Integrated treatment system
Fig. 1 shows the process of the integrated treatment system,
which consisted of the biofilm and ZVI reactors. The biofilm reactor
system is composed of one anaerobic reactor (A) and two aerobic reactors (O1 and O2), which were detailedly described in the previous study [20]. In the present study, Reactor A was mainly used for denitrification in the integrated system. The self-made FPUFS patent carriers were used in the three biofilm reactors as the support materials for biofilm formation, which were described and applied in earlier studies [20,25]. Reactor ZVI has an effective
volume of 12 l, which was filled with about 30 vol% of industrial
iron and some activated carbon (Fe/C = 3). Industrial iron consisted
of filings and shavings which were largely free from visible rust
and retained a metallic glaze. In order to eliminate the adsorption
effect, the activated carbon was saturated with the wastewater
sample before use. In Reactor ZVI, air diffusers and inflators were
used to mix the reaction system. Descriptions about addition and
pretreatment for iron and activated carbon could refer to literature