Adsorption of dyestuffs from aqueous solutions with activated carbon I: Equilibrium and batch contact-time studies

2007 ◽  
Vol 32 (7-12) ◽  
pp. 759-772 ◽  
Author(s):  
Gordon McKay
Author(s):  
Leela Gopal ◽  
V. V. Hanuman ◽  
G. Chakrapani

Investigations were carried out for separation/pre concentration of uranium from aqueous solutions of different TDS using Powdered Activated Carbon (PAC). Parameters like amount of PAC, contact time, pH, volume of solutions and reagents for desorption were optimized. The sorption of uranium is more than 95% at pH 4-5 using 0.5 gram PAC with a contact time of 10 minutes.  The sorbed uranium on PAC is recovered using 0.8N HNO<sub>3</sub> and determined by LED Fluorimetry.  Method was successfully applied to ground water, sea water and brine water.  Methodology is simple, selective, cost effective with minimal skills. RSD of the method varies ± 6-14 %.


2019 ◽  
Vol 9 (18) ◽  
pp. 3732 ◽  
Author(s):  
Sahira Joshi ◽  
Manobin Sharma ◽  
Anshu Kumari ◽  
Surendra Shrestha ◽  
Bhanu Shrestha

This study aimed to develop magnetic Fe3O4/sugarcane bagasse activated carbon composite for the adsorption of arsenic (III) from aqueous solutions. Activated carbon (AC) was prepared from sugarcane bagasse by chemical activation using H3PO4 as an activating agent at 400 °C. To enhance adsorption capacity for arsenic, the resultant AC was composited with Fe3O4 particles by facile one-pot hydrothermal treatment. This method involves mixing the AC with aqueous solution of iron (II) chloride tetrahydrate, polyvinyl pyrrolidone (PVP), and ethanol. Batch adsorption experiments were conducted for the adsorption of As (III) onto the composite. The effects of pH, adsorbent dosage, and contact time on the arsenic adsorption were studied. The result showed that the composite could remove the arsenic from the water far more effectively than the plain AC. The highest percentage of arsenic removal was found at pH at 8, adsorbent dose of 1.8 g/L, and contact time of 60 min. Langmuir and Freundlich adsorption isotherm was used to analyze the equilibrium experimental data. Langmuir model showed the best fit compared to the Freundlich model with a maximal capacity of 6.69 mg/g. These findings indicated that magnetic Fe3O4/sugarcane bagasse AC composite could be potentially applied for adsorptive removal of arsenic (III) from aqueous solutions.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wedad A. Al-Onazi ◽  
Mohamed H.H. Ali ◽  
Tahani Al-Garni

Some agricultural byproducts are useful for solving wastewater pollution problems. These byproducts are of low cost and are effective and ecofriendly. The study aim was to investigate the possibility of using pomegranate peel (PP) and date pit (DP) activated carbon (PPAC and DPAC, respectively) as sorbents to remove Cd(II) and Pb(II) from aqueous solutions. Agricultural wastes of DPs and PPs were subjected to carbonization and chemical activation with H3PO4 (60%) and ZnCl2 and used as adsorbents to remove Cd(II) and Pb(II) from their aqueous solutions. The physical characterizations of PPAC and DPAC, including determination of surface area, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy, were performed. The following factors affected adsorption: solution pH, adsorbent dosage, initial metal ion concentration, and contact time. These factors were studied to identify the optimal adsorption conditions. The results showed that the maximum adsorptions of Cd(II) and Pb(II) were achieved at pH ranging from 6 to 6.5, 90 min contact time, and 0.5 g/L for PPAC and 1 g/L for DPAC dosage. Furthermore, the adsorption efficiencies for both Pb(II) and Cd(II) were higher for PPAC than for DPAC. However, the recorded Qmax values for PPAC were 68.6 and 53.8 mg/g for Pb(II) and Cd(II) and for DPAC were 34.18 and 32.90 mg/g for Pb(II) and Cd(II), respectively. The Langmuir isotherm model fit the adsorption data better than the Freundlich model. Kinetically, the adsorption reaction followed a pseudo-second-order reaction model, with qe ranging from 12.0 to 22.37 mg/g and an R2 value of 0.99.


NANO ◽  
2021 ◽  
pp. 2150054
Author(s):  
Zongli Ren ◽  
Zhao Yang ◽  
Zhongwei Zhao ◽  
Xuan Yang

Malachite green (MG) pollution has a negative impact on human health. At present, the method of removing it is inconvenient to operate and the cost is high, which has aroused widespread concern. In this study, MgO functionalized magnetic activated carbon (MgO-mAC) prepared by the sol–gel method was used to remove MG in water. The physical and chemical properties of MgO-mAC were tested by SEM, TEM, FTIR, XRD, BET and VSM. The effects of adsorbent dosage, solution pH, contact time, initial MG concentration and temperature on adsorption were studied by batch experiments. The adsorption kinetics data is well described by a pseudo-second-order model. The equilibrium data fits the Langmuir isotherm well. When the pH is 8 and the contact time is 360[Formula: see text]min, the maximum adsorption capacity of MG is 3809[Formula: see text]mg[Formula: see text]g[Formula: see text]. In thermodynamic studies, [Formula: see text], [Formula: see text], [Formula: see text], MG adsorption is an endothermic and spontaneous adsorption process. The current synthesis method is simple in operation and cheap in raw materials, which can greatly reduce the cost of synthesis. Hence, the MgO-mAC material will be an effective adsorbent for removing MG from aqueous solutions.


2019 ◽  
Vol 6 (2) ◽  
pp. 81-88 ◽  
Author(s):  
Dariush Naghipour ◽  
Abdoliman Amouei ◽  
Kamran Taher Ghasemi ◽  
Kamran Taghavi

Background: Metoprolol (MTP) with its low biodegradability is one of the most dominant micropollutant in the effluent of wastewater treatment plants. The aim of this study was to investigate the removal of metoprolol from aqueous solutions by the activated carbon prepared from pine cones. Methods: The pine cones were activated using thermal activation method. Characteristics of the adsorbent were determined using Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM). In this study, the influent of different parameters such as pH, contact time, initial concentrations of metoprolol, adsorbent dose, temperature, adsorption isotherms, and kinetics were investigated. Results: The maximum removal efficiency of MTP (89.2%) was obtained at pH=8.5, adsorbent dose=1.5 g, contact time=60 min, and initial concentration=50 mg/L. By increasing the adsorbent dose, the removal efficiency also increased, but the adsorption capacity decreased, however, by increasing the initial concentration, the removal efficiency decreased, but the adsorption capacity increased. The isotherm experimental data for metoprolol was best fitted using the Langmuir model, and kinetic data were better described by pseudo-second-order kinetic model. The thermodynamic study indicated that the adsorption of MTP by the adsorbent was feasible, spontaneous, and endothermic. Conclusion: MTP removal by the activated carbon prepared from pine cones showed that this natural adsorbent is appropriate for removal of metoprolol from aqueous solutions regarding cost, efficiency, and production method.


2018 ◽  
Vol 19 (4) ◽  
pp. 1097-1102 ◽  
Author(s):  
Abooalfazl Azhdarpoor ◽  
Leila Khosrozadeh ◽  
Mohammadreza Shirdarreh

Abstract Pollution of surface and ground waters with nitrate is a serious issue in many regions of the world. Therefore, this study attempts to investigate the extent of nitrate removal from aqueous solutions using a new complex of activated carbon. The effects of operating parameters such as pH of solution (3 to 9), adsorbent dosage (0.4 to 5 g in 50 mL), contact time (5 to 300 min) and initial concentration of nitrate (50 to 300 mg L−1) were studied. The highest efficiency of nitrate removal (95.4%) was related to application of modified activated carbon to a solution with pH of 7 and 100 mg L−1 nitrate concentration. Increasing the amount of modified activated carbon from 0.5 to 1 g in 50 mL promoted removal of nitrate from 82.6% to 94.1%. Furthermore, increasing contact time from 5 to 30 min improved removal efficiency from 76.6% to 92.3%. The obtained experimental data were compatible with the Langmuir isotherm model. In general, the results demonstrated that employing Fe3+-modified activated carbon can be considered as a new method of nitrate removal from aqueous solutions due its convenience, safety and high efficiency.


Author(s):  
Tayyba Aftab ◽  
Naeem Abbas ◽  
Muhammad Irfan ◽  
Farah Deeba ◽  
Naz Imtiaz ◽  
...  

The objective of the present study was to investigate the adsorption of benzoic acid (BA), valeric acid (VA), propionic acid (PA) and butyric acid (BUA) from aqueous solutions at different dosing rate on the surface of activated carbon. Different trials were taken in order to determine the interaction betweenthe carbon surface and adsorbent species. The residual concentration of acids was calculated by the titrimetric method. Maximum adsorption capacity was found to be 93.37% at dosing rate of 8.75 g for BUA and minimum adsorption capacity was measured as 41.47% at dosing rate of 0.69 g for VA. Keeping the same contact time and mass of activated carbon (2.8 g), the adsorption capacity increases with increasing dosing rate. 


2015 ◽  
Vol 773-774 ◽  
pp. 1246-1250
Author(s):  
Zalilah Murni Yunus ◽  
Norzila Othman ◽  
Rafidah Hamdan ◽  
Nurun Ruslan Najwa ◽  
Norfarihah Abu Kasin ◽  
...  

In this study, activated carbon (AC) was produced from honeydew rind, a low-cost agricultural by-product, by chemical activation using H2SO4as an activator was used as an adsorbent for the removal of zinc ions from aqueous solutions. Preparation method on the effect of surface morphology at different carbonization temperatures 450°C, 470°C, 490°C and 510°C was studied. The AC was characterized using FEM-SEM, FTIR and TG. Batch adsorptions were carried out to optimize different variables such as zinc concentration, contact time, pH and biosorbent amount. The results from AAS analysis showed that the maximum adsorption of zinc onto honeydew rind AC was achieved at the conditions of pH 7.5, 1.5g biosorbent amount, 1000mg/L initial zn concentration and 45min contact time. The maximum metal uptake and maximum removal were 66.55mg/g and 99.79% respectively.


2015 ◽  
Vol 1088 ◽  
pp. 533-539
Author(s):  
Su Hong Chen ◽  
Jian Zhang ◽  
Zhi Jun Han ◽  
Cheng Lu Zhang ◽  
Qin Yan Yue

This study investigates the potential use of activated carbon prepared from Phragmites Australis for the removal of 2,4-dichlorophenol (DCP) and Rhodamine-B (RB) from aqueous solutions. P. Australis activated carbon (PAAC), a new adsorbent, was prepared from P. Australis by H3PO4 activation. Batch adsorption studies were conducted to evaluate the effect of various parameters such as pH, adsorbent dose, contact time and initial 2,4-DCP and RB concentration. Accordingly, the activated carbon developed in this study is effective and practical for utilization in wastewater treatment for 2,4-DCP and RB removal.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.


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