ZVI process is a new physico-chemical method developing
quickly in recent decades. Due to the strong reductive capacity,
ZVI can transform the structures and minimize the toxicity of
hazardous pollutants [21–23]. In our previous research [24], ZVI
process was found to be more feasible for advanced treatment of
coking wastewater than other physico-chemical processes, taking
the treatment effect and cost into consideration. Furthermore, ZVI
process enhanced the biodegradability of effluent obviously, which
could help to improve the biodegradation ability of biofilm reactor
system when they were combined.