Statistical analyses of the effect of rhamnolipid biosurfactant addition on the enzymatic removal of Bisphenol A from wastewater

Bisphenol A (BPA), a major phenolic pollutant, is hazardous, toxic, and mutagenic. Although there are some chemical and physical processes to treat wastewater polluted with BPA, most of these methods are either costly or detrimental to the environment (i.e., generate serious secondary pollution). Unlike chemical and physical treatment methods, enzymatic treatment is environmentally friendly, more selective towards the targeted phenolic pollutant(s) and uses sustainably produced materials (i.e., enzymes). In this work, a clean process based on enzyme (i.e., laccase) and biosurfactant (i.e., rhamnolipid) is developed in order to study the removal of BPA from wastewater. Several statistical analyses of the effect of rhamnolipid (RL) addition on the enzymatic removal of BPA under different process conditions have been performed. The results revealed a positive correlation between RL addition and BPA removal irrespective of the initial BPA concentration, reaction time, reaction temperature, pH of the reaction medium, and wastewater salinity. The statistical analyses also revealed that the two-way interactions between RL addition and reaction time and between RL addition and the initial BPA concentration are significant. However, the two-way interactions between RL addition and the reaction temperature, RL addition and the pH of the reaction medium, and RL addition and the wastewater salinity are insignificant, unlike the significant effects of the individual factors.