The major nutrient components in the synthetic wastewater
were soluble ammonium nitrogen and PO4-P. Therefore, the
AnMBR exhibited insignificant nutrient removal in the synthetic
wastewater treatment phase. In contrast to the synthetic wastewater,
the soluble ammonium nitrogen and PO4-P in the raw
brewery wastewater were only 7.0 ± 4.0 % of the total nitrogen and
44.0 ± 7.0% of the total phosphorus, respectively.. Fig. 6a–d illustrate
the total and inorganic nitrogen and phosphorus of the mixed
liquid in the feed, membrane permeate and 1.5-m filtrate during
the brewery wastewater treatment phase.
The TN concentration of the 1.5-m filtrate of the mixed liquor,
which fluctuated with time, was higher than that in the feed
wastewater. This was likely a result of the accumulated EPS, which
was produced by microbes in the reactor. The TN concentrations in
the membrane permeate were always lower than those in the feed
and the 1.5-m filtrate ofthe mixed liquor with an observed overall
TN removal of 54 ± 13% (Fig. 6a), indicating the role of the membrane
filtration in the TN removal. Since the membrane exhibited
a negligible retention of the total ammonia nitrogen (TAN), which
was mainly existed as NH4-N under the pH condition related to this
study, (Fig. 6b), the removal of nitrogen by the membrane filtration
can be attributed to the membrane retention to the organic nitrogen
containing EPS, such as proteins and nucleic acids. The TAN
concentrations in the raw brewery wastewater were always lower
than those in the reactor. The increased concentration of TAN in
the reactor was caused by the anaerobic degradation of the protein
substances in the wastewater.