scholarly journals Rice Husk Coated Chitosan Biocomposite as an Adsorbent for Cadmium Removal from Aqueous

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.

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)


2020 ◽  
Vol 3 (6) ◽  
pp. 857-870
Author(s):  
Shagufta Zafar ◽  
Muhammad Imran Khan ◽  
Mushtaq Hussain Lashari ◽  
Majeda Khraisheh ◽  
Fares Almomani ◽  
...  

AbstractThe present study investigates the removal of copper ions (Cu (II)) from aqueous solution using chemically treated rice husk (TRH). The chemical treatment was carried out using NaOH solution and the effect of contact time (tc), adsorbent dosage (Dad), initial Cu (II) concentration ([Cu]i), and temperature (T) on the percentage removals of Cu (II) (%RCu) were investigated. Different analytical techniques (FTIR, SEM, and EDX) were used to confirm the adsorption (ads) of Cu (II) onto the TRH. The ads kinetics was tested against pseudo-first-order (PFO) and pseudo-second-order (PSO) models as well as Langmuir and Freundlich isotherms. Treating RH with NaOH altered the surface and functional groups, and on the surface of RH, the ionic ligands with high electro-attraction to Cu increased and thus improved the removal efficiency. The %RCu decreased by increasing the [Cu]i and increased by increasing the ct, Dad, and T. Up to 97% Cu removal was achieved in ct of 30 min using Dad of 0.3 g [Cu]i of 25 mg L−1 and T = 280 K. The ads of Cu on TRH is endothermic, spontaneous, follows Langmuir isotherms, and exhibited a PSO kinetics. Moreover, the TRH was successfully regenerated and used for further adsorption cycles using 1 M HNO3.


2019 ◽  
Vol 14 (4) ◽  
pp. 897-907 ◽  
Author(s):  
Hosseinali Asgharnia ◽  
Hamidreza Nasehinia ◽  
Roohollah Rostami ◽  
Marziah Rahmani ◽  
Seyed Mahmoud Mehdinia

Abstract Phenol and its derivatives are organic pollutants with dangerous effects, such as poisoning, carcinogenicity, mutagenicity, and teratogenicity in humans and other organisms. In this study, the removal of phenol from aqueous solution by adsorption on silica and activated carbon of rice husk was investigated. In this regard, the effects of initial concentration of phenol, pH, dosage of the adsorbents, and contact time on the adsorption of phenol were investigated. The results showed that the maximum removal of phenol by rice husk silica (RHS) and rice husk activated carbon (RHAC) in the initial concentration of 1 mgL−1 phenol, 2 gL−1 adsorbent mass, 120 min contact time, and pH 5 (RHS) or pH 6 (RHAC) were obtained up to 91% and 97.88%, respectively. A significant correlation was also detected between increasing contact times and phenol removal for both adsorbents (p < 0.01). The adsorption process for both of the adsorbents was also more compatible with the Langmuir isotherm. The results of this study showed that RHS and RHAC can be considered as natural and inexpensive adsorbents for water treatment.


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.


2020 ◽  
Vol 9 (3) ◽  
pp. 197-206
Author(s):  
Thaharah Ramadhani ◽  
Faisal Abdullah ◽  
Indra Indra ◽  
Abrar Muslim ◽  
Suhendrayatna Suhendrayatna ◽  
...  

The use of a low-cost biosorbent prepared from Ipomoea pes-caprae stem for the adsorption of Cd(II) ions from aqueous solution at different contact times, biosorbent sizes, pH values, and initial Cd(II) ions concentration solution was investigated. The biosorbent was analyzed using Fourier-transform infrared spectroscopy (FT-IR) to find important IR-active functional groups. A scanning electron microscope (SEM) was used to examine the biosorbent morphology. The experimental results showed the highest Cd(II) ions adsorption was 29.513 mg/g  under an optimal condition as initial Cd(II) ions concentration of 662.77 mg/L, 1 g dose, 80-min contact time, pH 5, 75 rpm of stirring speed, 1 atm, and 30 oC. Cd(II) ions' adsorption kinetics obeys the linearized pseudo-second-order kinetics (R2 = 0.996), and the adsorption capacity is based on the optimal condition, and the rate attained was 44.444 mg/g and 0.097 g/mg. Min, respectively. Besides, the adsorption isotherms were very well fitted by the linearized Langmuir isotherm model, and the monolayer adsorption capacity and pore volume determined was 30.121 mg/g and 0.129 L/mg, respectively. These results indicated the chemisorption nature


2020 ◽  
Vol 12 (1) ◽  
pp. 167-177
Author(s):  
Ayuba Abdullahi Muhammad ◽  
Nyijime Thomas Aondofa

Carbonized Bambara GroundNut Shell (CBGNS) was used as adsorbent for the adsorption of paraquat dichloride (PQ) from aqueous solution. The prepared adsorbent was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy methods. Several parameters that might affect the adsorption process including pH, contact time, adsorbent dosage, temperature and initial concentration were investigated and optimized using batch adsorption technique. Results of the study revealed that maximum removal efficiency (98%) was achieved using 0.05g adsorbent dosage, solution pH of 5 and 60 min of contact time. The equilibrium experimental result revealed that Langmuir model best described the adsorption process with R2 value of 0.956.The heat of adsorption process was estimated from Temkin Isotherm model to be 19.99J/mol and the mean free energy was estimated from Duninin-Radushkevich (DRK) isotherm model to be 0.289KJ/mol indicating chemisorptions process. The kinetic and thermodynamic studies revealed that the adsorption processes followed pseudo-second-order kinetics with R2 value of 0.999 and the value of ∆G (- 27.74 kJ mol-1), ∆H (13.145 kJ mol-1) indicate the spontaneous and endothermic nature of PQ adsorption on CBGNS. The results suggested that CBGNS had the potential to become a promising material for PQ contaminated water treatment. Keywords: Adsorption, Paraquat dichloride, Carbonized Bambara Ground nut shell, Water treatment.


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>


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


2013 ◽  
Vol 68 (4) ◽  
pp. 848-855 ◽  
Author(s):  
Nevim Genç ◽  
Esra Can Dogan ◽  
Meral Yurtsever

Ciprofloxacin hydrochloride (CIP) is the second generation of fluoroquinolone antibiotics whose residues are found in wastewater and surface water. CIP has high aqueous solubility under different pH conditions and high stability in the soil system. In this study, bentonite was used as a potential sorbent for the removal of CIP from aqueous solutions using batch experiments. The effects of various parameters such as contact time, pH, adsorbent dosage, agitation speed, ionic strength and initial concentration of CIP in aqueous solution on the adsorption capacity were investigated. The optimum contact time, pH, agitation speed and adsorbent dosage were found to be 30 min, 4.5 pH, 150 rpm and 2.5 g L−1, respectively. When the ionic strength was increased from 5 to 50 mM, the adsorption of CIP decreased from 97.8 to 93.4%. The isotherm adsorption data fitted well with the Langmuir model, Kl and qe were found to be 0.27 L mg−1 and 147.06 mg g−1, and the data fitted well with the pseudo-second order kinetics, whereby k was found to be 2.19 g mg−1 h−1.


Author(s):  
Shamim A. Begum ◽  
A. H. M. Golam Hyder ◽  
Qwanikwia Hicklen ◽  
Taylor Crocker ◽  
Ben Oni

Abstract Ammonium contamination in water is a major concern worldwide. This study focuses on the removal of ammonium from aqueous solution by batch adsorption experiments using biochar derived from a combination of various wood chips (spruce, pine, and fir). Adsorption characteristics of ammonium onto biochar were evaluated as a function of biochar dosages, initial concentrations of ammonium, contact time and pH. Results demonstrated that ammonium removal increased with the increase of biochar dosage. The percentage of ammonium removal reached a value of 80% at a biochar dosage of 100 g/L. Ammonium removal decreased by 15% with the increase of initial ammonium concentration by 50 mg/L. The optimum pH for ammonium removal was considered in the range from 6 to 8. Ammonium removal reached its stable value within 3 days. The maximum adsorption capacity of ammonium was 0.96 mg/g for 80 mg/L of initial ammonium concentration. The adsorption isotherm followed both the Langmuir and Freundich models for ammonium adsorption onto biochar. Fourier Transform Infrared (FTIR) spectroscopy results indicated the presence of amine, amide and nitrile functional groups on the surface of biochar which could contribute to the adsorption of ammonium onto biochar. Thus, biochar derived from various wood chips showed the potential to remove ammonium from aqueous solution.


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