Decolorization of mixture of UV/ TiO2 pre-treated azo dyes by using developed bacterial consortium – An excellent outcome

2021 ◽  
Vol 16 (10) ◽  
pp. 111-119
Author(s):  
Shamsi Shoa ◽  
Fathima S.G. Bibi ◽  
K. Sangeetha ◽  
S. Niveditha ◽  
Krishna Bayineni Venkata

The degradation of the mixture of azo dyes by the developed bacterial consortium, photocatalytic process (TiO2/UV) and their combined effects were investigated in this study. The bacteria consortium was developed from waste disposal drains in the local textile dyeing industry. The consortium consists of two different bacteria which were identified as Stenotrophomonas pavanii and Bacillus licheniformis through 16S rDNA sequence alignment. The decolorization efficiency was estimated by spectrophotometry and it was observed that biological and photochemical methods alone could not effectively remove the dyes as the decolorization efficiency was low and the absorption peak in the UV region was not completely removed. After 5 days of incubation at 37°C, pH 7 and a dye concentration of 150 mg/L, the microbial dye degradation reached a decolorization efficiency of more than 55%. Additionally, the UV treatment alone was also able to decolorize the dye less than 20% at 45°C, pH 9 at 150 mg/L of dye. A two-step treatment process, namely, photocatalytic treatment followed by biological degradation, was assessed. Ultraviolet-Visible (UVVis) spectral analysis showed that the combined effects were most efficient in the dye degradation (97-98%) which involved a complex interaction of enzyme activity, biosorption and photocatalytic action. Here we also report the optimization of various operational parameters.

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.


2015 ◽  
Vol 73 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Eric da Cruz Severo ◽  
Chayene Gonçalves Anchieta ◽  
Vitória Segabinazzi Foletto ◽  
Raquel Cristine Kuhn ◽  
Gabriela Carvalho Collazzo ◽  
...  

FeWO4 particles were synthesized by a simple, rapid and facile microwave technique and their catalytic properties in heterogeneous photo-Fenton reaction were evaluated. This material was employed in the degradation of Amaranth azo dye. Individual and interactive effects of operational parameters such as pH, dye concentration and H2O2 dosage on the decolorization efficiency of Amaranth dye were evaluated by 23 central composite design. According to characterization techniques, a porous material and a well-crystallized phase of FeWO4 oxide were obtained. Regarding the photo-Fenton reaction assays, up to 97% color and 58% organic carbon removal were achieved in the best experimental conditions. In addition, the photo-Fenton process maintained treatment efficiency over five catalyst reuse cycles to indicate the durability of the FeWO4 catalyst. In summary, the results reveal that the synthesized FeWO4 material is a promising catalyst for wastewater treatment by heterogeneous photo-Fenton process.


Author(s):  
Amaia Menendez ◽  
Jose Ignacio Lombraña ◽  
Ana de Luis

AbstractSynthetic dyes are extensively used in textile dyeing, paper printing, colour photography, pharmaceuticals, food, cosmetics and other industries. In spite of their diversity there are a certain number of properties common to many dye compounds, such as aromatic constitution, chromophore groups and others. Similarly to other dyes and due to the formation of colour intermediates, in the case of Rhodamine 6G colour capacity is maintained in the initial steps of dye degradation. For this reason in the degradation of a dye it is necessary to distinguish between two processes that take place simultaneously: dye removal and decolourization. This study was conducted by using a water solution of 50 mg/L of Rhodamine 6G (Rh-6G), as a model of a dye wastewater, in the hydrogen peroxide/UV system. The kinetic model proposed in this paper for the removing of Rh- 6G is a sequential first-order reaction. This model describes acceptably the changes in two kinds of compound for a wide interval of H


2003 ◽  
Vol 48 (4) ◽  
pp. 53-60 ◽  
Author(s):  
E. Trably ◽  
D. Patureau ◽  
J.P. Delgenes

Anaerobically stabilized sewage sludge has potential to partially substitute synthetic fertilizers. The main risk with the recycling of urban sludge on agricultural soils is the accumulation of unwanted products, such as trace metals and organic micropollutants. In this context, the polycyclic aromatic hydrocarbons (PAHs) are particularly monitored because of their toxic properties at low concentrations and their high resistance to biological degradation. The aim of the present study was to optimize PAHs removal during anaerobic digestion of contaminated sewage sludge. Thirteen PAHs were monitored in laboratory-scale anaerobic bioreactors under mesophilic (35°C) and thermophilic (55°C) methanogenic conditions. Abiotic losses were statistically significant for the lightest PAHs, such as fluorene, phenanthrene and anthracene. It was shown that PAH removal was due to a specific biological activity. Biological PAHs removal was significantly enhanced by an increase of the temperature from 35°C to 55°C, especially for the heaviest PAHs. Bioaugmentation experiment was also performed by addition of a PAH-adapted bacterial consortium to a non-acclimated reactor. Significant enhancement of PAHs removal was observed. It was finally shown that PAH removal efficiencies and methanogenic performances were closely linked. The rate of biogas production may be used as an indicator of bacterial activity on PAH removal.


2005 ◽  
Vol 67 (1) ◽  
pp. 55-61 ◽  
Author(s):  
M KHEHRA ◽  
H SAINI ◽  
D SHARMA ◽  
B CHADHA ◽  
S CHIMNI

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Nedra Asses ◽  
Lamia Ayed ◽  
Neila Hkiri ◽  
Moktar Hamdi

Congo red is one of the best known and used azo dyes which has two azo bonds (-N=N-) chromophore in its molecular structure. Its structural stability makes it highly toxic and resistant to biodegradation. The objective of this study was to assess the congo red biodegradation and detoxification by Aspergillus niger. The effects of pH, initial dye concentration, temperature, and shaking speed on the decolorization rate and enzymes production were studied. The maximum decolorization was correlated with lignin peroxidase and manganese peroxidase production. Above 97% were obtained when 2 g mycelia were incubated at pH 5, in presence of 200 mg/L of dye during 6 days at 28°C and under 120 to 150 rpm shaking speed. The degraded metabolites were characterized by using LC-MS/MS analyses and the biodegradation mechanism was also studied. Congo red bioconversion formed degradation metabolites mainly by peroxidases activities, i.e., the sodium naphthalene sulfonate (m/z = 227) and the cycloheptadienylium (m/z = 91). Phytotoxicity and microtoxicity tests confirmed that degradation metabolites were less toxic than original dye.


Author(s):  
Veena Gayathri Krishnaswamy

The limited availability of fresh water is a global crisis. The growing consumption of fresh water due to anthropogenic activities has taken its toll on available water resources. Unfortunately, water bodies are still used as sinks for waste water from domestic and industrial sources. Azo dyes account for the majority of all dye stuffs, produced because they are extensively used in the textile, paper, food, leather, cosmetics, and pharmaceutical industries. Bacterial degradation of azo dyes under certain environmental conditions has gained momentum as a method of treatment, as these are inexpensive, eco-friendly, and can be applied to wide range of such complex dyes. The enzymatic approach has attracted much interest with regard to degradation of azo dyes from wastewater. The oxido-reductive enzymes are responsible for generating highly reactive free radicals that undergo complex series of spontaneous cleavage reactions, due to the susceptibility of enzymes to inactivation in the presence of the other chemicals. The oxidoreductive enzymes, such as lignin peroxidase, laccases, tyrosinase, azoreductase, riboflavin reductive, polyphenol oxidase, and aminopyrine n-demethylase, have been mainly utilized in the bacterial degradation of azo dye. Along with the reductive enzymes, some investigators have demonstrated the involvement in some other enzymes, such as Lignin peroxides and other enzymes. This chapter reviews the importance of enzymes in dye degradation.


2014 ◽  
Vol 575 ◽  
pp. 50-54 ◽  
Author(s):  
Nur Azrini Ramlee ◽  
M.N. Muhd Rodhi ◽  
A.D. Anak Brandah ◽  
A. Anuar ◽  
N.H. Alias ◽  
...  

The objectives of this study are mainly focusing on reviewing the potential of membrane bioreactor application in Batik dyes degradation and to identify the factors contributing to the permeability and selectivity of a membrane-coupled bacteria reactor. It is evidently that integrating membrane technology with biological reactors for the treatment of textile dyeing wastewaters has led to the development of three generic membrane processes within bioreactors: for separation and recycle of solids, for bubble-less aeration of the bioreactor, and for extraction of priority organic pollutants from hostile textile dyeing wastewaters. Thus, installation costs and usable floor area of the infrastructure are saved, due to the separation unit of MBR replaced the sedimentation basin that is used in current practice. It is well recognized that east coast states in Malaysia such as Kelantan and Terengganu are the main producers of “Batik” industries in which create a huge contribution to Malaysia textile economy development due to high demands from local and abroad. Batik textile wastewater is a complex and consist highly variable mixture of many polluting substances including dye. Existence of dyes in the wastewater plays a major issue and has raised significant concerns. Thus, selection of microorganism and the separation processes of the membrane bioreactor are vital to be evaluated towards an achievable productivity and efficient process separation. These are depended on several factors which include degradation of dye, temperature, retention time, pH and concentration of the textile wastewater.


Sign in / Sign up

Export Citation Format

Share Document