Harmonisation of chemical and biological process in development of a hybrid technology for treatment of recalcitrant metalworking fluid

► Fenton pre-treatment favours biological degradation of recalcitrant wastewater. ► Pre-treatment achieved 91% reduction in toxicity. ► Improvement in BOD5/COD ratio from 0.160 to 0.538. ► Overall decrease of 92% and 86% in COD and TOC, respectively.