Mespilus germanica (MG) and Tribulus terrestris (TT) Used as Biosorbents for Lead Removal from Aqueous Solutions: Adsorption Kinetics and Mechanisms

Today, most countries around the globe are facing water resources restrictions, and it is predicted freshwater resources will be more valuable than oil wells in the next century. In the present study, the ability of lead removal using both powders of Mespilus germanica (MG) and Tribulus terrestris (TT) seeds and optimization of the adsorption process have been investigated. Four main parameters were selected for experimental design, namely, pH, time of contact, the ratio of adsorbent to solution volume, and initial concentration of lead in solution, and the optimization of effective parameters on lead adsorption was performed based on central composite design (CCD) under response surface methodology (RSM). According to the statistical results, the proposed model for MG and TT is confirmed with 0.95 and 0.96 correlation coefficient and 0.92 and 0.94 adjusted correlation coefficient, respectively. The results of parameter optimization also showed that both adsorbents have the acceptable ability to adsorb lead from aqueous solutions. Under the optimum conditions with the initial lead concentration of 10 mg/l, MG powder had better performance in lead adsorption of 96.04%, and TT powder also had an acceptive performance of 93.20%. Moreover, the MG and TT adsorbents have the most accordance with the Freundlich and D-R isotherms, respectively.

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Adsorption of Lead Ions from Aqueous Solutions Using Gamma Irradiated Minerals

Journal of Chemistry ◽

10.1155/2016/8782469 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Julián Cruz-Olivares ◽

Gonzalo Martínez-Barrera ◽

César Pérez-Alonso ◽

Carlos Eduardo Barrera-Díaz ◽

María del Carmen Chaparro-Mercado ◽

...

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Magnesium Silicate ◽

Correlation Factor ◽

Lead Removal ◽

Order Kinetic ◽

Lead Adsorption ◽

Order Kinetic Model ◽

Calcium Magnesium ◽

Gamma Irradiated

For the first time, an irradiated mineral was used as a novel modified adsorbent for lead removal of aqueous solutions. The effects of gamma radiation doses and temperature on the lead adsorption capacity of an unknown mineral were evaluated. The results show that, in the chemisorption process, the highest adsorption capacity (9.91 mg/g) and the maximum percentage of lead removal (99.1%) were reached at 40°C when using an irradiated mineral at 150 kGy. The improvement on the lead adsorption speed was the most important feature of the irradiated mineral. The experimental results were successfully correlated with the pseudo second-order kinetic model. For all results, the average absolute relative deviations (AARD) were less than 13.20%, and the correlation factor (r2) was higher than 0.998. Moreover, the average values of the thermodynamic parameters (ΔG0=-10612 J/mol, ΔH0=-12360 J/mol, and ΔS0=171 J/mol K) suggest the feasibility of the proposed process, in terms of the endothermic and irreversible chemisorption results; moreover, ion exchange was evaluated through the EDS results. The X-ray diffraction analysis showed that the unknown irradiated mineral is mainly composed of quartz (SiO2), calcite (CaCO3), and calcium magnesium silicate (Ca0.15Mg0.85) Mg (SiO6).

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REMOVAL OF Ni2+ FROM AQUEOUS SOLUTION BY ADSORPTION ONTO TEA WASTE–DERIVED ACTIVATED CARBON

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/54/4b/12048 ◽

2018 ◽

Vol 54 (4B) ◽

pp. 251

Author(s):

Long Giang Bach

Keyword(s):

Activated Carbon ◽

Aqueous Solutions ◽

Polynomial Regression ◽

Raw Material ◽

Regression Equations ◽

Optimum Conditions ◽

Tea Waste ◽

Order Polynomial ◽

Efficient Adsorbent ◽

Central Composite

Activated carbon from a locally available and widespread tea waste source was fabricated, characterized and used as an efficient adsorbent for the removal of Ni2+ from aqueous solutions. The response surface methodology (RSM) and central composite design (CCD) were used to investigate the effect of the essential variables including initial concentration, adsorbent dosage and pH solution on the absorption of Ni2+. The order polynomial regression equations–based model has been developed and found to be statistically significant by values of the coefficients of determination (R2) closer than 1.0 and the P–values < 0.0001 from analysis of variance (ANOVA). Based on the predicted optimum conditions, actual experiment was employed to obtain the maximum percentage of Ni2+ removal efficiency (96.6 %). There is no doubt that the use of tea waste as abundant raw material for the preparation of activated carbon to remove Ni2+from aqueous solutions by five times with negligible change is a promising way.

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Study of potential oscillations during reaction of an aluminium single crystal with an aqueous KOH solution

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19900345 ◽

1990 ◽

Vol 55 (2) ◽

pp. 345-353 ◽

Cited By ~ 4

Author(s):

Ivan Halaša ◽

Milica Miadoková

Keyword(s):

Aqueous Solutions ◽

Single Crystal ◽

Single Crystals ◽

Periodic Potential ◽

Optimum Conditions ◽

Potential Oscillations ◽

Dilute Aqueous Solutions ◽

Experimental Findings ◽

Kinetics Of

The authors investigated periodic potential changes measured on oriented sections of Al single crystals during spontaneous dissolution in dilute aqueous solutions of KOH, with the aim to find optimum conditions for the formation of potential oscillations. It was found that this phenomenon is related with the kinetics of the reaction investigated, whose rate also changed periodically. The mechanism of the oscillations is discussed in view of the experimental findings.

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Leaching and solvent extraction purification of zinc from Mehdiabad complex oxide ore

Scientific Reports ◽

10.1038/s41598-021-81141-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Faraz Soltani ◽

Hossna Darabi ◽

Reza Aram ◽

Mahdi Ghadiri

Keyword(s):

Solvent Extraction ◽

Environmental Pollution ◽

Central Composite Design ◽

Complex Oxide ◽

Hydrometallurgical Process ◽

Purification Process ◽

Optimum Conditions ◽

Leaching Experiments ◽

Central Composite ◽

Sulphuric Acid Concentration

AbstractAn integrated hydrometallurgical process was used for the zinc leaching and purification from a zinc ore containing 9.75 wt% zinc. The zinc minerals in the ore were hemimorphite, willemite, and calcophanite. Main gangue minerals were quartz, goethite, hematite, and calcite. Central composite design (CCD) method was used to design leaching experiments and the optimum conditions were found as follows: 30% of solid fraction, 22.05% sulphuric acid concentration, and the leaching temperature of 45 °C. The PLS containing 35.07 g/L zinc, 3.16 g/L iron, and 4.58 g/L manganese impurities was produced. A special purification process including Fe precipitation and Zn solvent extraction was implemented. The results showed that after precipitation of iron, Zn extraction of 88.5% was obtained with the 2 stages extraction system composed of 30 vol% D2EHPA as extractant. The overall Zn recovery from the ore was 71.44%. Therefore, an appropriate solution containing 16.6 g/L Zn, 0.05 g/L Fe, and 0.11 g/L Mn was prepared for the electro-winning unit without using the roasting and calcination steps (conventional method), which result in environmental pollution.

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Optimization of processing parameters to control Maillard browning in ready-to-eat processed potatoes

Food Science and Technology International ◽

10.1177/1082013220984295 ◽

2021 ◽

pp. 108201322098429

Author(s):

Revenli Fernanda do Nascimento ◽

Maria Helene Giovanetti Canteri ◽

Sabrina Ávila Rodrigues ◽

Juliana Vitória Messias Bittencourt

Keyword(s):

Processing Parameters ◽

B Value ◽

Effective Parameters ◽

Browning Index ◽

Index Reduction ◽

L Value ◽

Processed Potatoes ◽

Maillard Browning ◽

Central Composite

Relationship among pH, aw and Maillard browning was investigated in processed potatoes ready-to-eat during cooking and sterilization in autoclave to prevent their colors changes. Central composite rotational design was used for optimization of color (L*, a* and b*), browning index and intermediate compounds index. Reduction in the L* value and increase in the a*, b* value and browning index, indicators for Maillard browning of the processed potatoes were mitigated at pH 4.0–5.0 and aw 0.96–1.00 and accelerated at pH less than 3.0 or more than 7.0 and aw less than 0.84. Formation of intermediate compounds was intensified at pH 5.0 and aw 0.99 and mitigated at pH 7.0 and aw 0.84. Adjustment of the pH to 5.0 and keeping aw at to 0.99 were the most effective parameters of to control Maillard browning in processed potatoes ready-to-eat.

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Biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus

Water Science & Technology ◽

10.2166/wst.2012.332 ◽

2012 ◽

Vol 66 (8) ◽

pp. 1699-1707 ◽

Cited By ~ 3

Author(s):

A. K. Giri ◽

R. K. Patel ◽

P. C. Mishra

Keyword(s):

Aqueous Solutions ◽

Bacillus Cereus ◽

Contact Time ◽

Living Cells ◽

Optimum Conditions ◽

Order Model ◽

Initial Concentration ◽

Pseudo Second Order ◽

Biomass Dosage ◽

Batch Biosorption

In this work, the biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus has been reported. The batch biosorption experiments were conducted with respect to biosorbent dosage 0.5 to 15 g/L, pH 2 to 9, contact time 5 to 90 min, initial concentration 1 to 10 mg/L and temperature 10 to 40 °C. The maximum biosorption capacity of B. cereus for As(V) was found to be 30.04 at pH 7.0, at optimum conditions of contact time of 30 min, biomass dosage of 6 g/L, and temperature of 30 ± 2 °C. Biosorption data were fitted to linearly transformed Langmuir isotherms with R2 (correlation coefficient) >0.99. Bacillus cereus cell surface was characterized using AFM and FTIR. The metal ions were desorbed from B. cereus using both 1 M HCl and 1 M HNO3. The pseudo-second-order model was successfully applied to predict the rate constant of biosorption.

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Kaempferol Extraction from Cuscuta reflexa using Supercritical Carbon Dioxide and Separation of Kaempferol from the Extracts

International Journal of Food Engineering ◽

10.2202/1556-3758.1768 ◽

2011 ◽

Vol 7 (4) ◽

Cited By ~ 1

Author(s):

Pranabendu Mitra ◽

Kyu -Seob Chang ◽

Dae-Seok Yoo

Keyword(s):

Supercritical Co2 ◽

Extraction Process ◽

Optimum Conditions ◽

Supercritical Co2 Extraction ◽

Independent Variables ◽

Cuscuta Reflexa ◽

Optimal Processing ◽

Layer Chromatography ◽

Temperature Time ◽

Central Composite

Kaempferol, a strong antioxidant, was extracted from Cuscuta reflexa (a medicinal plant) using supercritical CO2 and separated using thin-layer chromatography, column chromatography and HPLC analysis. A rotatable central composite design was used to determine the influence of process variables and arrive at optimal processing conditions in the supercritical CO2 extraction process of kaempferol. The kaempferol yield was effectively modelled as a function of the independent variables (temperature, time and pressure). The kaempferol yield increased with the increasing of temperature and time and decreasing of pressure of the supercritical CO2 extraction process. The predicted kaempferol yield at the optimum point was 52.92 µg/g and the optimum conditions were 50.7°C for 132.6 min and 15.9 MPa.

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PENAMBAHAN ASAM OLEAT TERHADAP Sistem transpor Cu(II) dengan zat pembawa oksin melalui teknik membran cair fasa ruah

Jurnal Riset Kimia ◽

10.25077/jrk.v2i1.88 ◽

2015 ◽

Vol 2 (1) ◽

pp. 45

Author(s):

Olly Norita Tetra ◽

Zaharasmi ◽

Refinel

Keyword(s):

Aqueous Solutions ◽

Liquid Membrane ◽

Bulk Liquid ◽

Optimum Conditions ◽

Membrane Phase ◽

Bulk Liquid Membrane ◽

Phase 0 ◽

Interface System ◽

Source Phase ◽

Feed Phase

ABSTRACT The removal of Cu(II) from aqueous solutions had been employed throught bulk liquid membrane techniques with arrange the optimization conditions of transport Cu(II) interface system. The optimum conditions of transport were found to be 3.1510-4 M of Cu(II) at pH 3 in the source phase, 17.510-4 M oxine dissolved into chloroform as membrane phase, 0,15 M H2SO4 as acceptor in receiving phase, stirring rate was 340 rpm and it was found that the transport of Cu(II) to receiving phase reached 97.41% during 6 hours. The effect of addition oleat acid 1.57 10-3 M as surfactant in membrane phase resulted a rapidly time of transport Cu(II) to be 3 hours, wherein Cu(II) transported into the receive phase reached 97.83% and remained in feed phase 0%. Keywords: bulk liquid membrane, oxine, oleat acid, Cu(II) )transport

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