained material was characterized by its yield, apparent density, ash content, thermogravimetric analysis, surface area, methylene blue and iodine indexes, pH and point of zero charge analysis, scanning electron microscopy and Boehm titration method. The AC was used as adsorbent for removing the metribuzin, 2,4-dichlorophenoxyacetic acid and furadan pesticides. The H3PO4/H2OAC had a surface area of 1196.30 m².g-1 and the obtained adsorption capacity was elevated for furadan (868.98 mg.g-1), metribuzin (756.47 mg.g-1) and 2,4-dichlorophenoxyacetic acid (274.70 mg.g-1).


2009 ◽  
Vol 59 (12) ◽  
pp. 2387-2394 ◽  
Author(s):  
X. Wang ◽  
N. Zhu ◽  
J. Xu ◽  
B. Yin

An improved method for preparing activated carbons from wet waste activated sludge (WAS) by direct chemical activation was studied in this paper. The effects of processing parameters on iodine adsorption capacity of the product were investigated. Results show that sludge-based activated carbon prepared with KOH had a larger iodine value than those activated with ZnCl2 and KCl. The maximum iodine value was observed at the KOH concentration of 0.50 M. Increasing the impregnation time from 10 to 20 h resulted in a 20% increase in the iodine value. The highest iodine value was obtained at the activation temperature of 600°C and holding time of 1 h. Sludge water content had insignificant effects on the iodine value of products. Raw WAS with a water content of 93.2% can be converted into an activated carbon with a high specific surface area of 737.6 m2 g−1 and iodine value of 864.8 mgg−1 under optimum experimental conditions. Other physical properties such as total pore volume, micropore volume and mean pore diameter of the product were also reported and compared with those of commercial activated carbon.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Nurgul Ozbay ◽  
Adife Seyda Yargic

Activated carbons were prepared by carbonization of tomato paste processing industry waste at 500°C followed by chemical activation with KOH, K2CO3, and HCl in N2 atmosphere at low temperature (500°C). The effects of different activating agents and impregnation ratios (25, 50, and 100 wt.%) on the materials’ characteristics were examined. Precursor, carbonized tomato waste (CTW), and activated carbons were characterized by using ultimate and proximate analysis, thermogravimetric analysis (TG/DTG), Fourier transform-infrared (FT-IR) spectroscopy, X-ray fluorescence (XRF) spectroscopy, point of zero charge measurements (pHPZC), particle size analyzer, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, nitrogen adsorption/desorption isotherms, and X-ray diffraction (XRD) analysis. Activation process improved pore formation and changed activated carbons’ surface characteristics. Activated carbon with the highest surface area (283 m3/g) was prepared by using 50 wt.% KOH as an activator. According to the experimental results, tomato paste waste could be used as an alternative precursor to produce low-cost activated carbon.


2020 ◽  
Vol 63 (9) ◽  
pp. 119-127
Author(s):  
Ilnar A. Valeev ◽  
◽  
Irina V. Zhukova ◽  
Azat A. Girfanutdinov ◽  
◽  
...  

Analysis of the consumption of activated carbon on the international market showed sufficient demand for this topic, both for medical and for most industries. Sorbents are a large class of drugs that are able to excrete a wide variety of toxic substances from the body. The activated carbon market in the Russian Federation was focused on the military-industrial complex, due to which the range of goods was very limited. Due to the current situation, activated carbons produced by our industry are universal and, therefore, ineffective for specific tasks. Based on this, the problem of inexpensive and effective sorbents is very relevant and the lack of active coal reaches several tens of thousands per year. This problem is being solved for the most part by importing the product. The urgency of the problem poses the task of quickly introducing this type of installation and effectively calculating its technical parameters for subsequent manufacturing. The task of the engineering method of calculation is the operational calculation of the given source data, the design parameters of the apparatus. The possibility of using waste wood processing enterprises has shown that the use of this type of raw material is justified and effective. Both in terms of cost, and in terms of beneficial use of tree illiquid. Technical innovations and proven solutions used in the experimental setup will significantly intensify the pyrolysis process while improving product quality and reducing its cost. An algorithm for calculating the main technical parameters of the camera. It includes several blocks responsible for each parameter. Calculation of geometric parameters allows you to develop an installation of strictly the required geometric size based on the necessary raw materials needs. Aerodynamic calculation takes into account the whole process of preparing raw materials and allows you to select the necessary attachments strictly according to the required parameters. Thermal calculation allows you to select the materials of the chamber from the required temperature range required for more efficient raw materials production with the optimal characteristics.


2019 ◽  
Vol 43 (2) ◽  
Author(s):  
Michelle Ferreira da Silva Rimoli ◽  
Roberta Martins Nogueira ◽  
Stela Regina Ferrarini ◽  
Pryscila Machado de Castro ◽  
Evaldo Martins Pires

ABSTRACT Activated carbon is the name of a big group of materials that presents high degree of porosity and, consequently, an extended internal surface area, with physical and chemical adsorption properties. Innumerous raw materials can be used as precursors, especially biomass. The objective of this study was to obtain activated carbon from physical activation of the fruit of Brazil nut tree (“ouriço”) and to evaluate its physical and chemical properties in function of the differences between the temperatures and atmospheres of activation. The samples were carbonized at 3 different temperatures and the carbons were activated under atmosphere saturated by CO2 or steam. The results showed the influence of activation temperature and atmosphere on physicochemical characteristics of carbon. The carbon from woody Brazil nut seed capsule activated by CO2 and steam at different temperatures had a microporous profile, indicating its use to adsorb organic molecules of small dimensions. Basic characteristic was observed on samples and the carbon produced was thermally stable. Best quality was attributed to carbon activated by steam at 800 °C.


2016 ◽  
Vol 75 (1) ◽  
pp. 196-206 ◽  
Author(s):  
V. E. Pakade ◽  
O. B. Nchoe ◽  
L. Hlungwane ◽  
N. T. Tavengwa

The purpose of this study was to investigate the feasibility of activated carbons prepared from Macadamia nutshells as an efficient adsorbent for the removal of hexavalent chromium (Cr(VI)) from aqueous solutions. The activated carbon was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), CHNS analyzer and Brunauer–Emmett–Teller (BET). For effective removal of Cr(VI), the optimum parameters found were pH 2, 120 min of contact time and 0.2 g of sorbent. The adsorption data fitted well into the Freundlich model, suggesting a multilayer sorption process. The results demonstrated that Macadamia activated carbon could be used as cost-effective biosorbent for the treatment of aqueous solutions contaminated by Cr(VI) with an adsorption capacity of 22.3 mg g−1. The mode of removal involved adsorption and reduction of Cr(VI) to Cr(III).


1986 ◽  
Vol 18 (1) ◽  
pp. 55-66 ◽  
Author(s):  
H. Keirsse ◽  
F. Van Hoof ◽  
J. Janssens ◽  
A. Buekens

Man's natural water supplies are threatened by a large number of nonbiodegradable and toxic organic compounds. Proper environmental standards often can only be attained using tertiary treatment processes, such as adsorption on activated carbon. The latter is an expensive process, owing to the initial cost of activated carbon and the losses occurring during regeneration. Methods are being investigated at the Free University of Brussels for producing and activating carbon, using various types of waste as a raw material. Following materials have already been used : cacao hulls, sawdust, fruit stones, bark, and waste tyres. Both carbonization and activation have been conducted under the carefully controlled conditions of a fluidized bed reactor. The influence of the following process parameters has been investigated : pyrolysis temperature and time, activation temperature and time, and composition of the furnace atmosphere. The resulting activated carbons should exhibit the following qualities : high adsorption capacity and rate, good resistance to attrition, and possibility of regenerating the carbon. The properties of the carbon obtained have been evaluated by means of a number of standard tests (Iodine-index, BET-surface, Tannin-index, Methylene blue-index, and Phenol-index), and adsorption isotherms of phenol, pentachlorophenol, p. toluene sulphonate and dodecyl benzenesulphonate. In general the properties of the carbons obtained were comparable to those of commercial qualities. Some of the activated carbons tested will soon be evaluated using synthetic and real phenolic industrial wastewaters (1.5 % of phenol).


Sign in / Sign up

Export Citation Format

Share Document