Acid pre-treatment as an effective strategy to improve bioflocculant-mediated decolorization

In this study, we prepared a bioflocculant (BF-TWB10) using Bacillus thuringiensis isolated from textile wastewater and subjected the bioflocculant to acid pretreatment. When the pH value of the entire solution was adjusted to 6.0, the bioflocculant without acid pretreatment showed decolorization efficiency of 48.30 % and 77.36 % against Turq Blue FBL-T and Tairus Light Scarlet F2G-T dyes, respectively. On the other hand, without adjusting the pH value of entire solution, the bioflocculant pretreated with acid achieved a decolorization efficiency of 76.36 % and 82.73 %, respectively. Note that the pretreatment does not affect much the pH value of the entire solution and its value is between 6.2 and 6.3. The acid pretreatment shows better decolorization efficiency in comparison to the case adjusting the pH value of the entire solution. Through zeta potential and FTIR analysis, it can be inferred that pretreatment enhances the bridging mechanism in the flocculation process. Furthermore, by adding calcium cation, the decolorization efficiency reached 81.36 % and 86.04 % against dyes Turq Blue FBL-T and Tairus Light Scarlet F2G-T, respectively. The acid pretreatment of bioflocculant greatly enhances its decolorization efficiency, highlighting its potential for effective treatment of textile wastewater.