scholarly journals Optimization of Strontium Removal Process From Contaminated Water Using Zeolite Nanocomposites

Author(s):  
Shamal Chandra Karmaker ◽  
Osama Eljamal ◽  
Bidyut Baran Saha

Abstract The effective removal of strontium from polluted water is an emerging issue worldwide, especially in Japan, after the destruction of Fukushima’s Daiichi Nuclear Power Plant. In the strontium removal process, statistical optimization of associated factors is needed to reduce the quantity of chemicals and the number of experimental trials. In this study, response surface methodology based on the central composite design was employed for assessing the influence of different factors and their interaction effects on the efficiency of strontium removal. We have considered nanoscale zero-valent iron-zeolite (nZVI-Z) and nano-Fe/Cu zeolite (nFe/Cu-Z) as adsorbents for the effective removal of strontium. The present study showed that the most statistically significant potential contributor was initial concentration, followed by contact time in the removal process. The study indicated that the interaction effect between contact time and initial concentration was statistically important, suggesting the need for a multi-mechanism technique in the removal phase of strontium. Tόth, Langmuir, Dubinin-Astakhov (D-A), Freundlich, and Hill isotherm models were also fitted with the experimental strontium adsorption data, in which the Tόth model fitted best compared to the other models based on the RMSD.

2019 ◽  
Vol 6 (2) ◽  
pp. 66-74 ◽  
Author(s):  
Raziyeh Hosseini ◽  
Mohammad Hossein Sayadi ◽  
Hossein Shekari

The research was conducted with an aim to assess the efficiency of copper oxide nanoparticles as an adsorbent to remove Ni and Cr. The effect of pH, adsorbent dosage, contact time, initial concentration of metals (Ni and Cr) on the adsorption rate was evaluated and removal of these elements from aqueous solutions was measured using Atomic Absorption Spectrum System (Conter AA700). Moreover, the kinetic and isotherm besides thermodynamic adsorption models were assessed. The highest Ni and Cr removal rate occurred at an optimal pH of 7, and an initial concentration of 30 mg/L, a time period of 30 minutes, and 1 g/L of copper oxide nanoparticles. In fact, with the increase of adsorbent dosage and contact time, the removal efficiency increased and with initial concentration increase of Ni and Cr ions, the removal efficiency reduced. The correlation coefficient of isotherm models viz. Langmuir, Freundlich, Temkin, Redlich-Peterson, and Koble-Corrigan showed that Ni and Cr adsorption via copper oxide nanoparticles better follows the Langmuir model in relation to other models. The results showed that kinetic adsorption of Ni and Cr via copper oxide nanoparticles follows the second order pseudo model with correlation coefficients above 0.99. In addition, the achieved thermodynamic constants revealed that the adsorption process of metals (i.e., Ni and Cr) via copper oxide nanoparticles was endothermic and spontaneous and the reaction enthalpy values for these metals were 17.727 and 11.862 kJ/mol, respectively. In conclusion, copper oxide nanoparticles can be used as effective and environmentally compatible adsorbents to remove Ni and Cr ions from the aqueous solutions


2019 ◽  
Vol 9 (7) ◽  
Author(s):  
Kamalesh Sen ◽  
Jayanta Kumar Datta ◽  
Naba Kumar Mondal

Abstract In this study, orthophosphoric acid-modified activated char was prepared from Eucalyptus camaldulensis bark (EBAC), and used for removing traces of [N-(phosphonomethyl)glycine] (glyphosate) herbicide from aqueous solution. The adsorption capacity was characterized by zero-point-charge pH, surface analysis, and Fourier transform infrared spectroscopy. Batch mode experiments were conducted to observe the effects of selected variables, namely dose, contact time, pH, temperature, and initial concentration, on adsorption capacity. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models were generated to describe the mechanisms involved in the multilayer adsorption process. The results show that high temperature enhanced the adsorption capacity of EBAC, with a temperature of 373 K yielding adsorption capacity (qmax) and Freundlich parameter (KF) of 66.76 mg g−1 and 9.64 (mg g−1) (L mg−1)−n, respectively. The thermodynamics study revealed entropy and enthalpy of −5281.3 J mol−1 and −20.416 J mol−1, respectively. Finally, glyphosate adsorption was optimized by the Box–Behnken model, and optimal conditions were recorded as initial concentration of 20.28 mg L−1, pH 10.18, adsorbent dose of 199.92 mg/50 mL, temperature of 303.23 K, and contact time of 78.42 min, with removal efficiency of 98%. Therefore, it can be suggested that EBAC could be used as an efficient, low-cost adsorbent for removal of glyphosate from aqueous solutions.


2019 ◽  
Vol 31 (6) ◽  
pp. 1327-1331
Author(s):  
P. KARUNASRI MEGHANA ◽  
K. VENKATA PRAVALIKA ◽  
P. JANAKI SRIRAM ◽  
K. RAVINDHRANATH

Phoenix sylvestris seed powder (PSSP) was investigated as an adsorbent for the removal of chromium(VI) ions from water using batch extraction method. The conditions for the maximum extraction were optimized. The adsorption capacity was found to be 22.5 mg/g at pH= 2, contact time: 60 min, PSSP dosage: 0.40 g/500mL, rpm: 300 and temp.: 28 ± 2 ºC and found to be more suitable adsorbant than compared to other reported adsorbents in the literature. Co-ions even in five-fold excess were less interfered. Regeneration studies revealed that Phoenix sylvestris seed powder can be used up to three cycles. The method developed was successfully applied to polluted water/industrial effluents samples.


2017 ◽  
Vol 68 (3) ◽  
pp. 470-473
Author(s):  
Corneliu Mircea Davidescu ◽  
Andreea Gabor ◽  
Adina Negrea ◽  
Mihaela Ciopec ◽  
Petru Negrea ◽  
...  

Cesium (Cs) removal from wastewater becomes an emerging issue after the Fukushima Daiichi Nuclear Power Plant disaster. Cs(I) is an metal ion present in high level radioactive waste and has to be removed for a better disposal in geological formation. The present study investigates the adsorption process of Cs(I) from aqueous solutions on an novel adsorbent material. The novelty of this material is that the solid support, magnesium silicate, is doped with a new extractant, thiourea dissolved in ethyl alcohol. In order to establish the adsorption capacities of the adsorbent material, it was used in the removal process of metal ions. Kinetically, the adsorption process of this metal ion has the best fit for the pseudo-second-order kinetic model. The removal process through adsorption is endothermic and spontaneous due to the thermodynamic studies. Equilibrium studies were also carried out for the Langmuir, Freundlich and Sips model. The new doped material proves to be favourable as adsorbent material in the removal of Cs(I) from polluted water.


Author(s):  
Davoud Balarak ◽  
Yousef Mahdavi ◽  
Ali Joghatayi

Presence of Fluoride in water is safe and effective when used as directed, but it can be harmful at high doses. In the present paper SiO2 nanoparticles as a adsorbent is used for removal of fluoride from aqueous solution. The effect of various operating parameters such as initial concentration of F-, Contact time, adsorbent dosage and pH were investigated. Equilibrium isotherms were used to identify the possible mechanism of the adsorption process. Maximum adsorption capacity of the SiO2 nanoparticles was 49.95 mg/g at PH=6, contact time 20 min, initial concentration of 25 mg/L, and 25±2 ◦C temperatures, when 99.4% of Fwere removed. The adsorption equilibriums were analyzed by Langmuir and Freundlich isotherm models. It was found that the data fitted to Langmuir (R2=0.992) better than Freundlich (R2=0.943) model. Kinetic analyses were conducted using pseudo first-and second-order models. The regression results showed that the adsorption kinetics was more accurately represented by a pseudo second-order model. These results indicate that SiO2 nanoparticles can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution.


2021 ◽  
Vol 10 (3) ◽  
pp. 2446-2458

The growth of heavy metals in wastewater is a widespread concern that affects thousands of lives and spread diseases worldwide. Its extraction is subject of concert from last few decades. Looking forward in the current study, Citrus Limon leaves were used as an adsorbent for the Biosorption of Co(II) and Cr(III) in a batch system. Citrus Limon leaves were brought from the local garden of Amakhel, Tank, Pakistan. The removal process of Co(II) and Cr(III) was examined under different conditions of pH, contact time, and initial concentration to get the optimum condition. It was found optimum contact time for Co(II) and Cr(II) was 20 and 10 minutes. By the increase of concentration of adsorbate, the value of qe was investigated for Co(II) and Cr(III) at 20oC. The optimum initial concentration for Cr(III) and Co(II) was 60 ppm and 40 ppm, respectively. The optimum shaking power for Cr(III) and Co(II) was found to be 150 rpm and 120 rpm, respectively.


2013 ◽  
Vol 678 ◽  
pp. 7-11
Author(s):  
Gomathinayagam Kanthimathi ◽  
P. Kotteeswaran ◽  
M. Kotaisammy

In the present study, the application for the removal of Nickel (II) ion from aqueous solution by using synthetic nano Fe3O4 with the average size of 20 nm was investigated by batch method, as a function of concentration, adsorbent dosage, contact time and pH. The equilibrium adsorption isotherm data are tested by applying both Freundlich and Langmuir isotherm models.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
T. Shanthi ◽  
V. M. Selvarajan

Carbon prepared from leaves of henna (Lawsonia inermis) was used to study the adsorption of Cr(VI) and Cu(II) ions from their aqueous solutions. The experimental conditions which include pH, contact time, initial concentration, and adsorbent dosage on the metal removal were investigated. The capacity of adsorption depends on pH value; it increases with an increase in pH value from 1 to 7 and then decreases. The highest percentage of metal removal was achieved in the adsorbent dosage of 0.7 g and at an initial concentration of 100 ppm metal ion. The adsorption isotherm studies revealed that data was confirmed with both the Langmuir and Freundlich isotherm models. The removal percentage was found to be higher for Cu(II) when compared with Cr(VI). The potential of carbon prepared from henna leaves for the removal of these two solutions containing heavy metals was substantiated.


2016 ◽  
Vol 74 (7) ◽  
pp. 1577-1584 ◽  
Author(s):  
Ai Phing Lim ◽  
Zufarzaana Zulkeflee ◽  
Ahmad Zaharin Aris

Dead calcareous skeletons (CSs) as low-cost adsorbents were studied to remove lead ions (Pb (II)) in an aqueous solution. Factors influencing the efficiency of CSs were evaluated by adsorbent size, contact time, initial concentration, dosage concentration and pH. The optimum CS size for removal of Pb (II) was 710 μm at an equilibrium time of 720 min. The best dosage of CS was 10 g/L for a 99% removal efficiency without pH adjustment. Pb (II) ions were effectively removed in the initial pH of the metal solution. CS was able to remove a high concentration (100 mg/L) of Pb (II) at a removal efficiency of 99.92% and at an adsorption capacity of 13.06 mg/g. Our results demonstrated the potential of CS as a metal adsorbent in the aqueous phase with a high-removal efficiency and distinct physical characteristics.


Author(s):  
Aderonke A. Okoya ◽  
Oyeyemi S. Adegbaju ◽  
Oyindamola E. Akinola ◽  
Abimbola B. Akinyele ◽  
Omotayo S. Amuda

Nigeria is currently the largest rice producing country in Africa. High volumes of waste such as rice husk are inevitable with high production. Also pesticides used to rid of pests, diseases and improve crop yield find their ways into available surface water that serves domestic purpose. This study therefore determined the efficiency of conventional water treatment procedure for pesticide/pesticide residue removal and evaluated the performance of rice husk-based biochar as adsorbent to remove chlorpyrifos from domestic water supply with a view to manage  solid waste (rice husk) for treating pesticide polluted water. Batch adsorption studies were carried out to assess the adsorption efficiency of rice husk biochar (RHB) for chlorpyrifos pesticide removal from surface water. Adsorbent dosage, initial concentration, contact time and dosage were optimized during simulation experiment. RHB and commercial activated carbon (CAC) were used for the removal of chlorpyrifos from surface water sample using the optimum condition from the simulation experiment after which the concentrations were determined using Gas Chromatography with Mass Spectrometry detector. Both Langmuir and Freundlich adsorption isotherms were investigated. RHB gave percentage moisture (5.27±0.94), carbon yield (39.44±0.47), ash (41.96±0.96), fixed carbon (35.24±0.55), volatile matter (35.67±1.01 mg/g), Iodine number (85.57±0.81), surface area (97.20 m2/g), pH (7.90±0.14) and Electrical conductivity (298.8±1.14). Of the elements present in the char, Carbon has the highest percentage of 59.14%. Best adsorption conditions for RHB in this study were 2.8 mg/L initial concentration; 0.8 g of adsorbent dosage; pH of 5 and contact time of 30 min. The data fitted Freundlich than Langmuir model (R2 0.996 and 0.8315 respectively). Percentage removal of chlorpyrifos for CAC and RHB was 93.7±3.96 and 94.5±5.23 respectively for the surface water sample. Results concluded that RHB was efficient for removal of chlorpyrifos present in water and could be used as alternative for CAC in water treatments.


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