PDF Textile Dyeing Wastewater Treatment Potential of Phanerochaete ... - Ernet

I hereby declare that the case described in this thesis is the result of research conducted by me at the Department of Biotechnology and the Department of Physics, Indian Institute of Technology Guwahati, Guwahati, India, under the supervision of Dr. It is certified that the work described in this thesis titled "Textile dyeing wastewater treatment potential of Phanerochaete chrysosporium: experiments and simulation" by KausikSen for the award of the Doctor of Philosophy degree is an authentic record of the results obtained from the research work carried out under our supervision in the Department of Biotechnology and Department of Physics, Indian Institute of Technology Guwahati, India, and this work has not been submitted for a degree elsewhere. I am indebted to the Department of Biotechnology and the Department of Physics, IIT Guwahati for providing the necessary facilities.

Azo Dyes

However, only a few of the studies on microbial azo dye reduction included a clear demonstration of total or partial, subsequent biodegradation of the resulting metabolites, aromatic amines. The basic limitations are the need for specific, adapted microbial strains and, in some cases, co-cultures of several species [Rieger et al., 2002], the tendency of some metabolites to undergo chemical oxidation to more resistant products, and the lack of knowledge on the bio-reactivity of most aromatic amines that can be formed in wastewater treatment plants or water streams as a result of the reduction of discharged azo dyes currently in use. The identified carcinogenic amines have been found to present a significant risk of bioaccumulation in the environment [Ollgaard et al., 1998], although, again, little is known about the more hydrophilic amines that may result from cleavage of the azo bond in water-soluble dyes. .

Phanerochaete chrysosporium

Azo compounds are compounds bearing the functional group R-N=N-R`, in which R and R` can be either aryl or alkyl and the N=N group is called an azo group. White-rot fungi are able to degrade dyes using enzymes, such as lignin peroxidases (LiP), manganese-dependent peroxidases (MnP). Other enzymes used for this purpose include enzymes that produce H2O2, such as glucose-1-oxidase and glucose-2-oxidase, along with laccase, and a phenoloxidase enzyme [Archibald and Roy, 1992].

Lignin Peroxidase

Azo dyes, the largest class of commercially produced dyes, are not easily degraded by microorganisms, but they can be degraded by P. LiP catalyzes the oxidation of non-phenolic lignin model compounds such as veratryl alcohol to veratrylaldehyde. Therefore, the unique property of this enzyme is that it can oxidize aromatic compounds with redox potentials beyond the range of HRP and many other peroxidases.

Aim and Scope of this Study

Organization of this Thesis

Degradation of dyes, II. part Behavior of dyes in aerobic biodegradation tests, Chemospheric degradation of azo compounds by ligninase from Phanerochaete chrysosporium, involvement of veratryl alcohol, Biochem.

Literature Review

Environmental Impact of Textile Dyeing Industry Wastewaters

Because of their recalcitrant nature, the dyes resist fading when exposed to light, water, and many chemicals [Poots and McKay, 1976a]. Many dyes are made from known carcinogens such as benzidine and other aromatic compounds, all of which can be altered as a result of microbial metabolism [Clarke and Anliker, 1980]. Anthraquinone-based dyes are the most resistant to degradation due to the fused aromatic structures that remain colored for a long time.

Major Treatment Techniques for Textile Dyeing Industry Wastewater

• Physical treatment methods 1. Adsorption
• Membrane filtration
• Ion exchange
• Irradiation
• Chemical methods 1. Oxidative processes
• Ozonation
• Photochemical
• Sodium hypochloride (NaOCl)
• Cucurbituril
• Electrochemical destruction
• MicrobialTreatment Processes
• Bacterial degradation of textile dyes
• Decolourization with algal cultures
• Biodegradation by fungi
• P. chrysosporium ligninase enymes

Performance depends on the type of carbon used and the characteristics of the wastewater. Chemical oxidation removes the dye from the dye-containing effluent through oxidation resulting in aromatic ring cleavage of the dye molecules [Raghavacharya, 1997]. Lignin peroxidase (LiP) and manganese peroxidase (MnP) have been shown to be important components of the lignin degradation system of P.

Computer Simulation onFungal Biomass Growth and Enzyme Secretion

Organic dyes and pigments, Handbook of Environmental Chemistry, Part A. 1981) Interaction between diazo dye, 'Vermelho Reanil' P8B. And Neurospora crassa strain 74A, Eur. 1990) Biodegradation of azo and heterocyclic dyes by Phanerochaete chrysosporium, Appl. Microbiology, Chemistry and Potential Applications, ed. 1994) Ozonation - an important technique for compliance with the new German legislation for the treatment of textile wastewater, Water Sci. 1983) Decolorization of several polymeric dyes by the lignin-degrading Basidiomycete Phanerochaete chrysosporium, Appl. 1999a) Effects of alkaline earth cations on the removal of reactive dyes by cucurbituril, Actahydrochim b) Removal of reactive dyes by sorption/complexation with cucurbituril, Water Sci. 1981) Aerobic bacterial degradation of azo dyes, Microbial degradation of xerobiotics and recalcitrant compounds, In, Leisinger, T., Cook, A.M., Hutter, R., Nuesch, J. 2009).

Biomass growth and enzyme secretion by P. Chrysosporium

• Experimental Methods
• Results
• Model
• Model Results and Comparison withExperiment
• Discussion

2 that the rate of consumption of glucose increases with initial glucose concentration in the medium. This phase is short in the case of high initial glucose concentration in the medium which may be due to faster consumption of glucose, Fig.3. All the cells present in the medium at the time were called upon for consumption of glucose.

In the model, it is assumed that the division of a cell depends only on the size of a cell. The rate of the enzyme-substrate reaction must be proportional to the concentrations of enzyme and substrate in the medium. The rate of glucose consumption is also found to be higher [Fig 8] for the higher initial concentration of glucose in the medium as in the experiment.

The saturation values ​​are also found to be directly proportional to the initial glucose concentration in the medium as in the experiment [Fig 10]. The experimental results indicate that both biomass growth and LiP activity are dependent on the initial glucose concentration in the medium. This can be attributed to the change in the cellular membrane capabilities of the cell [Gold and Alic, 1993].

With the developed model, we can observe a qualitatively similar behavior as was observed in the experiments to change the initial glucose concentration.

Figure 2: Residual glucose remained, Cg% (as % of the total medium) for different initial glucose concentration [0.5 (○), 1.0 (□), 1.5 (◊), 2.0 (∆), 2.5 () %w/v]

Biomass growth and enzyme secretion by P. chrysosporium in

Materials and Methods 1. Chemicals

• Microorganism and culture conditions

The azo dye Direct Red - 80 (Figure 1, page #6) and veratryl alcohol were purchased from Sigma (St. Louis, Mo, USA); all other chemicals and solvents were purchased from High Media, Mumbai (India), SRL (India) or Merck (India), all of which were of GR grade. All dye decolorization experiments in the study were performed using 250 ml flasks containing 100 ml of medium with initial pH 4.5; after inoculation the flasks were incubated in an orbital shaker set at 30oC and 150 rpm. The effect of initial concentration of glucose was studied in the range of 4-16 gL-1 by fixing the initial dye concentration at 0.02 gL-1.

To study the effect of initial dye concentration, it was varied in the range of 0.01-0.05 gL-1 while keeping the initial concentration of glucose at 10 gL-1. Fungal growth in experiments was measured by counting spores using a hemocytometer [Morrisand Nicholls, 1978].

• Assays for LiP and DR-80
• Results
• The Model
• Model Results
• Discussion

Variation of initial concentration of glucose in the medium shows a prominent effect on the growth of the fungus. The % decolorization of the dye increases [Fig 21] with increasing glucose as the LiP activity was also found to increase [Fig 22]. Increasing the initial dye concentration is found to decrease the % dye decolorization in the medium [Fig 24] and also the LiP activity at constant glucose [Fig 25].

The probability of glucose consumption is proportional to the instantaneous glucose concentration of the medium Gt and glucose uptake probability of a cell pi. The probability of enzyme production by a cell is then directly proportional to the immediate glucose concentration of the medium. For a given glucose concentration, the biomass growth decreases as the dye concentration in the medium increases, similar to the results found from experiments.

Usually, the cellular processes are affected due to the presence of toxic pollutant in the medium. In the model, however, only the interaction of the cells with the external medium is taken into account. However, increasing the glucose concentration in the medium at constant dye concentration increases biomass growth.

The dye decolorization in the medium is increased due to the increase in glucose concentration at constant dye but decreases when dye concentration is increased at constant glucose concentration.

Figure 20: Growth of the fungus in terms of generations (G N ) with increasing initial glucose concentration [4 (○), 8 (□), 10 (◊), 12 (∆), 16 () gL -1 ] at constant dye concentration [0.02 gL -1 ]

Effect of Physico-Chemical Parameters on Biomass growth and Enzyme

• Materials and Methods 1. DR-80 and other Chemicals
• Microorganism and Culture Conditions
• Effect of various physico-chemical parameters
• Analytical methods
• Results and Discussion
• Influence of various parameters in the absence of DR-80 1. Effect of initial pH of the medium
• Influence of various parameters in the presence of DR-80 in the medium 1. Effect of pH

The effect of different physicochemical parameters - temperature, agitation and initial pH of the medium - on fungal growth and LiP secretion were studied by changing the levels of these variables one by one. 31 shows the effect of different culture temperatures on fungal spore counts, which clearly shows that biomass growth decreases rapidly above 30°C. Mixing the culture medium ensures sufficient contact between cells and nutrients in the surrounding medium.

Thus, an increase in the fungal biomass growth was evident with increasing agitation from 0 to 200 rpm [Fig. 33]. Varying the initial pH of the medium in the range 3-7 showed that biomass growth was more at a lower pH than at a high pH [Fig 35] as it influences the biochemical reactions in the cell. This may also be due to a lower activity of cellular proteins on both sides of their optimal pH. This can also lead to an increase in the death of the cells initially added as inoculum.

Increased bioavailability of the dye at higher agitation to the degrading enzymes can also be attributed to this result. Among the various physico-chemical parameters examined, all the three factors, i.e. initial pH, temperature and agitation of the medium, significant effect on biomass growth as well as LiP activity of P. Variation in these parameter values ​​also had a great impact on the dye decolorization ability of the fungus, which was directly related to its biomass growth and LiP activity.

This study showed a very good potential of the ligninase-producing fungus in decolorizing wastewater from textile dyeing.

Figure 28.Growth in terms of generations (G N ) for different initial pH of the medium [3(ο), 4(□), 5(◊), 6(∆), 7()]

Summary and Conclusions

Therefore, fungal growth conditions must be suitable to produce and secrete LiP into the environment for effective dye degradation in wastewater. The experimental results clearly revealed that glucose had a significant effect on the growth of mushroom biomass. Fungal lip activity was found to be high for an increase in its biomass growth.

Both the efficiency and the rate of ink degradation are reduced with an increase in the initial concentration of the ink in the media. Similar patterns of biomass growth and LiP excretion were observed in the presence of dye by varying temperature, pH and agitation parameters. In order to understand the experimental results obtained in the study, a stochastic model of fungal growth and the activity of enzymes released by the fungus was developed.

The enzymatic activity of the cell is modeled by taking into account the concentration of glucose in the medium and the maturity of the cell. The effect of the toxic pollutant on growth and enzyme activity was modeled by including the corresponding inhibition effects as a function of dye concentration at all growth stages, viz. glucose uptake and cell division. The probability of enzyme production was also exponentially inhibited by the initial concentration of the dye in the medium and its rate of degradation depended on the number of enzyme molecules per molecule. Although the developed stochastic model showed close qualitative agreement with experiments, the initial assumptions for model development may limit the applicability of the model.

Thus, the model developed in this work can be used to predict the behavior of the fungus in the presence of other toxic pollutants in textile dyeing wastewater.

Appendix-I

Parameters used: V - Volume of the medium, Ng - Initial number of glucose molecules, Nd - Initial number of dye molecules, Ns - Initial number of spores, Csz - Final number of cells, Cs - Critical size of the cell, DVCST - Cell division cost, DVCST1 ( DVCST+1) - Cell division cost plus initial glucose for daughter cell, ENCST – Enzyme release cost, MXST – Maximum time step allowed, SMPL – number of samples, GAMMA – Constant for glucose availability, gamma – Constant for glucose consumption, sdd - Sigma for division, sgE - Sigma for enzyme production . As observed in earlier experiments, there exists an almost linear relationship between the biomass growth and cell count of the fungus under the given experimental conditions. They were strictly controlled to maintain the correlation between the biomass growth and spore count throughout the work.

Each set of experimental data has been analyzed and P and F values ​​were calculated as follows.

Published/Accepted in Refereed International Journals

Manuscript under Preparation