scholarly journals Adsorption of chromium ions from tannery effluents onto activated carbon prepared from rice husk and potato peel by H3PO4 activation

2021 ◽  
Vol 11 (9) ◽  
Author(s):  
Ephraim Vunain ◽  
Joel Brian Njewa ◽  
Timothy Tiwonge Biswick ◽  
Adewale Kabir Ipadeola

AbstractTwo biomass agricultural waste materials; rice husks (RH) and potato peels (PP) were used as precursors for preparation of activated carbons by chemical activation using phosphoric acid for adsorption of hexavalent chromium [Cr(VI)] from tannery effluents. The prepared rice husk (RH–AC) and potato peel activated carbon (PP–AC) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. Adsorption experiments were performed by varying pH, agitation speed, contact time, adsorbent dose and initial metal ion concentration. Freundlich, Langmuir and Temkin isotherms were used to analyze the equilibrium data obtained at different adsorption conditions. It was found that the adsorption isotherms were well fitted by the Freundlich equation and the adsorption process was found to follow pseudo-second-order rate kinetics. Adsorption results obtained show a maximum Cr(VI) uptake being attained at pH 2.0, with chromium removal efficiency of 99.88% and 99.52% for RH–AC and PP–AC, respectively. RH–AC and PP–AC are effective adsorbent for the removal of chromium(VI) ions from wastewater.

2005 ◽  
Vol 23 (2) ◽  
pp. 145-160 ◽  
Author(s):  
N. Vennilamani ◽  
K. Kadirvelu ◽  
Y. Sameena ◽  
S. Pattabhi

Activated carbon (AC) prepared from sago waste was characterized and used to remove chromium(VI) ions from aqueous solution and industrial effluent by adsorption methods using various conditions of agitation time, metal ion concentration, adsorbent dosage particle size and pH. Surface modification of the carbon adsorbent with a strong oxidizing agent like concentrated H2SO4 generates more active adsorption sites on the solid surface and pores for metal ion adsorption. Adsorption of the metal ion required a very short time and led to quantitative removal. Both the Langmuir and Freundlich isotherm models could describe the adsorption data. The calculated values of Q0 and b were 5.78 mg/g and 1.75 1/min, respectively. An effective adsorption capacity was noted for particle sizes in the range 125–250 μm at room temperature (30 ± 2°C) and an initial pH of 2.0 ± 0.2. The specific surface area of the activated carbon was determined and its properties studied by scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR). These studies revealed that AC prepared from sago waste is suitable for the removal of Cr(VI) ions from both synthetic and industrial effluents.


2020 ◽  
Vol 11 (3) ◽  
pp. 10265-10277

Activated carbons derived from rice husk pyrolysis (biochar) were prepared by chemical activation at different biochar/K2CO3 proportions in order to assess its capacity as adsorbent. The activated material was characterized by X-ray diffraction (DRX), Raman spectroscopy, scanning electron microscopy (SEM), the Brunauer, Emmet, and Teller (BET) method. The Barret, Joyner, and Halenda (BJH) method and functional density theory (DFT), presenting interesting texture properties, such as high surface area (BET 1850 m2 g-1) and microporosity, which allow its use as a sorbent phase in solid-phase extraction (SPE) of the main constituents of the aqueous pyrolysis phase. It was demonstrated that the activated carbon (RH-AC) adsorbs different compounds present in from rice husk pyrolysis wastewater through quantitative analysis by high-performance liquid chromatography with a diode-array detector (HPLC-DAD), presenting good linearity (R2 > 0.996) at 280 nm.


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.


Author(s):  
N.Z. Zabi ◽  
W.N. Wan Ibrahim ◽  
N.S. Mohammad Hanapi ◽  
N. Mat Hadzir

This paper aims to review recent studies in preparing activated carbons from different types of agricultural wastes in Malaysia and how it can help Malaysia manage agricultural waste. It can be seen that most biomasses can be used as precursors to produce activated carbon for a wide range of pollutants and this adsorbent can be modified to optimally function depending on the types of pollutants. Under optimum dosages, modification through chemical activation using acidic, basic, or drying agents has significant effects on the selectivity of the analyte adsorption. The acidic activating agent causes the activated carbon to have negatively charged acid groups which enable it to adsorb cationic adsorbate while the basic activating agent causes the adsorbent to have a positive surface charge and enable it to adsorb anionic adsorbate.


2013 ◽  
Vol 28 ◽  
pp. 94-101 ◽  
Author(s):  
Rajeshwar Man Shrestha ◽  
Raja Ram Pradhananga ◽  
Margit Varga ◽  
Imre Varga

The present study deals with the use of activated carbons prepared from Lapsi seed stone as adsorbents for the removal of Pb (II) ions from aqueous solution. Two series of carbon have been prepared from Lapsi seed stones by treating with conc. H2SO4 and a mixture of H2SO4 and HNO3 in the ratio of 1:1 by weight for removal of metal ions. Chemical characterization of the resultant activated carbon was studied by Fourier Transform Infrared Spectroscopy and Boehm titration which revealed the presence of oxygen containing surface functional groups like carboxylic, lactonic, phenolic in the carbons. The effect of pH and initial metal ion concentration on the adsorption was studied in a batch process mode. The optimum pH for lead adsorption is found to be equal to 5. The adsorption data were better fitted with the Langmuir equations than Freundlich adsorption equation to describe the equilibrium isotherms. The maximum adsorption capacity of Pb (II) on the resultant activated carbons was 277.8 mg g-1 with H2SO4 and 423.7 mg g-1 with a mixture of H2SO4 and HNO3. The waste material used in the preparation of the activated carbons is inexpensive and readily available. Hence the carbons prepared from Lapsi seed stones can act as potential low cost adsorbents for the removal of Pb (II) from water. DOI: http://dx.doi.org/10.3126/jncs.v28i0.8114 Journal of Nepal Chemical Society Vol. 28, 2011 Page: 94-101 Uploaded Date: May 24, 2013


2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Bachar Koubaissy ◽  
Joumana Toufaily ◽  
Safaa Cheikh ◽  
Malak Hassan ◽  
Tayssir Hamieh

AbstractActivated carbon derived from pine cones waste was prepared by carbonization at 450°C, activated by different activating agents: ZnCl 2, H 2 SO 4 and NaOH, and then pyrolyzed at 600°C. Adsorption of Cr VI and other heavy metals (Mn II, Fe II, Cu II) on activated carbons was investigated to evaluate the adsorption properties. Special attention was paid to the effects of carbon surface functionalities that were analyzed by FT-IR and zeta potential study. Moreover, XRD study of activated carbon was also carried out. Results had shown that activated carbon by NaOH was the best adsorbent for removal of chromium VI from wastewater. The solid-solution interaction was determined by analyzing the adsorption isotherms at room temperature at different pH. When pH is above 4, the removal fraction of Cr (VI) ions decreased with the increase of pH. The removal fraction of Cr (VI) ions decreased below pH 4. The preferable removal of Cu (II) over Mn(II) and Fe (II) could be due to its lower affinity to solvent.Pseudo-second order equation provided the better correlation for the adsorption kinetics data. Equilibrium isotherms were determined by Fowler-Guggenheim model.


2021 ◽  
Vol 16 (2) ◽  
pp. 118-125
Author(s):  
Cut Meurah Rosnelly ◽  
Lia Meiriza - Meiriza ◽  
Husni - Husin ◽  
Muhammad - Zaki ◽  
Muhammad Aqilussalim E ◽  
...  

Rice husk has been converted into activated carbon for the adsorbent to remove the heavy metal from the aqueous solution. This study aimed to convert rice husk to activated carbon (AC) for use in the adsorption of Fe ions in a fixed-bed column. Rice husk was first pyrolyzed in an atmosphere of nitrogen gas at 400 oC, then a chemical activation method using sodium hydroxide. The rice husk activated carbon (RH-AC) was characterized using Fourier transform infrared (FTIR) and Scanning electron microscope (SEM) to identify the functional group and microstructure of carbon. The performance of the carbon was tested on the Fe removal from an aqueous solution in a continuous column. The adsorption process was carried out using Fe solution with an initial concentration of 3 mg/L as an artificial sample. The amount of carbon is 25, and 50 g were filled in an adsorber column with a diameter of 5.4 cm and height of 40 cm. SEM images revealed that the activated carbons shown with well-developed pore sizes and pore structure were produced after the chemical activation.  The FTIR absorption bands observed in the RH-AC sample confirmed the presence of hydroxyl (-OH), carbonyl, and carboxylic (-COOH) groups of RH-AC adsorbent. The highest Fe removal efficiencies were 91.9% on chemically activated carbon and column mass 50 g at 400 minutes. The overall study revealed the potential value of chemically activated RH-AC as a possible commercial adsorbent in a continuous column wastewater treatment strategy.


Author(s):  
P Mullai Mullai ◽  
◽  
S. Kothai Nayaki ◽  
R. Nirmala Nirmala ◽  
◽  
...  

The adsorption of chromium (VI) onto activated carbon experimented in a batch reactor under two different conditions, namely, initial metal ion concentration and adsorbent dosages. For the five different initial metal ion concentrations such as 500, 600, 800, 900, 1000 mg/L, the steady-state values of chromium removal efficiency were 64, 92, 83, 71 and 66 %, respectively, using 5 grams of activated carbon under shaking at the end of 8th hour. The equilibrium of the process was found to fit into the two well-known adsorption models, Freundlich and Langmuir. It was also observed that the experimental kinetic data followed the first order rate expression.


2006 ◽  
Vol 3 (4) ◽  
pp. 218-229 ◽  
Author(s):  
R. Shanmugavalli ◽  
P. S. Syed Shabudeen ◽  
R. Venckatesh ◽  
K. Kadirvelu ◽  
S. Madhavakrishnan ◽  
...  

Activated carbon prepared from silk cotton hull (SCH) was used for the adsorptive removal of Pb(II) ion from aqueous solution. The raw material used for the preparation of activated carbon is the waste of agricultural product; the production of this carbon is expected to be economically feasible. Parameters such as agitation time, metal ion concentration, adsorbent dose,pH and Particle size were studied. Adsorption equilibrium was reached within 80 min for 10, 20, 30 and 40mg/l of Pb(II) ion with 50mg of carbon per mL of solution. Adsorption parameters were determined using both Langmuir and Freundlich isotherm models. The adsorption efficiency reached 100% for 20, 30 and 40mg/l of Pb(II) ion with 120, 140 and 150mg of carbon. Pb(II) ion removal increased as thepH increased from 2 to 5 and remains constant up topH 10. Desorption studies were also carried out with dilute hydrochloric acid to know the mechanism of adsorption. Quantitative desorption of Pb(II) ion from carbon indicates that adsorption of metal ion is by ion-exchange. Efficiency of the adsorption of SCH was also studied with Pb containing industrial wastewater by varyingpH and carbon concentration.


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.


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