This study evaluated the potential of Scenedesmus sp. MCC 26 as a new cost effective and efficient alternative for removing Zn(II) ions from viscose industrial effluent. Scenedesmus sp. MCC 26 (green microalgae) was isolated from a metal contaminated site and investigated for biosorption of Zn(II) from simulated viscose industrial effluent. Different biosorption parameters such as effect of pH (2–7), initial Zn(II) ion concentration (0–600 mg/L) and contact time (0–120 min) were investigated in order to optimize the process. The maximum absorption (142.85 mg/g) by the microalgal biomass was observed at pH 6 within 60 min of contact time at 28°C. Biosorption process was found to be rapid (6 mg of Zn/g biomass per min) for initial 10 min followed by a slower phase (0.6 mg of Zn/g biomass per min). The absorption data fitted well with Langmuir isotherm (qmax = 142.85 mg/g, r2 = 0.973) and Freundlich isotherm (kf = 1.447, r2 = 0.992). Treatment of Zn(II) loaded biomass with 0.1 M H2SO4 showed almost 99% recovery of zinc which can be reused in the industrial processes. After first cycle of Zn(II) removal and recovery, the same biomass was tested for its reusability in repeated cycles. The results showed that the same biomass can be used minimum for five cycles of Zn(II) absorption and recovery with similar efficiency.

Introduction-Release of different types of synthetic dyes into the aquatic environment by various industrial sources is a major area of concern worldwide due to their low biodegradable nature. Conventional methods of dye removal are effective but high operating cost and energy requirement, generation of toxic sludge and regeneration problem of adsorbent limits their use at large scale. Biosorption of dye molecules by microorganisms is an economic and eco friendly technology for the treatment of textile wastewater. Aims & objective-The study was carried out to isolate microalgae from industrial site and to evaluate its efficiency for adsorption of Orange G dye from aqueous solution. Materials and methods- A unicellular green micro alga was isolated from textile and dye contaminated site of Sanganer, Jaipur (India) .Biosorption studies were conducted in a batch system for the removal of orange G dye from aqueous solution. Different parameters of pH, time, and initial dye concentration were investigated to optimize the process. Kinetic and equilibrium isotherms were implemented to experimental data in order to investigate the mechanism of biosorption. Results- Microalgae isolated from industrial site was found to be highly efficient for absorption of Orange G dye from aqueous solution. Batch studies depicts that Acutodesmusobliquues strain PSV 2 can absorb orange G dye at optimum pH 2.0 and maximum absorption (56.49 mg/g) occurred within initial 60 min of contact time. Equilibrium studies showed that Freundlich isotherm fitted well with experimental data with high correlation coefficient (r2=0.995) and n value (n=1.192). Langmuir isotherm showed r2=0.96 and value of b=0.008, which represents favorable adsorption of dye on algal surface. FTIR analysis of adsorbent before and after dye adsorption showed the involvement of some functional groups in dye absorption. DOI: http://dx.doi.org/10.3126/ijasbt.v1i4.9141   Int J Appl Sci Biotechnol, Vol. 1(4): 247-252

Two unicellular green microalgae, were isolated from Amani Shah Nallah (Jaipur, India) that receives discharge of dyeing industries. Preliminary morphological characterization using light microscopy showed ovoid, fusiform shape of cells with single to two celled coenobia in a culture suspension. Transmission electron microscopy (TEM) analyses depict abundant chloroplast located at the periphery of the cell, a pyrenoid as well as nucleus is visible in the centre. A well developed cell wall with many layers is also evident in TEM. Phylogenetic position and genetic variabilty among the isolated microalgal strains were investigated by 18S rDNA sequence analysis. The results suggest that the isolated microalgae belongs to family chlorophyceae and corresponds to genus Scenedesmus and genus Acutodesmus. Growth profile of both microalgal strains showed a typical sigmoid curve with specific growth rate of µmax, 0.839 day-1 and 0.654 day-1 for Scenedesmus sp. and Acutodesmus obliquus, respectively. The strains were allotted with MCC numbers by IARI, New Delhi as MCC26 for Scenedesmus sp.  and MCC33 for Acutodesmus obliquus.Int. J. Appl. Sci. Biotechnol. Vol 5(4): 415-422

In the present study, Acutodesmus obliquus strain PSV2 was isolated from a textile and dyeing industrial site and investigated as a cost effective and potential adsorbent for Acid red 66 dye. Batch kinetic experiments were carried out as a function of pH (1.0-6.0), contact time (0-180 min) and initial dye concentration (10-50 mg/L) to determine the decolorization efficiency of microalgae. The maximum adsorption of dye was observed at pH 2.0 during the initial 60 min of contact time. The Langmuir and Freundlich adsorption isotherms were applied to experimental data to investigate the efficiency of adsorbent and mechanism of adsorption. It was observed that Langmuir and Freundlich isotherm fitted well with Acid Red 66 dye data. Langmuir isotherm, described maximum adsorption of dye (44.24 mg/g) with good correlation coefficient (r 2 = 0.980) while Freundlich isotherm showed a high correlation coefficient (r 2 = 0.994) with value of n greater than unity (n = 1.27). The present study showed that Acutodesmus obliquus strain PSV2 is an eco friendly and highly efficient adsorbent for removal of acid red 66 dye from dyeing and textile industrial wastewater.

No abstract