Water Treatment by Means of Activated Carbon, Prepared from Locally Available Waste Materials (II)

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).

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.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Wan Muhammad Hilmi Wan Ibrahim ◽  
Mohd Hazim Mohamad Amini ◽  
Nurul Syuhada Sulaiman ◽  
Wan Rasidah Wan Abdul Kadir

AbstractHeavy metal contamination in water is happening worldwide. Adsorption using activated carbon is a common choice for cleaning the wastewater. The drawback of activated carbon is the higher cost of production due to the need for high heat in the process. This work investigated on activated carbon produced from the abundantly available Leucaena leucocephala biomass in order to reduce the cost of raw material. The biomass was chemically activated at different activation temperatures. The produced activated carbon was characterized using SEM, FT-IR, surface analyzer, and TGA. Isothermic and thermodynamic studies were done to evaluate the adsorption properties of the activated carbon. It was found out that higher surface area can be obtained using the higher activation temperature. Higher NaOH to carbonized sample ratios also resulted in higher surface area for all activation temperatures, which are 662 m2g-1 for 700 °C activation temperature, 735 m2g-1 for 750 °C, and 776 m2g−1 for 800 °C. Isothermic studies showed that all of the activated carbon that is produced from Leucaena leucocephala biomass are fit to the Langmuir isotherm, regardless of any activation temperature. Lastly, the thermodynamic study found out the adsorption process is endothermic, reflected by the positive value of ΔHo. It can be concluded that Leucaena leucocephala is a promising alternative material for producing activated carbon.


2015 ◽  
Vol 730 ◽  
pp. 271-274
Author(s):  
Yan Kun Cheng

In urban sludge and sawdust as raw material,using zinc chloride activation method in the preparation of activated carbon under different operating conditions, through the detection of specific surface area activated carbon sample and methylene blue adsorption value and the iodine adsorption value, studies the impregnation ratio, activation time and activation temperature operating conditions affect the performance of activated carbon sample. Through to the physical and chemical modification of activated carbon,To the preparation of activated carbon adsorption purification treatment experiment was carried out in the discharge of sewage.


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.


Holzforschung ◽  
2015 ◽  
Vol 69 (6) ◽  
pp. 777-784 ◽  
Author(s):  
Galina Dobele ◽  
Aleksandrs Volperts ◽  
Galina Telysheva ◽  
Aivars Zhurinsh ◽  
Daria Vervikishko ◽  
...  

Abstract The thermocatalytical synthesis conditions required for the activation of wood charcoal with NaOH in terms of the formation of pores in its structure were investigated. The present study was conducted to explore the potential application of activated carbons as electrodes in supercapacitors with organic electrolyte. The total pore volume and micro- and mesopore ratio were controlled by the activation temperature and alkali addition rate. The working characteristics of carbon electrodes (e.g., specific capacity and ohmic losses) in supercapacitors are strongly influenced by the properties of the pores in their structures. Herein, the optimal ratio of raw material to activator and activation temperature are established: an increase in the ratio of NaOH to carbonizate rate by a factor of 2 and setting the synthesis temperature at 700°C positively influence the electrochemical characteristics of supercapacitors and provide them with specific capacities of up to 160 F g-1.


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.


2003 ◽  
Vol 21 (5) ◽  
pp. 463-473
Author(s):  
J. Barkauskas ◽  
A. Vinslovaite

The adsorption of polyvinyl alcohol (PVA) on activated carbons was studied in aqueous solutions. Each batch of activated carbon produced was obtained via a definite number of technological operations using wood as the raw material. The adsorption process was studied using a gel chromatography technique with potentiometric titrations being employed for evaluating the chemical composition of the activated carbons produced. The data obtained from the various activated carbon samples were compared to ascertain the adsorption mechanism. It was concluded that water molecules had a limited influence on the competitive process of polymer adsorption. A rather pronounced negative correlation between the number of phenol functional groups and PVA adsorption capacity was observed, indicating that these groups hindered the adsorption process. Assumptions concerning the role of phenol functional groups were made, taking into account not only the surface heterogeneity but also changes in the electron density of the graphene layers in the carbon substrate.


2014 ◽  
Vol 881-883 ◽  
pp. 579-583 ◽  
Author(s):  
Ling Zhi Chen ◽  
Dong Xu Miao ◽  
Xiao Jie Feng ◽  
Jian Zhong Xu

Activated carbons (AC) were produced by chemical activation with potassium hydroxide (KOH) at 800°C from chars that were carbonized from reedy grass leaves at 450°C in N2atmosphere. The effects of the weight ratio of KOH/char ( impregnation ratio), activation temperature and duration time were examined. Adsorption capacity was demonstrated with iodine number. BET surface area, pore volume and pore size of activated carbons were characterized by N2adsorption isotherms. The maximum surface area and iodine number of the AC was 1100 m2/g and 1080 mg/g produced at 800°C for2h and impregnation ratio is 4:1.The characteristics of activated carbons were determined by Infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Thermal gravimetry (TG/DTA) analysis of raw material was carried out.


2010 ◽  
Vol 6 (2) ◽  
pp. 1017-1023
Author(s):  
N.R.A. El-Mouhty ◽  
H. M. H. Gad ◽  
A. Y. El-Naggar

This study investigated the applicability of chemically (phosphoric acid) activated bagasse pith and date pits in the adsorption of water pollutants. The textural properties including porous parameters, monolayer equivalent surface area, total pore volumes, average pore radius, Methylene blue number and other physic-chemical characterization were investigated. The activated carbons were analyzed for moisture content, ash content. Ultimate analysis was done by using CHNS analyzer (Cairo University, Micro-analytical Center). To investigate the effect of phosphoric acid on the raw material, thermo gravimetric analysis (TGA) and differential thermo gravimetric (DTG) recordings were determined. The adsorption of heavy metals as pollutants, including Co, Sr, Cu, Cs, Pb, Cd, Ni, Fe, Zn, was studied in a batch experiments. Comparison of date pits activated carbon with commercial activated carbon was done, and the results indicated that using of prepared activated carbon for removal of Co, Sr, Cu, Cs, Pb, Cd, Ni,  Fe, Zn was  more effective than commercial activated carbon.


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