Activated carbon (AC) was prepared from hazelnut shells using two steps of carbonization followed by steam activation. Methylene blue dye was used as a probe for evaluation of the prepared activated carbon. In order to have a better comparison, a commercial grade of activated carbon (powdered) obtained from the Merck Company has also been used in this research as standard. In this paper we have also investigated adsorption of mercuric ion by impregnated activated carbon with different chemicals. It was found that sorption of mercuric ion from aqueous solution by activated carbon can be improved by impregnating AC with suitable chemicals such as sulfur-containing compounds.
Novel pollutant control equipment, which were called integrated pollutant control equipment, consisted of bag filters and activated carbon (AC) absorbers. The AC absorbers were put forward to absorb the additional pollutants between the old and new emission standards to satisfy Chinese emission standards. The absorbers could be fixed (mobile) bed, annular column, or fluidized bed. The numerical method was employed to simulate the inner flow fields in the integrated equipment. The results show that annular column absorbers can make the flow field more uniform than the others, but its absorption duration has to be discussed. The mobile bed and the annular column absorbers are recommended. The fluidized bed absorber can be applied only if strong heat and mass transfer during absorbtion are needed.
The present study looks at the adsorption of polyethylene glycol onto activated carbon with the different molecular weight. The amount of PEG adsorbed on activated carbon depends on temperatures and pH. The adsorption capacities were determined through the adsorption isotherms. The results of the adsorption isotherm and kinetic studies show that the adsorption process can be well described with the Langmuir model. After linearization of the Arrhenius equation the activated energy had been estimated.
Chlorine dioxide is widely used as a pre-oxidant and disinfectant but it has the disadvantage of inducing the formation of the inorganic by-products chlorites and chlorates. It is therefore of interest to decrease the chlorine dioxide demand and oxidation, and/or removal of natural organic matter (NOM). The objective of this study was to estimate the efficiency of the adsorption of oxidised and unoxidised NOM on granular activated carbon (GAC) filters. For this purpose, three pairs of columns filled with three types of GAC were set. The study showed that the efficiency of adsorption increased after the pre-oxidation of NOM with ClO2. GAC filters also efficiently removed the unwanted inorganic by-products.
The influence of modification by pre- and post-treatment of active carbons with ammonia on adsorption abilities from liquid and gas phases has been tested. Carbon materials with different surface chemistry were obtained by chemical activation of Polish brown and subbituminous coal. The products were microporous active carbon samples of well developed surface area (SBET from 1579 to 2,922 m²/g), containing from 0.3 to 7.4 wt% of nitrogen. The results obtained in our study have, moreover, proven that a suitable choice of the modification procedure for coals can produce activated carbons with high capacity of iodine adsorption (to 2,100 mg/g) and high nitrogen dioxide adsorption ability, reaching to 55.1 mg NO₂/g.
This study was aimed for removal of phenol from water using activated carbon synthesize from avocado kernel seeds by adsorption onto it. For adsorption process cleaned and washed avocado kernel seeds (Persea americana) were dried at 100°C in an oven overnight and carbonization was carried out by increasing the furnace temperature at a rate of 5 °C/min to a final temperature of 800 °C for 160 minutes. Then, the activated carbon was powdered and sieved, washed with distilled water until the solution pH reached 7.0. Optimization of activated carbon was performed through effects of solution pH, contact time; initial phenol concentration and temperature of the adsorption. The kinetic studies of the adsorption process were achieved by verifying various models and the data obtained was best fitted to pseudo-second-order kinetic model. The isotherms models were analyzed with Langmuir, Freundlich and Temkin to validate the adsorption process. It was found that Langmuir model was best fitted to the obtained result for both adsorbents.
The purpose of this study is to assess the efficiency of removal of phenoxyacetic pesticides from water by means of activated carbon sorption. The sorbents used in this study (WD-extra, CWZ-22, NP-5) were produced by GRYFSKAND, Ltd., Hajn–wka. The first step of the study was the steady-state test of the suitability of selected sorbents in herbicide removal. The steady-state test was conducted according to the Chemviron Carbon methodology. Its aim was to determine the Freundlich isotherm and sorption capacity, and to select the best sorbent in static conditions. The residual concentration of the contaminant in the filtrate was determined using relevant analytical techniques. Also, the concentration of phenoxyacetic acid was identified by TLC and HPLC methods. On the basis of the results obtained it was concluded that the best sorbents of phenoxyacetic acid from water in steady-state conditions are CWZ-22 and NP-5. No significant difference was noticed in the removal process of the whole group of phenoxyacetic acids by sorption.
Salix viminalis is a plant widely applied as a source of renewable energy. It is also known as a possible biofilter for extraction of soil and water contaminants. The current study presents preliminary results on heavy metal ion uptake (Cu²⁺, Cr³⁺, Zn²⁺) by living plants of Salix viminalis. In relation, a new concept of further utilization of ion-enriched wood is proposed as raw material for carbon-based catalyst fabrication by heat treatment of metal-impregnated partly dried biomass. Particular attention is paid to the distribution of heavy metal ions along the plant stem, since one intends to exploit natural transport and distribution of metal ions in living plants. The uptake from water solution and subsequent accumulation of ions in plant tissues was investigated regarding the form in which ions were present in water solution. Accumulation rates were higher for ion complexes with EDTA in comparison to aqua complexes.
Buraczany wywar melasowy jest produktem ubocznym powstającym podczas wytwarzania etanolu z melasy buraczanej. Jego ciemnobrązowa barwa jest efektem obecności karmeli, melanoidyn oraz produktów alkalicznej degradacji inwertu. Ciemno-brązowe zabarwienie wywaru nie jest usuwane metodami biologicznymi. Celem prezentowanych badań było porównanie zdolności i wydajności dekoloryzacji buraczanego wywaru melasowego na złożu glinki haloizytowej z wynikami uzyskanymi na złożach pylistego węgla aktywnego. Zbadano wpływ pH i stężenia wywaru, czasu reakcji z nośnikiem oraz ilości badanego złoża sorpcyjnego na skuteczność odbarwiania wywaru melasowego.
Chemical and elemental composition of selected lignocellulose materials was determined and next the materials were used to produce a series of active carbons for electrochemical hydrogen adsorption under strictly repeatable conditions. Chemical activation (900oC) with the application of KOH (4:1) was used for the development of the porous structure. Prior to activation all materials were pyrolysed at 700oC applying a slight temperature increase rate (3oC/min). Produced active carbons had diverse parameters of the porous structure and considerable BET surface areas ranging from 2178 to 2815 m2/g. Experiments showed feasibility of electrosorption of hydrogen on the surface of active carbons produced from commonly available, cheap and frequently waste lignocellulose materials. The type of the applied precursor has a significant effect on the development of the porous structure and hydrogen sorption. The highest hydrogen sorption value of Hc=1.91% weight and Hc=1.90% weight were obtained on AC from cherry stone shells and from oak wood.
Chemical composition of lignocellulose materials and porous structure of activated carbons. Chemical and elemental compositions of selected lignocellulose materials were determined and next a series of activated carbons was produced from these materials under strictly repeatable conditions. The chemical activation method (900oC) using KOH (4:1) was applied for the development of the porous structure. Prior to activation all raw materials were subjected to pyrolysis at 700oC using a slight temperature increase rate (3oC/min). Produced activated carbons had varied porous structure parameters and considerable BET surface areas ranging from 2026 to 2884 m2/g. It was shown that the type of the applied precursor has a significant effect on the development of the porous structure.
The paper describes results of vegetative tests of activated carbon as a detoxiсant of herbicide remains in soil on eight varieties of summer rapeseed. The tests were performed with the purpose to align soil fertility on different breeding and test sites. The research is based on attempts to apply coal absorbent as a means of soil detoxication to neutralize herbicides remains in the process of oilseed brassica crops breeding. Several summer rapeseed varieties were used as research objects. Similar approaches have not encountered in literature references available.
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