scholarly journals Adsorption of crystal violet from aqueous solution onto sugarcane bagasse: central composite design for optimization of process variables

2012 ◽  
Vol 2 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Sagnik Chakraborty ◽  
Shamik Chowdhury ◽  
Papita Das Saha
Keyword(s):  
Aqueous Solution ◽  
Central Composite Design ◽  
Sugarcane Bagasse ◽  
Crystal Violet ◽  
Agitation Speed ◽  
Initial Solution ◽  
Optimum Conditions ◽  
Solution Ph ◽  
Central Composite ◽  
Adsorbent Dose

The adsorption of crystal violet (CV) from aqueous solution by sugarcane bagasse (SCB), an agro-industrial residue, was investigated in a batch experimental setup. A two level four factor (24) full factorial central composite design (CCD) with the help of Design Expert Version 7.1.6 (Stat-Ease, USA) was used for adsorption process optimization and evaluation of interaction effects of different operating parameters: agitation speed (80–180 rpm), initial solution pH (4.0–8.0), initial dye concentration (100–200 mg L–1), and adsorbent dose (2–5 g L–1). A multiple coefficient of determination (R2) value of 0.98, model F value of 266.36 and its low P-value (<0.0001) along with lower value of coefficient of variation (2.70%) indicated the fitness of the response surface quadratic model developed during the present study. Numerical optimization applying desirability function was used to identify the optimum conditions for maximum removal of CV. The optimum conditions were found to be agitation speed = 165 rpm, initial solution pH = 8.0, initial dye concentration = 200 mg L–1 and adsorbent dose = 2.0 g L–1. A confirmatory experiment was performed to evaluate the accuracy of the optimization procedure and maximum CV removal of 93.21% was achieved under the optimized conditions.

scholarly journals Mass-transfer processes in the adsorption of crystal violet by activated carbon derived from pomegranate peels: Kinetics and thermodynamic studies

2020 ◽  
Vol 15 ◽  
pp. 155892502091984
Author(s):  
Moussa Abbas ◽  
Zahia Harrache ◽  
Mohamed Trari
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Crystal Violet ◽  
Agitation Speed ◽  
Second Order ◽  
Point Of Zero Charge ◽  
Order Kinetic ◽  
Solution Ph ◽  
Pseudo Second Order ◽  
Adsorbent Dose

This study investigates the potential use of activated carbon, prepared from pomegranate peels, as an adsorbent activated using H3PO4 and its ability to remove crystal violet from an aqueous solution. The adsorbent was characterized by the Brunauer–Emmett–Teller method (specific surface area: 51.0674 m2 g−1) and point of zero charge (pHPZC = 5.2). However, some examined factors were found to have significant impacts on the adsorption capacity of activated carbon derived from pomegranate peels such as the initial dye concentration (5–15 mg L−1), solution pH (2–14), adsorbent dose (1–8 g L−1), agitation speed (100–700 r/min), and temperature (298–338 K). The best adsorption capacity was found at pH 11 with an adsorbent dose of 1 g L−1, an agitation speed at 400 r/min, and a contact time of 45 min. The adsorption mechanism of crystal violet onto activated carbon derived from pomegranate peels was studied using the pseudo-first-order, pseudo-second-order, Elovich, and Webber–Morris diffusion models. The adsorption kinetics were found to rather follow a pseudo-second order kinetic model with a determination coefficient ( R2) of 0.999. The equilibrium adsorption data for crystal violet adsorbed onto activated carbon derived from pomegranate peels were analyzed by the Langmuir, Freundlich, Elovich, and Temkin models. The results indicate that the Langmuir model provides the best correlation with qmax capacities of 23.26 and 76.92 mg g−1 at 27°C and 32°C, respectively. The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters like the free energy, enthalpy, and entropy to predict the nature of adsorption process. The negative values Δ G0 (−5.221 to −1.571 kJ mol−1) and Δ H0 (−86.141 kJ mol−1) indicate that the overall adsorption is spontaneous and exothermic with a physisorption process. The adsorbent derived from pomegranate peels was found to be very effective and suitable for the removal of reactive dyes from aqueous solutions, due to its availability, low-cost preparation, and good adsorption capacity.

scholarly journals Tartaric Acid-Modified Holarrhena antidysenterica and Citrullus colocynthis Biowaste for Efficient Eradication of Crystal Violet Dye from Water

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Sumaira Basharat ◽  
Rabia Rehman ◽  
Tariq Mahmud ◽  
Sara Basharat ◽  
Liviu Mitu
Keyword(s):  
Tartaric Acid ◽  
Crystal Violet ◽  
Agitation Speed ◽  
Order Kinetic ◽  
Citrullus Colocynthis ◽  
Solution Ph ◽  
Dose Time ◽  
Holarrhena Antidysenterica ◽  
Adsorptive Behavior ◽  
Adsorbent Dose

Two novel adsorbents Holarrhena antidysenterica (HA) and Citrullus colocynthis (CC) were collected from native Pakistan and treated with tartaric acid. The adsorbents were characterized by Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy, and their adsorptive behavior was studied against model cationic dye crystal violet (CV). Role of biosorbent dose, time of contact, temperature studies, agitation rates, and solution pH was investigated. Optimum conditions obtained for the removal of CV dye for H. antidysenterica-tartaric acid modified (HA-TA) were as follows: 0.8 g adsorbent dose, 35 minutes contact time, 5.0 pH, 40°C temperature, and 150 rpm agitation rates as compared to H. antidysenterica that gave 1.4 g adsorbent dose, 40 minutes time of contact, 6.0 pH, 50°C temperature, and 150 rpm agitation speed. C. colocynthis-tartaric acid modified (CC-TA) removed CV dye at 0.6 g adsorbent dose, 30 minutes contact interval, 4.0 pH, 40°C temperature, and 125 rpm agitation speed in contrast to C. colocynthis which gave 0.8 g adsorbent dose, 40 minutes time of contact, 6.0 pH, 50°C temperature, and 125 rpm agitation speed, respectively. Isothermal studies for both raw and modified biosorbents were compliant with the Langmuir model indicating monolayer, chemisorption. The maximum Langmuir capacities were up to 128.20 mg/g, 136.98 mg/g, 144.92 mg/g, and 166.66 mg/g for HA, CC, HA-TA, and CC-TA. Pseudo-second-order kinetic model well fitted the dye removal data. The rate-determining steps involved both surface and intraparticle diffusion mechanisms. Adsorption of dye molecules on active surfaces was governed by electrostatic attractions and chelating abilities. Thermodynamics research revealed the spontaneous and exothermic nature of the reaction. The adsorbents serve promising candidates for the effective removal of hazardous dyes from aqueous solutions.

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

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.

scholarly journals Pineapple Bark Performance in Dyes Adsorption: Optimization by the Central Composite Design

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Ahlam Fegousse ◽  
Abdelali El Gaidoumi ◽  
Youssef Miyah ◽  
Rabea El Mountassir ◽  
Anissa Lahrichi
Keyword(s):  
Central Composite Design ◽  
Design Methodology ◽  
Brilliant Green ◽  
Optimal Conditions ◽  
Initial Concentration ◽  
Dyes Adsorption ◽  
Experimental Design Methodology ◽  
Central Composite ◽  
Adsorbent Dose ◽  
Scanning Electron

This work is concerned with the study of the adsorption in aqueous medium of a three-dye mixture which contains Methylene Blue, Brilliant Green, and Congo Red on the pineapple bark. This adsorbent material has been characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The experimental design methodology, based on the response surface methodology (RSM) by the central composite design (CCD), has been applied for the optimization of the parameters, namely, the temperature, dose of the adsorbent, and pH. The yield reached 98.91% under optimal conditions (T = 30°C; adsorbent dose = 2.5 g·L−1; pH = 9.8) at an initial concentration of 20 mg·L−1.

scholarly journals Carbon dots as absorbance promoter probes for detection of Cu(ii) ions in aqueous solution: central composite design approach

2018 ◽  
Vol 17 (2) ◽  
pp. 245-255 ◽  
Author(s):  
S. A. R. Shahamirifard ◽  
M. Ghaedi ◽  
M. Montazerozohori ◽  
A. Masoudiasl
Keyword(s):  
Aqueous Solution ◽  
Central Composite Design ◽  
Carbon Dots ◽  
Design Approach ◽  
Complexing Agent ◽  
Vis Spectroscopy ◽  
First Time ◽  
Central Composite ◽  
Determination Of Copper

In this work, the use of carbon dots (CDs) as a complexing agent and sensitizer in a polymeric matrix for determination of copper(ii) by UV-vis spectroscopy is reported for the first time.

Optimization of cellulose and sugarcane bagasse oxidation: Application for adsorptive removal of crystal violet and auramine-O from aqueous solution

2017 ◽  
Vol 494 ◽  
pp. 223-241 ◽  
Author(s):  
Luide Rodrigo Martins ◽  
Josilene Aparecida Vieira Rodrigues ◽  
Oscar Fernando Herrera Adarme ◽  
Tânia Márcia Sacramento Melo ◽  
Leandro Vinícius Alves Gurgel ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Sugarcane Bagasse ◽  
Crystal Violet ◽  
Adsorptive Removal ◽  
Auramine O
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