Adsorption Behavior of Barley Straw Carbon for Chromium (VI) Ion

2008 ◽  
Vol 569 ◽  
pp. 213-216
Author(s):  
Rumi Chand ◽  
Takanori Watari ◽  
Toshio Torikai ◽  
Mitsunori Yada ◽  
Katsutoshi Inoue

Porous carbon having surface area of 792 m2g-1 was prepared from barley straw by carbonization at 800 oC at a heating rate of 5 oCmin-1 to test the chromium (VI) adsorption from aqueous solution. The effects of pH, contact time and equilibrium Cr (VI) concentration on the adsorption were studied in detail. The optimum pH for Cr (VI) removal was found to be 2. The adsorption of Cr (VI) was very rapid and equilibrium was reached within 1 h. It was interpreted in terms of adsorption-coupled reduction mechanism. Accompanied by the decrease of Cr (VI) ion, Cr (III) ion was slightly released in the solution. Maximum loading capacity of total chromium was found to be 2.35 molkg-1 at pH 2.

2017 ◽  
Vol 76 (9) ◽  
pp. 2494-2502 ◽  
Author(s):  
María Teresa Garza-González ◽  
Jonathan Eduardo Ramírez-Vázquez ◽  
María de los Ángeles García-Hernández ◽  
María Elena Cantú-Cárdenas ◽  
Adriana Liñan-Montes ◽  
...  

Abstract The capacity of Cladosporium cladosporioides biomass for removal of Cr(VI) in aqueous solutions was evaluated. A 2 × 2 factorial experiment design was used to study the effects of pH and biomass doses. Lower pH values and larger biomass doses increased the capacity of C. cladosporioides biomass for removal of Cr(VI), reaching a reduction capacity of 492.85 mg g−1, a significantly higher value compared to other biomass reported. Cr(VI) removal kinetic rates followed a pseudo-second order model, like other fungal biomass reported previously. The apparent adsorption process was described well by the Freundlich isothermal model. However, determination of total chromium indicated that adsorption of Cr(VI) was followed by a redox reaction that released proportional quantities of Cr(III) into the experimental supernatant, suggesting a parallel adsorption-reduction process. Comparison of Fourier transform infrared spectroscopy spectra of C. cladosporioides biomass before and after the reduction process demonstrated the involvement of positively charged amino groups in the Cr(VI) adsorption-reduction process.


2015 ◽  
Vol 43 (3) ◽  
pp. 277-281 ◽  
Author(s):  
M Rahman ◽  
S Gul ◽  
M Ajmal ◽  
A Iqbal ◽  
Akk Achakzai

Removal of cadmium from aqueous solution was studied by using Quetta pine (Pinus halepensis Mill.) leaves. Batch adsorption experiments were performed as a function of appropriate equilibrium time, pH, concentration of adsorbate and amount of adsorbent. The optimum pH required for maximum adsorption was found to be 7.0 and the maximum contact time for the equilibrium was 30 minutes at adsorbent dose of 10 g. The maximum adsorption efficiency of cadmium removal was 98.50%. The results were better fitted by Langmuir than Freundlich isotherm. The separation factor of equilibrium 0.12 and 0.67 showed that Quetta pine leaves are good adsorbent of cadmium from aqueous solution DOI: http://dx.doi.org/10.3329/bjb.v43i3.21598 Bangladesh J. Bot. 43(3): 277-281, 2014 (December)


2021 ◽  
Vol 16 (2) ◽  
pp. 436-451
Author(s):  
Meghdad Sheikhi ◽  
Hassan Rezaei

Abstract Treatment of the industrial wastewater before discharging into aquatic ecosystems using a new technology such as nanotechnology seems necessary. There are different methods for the removal of the heavy metals in the wastewater. In this study, nano-chitin was purchased from the Nano-Novin Polymer Company and used as an adsorbent for the removal of chromium (VI) ions from aqueous solution in a batch system. The effects of pH, temperature, contact time, concentration, and adsorbent dose were investigated. According to the results, the optimum conditions of adsorption occurred at pH = 6, temperature = 25 °C, 60 minutes contact time, and 0.6 g·L−1 adsorbent dose. Investigation of equilibrium isotherms showed that the isotherm fitted the Freundlich model with a correlation coefficient of R2 = 0.9689. The pseudo second-order model with the larger correlation coefficient had a greater fitness against experimental data in the kinetic studies. Thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy were calculated, which indicated spontaneous, endothermic, and random processes, respectively. Given the good results of this project, nano-chitin can be suggested as a novel adsorbent which is highly capable of adsorbing hexavalent chromium from aqueous solutions.


2021 ◽  
Author(s):  
Thi-Thuy Luu ◽  
Duy-Khoi Nguyen ◽  
Tu Thi Phuong Nguyen ◽  
Thien-Hoang Ho ◽  
Van-Phuc Dinh ◽  
...  

Abstract To remove Ni(II) ions from an aqueous solution, researchers used red mud modified by chitosan (RM/CS) material as a new adsorbent. According to the findings, the surface area of red mud is nearly doubled after being treated with chitosan, from 68.6 m2/g to 105.7 m2/g. The effects of pH solution, contact time, and material dosage on the Ni(II) uptake were examined. In comparison with the pseudo-first-order and pseudo-second-order models, the intra-diffusion model was the most suitable kinetic model for the Ni(II) removal. Besides, the three-parameter Sips model was used to predict the Ni(II) adsorption of RM/CS from aqueous solution. Furthermore, the Langmuir maximum Ni(II) uptake capacity of this material was 31.66 mg/g at 323K, which was higher than red mud and several other natural materials. Notably, thermodynamic investigations demonstrated that Ni(II) adsorption on RM/CS is both exothermic and physic.


2015 ◽  
Vol 1113 ◽  
pp. 223-229
Author(s):  
Siti Nor Izuera Nor-Azemi ◽  
Farah Aimi Fuadi ◽  
Syed Shatir A. Syed-Hassan

The objective of this study is to investigate the ability of Elaeis guineensis fruit fiber or known as oil palm mesocarp fiber (OPMF) to adsorb nickel from aqueous solution. As one of the major oil palm producer, Malaysia has abundantly oil palm waste that potentially be used as biosorbent. Limited studies used OPMF as biosorbent to remove nickel, thus it was used in this study. The effects of pH, initial metal concentration and contact time on nickel uptake were studied. The OPMF was soaked in nickel nitrate aqueous solution and the Ni-loaded OPMF being digested to analyse the nickel concentration by using ICP-OES. The adsorption was investigated in the pH range of 2.0-8.0 and the optimum pH for nickel removal was found to be 7.0. The contact time was varied between 5 to 120 mins and the nickel adsorption was found to achieve equilibrium in a very short time (i.e.<5 mins). The percentage of nickel removal decreased from 3.3 to 1.7 % with increasing nickel concentration from 505 to 1683 mg/L. The adsorption isotherm was fitted well using Langmuir model with correlation coefficient, R2 of 0.98. The kinetic studies showed that the pseudo-second order model is the best model with the correlation coefficients of > 0.99 for all concentrations. Overall, the adsorption of nickel by OPMF gave positive results and the used of OPMF as biosorbent has great potential to be applied in the future.


2012 ◽  
Vol 518-523 ◽  
pp. 2708-2711 ◽  
Author(s):  
Ming Zhou ◽  
Hang Xu ◽  
Shu Fa Zhu ◽  
Ya Na Liu

The possible use of biowaste-banana skin as an alternative, low-cost biosorbent and reductant for removal of Cr from aqueous solutions was investigated. Effects of pH, contact time, Cr(VI) initial concentration and temperature on the reduction and biosorption of Cr by banana skin were studied. Experimental results showed that 1 g of dried banana skin could reduce about 230 mg of Cr(VI) to Cr(III), at the condition of 30°C, pH 2 and 300 rpm. The maximum Qeq of Cr(III) by banana skin was 6.3mg g-1 at the Cr(VI) initial concentration of 200mg L-1, 30°C , pH 2 and 300 rpm.


2014 ◽  
Vol 680 ◽  
pp. 146-149 ◽  
Author(s):  
Norzila Othman ◽  
Y.S. Kueh ◽  
F.H. Azizul-Rahman ◽  
R. Hamdan

The industrial revolution has significantly increase the discharge of wastewater into water bodies with heavy metals. In this study, watermelon rind was used as a biosorbent. Wastewater from mosaic industry was characterized by using flame AAS and zinc was found to have concentration range of 350mg/L to 450mg/L. Watermelon rind was characterized by using XRF and SEM. The results from XRF before biosorption shows the presence of Si to enhance biosorption. Zinc present after biosorption. The optimum pH, biosorbent amount, zinc concentration and contact time were found to be pH8, 1.5g, 400mg/L, and 30minutes respectively. The watermelon rind was proven as an effective biosorbent for zinc removal from aqueous solution


2011 ◽  
Vol 236-238 ◽  
pp. 155-158
Author(s):  
Li Fang Zhang ◽  
Shu Juan Dai ◽  
Ying Ying Chen

In this study, Biosorption of hexavalent chromium ions from aqueous solution by using biomass ofAspergillus nigerwas investigated. Different parameters such as initial pH, biosorbent amount, contact time and temperature were explored. The biosorption of Cr (VI) ions was highly pH dependent and the optimum pH for biosorption of Cr (VI) ions was found to be 2.0. Biosorption capacity of Cr (VI) ions decreased with increased biosorbent dosage. The biosorption equilibrium was established in about 120min of contact time. Equilibrium uptake of Cr (VI) ions onto biomass increased from 12.57 mg/g at 20°C to 19.48 mg/g at 40 °C for 20mg/L Cr (VI) ions concentration. The biosorption process followed the pseudo-second order kinetic model and the correlation coefficients from the pseudo-second order model were all higher than 0.997 in all studied temperatures. These results suggest that the biomass ofAspergillus nigeris a promising biosorbent for removal of chromium (VI) ions from the wastewater.


2020 ◽  
Vol 11 (1) ◽  
pp. 7746-7753

The main goal of this research was to evaluate the effectiveness of rice husk coated with chitosan as a green adsorbent for the removal of cadmium (II) in aqueous solution. The properties of prepared rice husk-chitosan (Chi-RH) were characterized using SEM, FTIR, and XRD analysis. The main parameters that influence cadmium sorption on the Chi-RH biocomposites were evaluated at different stirring and contact time, adsorbent dosage, and pH values. The results indicated that the best stirring time and contact time was 360 mins and 60 mins, respectively. The optimum adsorbent dosage was 1.0 g/L, with the highest percentage removal of 99%, and the optimum pH was 9. This study concluded that the Chi-RH biocomposites have the high ability as a green adsorbent for cadmium removal in aqueous solution and simultaneously reducing the environmental impact.


Author(s):  
Olaniyi K Yusuff ◽  
Abdulrahman A. Mukadam ◽  
Adenike M.o Abdulraheem ◽  
Aanuoluwapo Akerele

The biosorption of Cr (III) ions from aqueous solutions by groundnut husk, a low-cost biosorbent was studied on a laboratory scale batch experiments. The effects of pH, contact time, particle size, biosorbent dosage and temperature on the adsorption of Cr (III) ions were investigated. Determination of Chromium ion concentration in solution was done using Atomic Absorption Spectrophotometer (AAS). The results show that the removal mechanism is predominantly by chemisorption and it is dependent on the physical and chemical characteristics of the biosorbent material. From the initial concentration of 0.5 mM, optimum Cr (III) ions removal was obtained at pH of 4, particle size of 0.15 nm, contact time of 180 minutes and biosorbent dosage of 50 mg, with the highest biosorption efficiency of 81.15 %. The biosorption process was best described by the BET adsorption isotherm with R2 value 0.9814 indicating multiplayer adsorption. Analysis of the experimental data revealed that the biosorption of Cr (III) ions from aqueous solution by groundnut husk is a spontaneous process with a ?Go value of -24.38 kJmol-1 at 298 K and follow the pseudo second order kinetics with a rate constant of 0.0151 min-1. The results indicate that groundnut husk can be employed as a low cost alternative to commercial adsorbents in the removal of Cr (III) ions from wastewater.


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