Bioremoval of reactive dye Remazol Navy by kefir grains

Abstract

Potential use of living and non-living kefir grains (small, gelatinous white/yellow irregularly shaped masses consist of live bacteria and yeasts) on removal of reactive dye Remazol Navy RGB from aqueous solutions were investigated. Experiments were carried out under different process conditions in order to optimize and model the bioremoval processes. At all conditions the living kefir grains exhibited higher dye removal efficiencies than the non-living grains. In 180 min, 96.3% and 79.4% dye removal was obtained with living and non-leaving kefir grains respectively, at pH 2, 25 °C for 100 mg/L initial dye concentration by using 2.4 g/L kefir grain. Maximum adsorption capacities by living and inactivated kefir grains were obtained at 400 mg/L initial dye concentration as 134.59 and 56.92 mg/g respectively. Consecutive batch studies show that the living kefir grains could be reused over at least 5 cycles with high dye removal efficiency without any nutrition supplement. The biosorption kinetics both for living and non-living kefir grains were best described with pseudo-first-order kinetic model. On the other hand the biosorption equilibrium for living and non-living kefir grains were better defined by Temkin and Langmuir isotherm models respectively. Results suggest that the kefir grains could be used efficiently, eco-friendly and economically for removal of dyes from aqueous solutions.

Simultaneous biosorption of nickel and cadmium by the brown algae Cystoseria indica characterized by isotherm and kinetic models

“…9) [30]. The linearized pseudo-first-order, (5) pseudo-second-order, and intra-particle diffusion kinetic models are defined by Eqs. 7, (8) and (9), respectively [30,31]:…”

“…Soluble heavy metal components are not biodegradable and they tend to accumulate in living organisms as well as oceans, lakes, and rivers [4]. Common methods used to separate heavy metals from industrial wastewaters include chemical precipitation, filtration, reverse osmosis, membranes, ion exchange and adsorption [5]. There are a variety of treatment processes deployed to remove heavy metal ions from the environment, but these, typically, are associated with expensive running costs [6].…”

Isolation and Characterization of Lactobacillus spp. from Kefir Samples in Malaysia

“…Recent studies have reported the uses of kefir in terms of food applications, cosmetic purposes, and industries due to the physicochemical, microbiological, and bioactive compound contained in kefir [19,20,21]. Kefir has been used as an ingredient in wine production, kefir cereal-based beverages, kefir facial mask, and dyes [22]. Further studies into the characterization of specific microbial compositions in kefir grains, mainly the Lactobacillus species, is of utmost interest, especially from Malaysia where the production conditions vary between regions.…”

Potential Use of Probiotic Consortium Isolated from Kefir for Textile Azo Dye Decolorization

“…The absence of mutagenic effect of azo dye metabolite samples from aerobic cultures with probiotic could be clarified by the presence of an adequate level of dissolved oxygen that might limit the azo-reductase action and raise the oxygenase activity; thus granting the decolorization of the dye aromatic amines to which the mutagenic effects may be assigned. Marques et al [45], Nakayama et al [46], Sweeney et al [47], Erdoğdular and Dilek [48] and Jayalakshmi and Jeyanthi [49] reported that carcinogenicity via mutagenicity of some azo dyes and allied aromatic amines could be engendered Fig. 7.…”