activated carbon

VOCs are harmful air pollutants that must be detected, monitored and eliminated. Adsorber tubes are standard tools for this task, specifically activated carbon tubes with high adsorption and selectivity. This research aims to compare the structural and functional characteristics of domestically produced activated carbon tubes with the conventional commercial ones for sampling toluene, a volatile organic compound.

The characteristics of each adsorbent, such as structure, morphology, porosity, and element composition, were examined by SEM photography, BET testing, and EDAX analysis. The central composite design (CCD) method was employed to investigate the adsorption properties of the adsorbents. The input concentration and readsorption time of the samples were the variables considered in this study. Additionally, a field phase of personal air sampling was performed to evaluate the effectiveness of adsorbent tubes.

SEM and BET analyses indicated that the porous structure of domestic activated carbon was comparable to the model produced by SKC. EDAX analysis detected a minor impurity (1%) in the domestic activated carbon adsorbent. The adsorption performance was significantly influenced by the variations in readsorption time and pollutant input concentration. The accuracy and precision of the performance of the domestic adsorbent tube were obtained as 90.77% and 91.76%. The field phase results demonstrated that the amount of pollutant adsorbed in the SKC-activated charcoal adsorber did not differ significantly during 0 to 30 days. However, the domestic adsorber showed a significant difference in the same period. The overall performance of the two adsorbers did not exhibit a significant difference between 0 and 30 days.

Despite minor structural differences, the adsorption efficiency of toluene by domestic adsorbent tubes in sampling high concentrations is very similar to its commercial type. However, it is not recommended for use in low-concentration environments (10 ppm and less).

The emergence of new chemical industries has caused the release of a large amount of organic compounds including industrial by-products, insecticides and other chemicals in nature. Endocrine disrupting compounds are a known group of hazardous and complex pollutants that occurs in wastewater and water sources worldwide, either naturally or as a result of human activities. In this study, an attempt is made to remove diethyl phthalate from water environments by the advanced oxidation process of ozonation in the presence of activated carbon produced from the Skanbil tree.

methods and Materials:

 This experimental study was done in a reactor with a volume of 100 mL. In each experiment, diethyl phthalate solution was poured into the pilot in the desired concentration and ozone with 0.8 mg/min dose was injected into the reaction solution. Process parameters included pH (2-8), reaction times (2 to 30 min), pollutant concentration (5-25 mg/L) and catalyst dose (0.025-0.1 gram). In the end of each experiment, the sample was withdrawn from the pilot and analyzed using HPLC to determine the residual diethyl phthalate.

The results showed that under optimal conditions of pH = 6.8, ozone dose = 0.8 mg/min and contact time = 30 minutes, ozonation could only remove 60% of diethyl phthalate, and under the same conditions, catalytic ozonation with 0.075 g of carbon obtained from the skanbil tree could remove 94% of diethyl phthalate.

The results of this research showed that catalytic ozonation with carbon obtained from the wood waste of shanbil tree can be used as an advanced treatment method.

Today, heavy metals and organic compounds such as dyes are among the most dangerous pollutants that have entered surface and groundwater and threaten human health. The aim of this study was to investigate the removal of reactive orange 3R dye and chromium by adsorption separately and simultaneously activated carbon.

In this study, Sycamore carbon modified with NH4Cl was used to remove contaminants.  Effect of variables such as pH (2-9), adsorbent concentration (0.5-1-0 g/L), pollutant concentration (10-50 mg/L) and contact time (2-40 minutes) on dye and chromium removal (simultaneously and separately) were calculated. Freundlich and Langmuir adsorption isotherm models and kinetics were also investigated.

The results of this study showed that activated carbon at pH = 4, 0.4 g/L adsorbent at 15 min contact time has the best removal conditions for both paint and chromium contaminants. Under optimal conditions, activated carbon was able to remove 72% of chromium and 84% of dye separately and 59% of chromium and 67% of dye simultaneously in solution at a concentration of 25 mg/L. The study of adsorption isotherms also showed that the experiments were more consistent with the Freundlich model.The absorption kinetics follows Pseudo-second order equations.

According to the results, this adsorbent has a good performance in separate and simultaneous removal of paint and chromium and can be used to treat wastewater containing organic and inorganic contaminants.

 Heavy metals such as chromium are among the most common pollutants commonly found in high concentrations in industrial wastewater. They can damage aquatic environments and endanger the health of living organisms, especially humans. This study aims to determine the optimal removal of hexavalent chromium by magnetized activated carbon (AC / Fe3O4) from aqueous solutions.

 The structure and properties of AC/Fe3O4 were investigated by FESEM, FTIR, BET, and VSM techniques. The effect of solution pH parameter (3-11), initial concentration of hexavalent chromium (10-50) mg/L, and adsorbent dose (0.5-2) g/L on hexavalent chromium removal efficiency along with isotherm and kinetics studies was investigated. The concentration of hexavalent chromium was determined by direct reading at 540 nm with a spectrophotometer.

 The optimal conditions for maximum removal of hexavalent chromium at pH=3, contact time of 60 minutes, and adsorbent dose of 1.5 g/L were obtained with an initial concentration of hexavalent chromium of 30 mg/L. The isotherm and kinetics study showed that the experimental data followed the Langmuir and pseudo-second-order kinetics.

 Under desirable conditions, the maximum capacity of AC/Fe3O4 adsorption increased to 21.14 mg/g. The present study illustrated that AC/Fe3O4 could be used as an adsorbent to remove chromium from aqueous solutions.

Volatile organic compounds are the most common pollutants in the air, and among them, toluene is the most common form, which is toxic resulting in liver and kidneys damages. Regarding the fact that this compound is widely used in various chemical industries, implementing an efficient method for controlling its concentration is of great importance. The comparative survey of the capability of virgin activated carbon with the one immobilized by pseudomonas putida PTCC, and also the performance of the biofiltration system involving pseudomonas putida bacteria immobilized on activated carbon for the adsorption and degradation of toluene from the air as well as regenerating the activated carbon were aimed in the present study.

The microbial growth process was initiated by incubation of pre-culture in a rotary shaker, at 150rpm overnight. After 4 days, the strain pseudomonas putida, PTCC No: 1694 was immobilized on a certain amount of activated carbon. Subsequently, an airstream containing toluene was introduced into the biofilter, and the inlet and outlet concentrations of toluene were measured.

The obtained results illustrated that the increase in the volume of the media and decrease in the gas flow rate significantly enhances efficiency. The great performance of the biofilter was confirmed by the high efficiency of the immobilized activated carbon which exhibited 89% yield during 14 hours. On the second cycle, the biofiltration system was able to adsorb toluene at an efficiency of 81%, while the virgin activated carbon exhibited far less efficiency with the value of 28%.

The provided results demonstrated the feasibility and reusability of the biofilter system for toluene removal. The proposed technique also extends the activated carbon’s capacity, which could be a potential solution to re-use the activated carbon in industrial applications.

Antibiotics, comprising a significant amount of pharmaceutical compounds, are used as human and veterinary treatments . these antibiotics come to appear as contaminantoin soil, surface water, groundwater, and even drinkingwater.Advanced oxidation processes such as catalytic ozonation are effective to remove the antibiotics form water and wastewaterThe aim of this study was to investigate the efficiency of Catalytic Ozonation Process for tetracycline antibiotics removal from contaminated waters

In this design, an ozonation pilot with a volume of 200 cc was used. In each experiment, the tetracycline solution was poured into the desired concentration, the pH of the sample was adjusted with sulfuric acid and NaOH. At different times of 5 to 30 minutes and different pHs of 2 to 10 ozonation was performed at the dose of 0.8 mg/min. Then, under these conditions, ozonation was performed in the presence of activated carbon catalyst and a sample was discharged from the pilot and analyzed (HPLC) to determine the remaining tetracycline.

The results showed that under optimum conditions of pH= 8 and ozone dose of 0.8 mg / min and contact time of 30 minutes ozonation only eliminated 59% of tetracycline and in the same conditions catalytic ozonation with 0.01 g/L carbon. The Calligonum comosum tree was able to remove 100% tetracycline in 30 minutes.

The results of this study showed that carbon catalyzed ozonation from wood Calligonum comosum waste can be used as an advanced treatment method.

Ammonia is a colorless gas with a pungent and corrosive odor that can cause serious damages to human health and the environment. Ammonia is used in the industries of pharmacology, tanning, and silvering mirrors and the production of military explosives. This study aimed to investigate the efficiency of inexpensive adsorbent obtained from the walnut shell in the surface absorption of ammonia from water and the parameters affecting it.

In this quasi-experimental interventional study, charcoal of walnut shell was used and the effects of carbonization temperature, pH, ammonia concentration, adsorbent dose, and contact time on the adsorption of ammonia from the aqueous medium were investigated. Ammonia concentration was measured by a spectrophotometer at 640 nm. More than 712 samples were analyzed for this study.

In this study, the highest efficiency of ammonia removal from an aqueous medium was obtained at optimal pH 8, carbonization temperature of 850°C, and adsorbent dose of 20 g/l. According to the obtained adsorption capacity, the optimal concentration for ammonia removal was considered 60 mg/l. The results showed that the experiments followed the Freundlich isotherm (R²=0.9949). Kinetic studies also indicated a higher correlation with the first-order equation.

Based on the results of this study, it can be stated that the adsorbent obtained from the walnut shell, as a natural adsorbent, is able to remove a relatively desirable amount of ammonia from aqueous medium and is recommended for other environmental pollutants due to its high adsorption capacity.

Access to safe water is critical for protecting human health. Turbidity is one of the main physical parameters that affect the quality of water from both health and aesthetical points of view. Therefore, waters should be treated based on the standards set for turbidity before consumption. This study was performed to determine the performance of a bench-scale baffled filter system for removing the turbidity, microbial population, and total organic carbon (TOC) from the contaminated water.

  A lab-scale Plexiglas baffled filter consisting of five compartments with a total working volume of 2 L was designed and constructed. The polyurethane foam cubes were used as filter media. The effect of turbidity (10, 50, and 100 NTU) and surface overflow rate (SOR: 7.5, 10 and 15 m/h) was investigated on the performance of the developed system.

A direct relationship between turbidity, TOC, and microbial density was observed in the inlet water. The efficiency of the baffled filter in the removal of turbidity and the period of the filter operation run both enhanced as the SOR was either decreased or the inlet turbidity was increased. In addition, almost complete removal of TOC from the inlet water was noticed.

The results of the present study indicated that the baffled filter system with sponge media can be a novel and effective method for the removal of turbidity, microbial contaminants and TOC from the natural surface water.

Due to the water shortages and the presence of industrial pollutants in water resources, wastewater treatment, especially colored wastewater, is essential. The aim of this study was to treat wastewater containing Methylene Blue dye using activated carbon nanocomposite/zinc oxide nanoparticles (ZnO/AC) obtained from canola oil waste by green method.

In the present study, the effect of different parameters (pH, Methylene Blue concentration, adsorbent amount, temperature and contact time) on the adsorption of Methylene Blue was investigated. Design of Experiment 7 software (Response Surface Method (RSM)) was used to evaluate the influence of various parameters on Methylene Blue removal.

The results of the predicted experiments showed that the highest adsorption of Methylene Blue is at pH = 10, temperature 70 °C, contact time of 50 min, initial adsorption concentration of 10 mg/ L and adsorbent amount of 0.05 g. Under optimal conditions, ZnO/AC adsorbent was able to remove 98.22% of Methylene Blue from the aqueous medium.

Appropriate to the high potential of ZnO/AC nanocomposite in the removal of Methylene Blue pigment, it can be a good candidate for the removal of dye contaminants and wastewater treatment of textile factories.

This study was conducted for the first time to produce activated carbon (AC) from Milkvetch wood by physical activation in order to achieve the maximum adsorbent capacity in adsorption of dye. The aim of this study was to remove acid orange 7 (AO7) dye using AC produced by physical activation with nitrogen gas.

AC activation was performed by physical method using nitrogen gas at 700°C. Scanning electron microscopy and isotherm technique were used to determine the structural characteristics of the adsorbent. The effect of operating parameters was investigated. The isotherms and kinetics of the dye adsorption were also studied.

The synthesized AC-700°C sample had a specific surface area and a total pore volume of 774 m2/g and 181.49 m3/g, respectively. The maximum adsorption of dye was 57.125 mg/g (removal efficiency 91.4%) that occurred at pH= 3, 0.04 g absorbent in 50 ml of solution, and 50 mg/l of dye in 75 min. The adsorption data followed the Langmuir adsorption isotherm model and the pseudo-second order model kinetics. Also, the ability to reuse the adsorbent using the heating method showed that the synthesized adsorbent can be used for three consecutive times with good performance. Correlation coefficients (R2) for genetic program and neural network were 0.98 and 0.99, respectively, indicating the agreement of laboratory data with the models.

The as-prepared AC by physical activation has a high potential for adsorption of AO7 dye from aqueous solutions.

The presence of natural organic matter in water sources creates various problems, especially in common water treatment process. These compounds cause unfavorable taste and odor in water and are among the most important precursors of water disinfection by-products. This study was carried out to evaluate the efficiency of activated carbon (AC) and activated carbon modified with ZnO nanoparticles (AC-ZnO) in removal of humic acid (HA) from aqueous solutions.

In the present experimental study, the removal of HA with AC or AC-ZnO was discontinuously studied as a function of pH, contact time, HA concentration, and absorbent dose. The structure of absorbents and their morphology were investigated by FTIR, SEM, XRD and pHpzc techniques. The HA was measured using spectrophotometer at the wavelength of 245 nm. Absorption isotherm was determined by using Langmuir and Froundlich models and absorption kinetics by pseudo-first and pseudo second-order models.

The efficiency of removing HA had a direct relationship with absorbent dose and inverse relationship with pH and HA concentrations. The optimal removal rate of HA for 1.6 g/L dose of AC or AC-ZnO were reached to 82.44 % and 96/26%, respectively, in HA concentration of 50 mg/L and contact time of 40 minutes

The removal rate was considerably higher for AC-ZnO than AC, which indicates the effective role of nanoparticulate stabilization on activated carbon. As a result, the method of nanoparticulate stabilization on activated carbon can provide an effective and very efficient adsorbent and appropriate alternative to remove humic acid from aqueous media.