scholarly journals Effective Removal of Hexavalent Chromium from Polluted Water using Phoenix sylvestris Seed Powder as Adsorbent

2019 ◽  
Vol 31 (6) ◽  
pp. 1327-1331
Author(s):  
P. KARUNASRI MEGHANA ◽  
K. VENKATA PRAVALIKA ◽  
P. JANAKI SRIRAM ◽  
K. RAVINDHRANATH
Keyword(s):  
Adsorption Capacity ◽  
Hexavalent Chromium ◽  
Extraction Method ◽  
Contact Time ◽  
Industrial Effluents ◽  
Polluted Water ◽  
Chromium Vi ◽  
Effective Removal ◽  
Maximum Extraction ◽  
Fold Excess

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.

Purification of Contaminated Water with Chromium (VI) Using Pseudomonas aeruginosa

2016 ◽  
Vol 721 ◽  
pp. 143-148 ◽  
Author(s):  
Nora Noureddine ◽  
Samia Benhammadi ◽  
Fouad Kara ◽  
Hakim Aguedal ◽  
Abdelkader Iddou ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Hexavalent Chromium ◽  
Contact Time ◽  
Culture Broth ◽  
Contaminated Water ◽  
Toxic Heavy Metals ◽  
Initial Concentration ◽  
Chromium Vi ◽  
Batch System ◽  
Uncontaminated Soil

A bacterial strain Pseudomonas aeruginosa isolated from an uncontaminated soil has been used for the removal of hexavalent chromium (Cr (VI)). The experiments were carried out in batch system in a culture broth. The results obtained have shown that 100% of Cr (VI) are removed. Contact time, initial concentration of the hexavalent chromium, temperature, as well as the nature of the culture broth have influenced this elimination. To the initial concentration of 20g/L of Cr (VI) the elimination rates are lower, while the reverse occurs for an initial concentration of 8g/L. This study allows considering the use of Pseudomonas aeruginosa in the treatment of water polluted by toxic heavy metals such as Cr (VI).

scholarly journals Adsorption of hexavalent chromium ions from aqueous solutions using nano-chitin: kinetic, isotherms and thermodynamic studies

2021 ◽  
Vol 16 (2) ◽  
pp. 436-451
Author(s):  
Meghdad Sheikhi ◽  
Hassan Rezaei
Keyword(s):  
Aqueous Solutions ◽  
Correlation Coefficient ◽  
Hexavalent Chromium ◽  
Contact Time ◽  
New Technology ◽  
Kinetic Studies ◽  
Chromium Vi ◽  
Effects Of Ph ◽  
Pseudo Second Order ◽  
Adsorbent Dose

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.

Chromium (VI) adsorption onto activated sulfate lignin

2009 ◽  
Vol 4 (2) ◽  
Author(s):  
Nassima Tazrouti ◽  
Moussa Amrani
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Analytical Data ◽  
Order Equation ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Adsorption Model ◽  
Chromium Vi ◽  
Pseudo Second Order

Activated lignin having surface area of 1023 m2.g-1 has been prepared from sulfate lignin that was treated by 30 % H2O2 and carbonized at 300 °C in order to test the chromium (VI) adsorption from aqueous solution. The influence of contact time, pH, initial concentration of adsorbent and adsorbate and temperature on the adsorption capacity were investigated. The maximum removal of Cr(VI) was found to be 92,36 % at pH=2 and contact time of 80 min. Optimal concentration of lignin and Cr(VI) were found to be 3.8 g.l-1 and 180 mg.l-1, respectively. The adsorption kinetics was tested pseudo-first-order and pseudo-second-order equation. The analytical data were fitted well in a pseudo-second-order equation and the rate of removal of chromium was found to speed up with increasing temperature. Activation energy for the adsorption process was found to be 18.19 Kj.mol-1. The Langmuir and Freundlich adsorption isotherm models were applied to describe the isotherm and isotherm constants for the adsorption of Cr (VI) on lignin. These constants and correlation coefficients of the isotherm models were calculated and compared. Results indicated that Cr (VI) uptake could be described by the Langmuir adsorption model. The maximum adsorption capacity (qm) of Cr (VI) on lignin was 75.75 mg.g-1 at temperature of 40°C. The dimensionless equilibrium parameter (RL) signified a favorable adsorption of Cr (VI) on lignin and was found between 0.0601 and 0.818 (0<RL<1). The thermodynamic parameters like ΔG°, ΔS° and ΔH° were calculated and it has been found that the reaction was spontaneous and endothermic in nature. This study indicates that lignin has the potential to become an effective and economical adsorbent for removal Cr (VI) from the waste water.

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

2021 ◽  
Author(s):  
Shamal Chandra Karmaker ◽  
Osama Eljamal ◽  
Bidyut Baran Saha
Keyword(s):  
Contact Time ◽  
Nuclear Power ◽  
Polluted Water ◽  
Isotherm Models ◽  
Initial Concentration ◽  
Removal Process ◽  
Strontium Removal ◽  
Effective Removal ◽  
Potential Contributor ◽  
Experimental Trials

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.

scholarly journals Enhanced removal of chromium (VI) from wastewater using active carbon derived from Lantana camara plant as adsorbent

2018 ◽  
Vol 78 (6) ◽  
pp. 1377-1389 ◽  
Author(s):  
Sujitha Ravulapalli ◽  
Ravindhranath Kunta
Keyword(s):  
Adsorption Capacity ◽  
Active Carbon ◽  
Lantana Camara ◽  
Polluted Water ◽  
Isotherm Models ◽  
Equilibration Time ◽  
Kinetics Of Adsorption ◽  
Chromium Vi ◽  
Ir Studies ◽  
Pseudo Second Order

Abstract Activate carbon prepared from the stems of Lantana camara plant (ACSLC) is investigated as adsorbent for the removal of chromium (Cr) (VI) from polluted water using batch methods of extraction. Various extraction conditions such as pH, initial concentration of Cr (VI), sorbent dosage, temperature, equilibration time and presence of co-ions are optimized. The adsorption capacity is found to be 26.25 mg/g and is more than hitherto reported sorbents in the literature. The spent adsorbent can be regenerated and reused with a marginal reduction in its adsorption capacity. The active carbon is characterized by field emission scanning electron microscope (FESEM), X-ray diffraction (XRD) and Fourier-transform infrared (FT-IR) studies. The sorption mechanism is investigated using various isotherm models and found that the Freundlich model describes the adsorption process well. Thermodynamic studies reveal the endothermic and spontaneous nature of physisorption. The kinetics of adsorption is well defined by the pseudo-second-order model. The methodology developed is successfully applied to effluent samples collected at various industries.

scholarly journals ADSORPTIVE CAPACITY OF COFFEE HUSK IN THE REMOVAL OF CHROMIUM (VI) AND ZINK (II) FROM TANNERY EFFLUENT: KINETICS AND EQUILIBRIUM STUDIES

2020 ◽  
pp. 72-78
Author(s):  
Desalegn Abdissa ◽  
Temesgen Abeto ◽  
Yigezu Mekonnen ◽  
Dejene Beyene
Keyword(s):  
Hexavalent Chromium ◽  
Contact Time ◽  
Ph Value ◽  
Agitation Speed ◽  
Tannery Wastewater ◽  
Adsorptive Capacity ◽  
Coffee Husk ◽  
Chromium Vi ◽  
Removal Capacity ◽  
Adsorbent Dose

Tannery wastewater is the most challenging due to the complex toxic pollutants it releases into the environment. Similarly, coffee husk from coffee processing operations pollutes the environment. The use of coffee husk to remove hexavalent chromium (VI) and Zink (II)from tannery wastewater solves pollution problems due to untreated tannery wastewater and coffee husk. A batch adsorption process was conducted to determine chromium (VI) and Zink (II)adsorptive capacity of waste coffee husk to treat tannery wastewater. The effects of adsorbent dose (0.2-2.4 g/L), contact time (20- 60 min), agitation speed (50-250 rpm), and pH value (2-8) on the adsorptive capacity of coffee husk on the removal of hexavalent chromium (VI) & zinc (II) from tannery wastewater were studied. Using 2.4 g/L adsorbent dose, 250 rpm agitation speed, 60 min contact time, and pH value of 2, a maximum Cr(VI) removal capacity of coffee husk was 83%. The maximum Zn(II) removal capacity of coffee husk was found to be 79% at an adsorbent dose of 2.4 g/L, 60 min contact time, pH 7, and agitation speed of 250 rpm. Therefore, it can be concluded that coffee husk achieved significant removal of hexavalent chromium (VI) and zinc (II) from tannery wastewater.

scholarly journals Investigating the hexavalent chromium removal from aqueous solution applying bee carcasses and corpses modified with Polyaniline

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Ali Hosseini ◽  
Majid Riahi Samani ◽  
Davood Toghraie
Keyword(s):  
Heavy Metals ◽  
Polyethylene Glycol ◽  
Hexavalent Chromium ◽  
Adsorption Isotherms ◽  
Contact Time ◽  
Environmental Pollutants ◽  
Industrial Effluents ◽  
Xrd Analysis ◽  
Chromium Concentration ◽  
Polyethylene Composite

AbstractThere are currently heavy metals in most industrial effluents which are among the most significant environmental pollutants. Hexavalent chromium is one of the most significant heavy metals. In this research for the first time, eliminating the hexavalent chromium from the aqueous medium/aquedia applying bee carcasses and corpses modified with polyethylene was examined. Adsorption experiments were conducted discontinuously on laboratory solutions, including hexavalent chromium. The optimal adsorption conditions such as different pH factors, contact time, initial chromium concentration, and adsorbent value on the adsorption rate were examined at different levels, and adsorption isotherms were plotted. Some adsorbent properties were examined using Field Emission Scanning Electron Microscopy, XRD analysis, Fourier Transform Infrared Spectroscopy, and BET test to study the properties of the synthesized adsorbent. This study indicated that the highest percentage of removal related to polyethylene composite and bee carcasses in the presence of polyethylene glycol was 50.56% among the bee carcasses composites. The parameters effective on the adsorption process for polyethylene composite and bee carcasses and losses in the presence of polyethylene glycol suggested that the adsorption percentage increased for this composite by decreasing the pH, increasing the contact time, and increasing the adsorbent. The highest percentage of adsorption was obtained when the pH was 2, the contact time was 120 min and the adsorbent value was 8 g/L and the initial concentration of chromium was 100 ppm. The most optimal removal percentage was achieved at the pH = 2, the contact time was 30 min, and the adsorbent value was 2 g/L, and the initial chromium concentration was 100 ppm. The results of drawing adsorption isotherms also indicated that higher R2 had a better fit than Langmuir for polyethylene composite and bee carcasses in the polyethylene glycol Freundlich equation.

Chromium (VI) Adsorption on Activated Lignin

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
Nassima Tazerouti ◽  
Moussa Amrani
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Analytical Data ◽  
Correlation Coefficients ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Chromium Vi ◽  
Pseudo Second Order

Activated lignin, having a surface area of 1023 m2 g-1, has been prepared from lignin sulfate that was treated by 30% H2O2 and carbonized at 300°C in order to test the chromium (VI) adsorption from aqueous solution. The influence of contact time, pH, initial concentration of adsorbent and adsorbate and temperature on the adsorption capacity was investigated. The maximum removal of Cr(VI) was found to be 92.36% at pH=2 and a contact time of 80 min. Optimal concentration of lignin and Cr(VI) was found to be 3.8 gL-1 and 180mg L-1, respectively. The adsorption kinetics was examined with pseudo-first-order and pseudo-second-order equations. The analytical data fit well to the pseudo-second-order equation, and the rate of removal of chromium was found to speed up by increasing the temperature. Activation energy for the adsorption process was found to be 18.19 KJ mol-1. The Langmuir-Freundlich adsorption isotherm models were applied to describe the isotherm and its constants for the adsorption of Cr(VI) on lignin. These constants and correlation coefficients of the isotherm models were calculated and compared with each other. Results indicated that Cr(VI) uptake could be described by the Langmuir adsorption isotherm. The maximum adsorption capacity (qmax) of Cr(VI) on lignin was 75.75 mg g-1 at a temperature of 40°C. The dimensionless equilibrium parameter (RL) signified a favorable adsorption of Cr(VI) on lignin and was found to be between 0.0601 and 0.818 (0L<1). The thermodynamic parameters such as ?G°, ?S°, and ?H° were calculated and it has been found that the reaction was spontaneous and endothermic in nature. This study indicates that lignin has the potential to become an effective and economical adsorbent for the removal of Cr(VI) from waste water.

Breakthrough analysis for hexavalent chromium removal from drinking water in a fixed bed column

2009 ◽  
Vol 9 (6) ◽  
pp. 661-670 ◽  
Author(s):  
S. P. Dubey ◽  
K. Gopal
Keyword(s):  
Aqueous Solution ◽  
Hexavalent Chromium ◽  
Fixed Bed ◽  
Entropy Change ◽  
Spectroscopic Technique ◽  
Fixed Bed Column ◽  
Chromium Vi ◽  
Fixed Bed Adsorption ◽  
Optimal Column ◽  
Eucalyptus Bark

The activated carbon of Eucalyptus globulus was tested for their effectiveness in removing hexavalent chromium from aqueous solution using column experiments. Result revealed that adsorption of chromium(VI) on eucalyptus bark carbon was endothermic in nature. Thermodynamic parameters such as the entropy change, enthalpy change and Gibbs free energy change were found to be 1.39 kJ mol−1 K−1, 1.08 kJ mol−1 and −3.85 kJ mol−1, respectively. Different chromium concentrations were used for the fixed bed adsorption studies. The pre- and post-treated adsorbents were characterized using a FTIR spectroscopic technique. It was concluded that Eucalyptus bark carbon column could be used effectively for removal of hexavalent chromium from aqueous solution at optimal column conditions. This study showed that this biological material is potential adsorbent of Cr(VI) from water.

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