A novel strain (designated as SW-2) which could convert chromotropic acid into bioflocculants was isolated from chromotropic acid wastewater. Conditions for bioflocculants production were optimized by response surface methodology (RSM) and determined to be inoculum size 7.74%, initial pH 6.9, and CODcr of the chromotropic acid wastewater 425 mg/L. The yielded bioflocculant was primarily consisting of polysaccharide and protein. It could maintain its flocculating activity to 0.4% (w/w) kaolin suspensions over pH 3-9 and 20-80 degrees C. In addition, conditions for the removal of estrogens with the bioflocculant were investigated and determined to be bioflocculant dosage 50 mg/L, initial pH 3, reaction time 60 min, and temperature 45 degrees C. Under these optimal conditions, the removal efficiencies of El, E2, EE2, and E3 were 87%, 92%, 88% and 96%, respectively. The bioflocculant was shown to offer a promising alternative method of removing estrogens from water in pretreatment applications. (C) 2014 Elsevier B.V. All rights reserved.
A novel bioflocculant (MBF83) prepared using methanol wastewater as nutrient resource was systematically investigated in the study. The optimal conditions for bioflocculant production were determined to be an inoculum size of 8.6%, initial pH of 7.5, and a methanol concentration of 100.8 mg L-1. An MBF83 of 4.61 g L-1 was achieved as the maximum yield. MBF83 primarily comprised polysaccharide (74.1%) and protein (24.2%). The biopolymer, which was found to be safe in zebrafish in toxicity studies, was characterized using Fourier-transform infrared spectroscopy and elemental analysis. Additionally, conditions for the removal of arsenite by MBF83 were found to be MBF83 at 500 mg L-1, an initial pH of 7.0, and a contact time of 90 min. Under the optimal conditions, the removal efficiency of arsenite was 86.1%. Overall, these findings indicate bioflocculation offers an effective alternative method of decreasing arsenite during wastewater treatment. (C) 2015 Elsevier Ltd. All rights reserved.