Investigation of dye removal with isolated biomasses from whey wastewater

Abstract

In this work, as a new eco-friendly biosorbent, the removal of textile wastewater was carried out by biomass of mesophilic and thermophilic lactic acid bacteria (LAB), which form the natural flora of whey. Mesophilic and thermophilic LAB provide a wide variety of properties in the taste and texture of food products through the fermentation of raw materials in the production of dairy products. Whey is produced as waste after dairy products are produced. Decolorization tests of Dorasyn Red azo dye, which is widely used in the textile sector, have been carried out by obtaining biomass with LAB isolated from whey. Thus, the recovery of whey, which is accepted as waste, has been achieved. In this study, parameters affecting the dissociation reaction of different pH and biomass concentrations were investigated. The dye removal test for four different LAB biomasses (mesophilic lactobacilli and lactococci, and thermophilic lactobacilli and lactococci) was performed at ten different concentration levels (0, 0.5, 0.75, 1, 1.25, 1.5, and 5 g/L). The pH value was adjusted to pH 3 and 6.8 (original) and incubated for 3 h at 20 °C. Tested pH values were 1.5, 2, 3, 4, 5, 6, 7, 8, 9, and 10 with constant 2.5 g/L biomass concentration. Decolorization efficiencies for about 90% dye removal were obtained with mesophilic lactobacilli biomass (2.5 g/L) at pH 3 after 3-h reaction time. This study presents a report that the whey for environmental protection and paint recovery is an appropriate alternative to the decolorization of textile wastewater.