scholarly journals Cationic High Molecular Weight Lignin Polymer: A Flocculant for the Removal of Anionic Azo-Dyes from Simulated Wastewater

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2005 ◽  
Author(s):  
Shoujuan Wang ◽  
Fangong Kong ◽  
Pedram Fatehi ◽  
Qingxi Hou

The presence of dyes in wastewater effluents made from the textile industry is a major environmental problem due to their complex structure and poor biodegradability. In this study, a cationic lignin polymer was synthesized via the free radical polymerization of lignin with [2-(methacryloyloxy) ethyl] trimethyl ammonium chloride (METAC) and used to remove anionic azo-dyes (reactive black 5, RB5, and reactive orange 16, RO16) from simulated wastewater. The effects of pH, salt, and concentration of dyes, as well as the charge density and molecular weight of lignin-METAC polymer on dye removal were examined. Results demonstrated that lignin-METAC was an effective flocculant for the removal of dye via charge neutralization and bridging mechanisms. The dye removal efficiency of lignin-METAC polymer was independent of pH. The dosage of the lignin polymer required for reaching the maximum removal had a linear relationship with the dye concentration. The presence of inorganic salts including NaCl, NaNO3, and Na2SO4 had a marginal effect on the dye removal. Under the optimized conditions, greater than 98% of RB5 and 94% of RO16 were removed at lignin-METAC concentrations of 120 mg/L and 105 mg/L in the dye solutions, respectively.

Author(s):  
Shoujuan Wang ◽  
Fangong Kong ◽  
Pedram Fatehi ◽  
Qingxi Hou

The presence of dyes in wastewater effluents made from the textile industry is a major environmental problem due to their complex structure and poor biodegradability. In this study, a cationic lignin polymer was synthesized via the free radical polymerization of lignin with [2- (methacryloyloxy) ethyl] trimethylammonium chloride (METAC) and used to remove anionic azo-dyes (reactive black 5, RB5, and reactive orange 16, RO16) from simulated wastewater. The effects of pH, salt and concentration of dyes, well as the charge density and molecular weight of lignin-METAC polymer on dye removal were examined. Results demonstrated that lignin-METAC was an effective flocculant for the removal of dye via charge neutralization and bridging mechanisms. The dye removal efficiency of lignin-METAC polymer was independent of pH. The dosage of the lignin polymer required for reaching the maximum removal had a linear relationship with the dye concentration. The presence of inorganic salts including NaCl, NaNO3 and Na2SO4 had marginal effect on the dye removal. Under the optimized conditions, greater than 98 % of RB5 and 94 % of RO16 were removed at lignin-METAC concentrations of 120 mg/L and 105 mg/L in the dye solutions, respectively.


2021 ◽  
Author(s):  
Tanvir Arfin ◽  
Dipti A. Bhaisare ◽  
S. S. Waghmare

Polyaniline–iron(ii) nitrate was prepared by the polymerization of aniline hydrochloride with Fe(NO3)2.


2018 ◽  
Vol 38 (3) ◽  
pp. 8-14 ◽  
Author(s):  
María Alejandra Flórez-Restrepo ◽  
Madeleiner García Jiménez ◽  
Diego Fernando López Lugo ◽  
Luisa María Múnera Porras ◽  
Nancy Johanna Pino Rodríguez ◽  
...  

The textile industry is a generator of high volumes of waste water with a high content of pollutants such as azo dyes, which are recalcitrant and persistent in the environment, these ones have been of interest in the last decades for the entities in charge of the care of the environment. This study evaluated the ability to discolor of reactive black 5 (NR5) by a consortium and the microorganisms that constitute Rhodotorula mucilaginosa, Galactomyces pseudocandidum and Escherichia coli free and immobilized in calcium alginate, coffee husks and bagasse of sugar cane. The results show discoloration was evidenced, where the highest percentage corresponds to G. pseudocandidum (90,05%) and the lowest to R. mucilaginosa (79,31%). When comparing the percentages of discoloration between the free microorganisms and the immobilization matrices, it is observed that the former exhibit the highest percentages of discoloration. In addition, there are no significant differences between using cane bagasse or coffee husks as immobilization matrix.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Marco S. Lucas ◽  
Manuel Algarra ◽  
José Jiménez-Jiménez ◽  
Enrique Rodríguez-Castellón ◽  
José A. Peres

Fenton’s reaction is often used to decompose stable substances in wastewater. In this study, experiments based on the effect of porous phosphate heterostructures as catalyst sorbent of Fe2+synthesised by different procedures were planned. The examined PPH-Fe/H2O2as oxidant in a heterogeneous process under mild conditions at pH 5 was found to be very efficient for discoloration of a simulated wastewater containing 50 mg L−1of a commercial azo dye (Reactive Black 5) reaching 95% of decolourization. Under the described conditions total visual decolourization was achieved after 360 min. This study can provide a simple, effective, and economic system ideal for the treatment of toxic and nonbiodegradable azo dyes.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9858-9881
Author(s):  
Ambika Saxena ◽  
Sarika Gupta

In recent years, India has emerged as a promising industrial hub. It has a cluster of textile, dyeing, and printing industries. The adjoining rivers/water bodies receive mostly untreated discharge from these industries. Textile industrial effluent contains various contaminants (dyes, heavy metals, toxicants, and other organic/inorganic dissolved solids) that alter the physico-chemical properties of adjoining land and waterbodies in which it is discharged, thereby degrading the water quality and subsequently affecting the landscapes in the vicinity. This ultimately affects the flora and fauna of the locale and has adverse effects on human health. Out of the total dyes (approximately 10,000 dyes) exploited in the textile dyeing and printing units, azo dyes possess a complex structure and are synthetic in origin. They contribute nearly 70% to the total effluent discharge. Biological processes are based on the ability of inhabiting indigenous microorganisms in these contaminated environments to tolerate, resist, decolorize/degrade, and mitigate the recalcitrant compounds. Exploring microbes with higher efficacy of azo dye degradation can reduce the amount of chemical discharged from the process. The present review explores the potential of microbial diversity for the development of an effective bioremediation approach. The review also includes the impact of azo dyes on the flora and fauna, as well as conventional and microbe-assisted nanoparticle technology for treatment of the textile wastewater targeting the degradation of dye contaminants.


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