Chandrakant R. Holkar

A critical review on textile wastewater treatments: Possible approaches.

Waste water is a major environmental impediment for the growth of the textile industry besides the other minor issues like solid waste and resource waste management. Textile industry uses many kinds of synthetic dyes and discharge large amounts of highly colored wastewater as the uptake of these dyes by fabrics is very poor. This highly colored textile wastewater severely affects photosynthetic function in plant. It also has an impact on aquatic life due to low light penetration and oxygen consumption. It may also be lethal to certain forms of marine life due to the occurrence of component metals and chlorine present in the synthetic dyes. So, this textile wastewater must be treated before their discharge. In this article, different treatment methods to treat the textile wastewater have been presented along with cost per unit volume of treated water. Treatment methods discussed in this paper involve oxidation methods (cavitation, photocatalytic oxidation, ozone, H2O2, fentons process), physical methods (adsorption and filtration), biological methods (fungi, algae, bacteria, microbial fuel cell). This review article will also recommend the possible remedial measures to treat different types of effluent generated from each textile operation.

Investigation of TiO2 photocatalyst performance for decolorization in the presence of hydrodynamic cavitation as hybrid AOP

In this article, an acoustic cavitation engineered novel approach for the synthesis of TiO2, cerium and Fe doped TiO2 nanophotocatalysts is reported. The prepared TiO2, cerium and Fe doped TiO2 nanophotocatalysts were characterized by XRD and TEM analysis to evaluate its structure and morphology. Photo catalytic performance of undoped TiO2 catalyst was investigated for the decolorization of crystal violet dye in aqueous solution at pH of 6.5 in the presence of hydro dynamic cavitation. Effect of catalyst doping with Fe and Ce was also studied for the decolorization of crystal violet dye. The results shows that, 0.8% of Fe-doped TiO2 exhibits maximum photocatalytic activity in the decolorization study of crystal violet dye due to the presence of Fe in the TiO2 and it may acts as a fenton reagent. Kinetic studies have also been reported for the hybrid AOP (HAOP) that followed the pseudo first-order reaction kinetics.

Kinetics of biological decolorisation of anthraquinone based Reactive Blue 19 using an isolated strain of Enterobacter sp.F NCIM 5545.

In the present study, an attempt was made to evaluate the bacterial decolorisation of Reactive Blue 19 by an Enterobacter sp.F which was isolated from a mixed culture from anaerobic digester for biogas production. Phenotypic characterization and phylogenetic analysis based on DNA sequencing comparisons indicate that Enterobacter sp.F was 99.7% similar to Enterobacter cloacae ATCC13047. The kinetics of Reactive Blue 19 dye decolorisation by bacterium had been estimated. Effects of substrate concentration, oxygen, temperature, pH, glucose and glucose to microbe weight ratio on the rate of decolorisation were investigated to understand key factor that determines the performance of dye decolorisation. The maximum decolorisation efficiency of Reactive Blue 19 was 90% over period of 24 h for optimized parameter. To the best of our knowledge, this research study is the report where Enterobacter sp.F has been reported with about 90% decolorizing ability against anthraquinone based Reactive Blue 19 dye.

Energy Conversion on Differential Magnetization of Fe3O4 Ferrofluid

Ferrofluids are stable suspension of ferrimagnetic nanoparticles in hydrocarbon carrier. This flu id is used for harvesting energy using energy conversion device which is presented in this work. The device consists of two chambers, they are hot and cold chamber in which differential magnetization is linked with an inductor. Classically very small value of coupling coefficient |k| has been observed. System configuration shows an emf generation rate of about 44.4μV/K. Presented work shows another way of harvesting energy. Ferrofluid havin g a particle size o f 21nm was used in this case.