Micro-electrolysis biological fluidized bed process for coking wastewater treatment

In this study, the internal circulation iron-carbon micro-electrolysis (ICE) method was combined with activated sludge (AS) to form micro-electrolysis biological fluidized bed (MBFB) process for the treatment of coking wastewater with a low carbon-to-nitrogen (C/N) ratio. The MBFB process has chemical oxygen demand and total nitrogen removal rates of 92 and 95 %, respectively, which is much higher than those of the ICE process and single AS process. The results of three-dimensional fluorescence spectra showed that the MBFB process can not only remove protein-like substances, but can also degrade fulvic acid-like and humic acid-like substances. Fe2+/Fe3+ and active hydrogen atoms promoted the electron transfer inside and outside the microbial cells, thereby enhancing the metabolism of the microorganisms (such as Acidovorax), which is beneficial to the degradation of organics and nutriments. Therefore, the MBFB process has synergistic degradation properties and is promising for treating industrial wastewaters with low C/N ratios.