scholarly journals In Situ Disassembling Behavior of Composite Hydrogels for the Efficient Removal of Crystal Violet Dye from Aqueous Solution

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Venkatesan Srinivasan ◽  
Sundaram Thiraviam ◽  
Kullagounder Subramani ◽  
Sibi Srinivasan ◽  
Pragathiswaran Chelliah ◽  
...  

A novel method for the disassembly of synthetic hydrogels in situ and thereby enhanced adsorption of crystal violet dye is reported. Silicon present in the husk ashes of Panicum miliare is used as the trigger for disassembly of poly(2-acrylamido-1-propane sulfonic acid-co-itaconic acid) hydrogels. Disassembling ability of the ash was determined by changing the temperature of the husk ash. Surface area and particle sizes of both the disassembled and assembled forms of the hydrogels were determined by E. Suito’s method. Removal of crystal violet dye from aqueous solution and the respective adsorption capacities of disassembled and assembled forms of hydrogels were compared by varying parameters such as pH, temperature, and agitation speed. Concentration of the dye in aqueous solution was determined by using UV-Visible spectrophotometer. FTIR analysis was carried out for the characterization of the hydrogels, ash blended hydrogels, and the free ashes. SEM imaging was carried out to differentiate the surfaces of the assembled and disassembled hydrogels.

2019 ◽  
Vol 7 (2) ◽  
pp. 240-246
Author(s):  
Kaur Harpreet ◽  
Kaur Harpreet ◽  
Vandana Kamboj ◽  
Vandana Kamboj

Water is the most crucial thing to mankind and so its contamination by various agencies is posing a threat to the natural balance. So, in the present work, the efficiency of various adsorbents derived from plant waste, to remove different dyes from aqueous solution was evaluated. Parameters for study were contact time, concentration and pH. Various combinations of plant ashes were used for the study. It was found that adsorbent prepared from the combination of orange peels, pomegranate and banana peels ashes, exhibited good adsorption capacity for methylene blue, congo red and crystal violet. All these dyes were completely removed from the aqueous solution while methyl orange was not removed. Congo red was removed completely within 40 min of contact with the adsorbent while methyl orange took 3 hrs to be removed to the extent of 48% only. The adsorption coefficient of congo red was found to be 2.33 while value for methylene blue and crystal violet was 1 and 1.66 respectively. The characterization of adsorbent was done by Scanning Electron Microscopy and IR spectroscopy. SEM image revealed the surface of adsorbent to be made of differential pores. From the results it became evident that the low-cost adsorbent could be used as a replacement for costly traditional methods of removing colorants from water.


2009 ◽  
Vol 5 ◽  
pp. 79-85 ◽  
Author(s):  
Ranjit R. Hawaldar ◽  
M. Kulkarni ◽  
Sandesh R. Jadkar ◽  
Umapada Pal ◽  
Dinesh Amalnerkar

Conducting Polyaniline (Pani)-crooked Gold nanocomposites were synthesized by in situ chemo-oxidative polymerization of aniline with previously made crooked gold nanoparticles by using ammonium per oxidisulphate as oxidizing agent and p-toluene sulphonic acid (p-TSA) as dopant. The formation of nano gold was established by UV-visible spectroscopy with a SPR peak at 512 nm and crooked morphology was confirmed by TEM. Spectroscopic analysis confirmed the formation of the conducting emeraldine salt phase of the polymer. Due to clustering of composite nanoparticles, the polymer composite formed one-dimensional rod-like morphologies. Thermogravimetric analysis revealed a typical three-step decomposition pattern pertaining to polyaniline emeraldine salt. The conductivity of the nanocomposite was found to be lower (2.47 S/cm) than the virgin p-TSA doped polyaniline (5.55 S/cm).


2013 ◽  
Vol 67 (4) ◽  
pp. 737-744 ◽  
Author(s):  
J. X. Zhang ◽  
L. L. Ou

The adsorption of crystal violet dye from aqueous solutions onto an activated carbon prepared from peanut shells was analyzed in this study. The effects of particle size, initial concentration, time and temperature on crystal violet removal were studied in batch experiments. Experimental results showed that the adsorption equilibrium was achieved within 100 min for all studied concentrations. Analysis of adsorption results showed that the adsorption isotherms could be well fitted to the Langmuir model. Kinetic parameters, rate constants, equilibrium adsorption capacities and related correlation coefficients for pseudo first-order and second-order kinetic models were calculated and discussed. The results revealed that the adsorption kinetics was in good agreement with the pseudo second-order equation. Thermodynamic parameters such as the change of Gibbs free energy (ΔG°), change of enthalpy (ΔH°) and change of entropy (ΔS°) have also been determined and it has been found that the adsorption process should be spontaneous, endothermic and physisorption in nature.


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