scholarly journals Factorial Design Analysis of Zn(II) Ions Adsorption on Thermally Treated Rice Husk

2015 ◽  
Vol 10 (1) ◽  
pp. 121
Author(s):  
Keat Khim Ong ◽  
A. T. Ahmad Farhan ◽  
W. M. Z. Wan Yunus ◽  
Ahmad Mujahid Ahmad Zaidi ◽  
M. L. Jabit ◽  
...  

<p class="zhengwen"><span lang="EN-GB">Adsorption of Zn(II) ions from aqueous solutions by thermally treated rice husk was investigated using factorial experimental design to study effects of heating temperature and period of rice husk, pH, initial Zn(II) ion concentration, adsorption temperature and contact time, and adsorbent dosage. Main and interaction effects of these factors were analyzed using statistical techniques and the results were analyzed statistically using the Student’s t-analysis and analysis of variance which were used to determine significant factors that affect the percentage removal of Zn(II). These significant factors were heating temperature of rice husk, pH, initial metal concentration, contact time, and adsorbent dosage. The interaction between two different effects also affects the percentage removal of Zn(II) ions. These include the interactions between heating temperature of rice husk and initial metal concentration, pH and initial metal concentration, and pH and the adsorbent dosage.</span></p>

2019 ◽  
Author(s):  
Chem Int

A study of removal of heavy metal ions from heavy metal contaminated water using agro-waste was carried out with Musa paradisiaca peels as test adsorbent. The study was carried by adding known quantities of lead (II) ions and cadmium (II) ions each and respectively into specific volume of water and adding specific dose of the test adsorbent into the heavy metal ion solution, and the mixture was agitated for a specific period of time and then the concentration of the metal ion remaining in the solution was determined with Perkin Elmer Atomic absorption spectrophotometer model 2380. The effect of contact time, initial adsorbate concentration, adsorbent dose, pH and temperature were considered. From the effect of contact time results equilibrium concentration was established at 60minutes. The percentage removal of these metal ions studied, were all above 90%. Adsorption and percentage removal of Pb2+ and Cd2+ from their aqueous solutions were affected by change in initial metal ion concentration, adsorbent dose pH and temperature. Adsorption isotherm studies confirmed the adsorption of the metal ions on the test adsorbent with good mathematical fits into Langmuir and Freundlich adsorption isotherms. Regression correlation (R2) values of the isotherm plots are all positive (&gt;0.9), which suggests too, that the adsorption fitted into the isotherms considered.


2013 ◽  
Vol 330 ◽  
pp. 112-116 ◽  
Author(s):  
Nabilah A. Lutpi ◽  
N. Najihah Jamil ◽  
C.K. Kairulazam C.K. Abdullah ◽  
Yee Shian Wong ◽  
Soon An Ong ◽  
...  

The adsorption of Methylene Blue (MB) and Acid Orange 7 (AO7) dye onto Ananas Comosus Mixed Peels and Leaves (ACMPL) were carried out by conducting four different parameters such as initial concentration, pH, dosage of adsorbent, and contact time. Effect of initial concentration for both dyes showed that higher initial concentration would take longer contact time to attain equilibrium due to higher amount of adsorbate molecules. The effect of pH showed highest percentage removal for MB is at pH 9 which is 95.81%. Meanwhile for AO7 the highest percentage removal is 31.06% at pH 3. The percentage removal of MB had reached the equilibrium at dosage 0.5g while AO7 keep increasing with the increment of adsorbent dosage. The percentage removal of MB and AO7 had increased until hour 2.5 which was from 72.5% to 86.93% and 19.441% to 36.89% respectively and reached equilibrium at 3 hour contact time.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
S. Sugashini ◽  
K. M. Meera Sheriffa Begum

The objective of this present study is the optimization of process parameters in adsorption of Cr(VI) ions by ethylamine modified chitosan carbonized rice husk composite beads (EAM-CCRCBs) using response surface methodology (RSM) and continuous adsorption studies of Cr(VI) ions by ethylamine modified chitosan carbonized rice husk composite beads (EAM-CCRCBs). The effect of process variables such as initial metal ion concentration, adsorbent dosage and pH were optimized using RSM in order to ensure high adsorption capacity at low adsorbent dosage and high initial metal ion concentration of Cr(VI) in batch process. The optimum condition suggested by the model for the process variable such as adsorbent dosage, pH and initial metal ion concentration was 0.14 g, 300 mg/L and pH2 with maximum removal of 99.8% and adsorption capacity of 52.7 mg/g respectively. Continuous adsorption studies were conducted under optimized initial metal ion concentration and pH for the removal of Cr(VI) ions using EAM-CCRCBs. The breakthrough curve analysis was determined using the experimental data obtained from the continuous adsorption. Continuous adsorption modelling such as bed depth service model and Thomson model were established by fitting it with experimental data.


2020 ◽  
Vol 45 (6) ◽  
Author(s):  
K. A. ABDULSALAM ◽  
B. H. Amodu ◽  
O. K. Fakorede ◽  
J. M. Adelowo ◽  
A. P. Onifade ◽  
...  

One of the most problematic groups of water pollutants is dye, a main constituent of textile industrial wastewater, which is carcinogenic. Therefore, this research delved into adsorption of dyes from textiles and wastewater using acid-treated as an adsorbent. The adsorbent was prepared by functionalizing the pod of carob with concentrated H3PO4. The effects of operational parameters such as adsorbent dosage, contact time, initial concentration of dye and temperature were studied and optimized using central composite design of design of experiment (DOE). The effects of process parameters (contact time, concentration, adsorbent dosage and temperature) on the dye adsorption were determined and optimized. It was observed that the colour removal efficiency increased with an increase in adsorbent mass and contact time. The adsorption process is endothermic as the percentage removal increases with temperature. The optimum contact time, concentration, adsorbent dosage and temperature were found to be 60oC, 9.74hr, 10ppm, and 5g respectively for the maximum decolorization.


2021 ◽  
Vol 68 (4) ◽  
pp. 791-803
Author(s):  
Lei Yao ◽  
Chao Hong ◽  
Hani Dashtifard ◽  
Hossein Esmaeili

This study aimed to determine the best adsorbent among Moringa oleifera-derived activated carbon (AC), eggshell-derived CaO nanoparticles and CaO/Fe3O4 for sodium (Na+) removal from aqueous media. In the first step, the appropriate adsorbent for sodium adsorption was determined among the three adsorbents, which the results showed that the AC had the highest sorption efficiency. Then, response surface methodology (RSM) was used to evaluate the impact of different factors on the Na+ ion sorption efficiency using the AC. The highest removal efficiency was obtained to be 95.91% at optimum conditions such as pH of 11, contact time of 45 min, temperature of 25 °C, sodium ion concentration of 900 mg/L, and adsorbent dosage of 5 g/L. Also, the best conditions using the genetic algorithm was obtained at contact time of 94.97 min, adsorbent dosage of 3.52 g/L, Na+ ion concentration of 939.92 mg/L and pH value of 10.92. Moreover, the maximum sorption capacity using the Langmuir model was obtained to be 249.67 mg/g, which was a significant value. Besides, the equilibrium and kinetic studies indicated that the experimental data of sodium adsorption process were fitted well with the Langmuir isotherm model and the pseudo-second-order kinetic model, respectively. Furthermore, the thermodynamic study indicated that the sorption process was endothermic. Generally, among the three adsorbents used, activated carbon with a high removal efficiency and significant sorption capacity can be considered as a promising adsorbent for the removal of sodium from wastewater on an industrial scale.


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):  
G. G. Oseke ◽  
M. T. Isa ◽  
M. S. Galadima ◽  
A. O. Ameh

This study was aimed at developing chitosan-rice husk ash adsorbent for the removal of crude oil from contaminated water. Design Expert software 6.06 was used to design the adsorption experiment. The adsorption was tested for Langmuir, Freundlich and Temkin isotherms and the kinetic studies also carried out. The effect of influencing parameters such as contact time, adsorbate concentration, adsorbent dosage and formulation ratio were studied. It was generally shown that adsorption process increased with time and adsorbate concentration and decreased with adsorbent dosage. Models for the prediction of adsorption capacity for the composite was significant with R2 value of 0.8382 and P-value of 0.0017. Optimum conditions were found to be 0.90 wt/wt chitosan/silica ratio, contact time of 5 min, and oil/water ratio of 0.25 v/v, which gave 20.66 g/g sorption capacity respectively. Adsorption isotherm studies of Langmuir, Freundlich and Temkin were carried out for the chitosan-rice husk ash composite. Temkin isotherm best fitted with R2 value of 0.9999. The adsorption capacity of composite from isotherm studies was obtained to be 18.85 g/g adsorbent. The heat of adsorption bT (kJmol-1) obtained from Temkin isotherm study was -48.67 kJ/mol indicating physisorption of adsorbents to the crude oil.  Kinetic studies indicated that the pseudo-second order model suitably described the removal of crude oil by the composite with R2 value 0.9999.


Author(s):  
Ikemefuna Usifoh ◽  
Rosemary Odinigwe ◽  
M. U. Obidiegwu

Groundnut shells were modified through functionalization and carbonization processes to produce three distinct adsorbents for adsorption of Pb (II) ions from aqueous solution. Adsorption studies was carried out under varying conditions of pH, contact time, adsorbent dosage, metal ion concentration and temperature after the results were documented. Batch adsorption experiments revealed that the adsorbents performed optimally at a pH of 11 and the adsorption process was dependent upon changes in contact time. Adsorption capacity was observed to increase with increase in adsorbent dosage and decrease with increase in lead ion concentration across all adsorbents. Highest metal ion removal was by the GS-KOHC where 239.86 mg/g of lead ion was removed from the aqueous solution followed by the GS-HCLC at 228.0750 mg/g and then the GS-TPP adsorbent was least at 179.1235 mg/g.


2020 ◽  
Author(s):  
Fola Temilade Akinhanmi ◽  
Edwin Andrew Ofudje ◽  
Idowu Abideen Adeogun ◽  
Aina Peter ◽  
Joseph Mayowa Ilo

Abstract The presence of heavy metals in polluted water is known not only to cause stern harm to marine organisms but also to terrestial plants and animals including human beings. This research applied low-cost and environmental benign adsorbent primed from waste orange peel (OP) in the removal of Cd(II) ions from aqueous solution via the batch process. The surface properties of the orange peel powder was studied using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (XRD) and Fourier transform infrared spectroscopy FT-IR). Operational conditions like temperature, contact time, sorbent dosage, solution pH and initial adsorbate concentration were investigated. The utmost uptake of Cd(II) ion was obtained at the contact time of 120 min, initial metal concentration of 240 mg/L, adsorbent dosage of 0.04 g/L, temperature of 45 °C and solution pH of 5.5 on the adsorption of Cd(II) ion. Equilibrium results showed that the orange peel adsorbent has an adsorption capacity of 27.916 mg/g as obtained from the Langmuir isotherm. The adsorption kinetics data followed a Pseudo-first-order kinetic model with correlation coefficient (R2) > 0.9 and low standard % error values. The adsorption process was found to be spontaneous, feasible and with enthalpy of 0.0046 kJ mol− 1 and entropy of -636.865 Jmol− 1K− 1 respectively. Results from the optimization study indicated that higher adsorbent dosage and lower Cd(II) ion concentration increased the percentage of Cd (II) ion removal. Thus, orange peel could be used in the removal of Cd(II) ion from aqueous solutions.


2017 ◽  
Vol 76 (4) ◽  
pp. 776-784 ◽  
Author(s):  
Mijia Zhu ◽  
Jun Yao ◽  
Zhonghai Qin ◽  
Luning Lian ◽  
Chi Zhang

Wastewater produced from polymer flooding in oil production features high viscosity and chemical oxygen demand because of the residue of high-concentration polymer hydrolysed polyacrylamide (HPAM). In this study, steel slag, a waste from steel manufacturing, was studied as a low-cost adsorbent for HPAM in wastewater. Optimisation of HPAM adsorption by steel slag was performed with a central composite design under response surface methodology (RSM). Results showed that the maximum removal efficiency of 89.31% was obtained at an adsorbent dosage of 105.2 g/L, contact time of 95.4 min and pH of 5.6. These data were strongly correlated with the experimental values of the RSM model. Single and interactive effect analysis showed that HPAM removal efficiency increased with increasing adsorbent dosage and contact time. Efficiency increased when pH was increased from 2.6 to 5.6 and subsequently decreased from 5.6 to 9.3. It was observed that removal efficiency significantly increased (from 0% to 86.1%) at the initial stage (from 0 min to 60 min) and increased gradually after 60 min with an adsorbent dosage of 105.2 g/L, pH of 5.6. The adsorption kinetics was well correlated with the pseudo-second-order equation. Removal of HPAM from the studied water samples indicated that steel slag can be utilised for the pre-treatment of polymer-flooding wastewater.


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