scholarly journals EXPERIMENTAL INVESTIGATION ON CHROMIUM(VI) REMOVAL FROM AQUEOUS SOLUTION USING ACTIVATED CARBON RESORCINOL FORMALDEHYDE XEROGELS

2016 ◽  
Vol 56 (5) ◽  
pp. 373-378 ◽  
Author(s):  
Eghe A. Oyedoh ◽  
Michael C. Ekwonu
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Metal Ion ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Resorcinol Formaldehyde ◽  
Freundlich Isotherms ◽  
Chromium Vi ◽  
Endothermic Process ◽  
Best Fit

The adsorption of chromium(VI) metal ion in aqueous solutions by activated carbon resorcinol formaldehyde xerogels (ACRF) was investigated. The results showed that pore structure, surface area and the adsorbent surface chemistry are important factors in the control of the adsorption of chromium(VI) metal ions. The isotherm parameters were obtained from plots of the isotherms and from the application of Langmuir and Freundlich Isotherms. Based on regression analysis, the Langmuir isotherm model was the best fit. The maximum adsorption capacity of ACRF for chromium (VI) was 241.9 mg/g. The pseudo-second-order kinetic model was the best fit to the experimental data for the adsorption of chromium metal ions by activated carbon resorcinol formaldehyde xerogels. The thermodynamics of Cr(VI) ions adsorption onto ACRF was a spontaneous and endothermic process.

Extraction of Heavy Metals from Aqueous Medium by Husk Biomass: Adsorption Isotherm, Kinetic and Thermodynamic study

2019 ◽  
Vol 233 (2) ◽  
pp. 201-223 ◽  
Author(s):  
Khalida Naseem ◽  
Rahila Huma ◽  
Aiman Shahbaz ◽  
Jawaria Jamal ◽  
Muhammad Zia Ur Rehman ◽  
...  
Keyword(s):  
Metal Ions ◽  
Aqueous Medium ◽  
Contact Time ◽  
Metal Ion ◽  
Adsorption Process ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Adsorption Sites ◽  
Order Kinetic Model

Abstract This study describes the adsorption of Cu (II), Co (II) and Ni (II) ions from wastewater on Vigna radiata husk biomass. The ability of adsorbent to capture the metal ions has been found to be in the order of Ni (II)>Co (II) and Cu (II) depending upon the size and nature of metal ions to be adsorbed. It has been observed that percentage removal of Cu (II), Co (II) and Ni (II) ions increases with increase of adsorbent dosage, contact time and pH of the medium but up to a certain extent. Maximum adsorption capacity (qmax) for Cu (II), Co (II) and Ni (II) ions has been found to be 11.05, 15.04 and 19.88 mg/g, respectively, under optimum conditions of adsorbent dosage, contact time and pH of the medium. Langmuir model best fits the adsorption process with R2 value approaches to unity for all metal ions as compared to other models because adsorption sites are seemed to be equivalent and only monolayer adsorption may occur as a result of binding of metal ion with a functional moiety of adsorbent. Pseudo second order kinetic model best interprets the adsorption process of Cu (II), Co (II) and Ni (II) ions. Thermodynamic parameters such as negative value of Gibbs energy (∆G°) gives information about feasibility and spontaneity of the process. Adsorption process was found to be endothermic for Cu (II) ions while exothermic for Co (II) and Ni (II) ions as signified by the value of enthalpy change (∆H°). Husk biomass was recycled three times for removal of Ni (II) from aqueous medium to investigate its recoverability and reusability. Moreover V. radiata husk biomass has a potential to extract Cu (II) and Ni (II) from electroplating wastewater to overcome the industrial waste water pollution.

scholarly journals Microwave-assisted preparation of manganese dioxide modified activated carbon for adsorption of lead ions

2020 ◽  
Author(s):  
Heng Yan ◽  
Wenhai Hu ◽  
Song Cheng ◽  
Hongying Xia ◽  
Quan Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Manganese Dioxide ◽  
Microwave Heating ◽  
Metal Ion ◽  
Adsorption Mechanism ◽  
Lead Ions ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Fast Heating

Abstract In this study, manganese dioxide was evenly distributed on the surface of activated carbon (AC), and the porous structure of AC and the surface functional groups of manganese dioxide were used to adsorb the heavy metal ion Pb(II). The advantages of microwave heating are fast heating and high selectivity. The mole ratio control of the AC and MnO2 in 1:0.1, microwave heating to 800 °C, heat preservation for 30 min. The maximum adsorption capacity of the MnO2-AC prepared by this method on Pb(II) can reach 664 mg/L at pH = 6. It can be observed by SEM that manganese dioxide particles are dispersed evenly on the surface and pore diameter of AC, and there is almost no agglomeration. The specific surface area was 752.8 m2/g, and the micropore area was 483.9 m2/g. The adsorption mechanism was explored through adsorption isotherm, adsorption kinetics, FTIR, XRD, XPS. It is speculated that the adsorption mechanism includes electrostatic interaction and specific adsorption, indicating that lead ions enter into the void of manganese dioxide and form spherical complexes. The results showed that the adsorption behavior of Pb(II) by MnO2-AC was consistent with the Langmuir adsorption model, the quasi-second-order kinetic model, and the particle internal diffusion model.

scholarly journals Equilibrium, kinetic and thermodynamic studies on methylene blue adsorption by Trichosanthes kirilowii Maxim shell activated carbon

2019 ◽  
Vol 21 (4) ◽  
pp. 89-97 ◽  
Author(s):  
Yuqi Wang ◽  
Yanhui Li ◽  
Heng Zheng
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
Kinetic Studies ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Koh Activation ◽  
Order Kinetic ◽  
Freundlich Isotherms ◽  
Adsorbent Surface ◽  
Trichosanthes Kirilowii

Abstract New kind of adsorbent was produced from Trichosanthes kirilowii Maxim shell. The KOH activation technology for preparation of Trichosanthes kirilowii Maxim shell activated carbon (TKMCK) was optimized. Using methylene blue as the sample adsorbate, the adsorption behavior was systematically investigated in terms of the activation agent and temperature, the adsorption temperature and time, the initial adsorbate pH and concentration, as well as the dosage of adsorbent. Surface physical morphology of the TKMCK prepared was observed by scanning electron microscopy (SEM), while the functional groups were determined with Fourier transform infrared (FTIR) spectra. Kinetic studies indicated that the adsorption process was more consistent with the pseudo-second-order kinetic. Both Langmuir and Freundlich isotherms were employed to fit the adsorption data at equilibrium, with the former giving a maximum adsorption capacity of 793.65 mg/g at 323 K. BET surface area of as-prepared TKMCK was 657.78 m2/g.

scholarly journals Optimization of Preparation of Activated Carbon fromRicinus communisLeaves by Microwave-Assisted Zinc Chloride Chemical Activation: Competitive Adsorption of Ni2+Ions from Aqueous Solution

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
M. Makeswari ◽  
T. Santhi
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Zinc Chloride ◽  
Metal Ion ◽  
Competitive Adsorption ◽  
Ricinus Communis ◽  
Chemical Activation ◽  
The Other ◽  
Order Kinetic ◽  
Microwave Assisted

The preparation of activated carbon (AC) fromRicinus communisleaves was investigated in this paper. Orthogonal array experimental design method was used to optimize the preparation of AC using microwave assisted zinc chloride. Optimized parameters were radiation power of 100 W, radiation time of 8 min, concentration of zinc chloride of 30% by volume, and impregnation time of 24 h, respectively. The surface characteristics of the AC prepared under optimized conditions were examined by pHZPC, SEM-EDAX, XRD, and FTIR. Competitive adsorption of Ni2+ions onRicinus communisleaves by microwave assisted zinc chloride chemical activation (ZLRC) present in binary and ternary mixture was compared with the single metal solution. The effects of the presence of one metal ion on the adsorption of the other metal ion were investigated. The experimental results indicated that the uptake capacity of one metal ion was reduced by the presence of the other metal ion. The extent of adsorption capacity of the binary and ternary metal ions tested on ZLRC was low (48–69%) as compared to single metal ions. Comparisons with the biosorption of Ni2+ions by the biomass of ZLRC in the binary (48.98–68.41%-~Ni-Cu and 69.76–66.29%-~Ni-Cr) and ternary solution (67.32–57.07%-~Ni–Cu and Cr) could lead to the conclusion that biosorption of Ni2+ions was reduced by the influence of Cu2+and Cr3+ions. The equilibrium data of the adsorption was well fitted to the Langmuir isotherm. The adsorption process follows the pseudo-second-order kinetic model.

Nano platelets kaolinite for the adsorption of toxic metal ions in the environment

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Low Cost ◽  
Toxic Metal ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Toxic Heavy Metals ◽  
Toxic Metal Ions ◽  
Endothermic Process ◽  
Langmuir Isotherm Model

Contamination of water reservoirs with different toxic metal ions from industrial activities has emerged as one of major issues in recent years. The adsorption of Pb(II) ions from aqueous solution onto Nano platelets kaolinite has been investigated. The adsorption studies were determined as a function of pH, contact time, initial metal ion concentration, adsorbent dosage and temperature. Nano platelets kaolinite prepared from raw Jordanian kaolin clay showed size in the range of 12-80 nm. Maximum adsorption capacity as determined by Langmuir isotherm model is 175.44 mg/g for Pb(II). Thermodynamic parameters, ΔGo, ΔHo and ΔSo were revealed that the adsorption process is spontaneous and endothermic process. The results showed that Nano platelets kaolinite can be efficiently used as a low-cost alternative and eco-friendly adsorbent for the removal of toxic heavy metals from wastewater.

scholarly journals Adsorption of Cr (VI) From Polluted Water using Activated Carbon Prepared from Vincarosea Apocynaceae

2019 ◽  
Vol 9 (1) ◽  
pp. 2884-2892
Keyword(s):  
Activated Carbon ◽  
Metal Ion ◽  
Polluted Water ◽  
Activation Entropy ◽  
Order Kinetic ◽  
Metal Ion Removal ◽  
Ion Removal ◽  
Chromium Vi ◽  
Order Kinetic Model ◽  
Ph Level

The performance removal of chromium (VI) from polluted water is discussed in this paper. The sorption characteristic of Nitric Acid activated carbon derived from Vincarosea Apocynaceae plants through oxidation process and was proposed for the removal of Cr (VI) from polluted solutions. The surface chemistry characteristics of the prepared adsorbent were analysis by XRD, FTIR and SEM-EDAX. The effects are determined for removal of chromium they are initial concentration, PH level and adsorbent dose. The metal ion removal was pH dependent and, to a lesser extent, ionic strength. Kinetics data were found to follow the pseudo-second order kinetic model. Activation thermodynamic parameters, such as activation enthalpy (ΔH*), activation entropy (ΔS*), activation Gibbs free energy (ΔG*) and activation energy(E), have been evaluated and the possible adsorption mechanism also was suggested.

Adsorption of Chromium (VI) from Aqueous Solution by Agricultural Waste Derived Activated Carbon

2013 ◽  
Vol 726-731 ◽  
pp. 2100-2106 ◽  
Author(s):  
Hua Zhang ◽  
Xue Hong Zhang ◽  
Yi Nian Zhu ◽  
Shou Rui Yuan
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Agricultural Waste ◽  
Order Kinetic ◽  
Chromium Vi ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Grapefruit Peel ◽  
Pseudo Second Order ◽  
C 30

Activated carbon prepared from grapefruit peel, an agricultural solid waste by-product, has been used for the adsorption of Cr(VI) from aqueous solution. The effects of adsorbent dosage, pH and temperature on adsorption of Cr(VI) were investigated. The maximum adsorption yield was obtained at the initial pH of 3. The dynamical data fit very well with the pseudo-second-order kinetic model and the calculated adsorption capacities (23.98, 24.33 and 24.81 mg/g) were in good agreement with experiment results at 20°C, 30°C and 40 °C for the 100 mg/L Cr(VI) solution. The Freundlich model (R2 values were 0.9198-0.9871) fitted adsorption data better than the Langmuir model. The calculated parameters confirmed the favorable adsorption of Cr(VI) on the activated carbon prepared from grapefruit peel.

Ultrasonic Treatment of Activated Carbon Used in Adsorption of Basic Fuchsin

2011 ◽  
Vol 704-705 ◽  
pp. 486-491
Author(s):  
Yi Nan Hao ◽  
Xi Ming Wang ◽  
Li Jun Ding ◽  
Da Yan Ma
Keyword(s):  
Activated Carbon ◽  
Contact Time ◽  
Equilibrium Concentration ◽  
Acid Activation ◽  
Basic Fuchsin ◽  
Freundlich Isotherms ◽  
Langmuir And Freundlich Isotherms ◽  
Different Temperatures ◽  
Endothermic Process ◽  
Pseudo Second Order

Xanthoceras Sorbifolia Bunge hull activated carbon (XSBHAC) developed by phosphoric acid activation for removing basic fuchsin (BF) has been investigated. Experiments were carried out as function of contact time, pH (4-10) and temperature (303,313 and 323K). Adsorption isotherms were modeled with the Langmuir and Freundlich isotherms. The data fitted well with the Langmuir isotherm. The Langmuir monolayer saturation capacities of BF adsorbed onto activated carbon were 351.35, 354.96 and 355.94 mg/g at 303,313, and 323 K, respectively.The kinetic models were also studied .The rates of adsorption were found to conform to the pseudo-second-order kinetics with good correlation.Using the equilibrium concentration contents obtained at different temperatures, various thermodynamic parameters,such as △G,△H and △S, have been calculated. The thermodynamics parameters of system indicated spontaneous and endothermic process. Key words: Xanthoceras sorbifolia bunge hull;biosorption; basic fuchsin

Adsorption of chromium (VI) from aqueous solutions on activated carbon

1994 ◽  
Vol 30 (9) ◽  
pp. 191-197 ◽  
Author(s):  
R. Leyva Ramos ◽  
A. Juarez Martinez ◽  
R. M. Guerrero Coronado
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Ph Effect ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Experimental Adsorption ◽  
Ph Values ◽  
Chromium Vi ◽  
Adsorption Data

The adsorption isotherm of chromium (VI) on activated carbon was obtained in a batch adsorber. The experimental adsorption data were fitted reasonably well to the Freundlich isotherm. The effect of pH on the adsorption isotherm was investigated at pH values of 4, 6, 7, 8, 10 and 12. It was found that at pH < 6, Cr(VI) was adsorbed and reduced to Cr(III) by the catalytic action of the carbon and that at pH ≥ 12, Cr(VI) was not adsorbed on activated carbon. Maximum adsorption capacity was observed at pH 6 and the adsorption capacity was diminished about 17 times by increasing the pH from 6 to 10. The pH effect was attributed to the different complexes that Cr(VI) can form in aqueous solution. The adsorption isotherm was also affected by the temperature since the adsorption capacity was increased by raising the temperature from 25 to 40°C. It was concluded that Cr(VI) was adsorbed significantly on activated carbon at pH 6 and that the adsorption capacity was greatly dependent upon pH.

scholarly journals New Activated Carbon from Mine Coal for Adsorption of Dye in Simulated Water or Multiple Heavy Metals in Real Wastewater

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2498 ◽  
Author(s):  
Marwa Elkady ◽  
Hassan Shokry ◽  
Hesham Hamad
Keyword(s):  
Activated Carbon ◽  
Nitric Acid ◽  
Metal Ions ◽  
Low Cost ◽  
Dye Adsorption ◽  
Chemical Properties ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Physico Chemical ◽  
Multiple Heavy Metals

Nano-activated carbon (NAC) prepared from El-Maghara mine coal were modified with nitric acid solution. Their physico-chemical properties were investigated in terms of methylene blue (MB) adsorption, FTIR, and metal adsorption. Upon oxidation of the ACS with nitric acid, surface oxide groups were observed in the FTIR spectra by absorption peaks at 1750–1250 cm−1. The optimum processes parameters include HNO3/AC ratio (wt./wt.) of 20, oxidation time of 2 h, and the concentration of HNO3 of 10% reaching the maximum adsorption capacity of MB dye. Also, the prepared NAC was characterized by SEM, EDX, TEM, Raman Spectroscopy, and BET analyses. The batch adsorption of MB dye from solution was used for monitoring the behavior of the most proper produced NAC. Equilibrium isotherms of MB dye adsorption on NAC materials were acquired and the results discussed in relation to their surface chemistry. Langmuir model recorded the best interpretation of the dye adsorption data. Also, NAC was evaluated for simultaneous adsorption of six different metal ions (Fe2+, Ni2+, Mn2+, Pb2+, Cu2+, and Zn2+) that represented contaminates in petrochemical industrial wastewater. The results indicated that the extracted NAC from El-Maghara mine coal is considered as an efficient low-cost adsorbent material for remediation in both basic dyes and metal ions from the polluted solutions.

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