EVALUATION OF POTENTIAL OF Ulva lactuca IN BIODECOLORIZATION OF REACTIVE AZO DYE

Krishna Y. Pandya 1,2 , Rinku V. Patel 1,2 , Rakesh T. Jasrai 3 and Nayana Brahmbhatt 2 . 1. Sophasticated Instrumentation Centre for Applied Research and Testing, Vallabh vidhyanagar-388120, Gujarat, India. 2. Department of Biology, V. P. Science College, Sardar Patel University, Vallabh vidhyanagar-388120, Gujarat, India. 3. Department of Chemistry, R. K. Parikh Arts & Science College, Sardar Patel University, Petlad-388450, Gujarat, India. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

The present study investigated the potential of Ulva lactuca in dye decolorization and degradation. The optimum tolerance concentration of biomass was observed under lower concentrations of azo dye. The degradation potential of biomass was studied by FTIR (Fouriertransform infrared spectroscopy) analysis of azo dye for pre and post treatment. The biochemical response of the biomass by analysis of chlorophyll-a, chlorophyll-b, total chlorophyll and carotenoid, total soluble sugar and protein was observed decreased with increasing days and dye concentration. The surface characteristic of the biomass was studied by SEM (Scanning electron microscopy). The experimental results indicate the order of decolorization as reactive red-195 > reactive yellow -145 > reactive black -5. Thus, Ulva lactuca shows significant decolorization and degradation.

…………………………………………………………………………………………………….... Introduction:-
Many different groups of living organisms ranging from single celled to multicellular which are made up of eukaryotic cells are called algae. They possess nuclei, organelles, plastids, chlorophyll, protein, carbohydrate and fatty acid [1]. Algae capture carbon dioxide from the atmosphere, sunlight through photosynthesis and minerals from the environment which transforms inorganic substances into its simpler forms. Various methods are applied for the waste water treatment such as coagulation, flocculation, advanced oxidation process, ozonation, photocatalytic treatments etc [2]. These methods are costly and require heavy inputs of high energy [3]. On the other side biodegradation by biological methods such as bacterial, fungal and algal treatment proved to be best solution. The bacterial and fungal treatment methods are also required maintenance of the culture and environment conditions for the microorganism's survival. Algal treatments are helpful to remove phosphate, nitrogen, total dissolved solids and other contaminants and required low maintenance; It grows on nutrient rich waste water and generates no secondary waste [4] [5].
Industrial waste water are generated from pulp and paper, poultry, dairy, metal finishing, pharmaceutical, textile, dyes and pigments, pesticides, chemical and drug formulation industries etc; but the dye industrial waste water concerned mainly for environmental pollution because the color imparts the transparency of water and affects the ISSN: 2320-5407 Int. J. Adv. Res. 6(2), 517-528 518 photosynthesis of aquatic phytoplanktons and aquatic plants. It also causes various skin disease and carcinogenic effect on humans if consumed without prior treatment. Various reports are available on dye waste water treatment such as azo dye effluent and congo red dye by various species of microalgae [6][7] [8], methylene blue by Caulerpa racemosa and Ulva lactuca [9][10] [11], Organic dye removal by Sargassum horneri [12]. Various scientists have worked on accumulation of heavy metal such as chromium, lead, copper, cadmium, phosphate by algae from waste water [13] [14][15] [16]. The present paper attempts to evaluate decolorization and degradation of reactive azo dye prepared in aqueous solution. Furthermore, this accumulated alga after treatment was studied for its biochemical response and surface characterization.

Material and Methodology:-
Seaweed collection:-The algae Ulva lactuca was collected from Bet-dwarka near Okha coast of Gujarat, India shown in Image-1 (Longitude -68°20´ E to 70°40´ E Latitude -22°15´ N to 23°40´ N). It was washed there with seawater to remove sand particles and unwanted debris, particle adhered to it. Then kept in icebox and transferred to laboratory to wash three to four times with distilled water to remove surface particles and salts. Then it was kept on room drying at normal room temperature for 2-3 days, and used in the present study. The Image-2 indicates wet and dry algal biomass.

Fourier transform infrared analysis (FTIR):-
The FTIR analysis of pre and post treatment of azo dyes was obtained by FTIR spectrophotometer (Make: Perkin Elmer, U.S.A., Model: Spectrum GX) by K-Br disk (spectroscopic grade) method. The solutions were kept in oven in petri plates at 200°C temperature for 3-4 hours until the dry powder of the solution obtain. 2 mg of powder sample taken in 200 mg of K-Br with additional crushing and by hydraulic press prepared pallets and scanned under 4000 to 400 cm -1 range in ambient conditions and spectra was obtained.

Optimization of Tolerance concentration of dye on biomass: -
The optimization of tolerance concentration of dye on biomass was studied. All the experiments were conducted in triplicates and standard error mean mentioned in the results and conducted for 8-16-24 day interval. The effluent solutions were prepared in 0.
The percentage decolorization was estimated by below formula: ( )

Biochemical response of accumulated alga: -
The accumulated alga was collected from post treatment of dye. The biochemical changes after dye treatment was studied by biochemical analysis such as chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoid, protein and sugar with the help of standard methods of biochemical analysis by S. R. Thimmaiah [17].

Scanning electron microscopy (SEM):-
The surface characteristic of the alga for pre and post treatment with dye was studied by Field Emission Gun-Scanning Electron Microscopy (Make: FEI Ltd., Model: Nova NanoSEM 450)

Result and Discussion:-
The decolorization study indicates 90.66 %, 88% & 85 % reduction of color from the dye solutions of P 1 , P 4 and P 6 respectively (Fig-4) which shows that the Ulva lactuca has potential in the color removal from dye aqueous solution thus it can be used as decolorizing agent in waste water treatment system. The (λ max) maximum absorbance & Optical density is mentioned in Fig-2 & Fig-3.
Tolerance concentration of dye on alga was estimated under different concentration of dye in aqueous solution by determining % decolorization shown in Fig-5 This study indicates the maximum decolorization was observed in 0.2 % V/V of dye concentration and lower in 1 % V/V. it can be shown as 0.2 > 0.4 > 0.6 > 0.8 > 1 % V/V. Thus, it describes that with increasing dye concentration the % decolorization was observed decreased. The experiment also reveals that with increasing days the decolorization rate become steady from 16-24 day. This is occurred due to the availability of vacant space in the tissues of the biomass initially and with increasing time and dye concentration it gets more accumulated by dye components which lowers the adsorption and results the decreasing rate of decolorization. After this treatment, the accumulated alga was studied further for its biochemical response by biochemical analysis of chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoid, protein and total soluble sugar, In the present study values of chlorophyll-a, chlorophyll-b, total chlorophyll was observed maximum in 8 day under 0.2 % V/V concentration of dye and minimum value was observed in higher concentration. Similar result was observed in carotenoid, protein, total soluble sugar content. The results are shown in Fig-6 to Fig-9 Thus the experimental results indicates that with increasing dye concentration and time the biochemical content of the biomass was observed decreased.
The scanning electron microscopy (SEM) for pre and post treatment of dye by Ulva lactuca indicated in Image-1 which shows in pre treatment the algal surface was observed smooth and even but after the post treatment with dye it was observed damaged, uneven surface and swollen cells. This is occurred because of accumulation of dye functional groups inside the cells.
The Fourier transform infrared analysis (FT-IR) gives the information concerning functional groups variations for pre and post treatment of dye (Fig-10 to Fig-15).

Conclusion: -
All the above discussion suggests that Ulva lactuca has potential ability in decolorization of dye. The FT-IR spectra show removal of dye components after treatment which represents the degradation of dye. It shows potential ability of decolorization under lower concentration of dye. Optimum tolerance concentration of biomass was observed under lower concentration of azo dye. Biochemical response of the alga after treatment shows with increasing dye amount the biochemical content inside the biomass was found decreased. The scanning electron microscopy analysis reveals after exposure the surface of the biomass was found uneven, swollen and broken due to accumulation of dye component inside the cells of the alga. Thus, the present study indicates the Ulva lactuca has potential capability for dye degradation and decolorization.