scholarly journals Bioremediation of Ni2+, Cd2+ and Pb2+ from aqueous solution using chemically modified Newbouldia Leavis seed pod. Kinetics and Intraparticle Diffusivities.

2021 ◽  
Vol 46 (2) ◽  
Author(s):  
O.K. Amadi ◽  
F.K. Ekuma ◽  
B. N. Uche

This study investigates the biosorption of Ni2+, Cd2+ and Pb2+ from aqueous solution by modified Newbouldia Leavis seed pod. The modification was done by acid treating air-dried activated Newbouldia Leavis seed pod by dissolving it in excess 1.0 M Mercapto acetic acid (HSCH2COOH) solution, stirred for 30 minutes and left to stand for 24 hours at 30 oC, filtered off using WhatmanNo. 41 filter paper and were air dried. The effects of solution pH and contact time were evaluated. The results showed that maximum Cd2+ and Ni2+ adsorption of 7.9872 mg/g and 7.9809 mg/g respectively occurred at pH of 6.0 while that of Pb2+ was 8.0000 mg/g, at a pH of 4.0. The optimum time for maximum adsorption of the three heavy metal ions were 110 min. The kinetic data revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots were unity and were higher than first order reversible model and pseudo – first order plots. Moreover, the values of qcal and qexp obtained for pseudo – second order plots were very close indicating that the biosorption process followed the pseudo-second order kinetics. However, the transport mechanism for the process involved both intra-particle and liquid film diffusion.

2014 ◽  
Vol 556-562 ◽  
pp. 286-289
Author(s):  
Li Fang Zhang ◽  
Chun Yang Jiang ◽  
Zhao Shao

In this study, Biosorption of Cr (VI) ions from aqueous solution by using biomass of Aspergillus niger was investigated. The effects of initial solution pH, biosorbent amount, contact time, initial concentration and temperature were explored. In batch experiments, the biosorption capacity of Cr (VI) decreased with increase in solution pH. The biosorption of Cr (VI) ions with pH range of 2.0-8.0 was found to be optimal at pH 2. Biosorption capacity of Cr (VI) ions decreased with increased biosorbent dosage. The bosorption capacity was increased with the increasing initial Cr (VI) concentration and temperature in studied range. The biosorption process followed the pseudo-second order kinetic model and the correlation coefficients from the pseudo-second order model were all higher than 0.9997 in all studied temperatures. These results suggest that the biomass of Aspergillus niger is a promising biosorbent for removal of Cr (VI) ions from the wastewater.


2011 ◽  
Vol 80-81 ◽  
pp. 421-425
Author(s):  
Li Fang Zhang ◽  
Ying Ying Chen ◽  
Shu Juan Dai

In this study, the biosorption of Malachite Green, a cationic dye from aqueous solution onto pretreated biomass of Penicilium sp. was examined. The biosorption studies were carried out under various parameters such as initial pH, contact time and initial dye concentration. The experimental results show that optimum pH for efficient dye biosorption was found to be 5.0-6.0 for pretreated biomass. The bosorption capacity was increased with the increasing initial dye concentration in studied dye concentration range. The kinetic data obtained at different concentrations were analyzed using pseudo-first-order, pseudo-second-order and intra-particle diffusion models. It was obtained that the biosorption process followed the pseudo-second-order kinetic model.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Siti Kartina Abdul Karim ◽  
Soh Fong Lim ◽  
S. N. David Chua ◽  
Shanti Faridah Salleh ◽  
Puong Ling Law

In this study, banana fibers extracted from banana leaves, stem, and stalk were used to remove acid green dye from aqueous solution. Three initial concentrations (750, 1000, and 1500 ppm) were chosen to determine the kinetic characteristics of the banana fiber sorbents at 25°C, agitation speed of 200 rpm, and total contact time of 3 hours. The pseudo-first-order, pseudo-second-order, and Dunwald-Wagner kinetic models were applied to the experimental kinetic data. For isotherm study, the batch experiments were performed at 25°C, initial pH 2, agitation speed of 200 rpm, and initial concentrations between 100 and 2000 ppm. The experimental data was fitted to the Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherms. The equilibrium was achieved in less than 90 minutes. The removal of the acid green dye was found to be following closely the pseudo-second-order kinetic model. For equilibrium study, the Freundlich isotherm was found to fit well with adsorption of acid green dye on the banana leaves, stem, and stalk sorbents. The calculated mean free energy of 4–11 J/mol indicated that the sorption process was mostly physical in nature. Experimental results also showed the adsorption performance is greatly affected by the initial solution pH.


2021 ◽  
Vol 68 (2) ◽  
pp. 363-373
Author(s):  
Roya Salahshour ◽  
Mehdi Shanbedi ◽  
Hossein Esmaeili

In the present work, methylene blue was eliminated from aqueous solution using activated carbon prepared by lotus leaves. To perform the experiments, batch method was applied. Also, several analyses such as SEM, FTIR, EDAX and BET were done to determine the surface properties of the activated carbon. The results showed that the maximum sorption efficiency of 97.59% was obtained in initial dye concentration of 10 mg/L, pH of 9, adsorbent dosage of 4 g/L, temperature of 25 °C, contact time of 60 min and mixture speed of 400 rpm. Furthermore, the maximum adsorption capacity was determined 80 mg/g, which was a significant value. The experimental data was analyzed using pseudo-first order, pseudo-second order and intra-particle diffusion kinetic models, which the results showed that the pseudo-second order kinetic model could better describe the kinetic behavior of the sorption process. Also, the constant rate of the pseudo-second order kinetic model was obtained in the range of 0.0218–0.0345 g/mg.min. Moreover, the adsorption equilibrium was well described using Freundlich isotherm model. Furthermore, the thermodynamic studies indicated that the sorption process of methylene blue dye using the activated carbon was spontaneous and exothermic.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Hamid Raza ◽  
Aqsa Sadiq ◽  
Umar Farooq ◽  
Makshoof Athar ◽  
Tajamal Hussain ◽  
...  

Batch scale studies for the adsorption potential of novel biosorbentPhragmites karka(Trin), in its natural and treated forms, were performed for removal of mercury ions from aqueous solution. The study was carried out at different parameters to obtain optimum conditions of pH, biosorbent dose, agitation speed, time of contact, temperature, and initial metal ion concentration. To analyze the suitability of the process and maximum amount of metal uptake, Dubinin-Radushkevich (D-R) model, Freundlich isotherm, and Langmuir isotherm were applied. The values ofqmaxfor natural and treated biosorbents were found at 1.79 and 2.27 mg/g, respectively. The optimum values of contact time and agitation speed were found at 50 min and 150 rpm for natural biosorbent whereas 40 min and 100 rpm for treated biosorbent, respectively. The optimum biosorption capacities were observed at pH 4 and temperature 313 K for both naturalP. karkaand treatedP. karka.RLvalues indicate that comparatively treatedP. karkawas more feasible for mercury adsorption compared to naturalP. karka. Both pseudo-first-order and pseudo-second-order kinetic models were applied and it was found that data fit best to the pseudo-second-order kinetic model. Thermodynamic studies indicate that adsorption process was spontaneous, feasible, and endothermic.


2015 ◽  
Vol 72 (9) ◽  
pp. 1505-1515 ◽  
Author(s):  
H. Asnaoui ◽  
A. Laaziri ◽  
M. Khalis

Batch experiments were conducted to study the adsorption of hazardous cadmium onto low-cost algae biomass in aqueous solution with respect to concentration of adsorbate, adsorbent dosage, contact time, solution pH and temperature. Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were determined. The activation energy of adsorption was also evaluated for the adsorption of cadmium onto Ulva lactuca biomass. Experimental data were tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. The results showed that the biosorption processes of Cd(II) followed well pseudo-second-order kinetics. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the metal ions by Ulva lactuca biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The biosorption capacity of Ulva lactuca biomass for cadmium was found to be 3.02 mg/g at pH 5.60 min equilibrium time and 20 °C. The mean free energy which was calculated was 6.24 kJ/mol for Cd(II) biosorption, which shows that the adsorption is physical. The calculated thermodynamic parameters (ΔG0, ΔH0 and ΔS0) showed that the biosorption of Cd(II) onto Ulva lactuca biomass was feasible, spontaneous and exothermic under examined conditions. The results indicate that algae Ulva lactuca could be employed as a low-cost material for the removal of metal ions 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.


2017 ◽  
Vol 8 (2) ◽  
pp. 214-224 ◽  
Author(s):  
M. Farnane ◽  
H. Tounsadi ◽  
A. Machrouhi ◽  
A. Elhalil ◽  
F. Z. Mahjoubi ◽  
...  

AbstractThe focus of this study is the investigation of removal ability of methylene blue (MB) and malachite green (MG) dyes from aqueous solution by raw maize corncob (RMC) and H3PO4 activated maize corncob (AMC). Maize corncobs were carbonized at 500 °C for 2 h, and then impregnated at a phosphoric acid to maize corncob ratio of 2.5 g/g. The impregnated maize corncob was activated in a tubular vertical furnace at 450 °C for 2 h. Samples were characterized by different methods. Adsorption experiments were carried out as a function of solution pH, adsorbent dosage, contact time, initial concentration of dyes and the temperature. Experimental results show that the activation of maize corncob boosts four times the adsorption performance for the selected dyes. The adsorption process is very rapid and was pH dependent with high adsorption capacities in the basic range. The kinetic data were fitted with the pseudo-second-order kinetic model. The best fit of equilibrium data was obtained by the Langmuir model with maximum monolayer adsorption capacities of 75.27 and 271.19 mg/g for MB, 76.42 and 313.63 mg/g for MG, respectively, in the case of RMC and AMC. The temperature did not have much influence on the adsorption performance.


2019 ◽  
Vol 70 (4) ◽  
pp. 1108-1113 ◽  
Author(s):  
Rana Abdullah Abbas ◽  
Ahlam Abdul-Rheem Farhan ◽  
Hussam Nadum Abdalraheem Al Ani ◽  
Aurelia Cristina Nechifor

Eggshells was used as a natural adsorbent to remove direct blue(DB) dye from aqueous solution and investigating the four factors that affect the adsorption of DB dye ; amount of eggshell rang (0.1 - 1g), initial concentration (10 - 60 mg/L ), time ( 5 - 45 min.) and pH (3 - 11). Central Composition Design with four variables and five levels coupled with response surface method was adopted to get a second order polynomial equation for dye removal percentage as the response, and to obtain the optimum conditions for maximum dye removal percentage ; which reach 84% with optimum point , eggshell (0.835 g) ,time (24min.) , initial dye concentration ( 10 mg/L) , pH (4.2). The most effecting factors on dye removal are pH and initial dye concentration. Langmuir, Freundich model gives good fitting with (R2 ]0.98). The process of adsorption of DB dye on eggshell fitted a pseudo-second order kinetic model.


2009 ◽  
Vol 27 (4) ◽  
pp. 435-445 ◽  
Author(s):  
Laura Bulgariu ◽  
Dumitru Bulgariu ◽  
Theodor Malutan ◽  
Matei Macoveanu

The adsorption of lead(II) ions from aqueous solution onto lignin was investigated in this study. Thus, the influence of the initial solution pH, the lignin dosage, the initial Pb(II) ion concentration and the contact time were investigated at room temperature (19 ± 0.5 °C) in a batch system. Adsorption equilibrium was approached within 30 min. The adsorption kinetic data could be well described by the pseudo-second-order kinetic model, while the equilibrium data were well fitted using the Langmuir isotherm model. A maximum adsorption capacity of 32.36 mg/g was observed. The results of this study indicate that lignin has the potential to become an effective and economical adsorbent for the removal of Pb(II) ions from industrial wastewaters.


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