Pretreatment of evaporated condensate generated during metal cutting process by Fe-C micro-electrolysis.

Fe-C micro-electrolysis was employed to the pretreatment of evaporated condensate generated during metal cutting process. The effect of the reaction conditions on the contaminant removal and degradation mechanism were studied. Through single-factor experiments, the effects of solid-liquid ratio, gas-liquid ratio and reaction time on the treatment of wastewater were preliminarily determined. The optimal reaction condition obtained was: 500 g/L solid-liquid ratio, 30:1 gas-liquid ratio with 4 h reaction time. Under the optimal condition, the chemical oxygen demand (COD) removal efficiency of micro-electrolysis could reach around 25%, and the biodegradability of wastewater increased from 0.12 to 0.32. According to the analysis results of gas chromatography-mass spectrometry (GC-MS) qualitative analysis, it was observed that the most organic contaminants in the influent were degraded or converted into simple structures under Fe-C micro-electrolysis, indicates that Fe-C micro-electrolysis pretreatment could improve the biodegradability of the evaporated condensate generated during metal cutting process and achieve certain degree removal of COD.